Merge pull request #3066 from SixLabors/js/expose-buffer-helpers

Add row-stride overloads for memory APIs

src/ImageSharp/Image.LoadPixelData.cs

@@ -2,7 +2,6 @@
 // Licensed under the Six Labors Split License.
 
 using System.Runtime.InteropServices;
-using SixLabors.ImageSharp.Memory;
 using SixLabors.ImageSharp.PixelFormats;
 
 namespace SixLabors.ImageSharp;
@@ -25,6 +24,27 @@ public abstract partial class Image
         where TPixel : unmanaged, IPixel<TPixel>
         => LoadPixelData(Configuration.Default, data, width, height);
 
+    /// <summary>
+    /// Create a new instance of the <see cref="Image{TPixel}"/> class from raw <typeparamref name="TPixel"/> data
+    /// using <paramref name="rowStride"/> pixels between source row starts.
+    /// </summary>
+    /// <param name="data">The readonly span containing image data.</param>
+    /// <param name="width">The width of the final image.</param>
+    /// <param name="height">The height of the final image.</param>
+    /// <param name="rowStride">The number of pixels between row starts in <paramref name="data"/>.</param>
+    /// <typeparam name="TPixel">The pixel format.</typeparam>
+    /// <exception cref="ArgumentOutOfRangeException">
+    /// <paramref name="width"/> or <paramref name="height"/> is not positive,
+    /// or <paramref name="rowStride"/> is less than <paramref name="width"/>.
+    /// </exception>
+    /// <exception cref="ArgumentException">
+    /// <paramref name="data"/> is smaller than <c>((height - 1) * rowStride) + width</c>.
+    /// </exception>
+    /// <returns>A new <see cref="Image{TPixel}"/>.</returns>
+    public static Image<TPixel> LoadPixelData<TPixel>(ReadOnlySpan<TPixel> data, int width, int height, int rowStride)
+        where TPixel : unmanaged, IPixel<TPixel>
+        => LoadPixelData(Configuration.Default, data, width, height, rowStride);
+
     /// <summary>
     /// Create a new instance of the <see cref="Image{TPixel}"/> class from the given readonly span of bytes in <typeparamref name="TPixel"/> format.
     /// </summary>
@@ -38,6 +58,28 @@ public abstract partial class Image
         where TPixel : unmanaged, IPixel<TPixel>
         => LoadPixelData<TPixel>(Configuration.Default, data, width, height);
 
+    /// <summary>
+    /// Create a new instance of the <see cref="Image{TPixel}"/> class from a readonly span of bytes in
+    /// <typeparamref name="TPixel"/> format using <paramref name="rowStrideInBytes"/> bytes between source row starts.
+    /// </summary>
+    /// <param name="data">The readonly span containing image data.</param>
+    /// <param name="width">The width of the final image.</param>
+    /// <param name="height">The height of the final image.</param>
+    /// <param name="rowStrideInBytes">The number of bytes between row starts in <paramref name="data"/>.</param>
+    /// <typeparam name="TPixel">The pixel format.</typeparam>
+    /// <exception cref="ArgumentOutOfRangeException">
+    /// <paramref name="width"/> or <paramref name="height"/> is not positive,
+    /// or <paramref name="rowStrideInBytes"/> resolves to fewer than <paramref name="width"/> pixels.
+    /// </exception>
+    /// <exception cref="ArgumentException">
+    /// <paramref name="rowStrideInBytes"/> is not divisible by the pixel size,
+    /// or <paramref name="data"/> is smaller than the required strided image length.
+    /// </exception>
+    /// <returns>A new <see cref="Image{TPixel}"/>.</returns>
+    public static Image<TPixel> LoadPixelData<TPixel>(ReadOnlySpan<byte> data, int width, int height, int rowStrideInBytes)
+        where TPixel : unmanaged, IPixel<TPixel>
+        => LoadPixelData<TPixel>(Configuration.Default, data, width, height, rowStrideInBytes);
+
     /// <summary>
     /// Create a new instance of the <see cref="Image{TPixel}"/> class from the given readonly span of bytes in <typeparamref name="TPixel"/> format.
     /// </summary>
@@ -53,6 +95,40 @@ public abstract partial class Image
         where TPixel : unmanaged, IPixel<TPixel>
         => LoadPixelData(configuration, MemoryMarshal.Cast<byte, TPixel>(data), width, height);
 
+    /// <summary>
+    /// Create a new instance of the <see cref="Image{TPixel}"/> class from a readonly span of bytes in
+    /// <typeparamref name="TPixel"/> format using <paramref name="rowStrideInBytes"/> bytes between source row starts.
+    /// </summary>
+    /// <param name="configuration">The configuration for the decoder.</param>
+    /// <param name="data">The readonly span containing image data.</param>
+    /// <param name="width">The width of the final image.</param>
+    /// <param name="height">The height of the final image.</param>
+    /// <param name="rowStrideInBytes">The number of bytes between row starts in <paramref name="data"/>.</param>
+    /// <typeparam name="TPixel">The pixel format.</typeparam>
+    /// <exception cref="ArgumentNullException">The configuration is null.</exception>
+    /// <exception cref="ArgumentOutOfRangeException">
+    /// <paramref name="width"/> or <paramref name="height"/> is not positive,
+    /// or <paramref name="rowStrideInBytes"/> resolves to fewer than <paramref name="width"/> pixels.
+    /// </exception>
+    /// <exception cref="ArgumentException">
+    /// <paramref name="rowStrideInBytes"/> is not divisible by the pixel size,
+    /// or <paramref name="data"/> is smaller than the required strided image length.
+    /// </exception>
+    /// <returns>A new <see cref="Image{TPixel}"/>.</returns>
+    public static Image<TPixel> LoadPixelData<TPixel>(
+        Configuration configuration,
+        ReadOnlySpan<byte> data,
+        int width,
+        int height,
+        int rowStrideInBytes)
+        where TPixel : unmanaged, IPixel<TPixel>
+    {
+        Guard.NotNull(configuration, nameof(configuration));
+
+        int rowStride = GetPixelRowStrideFromByteStride<TPixel>(width, rowStrideInBytes, nameof(rowStrideInBytes));
+        return LoadPixelData(configuration, MemoryMarshal.Cast<byte, TPixel>(data), width, height, rowStride);
+    }
+
     /// <summary>
     /// Create a new instance of the <see cref="Image{TPixel}"/> class from the raw <typeparamref name="TPixel"/> data.
     /// </summary>
@@ -66,20 +142,42 @@ public abstract partial class Image
     /// <returns>A new <see cref="Image{TPixel}"/>.</returns>
     public static Image<TPixel> LoadPixelData<TPixel>(Configuration configuration, ReadOnlySpan<TPixel> data, int width, int height)
         where TPixel : unmanaged, IPixel<TPixel>
+        => LoadPixelData(configuration, data, width, height, width);
+
+    /// <summary>
+    /// Create a new instance of the <see cref="Image{TPixel}"/> class from raw <typeparamref name="TPixel"/> data
+    /// using <paramref name="rowStride"/> pixels between source row starts.
+    /// </summary>
+    /// <param name="configuration">The configuration for the decoder.</param>
+    /// <param name="data">The readonly span containing the image pixel data.</param>
+    /// <param name="width">The width of the final image.</param>
+    /// <param name="height">The height of the final image.</param>
+    /// <param name="rowStride">The number of pixels between row starts in <paramref name="data"/>.</param>
+    /// <exception cref="ArgumentNullException">The configuration is null.</exception>
+    /// <exception cref="ArgumentOutOfRangeException">
+    /// <paramref name="width"/> or <paramref name="height"/> is not positive,
+    /// or <paramref name="rowStride"/> is less than <paramref name="width"/>.
+    /// </exception>
+    /// <exception cref="ArgumentException">
+    /// <paramref name="data"/> is smaller than <c>((height - 1) * rowStride) + width</c>.
+    /// </exception>
+    /// <typeparam name="TPixel">The pixel format.</typeparam>
+    /// <returns>A new <see cref="Image{TPixel}"/>.</returns>
+    public static Image<TPixel> LoadPixelData<TPixel>(
+        Configuration configuration,
+        ReadOnlySpan<TPixel> data,
+        int width,
+        int height,
+        int rowStride)
+        where TPixel : unmanaged, IPixel<TPixel>
     {
         Guard.NotNull(configuration, nameof(configuration));
-
-        if (data.IsEmpty)
-        {
-            throw new ArgumentException("Pixel data cannot be empty.", nameof(data));
-        }
-
-        int count = width * height;
-        Guard.MustBeGreaterThanOrEqualTo(data.Length, count, nameof(data));
+        ValidateWrapMemoryStride(width, height, rowStride, nameof(rowStride));
+        long requiredLength = GetRequiredLength(width, height, rowStride);
+        Guard.MustBeGreaterThanOrEqualTo(data.Length, requiredLength, nameof(data));
 
         Image<TPixel> image = new(configuration, width, height);
-        data = data[..count];
-        data.CopyTo(image.Frames.RootFrame.PixelBuffer.FastMemoryGroup);
+        image.Frames.RootFrame.PixelBuffer.CopyFrom(data, rowStride);
 
         return image;
     }

src/ImageSharp/Image.WrapMemory.cs

@@ -2,6 +2,7 @@
 // Licensed under the Six Labors Split License.
 
 using System.Buffers;
+using System.Runtime.CompilerServices;
 using SixLabors.ImageSharp.Memory;
 using SixLabors.ImageSharp.Metadata;
 using SixLabors.ImageSharp.PixelFormats;
@@ -58,29 +59,55 @@ public abstract partial class Image
 
     /// <summary>
     /// <para>
-    /// Wraps an existing contiguous memory area of at least 'width' x 'height' pixels allowing viewing/manipulation as
-    /// an <see cref="Image{TPixel}"/> instance.
-    /// </para>
-    /// <para>
-    /// Please note: using this method does not transfer the ownership of the underlying buffer of the input <see cref="Memory{T}"/>
-    /// to the new <see cref="Image{TPixel}"/> instance. This means that consumers of this method must ensure that the input buffer
-    /// is either self-contained, (for example, a <see cref="Memory{T}"/> instance wrapping a new array that was
-    /// created), or that the owning object is not disposed until the returned <see cref="Image{TPixel}"/> is disposed.
+    /// Wraps an existing memory area allowing viewing/manipulation as an <see cref="Image{TPixel}"/>
+    /// with <paramref name="rowStride"/> pixels between row starts.
     /// </para>
     /// <para>
-    /// If the input <see cref="Memory{T}"/> instance is one retrieved from an <see cref="IMemoryOwner{T}"/> instance
-    /// rented from a memory pool (such as <see cref="MemoryPool{T}"/>), and that owning instance is disposed while the image is still
-    /// in use, this will lead to undefined behavior and possibly runtime crashes (as the same buffer might then be modified by other
-    /// consumers while the returned image is still working on it). Make sure to control the lifetime of the input buffers appropriately.
+    /// Please note: using this method does not transfer the ownership of the underlying buffer of the input
+    /// <see cref="Memory{T}"/> to the new <see cref="Image{TPixel}"/> instance. Consumers must ensure that
+    /// the input buffer remains valid for the full lifetime of the returned image.
     /// </para>
     /// </summary>
-    /// <typeparam name="TPixel">The pixel type</typeparam>
-    /// <param name="configuration">The <see cref="Configuration"/></param>
-    /// <param name="pixelMemory">The pixel memory.</param>
-    /// <param name="width">The width of the memory image.</param>
-    /// <param name="height">The height of the memory image.</param>
+    /// <typeparam name="TPixel">The pixel type.</typeparam>
+    /// <param name="configuration">The <see cref="Configuration"/>.</param>
+    /// <param name="pixelMemory">The source pixel memory.</param>
+    /// <param name="width">The width of the memory image in pixels.</param>
+    /// <param name="height">The height of the memory image in pixels.</param>
+    /// <param name="rowStride">The number of pixels between row starts in <paramref name="pixelMemory"/>.</param>
+    /// <param name="metadata">The <see cref="ImageMetadata"/>.</param>
     /// <exception cref="ArgumentNullException">The configuration is null.</exception>
+    /// <exception cref="ArgumentNullException">The metadata is null.</exception>
+    /// <exception cref="ArgumentOutOfRangeException">
+    /// <paramref name="width"/> or <paramref name="height"/> is not positive,
+    /// or <paramref name="rowStride"/> is less than <paramref name="width"/>.
+    /// </exception>
+    /// <exception cref="ArgumentException">
+    /// The length of <paramref name="pixelMemory"/> is less than
+    /// <c>((height - 1) * rowStride) + width</c>.
+    /// </exception>
     /// <returns>An <see cref="Image{TPixel}"/> instance.</returns>
+    public static Image<TPixel> WrapMemory<TPixel>(
+        Configuration configuration,
+        Memory<TPixel> pixelMemory,
+        int width,
+        int height,
+        int rowStride,
+        ImageMetadata metadata)
+        where TPixel : unmanaged, IPixel<TPixel>
+    {
+        Guard.NotNull(configuration, nameof(configuration));
+        Guard.NotNull(metadata, nameof(metadata));
+
+        ValidateWrapMemoryStride(width, height, rowStride, nameof(rowStride));
+
+        long requiredLength = GetRequiredLength(width, height, rowStride);
+        Guard.IsTrue(pixelMemory.Length >= requiredLength, nameof(pixelMemory), "The length of the input memory is less than the specified image size");
+
+        MemoryGroup<TPixel> memorySource = MemoryGroup<TPixel>.Wrap(pixelMemory);
+        return new Image<TPixel>(configuration, memorySource, width, height, rowStride, metadata);
+    }
+
+    /// <inheritdoc cref="WrapMemory{TPixel}(Configuration, Memory{TPixel}, int, int, ImageMetadata)"/>
     public static Image<TPixel> WrapMemory<TPixel>(
         Configuration configuration,
         Memory<TPixel> pixelMemory,
@@ -89,29 +116,17 @@ public abstract partial class Image
         where TPixel : unmanaged, IPixel<TPixel>
         => WrapMemory(configuration, pixelMemory, width, height, new ImageMetadata());
 
-    /// <summary>
-    /// <para>
-    /// Wraps an existing contiguous memory area of at least 'width' x 'height' pixels allowing viewing/manipulation as
-    /// an <see cref="Image{TPixel}"/> instance.
-    /// </para>
-    /// <para>
-    /// Please note: using this method does not transfer the ownership of the underlying buffer of the input <see cref="Memory{T}"/>
-    /// to the new <see cref="Image{TPixel}"/> instance. This means that consumers of this method must ensure that the input buffer
-    /// is either self-contained, (for example, a <see cref="Memory{T}"/> instance wrapping a new array that was
-    /// created), or that the owning object is not disposed until the returned <see cref="Image{TPixel}"/> is disposed.
-    /// </para>
-    /// <para>
-    /// If the input <see cref="Memory{T}"/> instance is one retrieved from an <see cref="IMemoryOwner{T}"/> instance
-    /// rented from a memory pool (such as <see cref="MemoryPool{T}"/>), and that owning instance is disposed while the image is still
-    /// in use, this will lead to undefined behavior and possibly runtime crashes (as the same buffer might then be modified by other
-    /// consumers while the returned image is still working on it). Make sure to control the lifetime of the input buffers appropriately.
-    /// </para>
-    /// </summary>
-    /// <typeparam name="TPixel">The pixel type.</typeparam>
-    /// <param name="pixelMemory">The pixel memory.</param>
-    /// <param name="width">The width of the memory image.</param>
-    /// <param name="height">The height of the memory image.</param>
-    /// <returns>An <see cref="Image{TPixel}"/> instance.</returns>
+    /// <inheritdoc cref="WrapMemory{TPixel}(Configuration, Memory{TPixel}, int, int, int, ImageMetadata)"/>
+    public static Image<TPixel> WrapMemory<TPixel>(
+        Configuration configuration,
+        Memory<TPixel> pixelMemory,
+        int width,
+        int height,
+        int rowStride)
+        where TPixel : unmanaged, IPixel<TPixel>
+        => WrapMemory(configuration, pixelMemory, width, height, rowStride, new ImageMetadata());
+
+    /// <inheritdoc cref="WrapMemory{TPixel}(Configuration, Memory{TPixel}, int, int, ImageMetadata)"/>
     public static Image<TPixel> WrapMemory<TPixel>(
         Memory<TPixel> pixelMemory,
         int width,
@@ -119,6 +134,15 @@ public abstract partial class Image
         where TPixel : unmanaged, IPixel<TPixel>
         => WrapMemory(Configuration.Default, pixelMemory, width, height);
 
+    /// <inheritdoc cref="WrapMemory{TPixel}(Configuration, Memory{TPixel}, int, int, int, ImageMetadata)"/>
+    public static Image<TPixel> WrapMemory<TPixel>(
+        Memory<TPixel> pixelMemory,
+        int width,
+        int height,
+        int rowStride)
+        where TPixel : unmanaged, IPixel<TPixel>
+        => WrapMemory(Configuration.Default, pixelMemory, width, height, rowStride);
+
     /// <summary>
     /// Wraps an existing contiguous memory area of at least 'width' x 'height' pixels,
     /// allowing to view/manipulate it as an <see cref="Image{TPixel}"/> instance.
@@ -152,19 +176,55 @@ public abstract partial class Image
     }
 
     /// <summary>
-    /// Wraps an existing contiguous memory area of at least 'width' x 'height' pixels,
-    /// allowing to view/manipulate it as an <see cref="Image{TPixel}"/> instance.
-    /// The ownership of the <paramref name="pixelMemoryOwner"/> is being transferred to the new <see cref="Image{TPixel}"/> instance,
-    /// meaning that the caller is not allowed to dispose <paramref name="pixelMemoryOwner"/>.
-    /// It will be disposed together with the result image.
+    /// <para>
+    /// Wraps an existing memory owner allowing viewing/manipulation as an <see cref="Image{TPixel}"/>
+    /// with <paramref name="rowStride"/> pixels between row starts.
+    /// </para>
+    /// <para>
+    /// Ownership of <paramref name="pixelMemoryOwner"/> is transferred to the returned image. The caller
+    /// must not dispose the owner manually.
+    /// </para>
     /// </summary>
     /// <typeparam name="TPixel">The pixel type.</typeparam>
-    /// <param name="configuration">The <see cref="Configuration"/></param>
-    /// <param name="pixelMemoryOwner">The <see cref="IMemoryOwner{T}"/> that is being transferred to the image.</param>
-    /// <param name="width">The width of the memory image.</param>
-    /// <param name="height">The height of the memory image.</param>
+    /// <param name="configuration">The <see cref="Configuration"/>.</param>
+    /// <param name="pixelMemoryOwner">The pixel memory owner transferred to the image.</param>
+    /// <param name="width">The width of the memory image in pixels.</param>
+    /// <param name="height">The height of the memory image in pixels.</param>
+    /// <param name="rowStride">The number of pixels between row starts in the source memory.</param>
+    /// <param name="metadata">The <see cref="ImageMetadata"/>.</param>
     /// <exception cref="ArgumentNullException">The configuration is null.</exception>
-    /// <returns>An <see cref="Image{TPixel}"/> instance</returns>
+    /// <exception cref="ArgumentNullException">The metadata is null.</exception>
+    /// <exception cref="ArgumentOutOfRangeException">
+    /// <paramref name="width"/> or <paramref name="height"/> is not positive,
+    /// or <paramref name="rowStride"/> is less than <paramref name="width"/>.
+    /// </exception>
+    /// <exception cref="ArgumentException">
+    /// The length of <paramref name="pixelMemoryOwner"/> is less than
+    /// <c>((height - 1) * rowStride) + width</c>.
+    /// </exception>
+    /// <returns>An <see cref="Image{TPixel}"/> instance.</returns>
+    public static Image<TPixel> WrapMemory<TPixel>(
+        Configuration configuration,
+        IMemoryOwner<TPixel> pixelMemoryOwner,
+        int width,
+        int height,
+        int rowStride,
+        ImageMetadata metadata)
+        where TPixel : unmanaged, IPixel<TPixel>
+    {
+        Guard.NotNull(configuration, nameof(configuration));
+        Guard.NotNull(metadata, nameof(metadata));
+
+        ValidateWrapMemoryStride(width, height, rowStride, nameof(rowStride));
+
+        long requiredLength = GetRequiredLength(width, height, rowStride);
+        Guard.IsTrue(pixelMemoryOwner.Memory.Length >= requiredLength, nameof(pixelMemoryOwner), "The length of the input memory is less than the specified image size");
+
+        MemoryGroup<TPixel> memorySource = MemoryGroup<TPixel>.Wrap(pixelMemoryOwner);
+        return new Image<TPixel>(configuration, memorySource, width, height, rowStride, metadata);
+    }
+
+    /// <inheritdoc cref="WrapMemory{TPixel}(Configuration, IMemoryOwner{TPixel}, int, int, ImageMetadata)"/>
     public static Image<TPixel> WrapMemory<TPixel>(
         Configuration configuration,
         IMemoryOwner<TPixel> pixelMemoryOwner,
@@ -173,18 +233,17 @@ public abstract partial class Image
         where TPixel : unmanaged, IPixel<TPixel>
         => WrapMemory(configuration, pixelMemoryOwner, width, height, new ImageMetadata());
 
-    /// <summary>
-    /// Wraps an existing contiguous memory area of at least 'width' x 'height' pixels,
-    /// allowing to view/manipulate it as an <see cref="Image{TPixel}"/> instance.
-    /// The ownership of the <paramref name="pixelMemoryOwner"/> is being transferred to the new <see cref="Image{TPixel}"/> instance,
-    /// meaning that the caller is not allowed to dispose <paramref name="pixelMemoryOwner"/>.
-    /// It will be disposed together with the result image.
-    /// </summary>
-    /// <typeparam name="TPixel">The pixel type</typeparam>
-    /// <param name="pixelMemoryOwner">The <see cref="IMemoryOwner{T}"/> that is being transferred to the image.</param>
-    /// <param name="width">The width of the memory image.</param>
-    /// <param name="height">The height of the memory image.</param>
-    /// <returns>An <see cref="Image{TPixel}"/> instance.</returns>
+    /// <inheritdoc cref="WrapMemory{TPixel}(Configuration, IMemoryOwner{TPixel}, int, int, int, ImageMetadata)"/>
+    public static Image<TPixel> WrapMemory<TPixel>(
+        Configuration configuration,
+        IMemoryOwner<TPixel> pixelMemoryOwner,
+        int width,
+        int height,
+        int rowStride)
+        where TPixel : unmanaged, IPixel<TPixel>
+        => WrapMemory(configuration, pixelMemoryOwner, width, height, rowStride, new ImageMetadata());
+
+    /// <inheritdoc cref="WrapMemory{TPixel}(Configuration, IMemoryOwner{TPixel}, int, int, ImageMetadata)"/>
     public static Image<TPixel> WrapMemory<TPixel>(
         IMemoryOwner<TPixel> pixelMemoryOwner,
         int width,
@@ -192,6 +251,15 @@ public abstract partial class Image
         where TPixel : unmanaged, IPixel<TPixel>
         => WrapMemory(Configuration.Default, pixelMemoryOwner, width, height);
 
+    /// <inheritdoc cref="WrapMemory{TPixel}(Configuration, IMemoryOwner{TPixel}, int, int, int, ImageMetadata)"/>
+    public static Image<TPixel> WrapMemory<TPixel>(
+        IMemoryOwner<TPixel> pixelMemoryOwner,
+        int width,
+        int height,
+        int rowStride)
+        where TPixel : unmanaged, IPixel<TPixel>
+        => WrapMemory(Configuration.Default, pixelMemoryOwner, width, height, rowStride);
+
     /// <summary>
     /// <para>
     /// Wraps an existing contiguous memory area of at least 'width' x 'height' pixels allowing viewing/manipulation as
@@ -240,29 +308,56 @@ public abstract partial class Image
 
     /// <summary>
     /// <para>
-    /// Wraps an existing contiguous memory area of at least 'width' x 'height' pixels allowing viewing/manipulation as
-    /// an <see cref="Image{TPixel}"/> instance.
+    /// Wraps an existing byte memory area allowing viewing/manipulation as an <see cref="Image{TPixel}"/>
+    /// with <paramref name="rowStrideInBytes"/> bytes between row starts.
     /// </para>
     /// <para>
-    /// Please note: using this method does not transfer the ownership of the underlying buffer of the input <see cref="Memory{T}"/>
-    /// to the new <see cref="Image{TPixel}"/> instance. This means that consumers of this method must ensure that the input buffer
-    /// is either self-contained, (for example, a <see cref="Memory{T}"/> instance wrapping a new array that was
-    /// created), or that the owning object is not disposed until the returned <see cref="Image{TPixel}"/> is disposed.
-    /// </para>
-    /// <para>
-    /// If the input <see cref="Memory{T}"/> instance is one retrieved from an <see cref="IMemoryOwner{T}"/> instance
-    /// rented from a memory pool (such as <see cref="MemoryPool{T}"/>), and that owning instance is disposed while the image is still
-    /// in use, this will lead to undefined behavior and possibly runtime crashes (as the same buffer might then be modified by other
-    /// consumers while the returned image is still working on it). Make sure to control the lifetime of the input buffers appropriately.
+    /// Please note: using this method does not transfer the ownership of the underlying buffer of the input
+    /// <see cref="Memory{T}"/> to the new <see cref="Image{TPixel}"/> instance. Consumers must ensure that
+    /// the input buffer remains valid for the full lifetime of the returned image.
     /// </para>
     /// </summary>
-    /// <typeparam name="TPixel">The pixel type</typeparam>
-    /// <param name="configuration">The <see cref="Configuration"/></param>
-    /// <param name="byteMemory">The byte memory representing the pixel data.</param>
-    /// <param name="width">The width of the memory image.</param>
-    /// <param name="height">The height of the memory image.</param>
+    /// <typeparam name="TPixel">The pixel type.</typeparam>
+    /// <param name="configuration">The <see cref="Configuration"/>.</param>
+    /// <param name="byteMemory">The source byte memory.</param>
+    /// <param name="width">The width of the memory image in pixels.</param>
+    /// <param name="height">The height of the memory image in pixels.</param>
+    /// <param name="rowStrideInBytes">The number of bytes between row starts in <paramref name="byteMemory"/>.</param>
+    /// <param name="metadata">The <see cref="ImageMetadata"/>.</param>
     /// <exception cref="ArgumentNullException">The configuration is null.</exception>
+    /// <exception cref="ArgumentNullException">The metadata is null.</exception>
+    /// <exception cref="ArgumentOutOfRangeException">
+    /// <paramref name="width"/> or <paramref name="height"/> is not positive,
+    /// or <paramref name="rowStrideInBytes"/> resolves to less than <paramref name="width"/> pixels.
+    /// </exception>
+    /// <exception cref="ArgumentException">
+    /// <paramref name="rowStrideInBytes"/> is not divisible by the size of <typeparamref name="TPixel"/>,
+    /// or <paramref name="byteMemory"/> is smaller than the required strided image length.
+    /// </exception>
     /// <returns>An <see cref="Image{TPixel}"/> instance.</returns>
+    public static Image<TPixel> WrapMemory<TPixel>(
+        Configuration configuration,
+        Memory<byte> byteMemory,
+        int width,
+        int height,
+        int rowStrideInBytes,
+        ImageMetadata metadata)
+        where TPixel : unmanaged, IPixel<TPixel>
+    {
+        Guard.NotNull(configuration, nameof(configuration));
+        Guard.NotNull(metadata, nameof(metadata));
+
+        int rowStride = GetPixelRowStrideFromByteStride<TPixel>(width, rowStrideInBytes, nameof(rowStrideInBytes));
+        long requiredLength = GetRequiredLength(width, height, rowStride);
+
+        ByteMemoryManager<TPixel> memoryManager = new(byteMemory);
+        Guard.IsTrue(memoryManager.Memory.Length >= requiredLength, nameof(byteMemory), "The length of the input memory is less than the specified image size");
+
+        MemoryGroup<TPixel> memorySource = MemoryGroup<TPixel>.Wrap(memoryManager.Memory);
+        return new Image<TPixel>(configuration, memorySource, width, height, rowStride, metadata);
+    }
+
+    /// <inheritdoc cref="WrapMemory{TPixel}(Configuration, Memory{byte}, int, int, ImageMetadata)"/>
     public static Image<TPixel> WrapMemory<TPixel>(
         Configuration configuration,
         Memory<byte> byteMemory,
@@ -271,29 +366,17 @@ public abstract partial class Image
         where TPixel : unmanaged, IPixel<TPixel>
         => WrapMemory<TPixel>(configuration, byteMemory, width, height, new ImageMetadata());
 
-    /// <summary>
-    /// <para>
-    /// Wraps an existing contiguous memory area of at least 'width' x 'height' pixels allowing viewing/manipulation as
-    /// an <see cref="Image{TPixel}"/> instance.
-    /// </para>
-    /// <para>
-    /// Please note: using this method does not transfer the ownership of the underlying buffer of the input <see cref="Memory{T}"/>
-    /// to the new <see cref="Image{TPixel}"/> instance. This means that consumers of this method must ensure that the input buffer
-    /// is either self-contained, (for example, a <see cref="Memory{T}"/> instance wrapping a new array that was
-    /// created), or that the owning object is not disposed until the returned <see cref="Image{TPixel}"/> is disposed.
-    /// </para>
-    /// <para>
-    /// If the input <see cref="Memory{T}"/> instance is one retrieved from an <see cref="IMemoryOwner{T}"/> instance
-    /// rented from a memory pool (such as <see cref="MemoryPool{T}"/>), and that owning instance is disposed while the image is still
-    /// in use, this will lead to undefined behavior and possibly runtime crashes (as the same buffer might then be modified by other
-    /// consumers while the returned image is still working on it). Make sure to control the lifetime of the input buffers appropriately.
-    /// </para>
-    /// </summary>
-    /// <typeparam name="TPixel">The pixel type.</typeparam>
-    /// <param name="byteMemory">The byte memory representing the pixel data.</param>
-    /// <param name="width">The width of the memory image.</param>
-    /// <param name="height">The height of the memory image.</param>
-    /// <returns>An <see cref="Image{TPixel}"/> instance.</returns>
+    /// <inheritdoc cref="WrapMemory{TPixel}(Configuration, Memory{byte}, int, int, int, ImageMetadata)"/>
+    public static Image<TPixel> WrapMemory<TPixel>(
+        Configuration configuration,
+        Memory<byte> byteMemory,
+        int width,
+        int height,
+        int rowStrideInBytes)
+        where TPixel : unmanaged, IPixel<TPixel>
+        => WrapMemory<TPixel>(configuration, byteMemory, width, height, rowStrideInBytes, new ImageMetadata());
+
+    /// <inheritdoc cref="WrapMemory{TPixel}(Configuration, Memory{byte}, int, int, ImageMetadata)"/>
     public static Image<TPixel> WrapMemory<TPixel>(
         Memory<byte> byteMemory,
         int width,
@@ -301,6 +384,15 @@ public abstract partial class Image
         where TPixel : unmanaged, IPixel<TPixel>
         => WrapMemory<TPixel>(Configuration.Default, byteMemory, width, height);
 
+    /// <inheritdoc cref="WrapMemory{TPixel}(Configuration, Memory{byte}, int, int, int, ImageMetadata)"/>
+    public static Image<TPixel> WrapMemory<TPixel>(
+        Memory<byte> byteMemory,
+        int width,
+        int height,
+        int rowStrideInBytes)
+        where TPixel : unmanaged, IPixel<TPixel>
+        => WrapMemory<TPixel>(Configuration.Default, byteMemory, width, height, rowStrideInBytes);
+
     /// <summary>
     /// Wraps an existing contiguous memory area of at least 'width' x 'height' pixels,
     /// allowing to view/manipulate it as an <see cref="Image{TPixel}"/> instance.
@@ -337,19 +429,56 @@ public abstract partial class Image
     }
 
     /// <summary>
-    /// Wraps an existing contiguous memory area of at least 'width' x 'height' pixels,
-    /// allowing to view/manipulate it as an <see cref="Image{TPixel}"/> instance.
-    /// The ownership of the <paramref name="byteMemoryOwner"/> is being transferred to the new <see cref="Image{TPixel}"/> instance,
-    /// meaning that the caller is not allowed to dispose <paramref name="byteMemoryOwner"/>.
-    /// It will be disposed together with the result image.
+    /// <para>
+    /// Wraps an existing byte memory owner allowing viewing/manipulation as an <see cref="Image{TPixel}"/>
+    /// with <paramref name="rowStrideInBytes"/> bytes between row starts.
+    /// </para>
+    /// <para>
+    /// Ownership of <paramref name="byteMemoryOwner"/> is transferred to the returned image. The caller
+    /// must not dispose the owner manually.
+    /// </para>
     /// </summary>
     /// <typeparam name="TPixel">The pixel type.</typeparam>
-    /// <param name="configuration">The <see cref="Configuration"/></param>
-    /// <param name="byteMemoryOwner">The <see cref="IMemoryOwner{T}"/> that is being transferred to the image.</param>
-    /// <param name="width">The width of the memory image.</param>
-    /// <param name="height">The height of the memory image.</param>
+    /// <param name="configuration">The <see cref="Configuration"/>.</param>
+    /// <param name="byteMemoryOwner">The byte memory owner transferred to the image.</param>
+    /// <param name="width">The width of the memory image in pixels.</param>
+    /// <param name="height">The height of the memory image in pixels.</param>
+    /// <param name="rowStrideInBytes">The number of bytes between row starts in the source memory.</param>
+    /// <param name="metadata">The <see cref="ImageMetadata"/>.</param>
     /// <exception cref="ArgumentNullException">The configuration is null.</exception>
-    /// <returns>An <see cref="Image{TPixel}"/> instance</returns>
+    /// <exception cref="ArgumentNullException">The metadata is null.</exception>
+    /// <exception cref="ArgumentOutOfRangeException">
+    /// <paramref name="width"/> or <paramref name="height"/> is not positive,
+    /// or <paramref name="rowStrideInBytes"/> resolves to less than <paramref name="width"/> pixels.
+    /// </exception>
+    /// <exception cref="ArgumentException">
+    /// <paramref name="rowStrideInBytes"/> is not divisible by the size of <typeparamref name="TPixel"/>,
+    /// or <paramref name="byteMemoryOwner"/> is smaller than the required strided image length.
+    /// </exception>
+    /// <returns>An <see cref="Image{TPixel}"/> instance.</returns>
+    public static Image<TPixel> WrapMemory<TPixel>(
+        Configuration configuration,
+        IMemoryOwner<byte> byteMemoryOwner,
+        int width,
+        int height,
+        int rowStrideInBytes,
+        ImageMetadata metadata)
+        where TPixel : unmanaged, IPixel<TPixel>
+    {
+        Guard.NotNull(configuration, nameof(configuration));
+        Guard.NotNull(metadata, nameof(metadata));
+
+        int rowStride = GetPixelRowStrideFromByteStride<TPixel>(width, rowStrideInBytes, nameof(rowStrideInBytes));
+
+        ByteMemoryOwner<TPixel> pixelMemoryOwner = new(byteMemoryOwner);
+        long requiredLength = GetRequiredLength(width, height, rowStride);
+        Guard.IsTrue(pixelMemoryOwner.Memory.Length >= requiredLength, nameof(byteMemoryOwner), "The length of the input memory is less than the specified image size");
+
+        MemoryGroup<TPixel> memorySource = MemoryGroup<TPixel>.Wrap(pixelMemoryOwner);
+        return new Image<TPixel>(configuration, memorySource, width, height, rowStride, metadata);
+    }
+
+    /// <inheritdoc cref="WrapMemory{TPixel}(Configuration, IMemoryOwner{byte}, int, int, ImageMetadata)"/>
     public static Image<TPixel> WrapMemory<TPixel>(
         Configuration configuration,
         IMemoryOwner<byte> byteMemoryOwner,
@@ -358,18 +487,17 @@ public abstract partial class Image
         where TPixel : unmanaged, IPixel<TPixel>
         => WrapMemory<TPixel>(configuration, byteMemoryOwner, width, height, new ImageMetadata());
 
-    /// <summary>
-    /// Wraps an existing contiguous memory area of at least 'width' x 'height' pixels,
-    /// allowing to view/manipulate it as an <see cref="Image{TPixel}"/> instance.
-    /// The ownership of the <paramref name="byteMemoryOwner"/> is being transferred to the new <see cref="Image{TPixel}"/> instance,
-    /// meaning that the caller is not allowed to dispose <paramref name="byteMemoryOwner"/>.
-    /// It will be disposed together with the result image.
-    /// </summary>
-    /// <typeparam name="TPixel">The pixel type</typeparam>
-    /// <param name="byteMemoryOwner">The <see cref="IMemoryOwner{T}"/> that is being transferred to the image.</param>
-    /// <param name="width">The width of the memory image.</param>
-    /// <param name="height">The height of the memory image.</param>
-    /// <returns>An <see cref="Image{TPixel}"/> instance.</returns>
+    /// <inheritdoc cref="WrapMemory{TPixel}(Configuration, IMemoryOwner{byte}, int, int, int, ImageMetadata)"/>
+    public static Image<TPixel> WrapMemory<TPixel>(
+        Configuration configuration,
+        IMemoryOwner<byte> byteMemoryOwner,
+        int width,
+        int height,
+        int rowStrideInBytes)
+        where TPixel : unmanaged, IPixel<TPixel>
+        => WrapMemory<TPixel>(configuration, byteMemoryOwner, width, height, rowStrideInBytes, new ImageMetadata());
+
+    /// <inheritdoc cref="WrapMemory{TPixel}(Configuration, IMemoryOwner{byte}, int, int, ImageMetadata)"/>
     public static Image<TPixel> WrapMemory<TPixel>(
         IMemoryOwner<byte> byteMemoryOwner,
         int width,
@@ -377,6 +505,15 @@ public abstract partial class Image
         where TPixel : unmanaged, IPixel<TPixel>
         => WrapMemory<TPixel>(Configuration.Default, byteMemoryOwner, width, height);
 
+    /// <inheritdoc cref="WrapMemory{TPixel}(Configuration, IMemoryOwner{byte}, int, int, int, ImageMetadata)"/>
+    public static Image<TPixel> WrapMemory<TPixel>(
+        IMemoryOwner<byte> byteMemoryOwner,
+        int width,
+        int height,
+        int rowStrideInBytes)
+        where TPixel : unmanaged, IPixel<TPixel>
+        => WrapMemory<TPixel>(Configuration.Default, byteMemoryOwner, width, height, rowStrideInBytes);
+
     /// <summary>
     /// <para>
     /// Wraps an existing contiguous memory area of at least 'width' x 'height' pixels allowing viewing/manipulation as
@@ -434,35 +571,60 @@ public abstract partial class Image
 
     /// <summary>
     /// <para>
-    /// Wraps an existing contiguous memory area of at least 'width' x 'height' pixels allowing viewing/manipulation as
-    /// an <see cref="Image{TPixel}"/> instance.
+    /// Wraps an unmanaged memory area allowing viewing/manipulation as an <see cref="Image{TPixel}"/>
+    /// with <paramref name="rowStrideInBytes"/> bytes between row starts.
     /// </para>
     /// <para>
-    /// Please note: this method relies on callers to carefully manage the target memory area being referenced by the
-    /// pointer and that the lifetime of such a memory area is at least equal to that of the returned
-    /// <see cref="Image{TPixel}"/> instance. For example, if the input pointer references an unmanaged memory area,
-    /// callers must ensure that the memory area is not freed as long as the returned <see cref="Image{TPixel}"/> is
-    /// in use and not disposed. The same applies if the input memory area points to a pinned managed object, as callers
-    /// must ensure that objects will remain pinned as long as the <see cref="Image{TPixel}"/> instance is in use.
-    /// Failing to do so constitutes undefined behavior and will likely lead to memory corruption and runtime crashes.
-    /// </para>
-    /// <para>
-    /// Note also that if you have a <see cref="Memory{T}"/> or an array (which can be cast to <see cref="Memory{T}"/>) of
-    /// either <see cref="byte"/> or <typeparamref name="TPixel"/> values, it is highly recommended to use one of the other
-    /// available overloads of this method instead (such as <see cref="WrapMemory{TPixel}(Configuration, Memory{byte}, int, int)"/>
-    /// or <see cref="WrapMemory{TPixel}(Configuration, Memory{TPixel}, int, int)"/>, to make the resulting code less error
-    /// prone and avoid having to pin the underlying memory buffer in use. This method is primarily meant to be used when
-    /// doing interop or working with buffers that are located in unmanaged memory.
+    /// Callers must ensure the memory referenced by <paramref name="pointer"/> remains valid for the full
+    /// lifetime of the returned image.
     /// </para>
     /// </summary>
-    /// <typeparam name="TPixel">The pixel type</typeparam>
-    /// <param name="configuration">The <see cref="Configuration"/></param>
-    /// <param name="pointer">The pointer to the target memory buffer to wrap.</param>
-    /// <param name="bufferSizeInBytes">The byte length of the memory allocated.</param>
-    /// <param name="width">The width of the memory image.</param>
-    /// <param name="height">The height of the memory image.</param>
+    /// <typeparam name="TPixel">The pixel type.</typeparam>
+    /// <param name="configuration">The <see cref="Configuration"/>.</param>
+    /// <param name="pointer">The pointer to the source memory.</param>
+    /// <param name="bufferSizeInBytes">The byte length of the source memory.</param>
+    /// <param name="width">The width of the memory image in pixels.</param>
+    /// <param name="height">The height of the memory image in pixels.</param>
+    /// <param name="rowStrideInBytes">The number of bytes between row starts in the source memory.</param>
+    /// <param name="metadata">The <see cref="ImageMetadata"/>.</param>
     /// <exception cref="ArgumentNullException">The configuration is null.</exception>
+    /// <exception cref="ArgumentNullException">The metadata is null.</exception>
+    /// <exception cref="ArgumentException">
+    /// <paramref name="pointer"/> is null,
+    /// <paramref name="rowStrideInBytes"/> is not divisible by the size of <typeparamref name="TPixel"/>,
+    /// or <paramref name="bufferSizeInBytes"/> is smaller than the required strided image length.
+    /// </exception>
+    /// <exception cref="ArgumentOutOfRangeException">
+    /// <paramref name="width"/> or <paramref name="height"/> is not positive,
+    /// or <paramref name="rowStrideInBytes"/> resolves to less than <paramref name="width"/> pixels.
+    /// </exception>
     /// <returns>An <see cref="Image{TPixel}"/> instance.</returns>
+    public static unsafe Image<TPixel> WrapMemory<TPixel>(
+        Configuration configuration,
+        void* pointer,
+        int bufferSizeInBytes,
+        int width,
+        int height,
+        int rowStrideInBytes,
+        ImageMetadata metadata)
+        where TPixel : unmanaged, IPixel<TPixel>
+    {
+        Guard.IsFalse(pointer == null, nameof(pointer), "Pointer must not be null");
+        Guard.NotNull(configuration, nameof(configuration));
+        Guard.NotNull(metadata, nameof(metadata));
+
+        int rowStride = GetPixelRowStrideFromByteStride<TPixel>(width, rowStrideInBytes, nameof(rowStrideInBytes));
+        long requiredLength = GetRequiredLength(width, height, rowStride);
+
+        Guard.MustBeLessThanOrEqualTo(requiredLength, int.MaxValue, nameof(requiredLength));
+        Guard.MustBeGreaterThanOrEqualTo(bufferSizeInBytes / Unsafe.SizeOf<TPixel>(), requiredLength, nameof(bufferSizeInBytes));
+
+        UnmanagedMemoryManager<TPixel> memoryManager = new(pointer, (int)requiredLength);
+        MemoryGroup<TPixel> memorySource = MemoryGroup<TPixel>.Wrap(memoryManager.Memory);
+        return new Image<TPixel>(configuration, memorySource, width, height, rowStride, metadata);
+    }
+
+    /// <inheritdoc cref="WrapMemory{TPixel}(Configuration, void*, int, int, int, ImageMetadata)"/>
     public static unsafe Image<TPixel> WrapMemory<TPixel>(
         Configuration configuration,
         void* pointer,
@@ -472,35 +634,18 @@ public abstract partial class Image
         where TPixel : unmanaged, IPixel<TPixel>
         => WrapMemory<TPixel>(configuration, pointer, bufferSizeInBytes, width, height, new ImageMetadata());
 
-    /// <summary>
-    /// <para>
-    /// Wraps an existing contiguous memory area of at least 'width' x 'height' pixels allowing viewing/manipulation as
-    /// an <see cref="Image{TPixel}"/> instance.
-    /// </para>
-    /// <para>
-    /// Please note: this method relies on callers to carefully manage the target memory area being referenced by the
-    /// pointer and that the lifetime of such a memory area is at least equal to that of the returned
-    /// <see cref="Image{TPixel}"/> instance. For example, if the input pointer references an unmanaged memory area,
-    /// callers must ensure that the memory area is not freed as long as the returned <see cref="Image{TPixel}"/> is
-    /// in use and not disposed. The same applies if the input memory area points to a pinned managed object, as callers
-    /// must ensure that objects will remain pinned as long as the <see cref="Image{TPixel}"/> instance is in use.
-    /// Failing to do so constitutes undefined behavior and will likely lead to memory corruption and runtime crashes.
-    /// </para>
-    /// <para>
-    /// Note also that if you have a <see cref="Memory{T}"/> or an array (which can be cast to <see cref="Memory{T}"/>) of
-    /// either <see cref="byte"/> or <typeparamref name="TPixel"/> values, it is highly recommended to use one of the other
-    /// available overloads of this method instead (such as <see cref="WrapMemory{TPixel}(Configuration, Memory{byte}, int, int)"/>
-    /// or <see cref="WrapMemory{TPixel}(Configuration, Memory{TPixel}, int, int)"/>, to make the resulting code less error
-    /// prone and avoid having to pin the underlying memory buffer in use. This method is primarily meant to be used when
-    /// doing interop or working with buffers that are located in unmanaged memory.
-    /// </para>
-    /// </summary>
-    /// <typeparam name="TPixel">The pixel type.</typeparam>
-    /// <param name="pointer">The pointer to the target memory buffer to wrap.</param>
-    /// <param name="bufferSizeInBytes">The byte length of the memory allocated.</param>
-    /// <param name="width">The width of the memory image.</param>
-    /// <param name="height">The height of the memory image.</param>
-    /// <returns>An <see cref="Image{TPixel}"/> instance.</returns>
+    /// <inheritdoc cref="WrapMemory{TPixel}(Configuration, void*, int, int, int, int, ImageMetadata)"/>
+    public static unsafe Image<TPixel> WrapMemory<TPixel>(
+        Configuration configuration,
+        void* pointer,
+        int bufferSizeInBytes,
+        int width,
+        int height,
+        int rowStrideInBytes)
+        where TPixel : unmanaged, IPixel<TPixel>
+        => WrapMemory<TPixel>(configuration, pointer, bufferSizeInBytes, width, height, rowStrideInBytes, new ImageMetadata());
+
+    /// <inheritdoc cref="WrapMemory{TPixel}(Configuration, void*, int, int, int, ImageMetadata)"/>
     public static unsafe Image<TPixel> WrapMemory<TPixel>(
         void* pointer,
         int bufferSizeInBytes,
@@ -508,4 +653,41 @@ public abstract partial class Image
         int height)
         where TPixel : unmanaged, IPixel<TPixel>
         => WrapMemory<TPixel>(Configuration.Default, pointer, bufferSizeInBytes, width, height);
+
+    /// <inheritdoc cref="WrapMemory{TPixel}(Configuration, void*, int, int, int, int, ImageMetadata)"/>
+    public static unsafe Image<TPixel> WrapMemory<TPixel>(
+        void* pointer,
+        int bufferSizeInBytes,
+        int width,
+        int height,
+        int rowStrideInBytes)
+        where TPixel : unmanaged, IPixel<TPixel>
+        => WrapMemory<TPixel>(Configuration.Default, pointer, bufferSizeInBytes, width, height, rowStrideInBytes);
+
+    private static void ValidateWrapMemoryStride(int width, int height, int rowStride, string rowStrideParamName)
+    {
+        Guard.MustBeGreaterThan(width, 0, nameof(width));
+        Guard.MustBeGreaterThan(height, 0, nameof(height));
+        Guard.MustBeGreaterThanOrEqualTo(rowStride, width, rowStrideParamName);
+    }
+
+    private static int GetPixelRowStrideFromByteStride<TPixel>(int width, int rowStrideInBytes, string rowStrideParamName)
+        where TPixel : unmanaged, IPixel<TPixel>
+    {
+        int pixelSizeInBytes = Unsafe.SizeOf<TPixel>();
+
+        Guard.MustBeGreaterThan(width, 0, nameof(width));
+        Guard.MustBeGreaterThan(rowStrideInBytes, 0, rowStrideParamName);
+        Guard.IsTrue(
+            rowStrideInBytes % pixelSizeInBytes == 0,
+            rowStrideParamName,
+            "The row stride in bytes must be divisible by the pixel size.");
+
+        int rowStride = rowStrideInBytes / pixelSizeInBytes;
+        Guard.MustBeGreaterThanOrEqualTo(rowStride, width, rowStrideParamName);
+        return rowStride;
+    }
+
+    private static long GetRequiredLength(int width, int height, int rowStride)
+        => checked(((long)(height - 1) * rowStride) + width);
 }

src/ImageSharp/ImageFrame.LoadPixelData.cs

@@ -1,6 +1,7 @@
 // Copyright (c) Six Labors.
 // Licensed under the Six Labors Split License.
 
+using System.Runtime.CompilerServices;
 using System.Runtime.InteropServices;
 using SixLabors.ImageSharp.Memory;
 using SixLabors.ImageSharp.PixelFormats;
@@ -25,6 +26,36 @@ public partial class ImageFrame
         where TPixel : unmanaged, IPixel<TPixel>
         => LoadPixelData(configuration, MemoryMarshal.Cast<byte, TPixel>(data), width, height);
 
+    /// <summary>
+    /// Create a new instance of the <see cref="Image{TPixel}"/> class from the given byte array in <typeparamref name="TPixel"/> format.
+    /// </summary>
+    /// <param name="configuration">The configuration which allows altering default behaviour or extending the library.</param>
+    /// <param name="data">The byte array containing image data.</param>
+    /// <param name="width">The width of the final image.</param>
+    /// <param name="height">The height of the final image.</param>
+    /// <param name="rowStrideInBytes">The number of bytes between row starts in <paramref name="data"/>.</param>
+    /// <typeparam name="TPixel">The pixel format.</typeparam>
+    /// <returns>A new <see cref="Image{TPixel}"/>.</returns>
+    internal static ImageFrame<TPixel> LoadPixelData<TPixel>(
+        Configuration configuration,
+        ReadOnlySpan<byte> data,
+        int width,
+        int height,
+        int rowStrideInBytes)
+        where TPixel : unmanaged, IPixel<TPixel>
+    {
+        int pixelSizeInBytes = Unsafe.SizeOf<TPixel>();
+        Guard.MustBeGreaterThan(width, 0, nameof(width));
+        Guard.MustBeGreaterThan(rowStrideInBytes, 0, nameof(rowStrideInBytes));
+        Guard.IsTrue(
+            rowStrideInBytes % pixelSizeInBytes == 0,
+            nameof(rowStrideInBytes),
+            "The row stride in bytes must be divisible by the pixel size.");
+
+        int rowStride = rowStrideInBytes / pixelSizeInBytes;
+        return LoadPixelData(configuration, MemoryMarshal.Cast<byte, TPixel>(data), width, height, rowStride);
+    }
+
     /// <summary>
     /// Create a new instance of the <see cref="Image{TPixel}"/> class from the raw <typeparamref name="TPixel"/> data.
     /// </summary>
@@ -36,14 +67,36 @@ public partial class ImageFrame
     /// <returns>A new <see cref="Image{TPixel}"/>.</returns>
     internal static ImageFrame<TPixel> LoadPixelData<TPixel>(Configuration configuration, ReadOnlySpan<TPixel> data, int width, int height)
         where TPixel : unmanaged, IPixel<TPixel>
+        => LoadPixelData(configuration, data, width, height, width);
+
+    /// <summary>
+    /// Create a new instance of the <see cref="Image{TPixel}"/> class from raw <typeparamref name="TPixel"/> data
+    /// using <paramref name="rowStride"/> pixels between source row starts.
+    /// </summary>
+    /// <param name="configuration">The configuration which allows altering default behaviour or extending the library.</param>
+    /// <param name="data">The span containing the image pixel data.</param>
+    /// <param name="width">The width of the final image.</param>
+    /// <param name="height">The height of the final image.</param>
+    /// <param name="rowStride">The number of pixels between row starts in <paramref name="data"/>.</param>
+    /// <typeparam name="TPixel">The pixel format.</typeparam>
+    /// <returns>A new <see cref="Image{TPixel}"/>.</returns>
+    internal static ImageFrame<TPixel> LoadPixelData<TPixel>(
+        Configuration configuration,
+        ReadOnlySpan<TPixel> data,
+        int width,
+        int height,
+        int rowStride)
+        where TPixel : unmanaged, IPixel<TPixel>
     {
-        int count = width * height;
-        Guard.MustBeGreaterThanOrEqualTo(data.Length, count, nameof(data));
+        Guard.MustBeGreaterThan(width, 0, nameof(width));
+        Guard.MustBeGreaterThan(height, 0, nameof(height));
+        Guard.MustBeGreaterThanOrEqualTo(rowStride, width, nameof(rowStride));
 
-        ImageFrame<TPixel> image = new(configuration, width, height);
+        long requiredLength = checked(((long)(height - 1) * rowStride) + width);
+        Guard.MustBeGreaterThanOrEqualTo(data.Length, requiredLength, nameof(data));
 
-        data = data[..count];
-        data.CopyTo(image.PixelBuffer.FastMemoryGroup);
+        ImageFrame<TPixel> image = new(configuration, width, height);
+        image.PixelBuffer.CopyFrom(data, rowStride);
 
         return image;
     }

src/ImageSharp/ImageFrame.cs

@@ -71,7 +71,7 @@ public abstract partial class ImageFrame : IConfigurationProvider, IDisposable
     /// <param name="disposing">Whether to dispose of managed and unmanaged objects.</param>
     protected abstract void Dispose(bool disposing);
 
-    internal abstract void CopyPixelsTo<TDestinationPixel>(MemoryGroup<TDestinationPixel> destination)
+    internal abstract void CopyPixelsTo<TDestinationPixel>(Buffer2D<TDestinationPixel> destination)
         where TDestinationPixel : unmanaged, IPixel<TDestinationPixel>;
 
     /// <summary>

src/ImageSharp/ImageFrameCollection{TPixel}.cs

@@ -27,11 +27,16 @@ public sealed class ImageFrameCollection<TPixel> : ImageFrameCollection, IEnumer
     }
 
     internal ImageFrameCollection(Image<TPixel> parent, int width, int height, MemoryGroup<TPixel> memorySource)
+        : this(parent, width, height, width, memorySource)
+    {
+    }
+
+    internal ImageFrameCollection(Image<TPixel> parent, int width, int height, int rowStride, MemoryGroup<TPixel> memorySource)
     {
         this.parent = parent ?? throw new ArgumentNullException(nameof(parent));
 
         // Frames are already cloned within the caller
-        this.frames.Add(new ImageFrame<TPixel>(parent.Configuration, width, height, memorySource));
+        this.frames.Add(new ImageFrame<TPixel>(parent.Configuration, width, height, rowStride, memorySource));
     }
 
     internal ImageFrameCollection(Image<TPixel> parent, IEnumerable<ImageFrame<TPixel>> frames)
@@ -416,7 +421,7 @@ public sealed class ImageFrameCollection<TPixel> : ImageFrameCollection, IEnumer
             this.parent.Configuration,
             source.Size,
             source.Metadata.DeepClone());
-        source.CopyPixelsTo(result.PixelBuffer.FastMemoryGroup);
+        source.CopyPixelsTo(result.PixelBuffer);
         return result;
     }
 }

src/ImageSharp/ImageFrame{TPixel}.cs

@@ -114,7 +114,20 @@ public sealed class ImageFrame<TPixel> : ImageFrame, IPixelSource<TPixel>
     /// <param name="height">The height of the image in pixels.</param>
     /// <param name="memorySource">The memory source.</param>
     internal ImageFrame(Configuration configuration, int width, int height, MemoryGroup<TPixel> memorySource)
-        : this(configuration, width, height, memorySource, new ImageFrameMetadata())
+        : this(configuration, width, height, width, memorySource, new ImageFrameMetadata())
+    {
+    }
+
+    /// <summary>
+    /// Initializes a new instance of the <see cref="ImageFrame{TPixel}" /> class wrapping an existing buffer.
+    /// </summary>
+    /// <param name="configuration">The configuration providing initialization code which allows extending the library.</param>
+    /// <param name="width">The width of the image in pixels.</param>
+    /// <param name="height">The height of the image in pixels.</param>
+    /// <param name="rowStride">The number of elements between row starts.</param>
+    /// <param name="memorySource">The memory source.</param>
+    internal ImageFrame(Configuration configuration, int width, int height, int rowStride, MemoryGroup<TPixel> memorySource)
+        : this(configuration, width, height, rowStride, memorySource, new ImageFrameMetadata())
     {
     }
 
@@ -127,12 +140,26 @@ public sealed class ImageFrame<TPixel> : ImageFrame, IPixelSource<TPixel>
     /// <param name="memorySource">The memory source.</param>
     /// <param name="metadata">The metadata.</param>
     internal ImageFrame(Configuration configuration, int width, int height, MemoryGroup<TPixel> memorySource, ImageFrameMetadata metadata)
+        : this(configuration, width, height, width, memorySource, metadata)
+    {
+    }
+
+    /// <summary>
+    /// Initializes a new instance of the <see cref="ImageFrame{TPixel}" /> class wrapping an existing buffer.
+    /// </summary>
+    /// <param name="configuration">The configuration providing initialization code which allows extending the library.</param>
+    /// <param name="width">The width of the image in pixels.</param>
+    /// <param name="height">The height of the image in pixels.</param>
+    /// <param name="rowStride">The number of elements between row starts.</param>
+    /// <param name="memorySource">The memory source.</param>
+    /// <param name="metadata">The metadata.</param>
+    internal ImageFrame(Configuration configuration, int width, int height, int rowStride, MemoryGroup<TPixel> memorySource, ImageFrameMetadata metadata)
         : base(configuration, width, height, metadata)
     {
         Guard.MustBeGreaterThan(width, 0, nameof(width));
         Guard.MustBeGreaterThan(height, 0, nameof(height));
 
-        this.PixelBuffer = new Buffer2D<TPixel>(memorySource, width, height);
+        this.PixelBuffer = new Buffer2D<TPixel>(memorySource, width, height, rowStride);
     }
 
     /// <summary>
@@ -150,7 +177,7 @@ public sealed class ImageFrame<TPixel> : ImageFrame, IPixelSource<TPixel>
             source.PixelBuffer.Width,
             source.PixelBuffer.Height,
             configuration.PreferContiguousImageBuffers);
-        source.PixelBuffer.FastMemoryGroup.CopyTo(this.PixelBuffer.FastMemoryGroup);
+        source.PixelBuffer.CopyTo(this.PixelBuffer);
     }
 
     /// <inheritdoc/>
@@ -270,16 +297,23 @@ public sealed class ImageFrame<TPixel> : ImageFrame, IPixelSource<TPixel>
     }
 
     /// <summary>
-    /// Copy image pixels to <paramref name="destination"/>.
+    /// Copy image pixels to <paramref name="destination"/> using the backing row layout.
     /// </summary>
+    /// <remarks>
+    /// Destination length must be at least <c>((Height - 1) * PixelBuffer.RowStride) + Width</c>.
+    /// </remarks>
     /// <param name="destination">The <see cref="Span{TPixel}"/> to copy image pixels to.</param>
-    public void CopyPixelDataTo(Span<TPixel> destination) => this.GetPixelMemoryGroup().CopyTo(destination);
+    public void CopyPixelDataTo(Span<TPixel> destination) => this.PixelBuffer.CopyTo(destination);
 
     /// <summary>
-    /// Copy image pixels to <paramref name="destination"/>.
+    /// Copy image pixels to <paramref name="destination"/> using the backing row layout.
     /// </summary>
+    /// <remarks>
+    /// Destination length must be at least
+    /// <c>(((Height - 1) * PixelBuffer.RowStride) + Width) * sizeof(TPixel)</c> bytes.
+    /// </remarks>
     /// <param name="destination">The <see cref="Span{T}"/> of <see cref="byte"/> to copy image pixels to.</param>
-    public void CopyPixelDataTo(Span<byte> destination) => this.GetPixelMemoryGroup().CopyTo(MemoryMarshal.Cast<byte, TPixel>(destination));
+    public void CopyPixelDataTo(Span<byte> destination) => this.PixelBuffer.CopyTo(MemoryMarshal.Cast<byte, TPixel>(destination));
 
     /// <summary>
     /// Gets the representation of the pixels as a <see cref="Memory{T}"/> in the source image's pixel format
@@ -294,17 +328,7 @@ public sealed class ImageFrame<TPixel> : ImageFrame, IPixelSource<TPixel>
     /// <param name="memory">The <see cref="Memory{T}"/> referencing the image buffer.</param>
     /// <returns>The <see cref="bool"/> indicating the success.</returns>
     public bool DangerousTryGetSinglePixelMemory(out Memory<TPixel> memory)
-    {
-        IMemoryGroup<TPixel> mg = this.GetPixelMemoryGroup();
-        if (mg.Count > 1)
-        {
-            memory = default;
-            return false;
-        }
-
-        memory = mg.Single();
-        return true;
-    }
+        => this.PixelBuffer.DangerousTryGetSingleMemory(out memory);
 
     /// <summary>
     /// Gets a reference to the pixel at the specified position.
@@ -327,7 +351,7 @@ public sealed class ImageFrame<TPixel> : ImageFrame, IPixelSource<TPixel>
             throw new ArgumentException("ImageFrame<TPixel>.CopyTo(): target must be of the same size!", nameof(target));
         }
 
-        this.PixelBuffer.FastMemoryGroup.CopyTo(target.FastMemoryGroup);
+        this.PixelBuffer.CopyTo(target);
     }
 
     /// <summary>
@@ -370,20 +394,32 @@ public sealed class ImageFrame<TPixel> : ImageFrame, IPixelSource<TPixel>
         this.isDisposed = true;
     }
 
-    internal override void CopyPixelsTo<TDestinationPixel>(MemoryGroup<TDestinationPixel> destination)
+    internal override void CopyPixelsTo<TDestinationPixel>(Buffer2D<TDestinationPixel> destination)
     {
+        Guard.NotNull(destination, nameof(destination));
+        Guard.IsTrue(
+            destination.Width == this.Width && destination.Height == this.Height,
+            nameof(destination),
+            "Destination buffer must have the same dimensions as the source frame.");
+
         if (typeof(TPixel) == typeof(TDestinationPixel))
         {
-            this.PixelBuffer.FastMemoryGroup.TransformTo(destination, (s, d) =>
+            for (int y = 0; y < this.Height; y++)
             {
-                Span<TPixel> d1 = MemoryMarshal.Cast<TDestinationPixel, TPixel>(d);
-                s.CopyTo(d1);
-            });
+                Span<TPixel> sourceRow = this.PixelBuffer.DangerousGetRowSpan(y);
+                Span<TDestinationPixel> destinationRow = destination.DangerousGetRowSpan(y);
+                sourceRow.CopyTo(MemoryMarshal.Cast<TDestinationPixel, TPixel>(destinationRow));
+            }
+
             return;
         }
 
-        this.PixelBuffer.FastMemoryGroup.TransformTo(destination, (s, d)
-            => PixelOperations<TPixel>.Instance.To(this.Configuration, s, d));
+        for (int y = 0; y < this.Height; y++)
+        {
+            Span<TPixel> sourceRow = this.PixelBuffer.DangerousGetRowSpan(y);
+            Span<TDestinationPixel> destinationRow = destination.DangerousGetRowSpan(y);
+            PixelOperations<TPixel>.Instance.To(this.Configuration, sourceRow, destinationRow);
+        }
     }
 
     /// <inheritdoc/>
@@ -441,16 +477,7 @@ public sealed class ImageFrame<TPixel> : ImageFrame, IPixelSource<TPixel>
     /// <param name="value">The value to initialize the bitmap with.</param>
     internal void Clear(TPixel value)
     {
-        MemoryGroup<TPixel> group = this.PixelBuffer.FastMemoryGroup;
-
-        if (value.Equals(default))
-        {
-            group.Clear();
-        }
-        else
-        {
-            group.Fill(value);
-        }
+        this.PixelBuffer.Clear(value);
     }
 
     [MethodImpl(InliningOptions.ShortMethod)]

src/ImageSharp/Image{TPixel}.cs

@@ -91,7 +91,7 @@ public sealed class Image<TPixel> : Image
         Configuration configuration,
         Buffer2D<TPixel> pixelBuffer,
         ImageMetadata metadata)
-        : this(configuration, pixelBuffer.FastMemoryGroup, pixelBuffer.Width, pixelBuffer.Height, metadata)
+        : this(configuration, pixelBuffer.FastMemoryGroup, pixelBuffer.Width, pixelBuffer.Height, pixelBuffer.RowStride, metadata)
     {
     }
 
@@ -110,8 +110,29 @@ public sealed class Image<TPixel> : Image
         int width,
         int height,
         ImageMetadata metadata)
+        : this(configuration, memoryGroup, width, height, width, metadata)
+    {
+    }
+
+    /// <summary>
+    /// Initializes a new instance of the <see cref="Image{TPixel}"/> class
+    /// wrapping an external <see cref="MemoryGroup{T}"/>.
+    /// </summary>
+    /// <param name="configuration">The configuration providing initialization code which allows extending the library.</param>
+    /// <param name="memoryGroup">The memory source.</param>
+    /// <param name="width">The width of the image in pixels.</param>
+    /// <param name="height">The height of the image in pixels.</param>
+    /// <param name="rowStride">The number of elements between row starts.</param>
+    /// <param name="metadata">The images metadata.</param>
+    internal Image(
+        Configuration configuration,
+        MemoryGroup<TPixel> memoryGroup,
+        int width,
+        int height,
+        int rowStride,
+        ImageMetadata metadata)
         : base(configuration, TPixel.GetPixelTypeInfo(), metadata, width, height)
-        => this.frames = new ImageFrameCollection<TPixel>(this, width, height, memoryGroup);
+        => this.frames = new ImageFrameCollection<TPixel>(this, width, height, rowStride, memoryGroup);
 
     /// <summary>
     /// Initializes a new instance of the <see cref="Image{TPixel}"/> class
@@ -287,16 +308,24 @@ public sealed class Image<TPixel> : Image
     }
 
     /// <summary>
-    /// Copy image pixels to <paramref name="destination"/>.
+    /// Copy image pixels to <paramref name="destination"/> using the root frame backing row layout.
     /// </summary>
+    /// <remarks>
+    /// Destination length must be at least
+    /// <c>((Height - 1) * Frames.RootFrame.PixelBuffer.RowStride) + Width</c>.
+    /// </remarks>
     /// <param name="destination">The <see cref="Span{TPixel}"/> to copy image pixels to.</param>
-    public void CopyPixelDataTo(Span<TPixel> destination) => this.GetPixelMemoryGroup().CopyTo(destination);
+    public void CopyPixelDataTo(Span<TPixel> destination) => this.Frames.RootFrame.CopyPixelDataTo(destination);
 
     /// <summary>
-    /// Copy image pixels to <paramref name="destination"/>.
+    /// Copy image pixels to <paramref name="destination"/> using the root frame backing row layout.
     /// </summary>
+    /// <remarks>
+    /// Destination length must be at least
+    /// <c>(((Height - 1) * Frames.RootFrame.PixelBuffer.RowStride) + Width) * sizeof(TPixel)</c> bytes.
+    /// </remarks>
     /// <param name="destination">The <see cref="Span{T}"/> of <see cref="byte"/> to copy image pixels to.</param>
-    public void CopyPixelDataTo(Span<byte> destination) => this.GetPixelMemoryGroup().CopyTo(MemoryMarshal.Cast<byte, TPixel>(destination));
+    public void CopyPixelDataTo(Span<byte> destination) => this.Frames.RootFrame.CopyPixelDataTo(destination);
 
     /// <summary>
     /// Gets the representation of the pixels as a <see cref="Memory{T}"/> in the source image's pixel format
@@ -311,17 +340,7 @@ public sealed class Image<TPixel> : Image
     /// <param name="memory">The <see cref="Memory{T}"/> referencing the image buffer.</param>
     /// <returns>The <see cref="bool"/> indicating the success.</returns>
     public bool DangerousTryGetSinglePixelMemory(out Memory<TPixel> memory)
-    {
-        IMemoryGroup<TPixel> mg = this.GetPixelMemoryGroup();
-        if (mg.Count > 1)
-        {
-            memory = default;
-            return false;
-        }
-
-        memory = mg.Single();
-        return true;
-    }
+        => this.Frames.RootFrame.DangerousTryGetSinglePixelMemory(out memory);
 
     /// <summary>
     /// Clones the current image.

src/ImageSharp/Memory/Buffer2DExtensions.cs

@@ -45,7 +45,7 @@ public static class Buffer2DExtensions
         Buffer2DRegion<T> sourceRegion = source.GetRegion(rectangle);
         if (sourceRegion.IsFullBufferArea)
         {
-            sourceRegion.Buffer.FastMemoryGroup.CopyTo(buffer.FastMemoryGroup);
+            sourceRegion.Buffer.CopyTo(buffer);
         }
         else
         {
@@ -81,7 +81,7 @@ public static class Buffer2DExtensions
         CheckColumnRegionsDoNotOverlap(buffer, sourceIndex, destinationIndex, columnCount);
 
         int elementSize = Unsafe.SizeOf<T>();
-        int width = buffer.Width * elementSize;
+        int rowByteStride = buffer.RowStride * elementSize;
         int sOffset = sourceIndex * elementSize;
         int dOffset = destinationIndex * elementSize;
         long count = columnCount * elementSize;
@@ -98,7 +98,7 @@ public static class Buffer2DExtensions
 
                 Buffer.MemoryCopy(sPtr, dPtr, count, count);
 
-                basePtr += width;
+                basePtr += rowByteStride;
             }
         }
     }

src/ImageSharp/Memory/Buffer2DRegion{T}.cs

@@ -59,9 +59,9 @@ public readonly struct Buffer2DRegion<T>
     public int Height => this.Rectangle.Height;
 
     /// <summary>
-    /// Gets the pixel stride which is equal to the width of <see cref="Buffer"/>.
+    /// Gets the number of elements between row starts in <see cref="Buffer"/>.
     /// </summary>
-    public int Stride => this.Buffer.Width;
+    public int Stride => this.Buffer.RowStride;
 
     /// <summary>
     /// Gets the size of the area.
@@ -146,9 +146,9 @@ public readonly struct Buffer2DRegion<T>
     internal void Clear()
     {
         // Optimization for when the size of the area is the same as the buffer size.
-        if (this.IsFullBufferArea)
+        if (this.IsFullBufferArea && this.Buffer.RowStride == this.Buffer.Width)
         {
-            this.Buffer.FastMemoryGroup.Clear();
+            this.Buffer.Clear(default);
             return;
         }
 
@@ -166,9 +166,9 @@ public readonly struct Buffer2DRegion<T>
     internal void Fill(T value)
     {
         // Optimization for when the size of the area is the same as the buffer size.
-        if (this.IsFullBufferArea)
+        if (this.IsFullBufferArea && this.Buffer.RowStride == this.Buffer.Width)
         {
-            this.Buffer.FastMemoryGroup.Fill(value);
+            this.Buffer.Clear(value);
             return;
         }
 

src/ImageSharp/Memory/Buffer2D{T}.cs

@@ -1,6 +1,7 @@
 // Copyright (c) Six Labors.
 // Licensed under the Six Labors Split License.
 
+using System.Buffers;
 using System.Runtime.CompilerServices;
 
 namespace SixLabors.ImageSharp.Memory;
@@ -20,10 +21,27 @@ public sealed class Buffer2D<T> : IDisposable
     /// <param name="width">The number of elements in a row.</param>
     /// <param name="height">The number of rows.</param>
     internal Buffer2D(MemoryGroup<T> memoryGroup, int width, int height)
+        : this(memoryGroup, width, height, width)
     {
+    }
+
+    /// <summary>
+    /// Initializes a new instance of the <see cref="Buffer2D{T}"/> class.
+    /// </summary>
+    /// <param name="memoryGroup">The <see cref="MemoryGroup{T}"/> to wrap.</param>
+    /// <param name="width">The number of elements in a row.</param>
+    /// <param name="height">The number of rows.</param>
+    /// <param name="rowStride">The number of elements between row starts.</param>
+    internal Buffer2D(MemoryGroup<T> memoryGroup, int width, int height, int rowStride)
+    {
+        Guard.MustBeGreaterThan(width, 0, nameof(width));
+        Guard.MustBeGreaterThan(height, 0, nameof(height));
+        Guard.MustBeGreaterThanOrEqualTo(rowStride, width, nameof(rowStride));
+
         this.FastMemoryGroup = memoryGroup;
         this.Width = width;
         this.Height = height;
+        this.RowStride = rowStride;
     }
 
     /// <summary>
@@ -36,6 +54,11 @@ public sealed class Buffer2D<T> : IDisposable
     /// </summary>
     public int Height { get; private set; }
 
+    /// <summary>
+    /// Gets the number of elements between row starts in the backing memory.
+    /// </summary>
+    public int RowStride { get; private set; }
+
     /// <summary>
     /// Gets the backing <see cref="IMemoryGroup{T}"/>.
     /// </summary>
@@ -75,6 +98,168 @@ public sealed class Buffer2D<T> : IDisposable
         }
     }
 
+    /// <summary>
+    /// Wraps an existing memory area as a <see cref="Buffer2D{T}"/> with tightly packed rows.
+    /// </summary>
+    /// <remarks>
+    /// This method does not transfer ownership of <paramref name="memory"/> to the returned <see cref="Buffer2D{T}"/>.
+    /// The caller is responsible for ensuring that the memory remains valid for the entire lifetime of the returned buffer.
+    /// If <paramref name="memory"/> originates from an <see cref="IMemoryOwner{T}"/> (for example from <see cref="MemoryPool{T}"/>),
+    /// do not dispose that owner while the returned buffer is still in use.
+    /// </remarks>
+    /// <param name="memory">The source memory.</param>
+    /// <param name="width">The number of elements in each row.</param>
+    /// <param name="height">The number of rows.</param>
+    /// <returns>The wrapped <see cref="Buffer2D{T}"/> instance.</returns>
+    /// <exception cref="ArgumentOutOfRangeException">Thrown when <paramref name="width"/> or <paramref name="height"/> is not positive.</exception>
+    /// <exception cref="ArgumentException">Thrown when <paramref name="memory"/> is shorter than <c>width * height</c>.</exception>
+#pragma warning disable CA1000 // Do not declare static members on generic types
+    public static Buffer2D<T> WrapMemory(Memory<T> memory, int width, int height)
+#pragma warning restore CA1000 // Do not declare static members on generic types
+        => WrapMemory(memory, width, height, width);
+
+    /// <summary>
+    /// Wraps an existing memory area as a <see cref="Buffer2D{T}"/> using the specified row stride.
+    /// </summary>
+    /// <remarks>
+    /// This method does not transfer ownership of <paramref name="memory"/> to the returned <see cref="Buffer2D{T}"/>.
+    /// The caller is responsible for ensuring that the memory remains valid for the entire lifetime of the returned buffer.
+    /// If <paramref name="memory"/> originates from an <see cref="IMemoryOwner{T}"/> (for example from <see cref="MemoryPool{T}"/>),
+    /// do not dispose that owner while the returned buffer is still in use.
+    /// The minimum required length is <c>((height - 1) * stride) + width</c> elements.
+    /// </remarks>
+    /// <param name="memory">The source memory.</param>
+    /// <param name="width">The number of elements in each row.</param>
+    /// <param name="height">The number of rows.</param>
+    /// <param name="stride">The number of elements between row starts in the source memory.</param>
+    /// <returns>The wrapped <see cref="Buffer2D{T}"/> instance.</returns>
+    /// <exception cref="ArgumentOutOfRangeException">
+    /// Thrown when <paramref name="width"/> or <paramref name="height"/> is not positive,
+    /// or when <paramref name="stride"/> is less than <paramref name="width"/>.
+    /// </exception>
+    /// <exception cref="ArgumentException">Thrown when <paramref name="memory"/> is shorter than the required buffer size.</exception>
+#pragma warning disable CA1000 // Do not declare static members on generic types
+    public static Buffer2D<T> WrapMemory(Memory<T> memory, int width, int height, int stride)
+#pragma warning restore CA1000 // Do not declare static members on generic types
+    {
+        Guard.MustBeGreaterThan(width, 0, nameof(width));
+        Guard.MustBeGreaterThan(height, 0, nameof(height));
+        Guard.MustBeGreaterThanOrEqualTo(stride, width, nameof(stride));
+
+        long requiredLength = checked(((long)(height - 1) * stride) + width);
+        Guard.IsTrue(memory.Length >= requiredLength, nameof(memory), "The length of the input memory is less than the specified buffer size");
+
+        MemoryGroup<T> memorySource = MemoryGroup<T>.Wrap(memory);
+        return new Buffer2D<T>(memorySource, width, height, stride);
+    }
+
+    /// <summary>
+    /// Gets the representation of the values as a single contiguous <see cref="Memory{T}"/>
+    /// when the backing group is a single tightly packed segment.
+    /// </summary>
+    /// <param name="memory">The <see cref="Memory{T}"/> referencing the buffer.</param>
+    /// <returns>
+    /// <see langword="true"/> when the buffer can be copied as one contiguous block
+    /// without per-row handling; otherwise <see langword="false"/>.
+    /// </returns>
+    public bool DangerousTryGetSingleMemory(out Memory<T> memory)
+    {
+        if (this.MemoryGroup.Count > 1 || this.RowStride != this.Width)
+        {
+            memory = default;
+            return false;
+        }
+
+        int logicalLength = checked((int)((long)this.Width * this.Height));
+        memory = this.MemoryGroup[0][..logicalLength];
+        return true;
+    }
+
+    /// <summary>
+    /// Copies this buffer into <paramref name="destination"/> using the source logical row layout.
+    /// </summary>
+    /// <remarks>
+    /// When dimensions are equal, destination stride is respected.
+    /// When dimensions differ, source stride is used to copy the source logical layout into destination memory.
+    /// </remarks>
+    /// <param name="destination">The destination buffer.</param>
+    internal void CopyTo(Buffer2D<T> destination)
+    {
+        Guard.NotNull(destination, nameof(destination));
+
+        bool sameDimensions = this.Width == destination.Width && this.Height == destination.Height;
+        int destinationStride = sameDimensions ? destination.RowStride : this.RowStride;
+
+        // Different dimensions use source logical layout. This supports SwapOrCopyContent,
+        // where metadata is swapped after data copy.
+        this.FastMemoryGroup.CopyTo(
+            this.RowStride,
+            destination.FastMemoryGroup,
+            destinationStride,
+            this.Width,
+            this.Height);
+    }
+
+    /// <summary>
+    /// Copies this buffer into <paramref name="destination"/> using the source row stride as destination layout.
+    /// </summary>
+    /// <param name="destination">The destination span.</param>
+    internal void CopyTo(Span<T> destination)
+    {
+        long requiredLength = checked(((long)(this.Height - 1) * this.RowStride) + this.Width);
+        Guard.MustBeGreaterThanOrEqualTo(destination.Length, requiredLength, nameof(destination));
+
+        this.FastMemoryGroup.CopyTo(
+            this.RowStride,
+            destination,
+            this.RowStride,
+            this.Width,
+            this.Height);
+    }
+
+    /// <summary>
+    /// Copies tightly packed row-major data from <paramref name="source"/> into this buffer.
+    /// </summary>
+    /// <param name="source">The source data.</param>
+    internal void CopyFrom(ReadOnlySpan<T> source) => this.CopyFrom(source, this.Width);
+
+    /// <summary>
+    /// Copies row-major data from <paramref name="source"/> into this buffer using
+    /// <paramref name="sourceStride"/> elements between source row starts.
+    /// </summary>
+    /// <param name="source">The source data.</param>
+    /// <param name="sourceStride">The number of elements between source row starts.</param>
+    internal void CopyFrom(ReadOnlySpan<T> source, int sourceStride)
+    {
+        Guard.MustBeGreaterThanOrEqualTo(sourceStride, this.Width, nameof(sourceStride));
+
+        long requiredLength = checked(((long)(this.Height - 1) * sourceStride) + this.Width);
+        Guard.MustBeGreaterThanOrEqualTo(source.Length, requiredLength, nameof(source));
+
+        // Copy row by row so padded source rows map correctly into the destination logical rows.
+        int sourceOffset = 0;
+        for (int y = 0; y < this.Height; y++)
+        {
+            source.Slice(sourceOffset, this.Width).CopyTo(this.DangerousGetRowSpan(y));
+            sourceOffset += sourceStride;
+        }
+    }
+
+    /// <summary>
+    /// Clears this buffer when <paramref name="value"/> is default; otherwise fills it with <paramref name="value"/>.
+    /// </summary>
+    /// <param name="value">The fill value.</param>
+    internal void Clear(T value)
+    {
+        if (value.Equals(default))
+        {
+            this.FastMemoryGroup.Clear();
+            return;
+        }
+
+        this.FastMemoryGroup.Fill(value);
+    }
+
     /// <summary>
     /// Disposes the <see cref="Buffer2D{T}"/> instance
     /// </summary>
@@ -102,7 +287,13 @@ public sealed class Buffer2D<T> : IDisposable
             this.ThrowYOutOfRangeException(y);
         }
 
-        return this.FastMemoryGroup.GetRowSpanCoreUnsafe(y, this.Width);
+        if (this.RowStride == this.Width)
+        {
+            return this.FastMemoryGroup.GetRowSpanCoreUnsafe(y, this.Width);
+        }
+
+        int rowStart = checked(y * this.RowStride);
+        return this.FastMemoryGroup[0].Span.Slice(rowStart, this.Width);
     }
 
     internal bool DangerousTryGetPaddedRowSpan(int y, int padding, out Span<T> paddedSpan)
@@ -111,8 +302,10 @@ public sealed class Buffer2D<T> : IDisposable
         DebugGuard.MustBeLessThan(y, this.Height, nameof(y));
 
         int stride = this.Width + padding;
-
-        Span<T> slice = this.FastMemoryGroup.GetRemainingSliceOfBuffer(y * (long)this.Width);
+        long rowStart = y * (long)this.RowStride;
+        Span<T> slice = this.RowStride == this.Width
+            ? this.FastMemoryGroup.GetRemainingSliceOfBuffer(rowStart)
+            : this.FastMemoryGroup[0].Span[checked((int)rowStart)..];
 
         if (slice.Length < stride)
         {
@@ -127,7 +320,10 @@ public sealed class Buffer2D<T> : IDisposable
     [MethodImpl(InliningOptions.ShortMethod)]
     internal ref T GetElementUnsafe(int x, int y)
     {
-        Span<T> span = this.FastMemoryGroup.GetRowSpanCoreUnsafe(y, this.Width);
+        Span<T> span = this.RowStride == this.Width
+            ? this.FastMemoryGroup.GetRowSpanCoreUnsafe(y, this.Width)
+            : this.FastMemoryGroup[0].Span.Slice(checked(y * this.RowStride), this.Width);
+
         return ref span[x];
     }
 
@@ -141,6 +337,13 @@ public sealed class Buffer2D<T> : IDisposable
     {
         DebugGuard.MustBeGreaterThanOrEqualTo(y, 0, nameof(y));
         DebugGuard.MustBeLessThan(y, this.Height, nameof(y));
+
+        if (this.RowStride != this.Width)
+        {
+            int rowStart = checked(y * this.RowStride);
+            return this.FastMemoryGroup[0].Slice(rowStart, this.Width);
+        }
+
         return this.FastMemoryGroup.View.GetBoundedMemorySlice(y * (long)this.Width, this.Width);
     }
 
@@ -185,21 +388,31 @@ public sealed class Buffer2D<T> : IDisposable
         }
         else
         {
-            if (destination.FastMemoryGroup.TotalLength != source.FastMemoryGroup.TotalLength)
+            long sourceLayoutLength = GetRequiredLength(source.Width, source.Height, source.RowStride);
+            long destinationLayoutLength = GetRequiredLength(destination.Width, destination.Height, destination.RowStride);
+
+            bool destinationCanRepresentSource = destination.FastMemoryGroup.TotalLength >= sourceLayoutLength;
+            bool sourceCanRepresentDestination = source.FastMemoryGroup.TotalLength >= destinationLayoutLength;
+            if (!destinationCanRepresentSource || !sourceCanRepresentDestination)
             {
                 throw new InvalidMemoryOperationException(
                     "Trying to copy/swap incompatible buffers. This is most likely caused by applying an unsupported processor to wrapped-memory images.");
             }
 
-            source.FastMemoryGroup.CopyTo(destination.MemoryGroup);
+            source.CopyTo(destination);
         }
 
         (destination.Width, source.Width) = (source.Width, destination.Width);
         (destination.Height, source.Height) = (source.Height, destination.Height);
+        (destination.RowStride, source.RowStride) = (source.RowStride, destination.RowStride);
         return swapped;
     }
 
     [MethodImpl(InliningOptions.ColdPath)]
     private void ThrowYOutOfRangeException(int y)
         => throw new ArgumentOutOfRangeException($"DangerousGetRowSpan({y}). Y was out of range. Height={this.Height}");
+
+    [MethodImpl(InliningOptions.ShortMethod)]
+    private static long GetRequiredLength(int width, int height, int stride)
+        => checked(((long)(height - 1) * stride) + width);
 }

src/ImageSharp/Memory/DiscontiguousBuffers/MemoryGroupExtensions.cs

@@ -71,128 +71,159 @@ internal static class MemoryGroupExtensions
         return memory.Slice(bufferStart, length);
     }
 
-    internal static void CopyTo<T>(this IMemoryGroup<T> source, Span<T> target)
+    /// <summary>
+    /// Copies a 2D logical region from <paramref name="source"/> into <paramref name="target"/>
+    /// using the provided source and target strides.
+    /// </summary>
+    /// <typeparam name="T">The element type.</typeparam>
+    /// <param name="source">The source memory group.</param>
+    /// <param name="sourceStride">Elements between source row starts.</param>
+    /// <param name="target">The destination span.</param>
+    /// <param name="targetStride">Elements between destination row starts.</param>
+    /// <param name="width">The logical row width to copy.</param>
+    /// <param name="height">The number of rows to copy.</param>
+    internal static void CopyTo<T>(
+        this IMemoryGroup<T> source,
+        int sourceStride,
+        Span<T> target,
+        int targetStride,
+        int width,
+        int height)
         where T : struct
     {
         Guard.NotNull(source, nameof(source));
-        Guard.MustBeGreaterThanOrEqualTo(target.Length, source.TotalLength, nameof(target));
+        Guard.MustBeGreaterThanOrEqualTo(width, 0, nameof(width));
+        Guard.MustBeGreaterThanOrEqualTo(height, 0, nameof(height));
+        Guard.MustBeGreaterThanOrEqualTo(sourceStride, width, nameof(sourceStride));
+        Guard.MustBeGreaterThanOrEqualTo(targetStride, width, nameof(targetStride));
 
-        MemoryGroupCursor<T> cur = new(source);
-        long position = 0;
-        while (position < source.TotalLength)
-        {
-            int fwd = Math.Min(cur.LookAhead(), target.Length);
-            cur.GetSpan(fwd).CopyTo(target);
+        long sourceRequired = height == 0 ? 0 : checked(((long)(height - 1) * sourceStride) + width);
+        long targetRequired = height == 0 ? 0 : checked(((long)(height - 1) * targetStride) + width);
+        Guard.MustBeGreaterThanOrEqualTo(source.TotalLength, sourceRequired, nameof(source));
+        Guard.MustBeGreaterThanOrEqualTo(target.Length, targetRequired, nameof(target));
 
-            cur.Forward(fwd);
-            target = target[fwd..];
-            position += fwd;
+        if (width == 0 || height == 0)
+        {
+            return;
         }
-    }
 
-    internal static void CopyTo<T>(this Span<T> source, IMemoryGroup<T> target)
-        where T : struct
-        => CopyTo((ReadOnlySpan<T>)source, target);
+        MemoryGroupCursor<T> sourceCursor = new(source);
+        int sourceSkip = sourceStride - width;
 
-    internal static void CopyTo<T>(this ReadOnlySpan<T> source, IMemoryGroup<T> target)
-        where T : struct
-    {
-        Guard.NotNull(target, nameof(target));
-        Guard.MustBeGreaterThanOrEqualTo(target.TotalLength, source.Length, nameof(target));
-
-        MemoryGroupCursor<T> cur = new(target);
-
-        while (!source.IsEmpty)
+        for (int y = 0; y < height; y++)
         {
-            int fwd = Math.Min(cur.LookAhead(), source.Length);
-            source[..fwd].CopyTo(cur.GetSpan(fwd));
-            cur.Forward(fwd);
-            source = source[fwd..];
+            int rowStart = checked(y * targetStride);
+            Span<T> destinationRow = target.Slice(rowStart, width);
+            CopyFromCursorToSpan(ref sourceCursor, destinationRow);
+
+            // Trailing padding after the last row is optional, so only skip between rows.
+            if (y < height - 1)
+            {
+                ForwardCursor(ref sourceCursor, sourceSkip);
+            }
         }
     }
 
-    internal static void CopyTo<T>(this IMemoryGroup<T>? source, IMemoryGroup<T>? target)
+    /// <summary>
+    /// Copies a 2D logical region from <paramref name="source"/> into <paramref name="target"/>
+    /// using the provided source and target strides.
+    /// </summary>
+    /// <typeparam name="T">The element type.</typeparam>
+    /// <param name="source">The source memory group.</param>
+    /// <param name="sourceStride">Elements between source row starts.</param>
+    /// <param name="target">The destination memory group.</param>
+    /// <param name="targetStride">Elements between destination row starts.</param>
+    /// <param name="width">The logical row width to copy.</param>
+    /// <param name="height">The number of rows to copy.</param>
+    internal static void CopyTo<T>(
+        this IMemoryGroup<T> source,
+        int sourceStride,
+        IMemoryGroup<T> target,
+        int targetStride,
+        int width,
+        int height)
         where T : struct
     {
         Guard.NotNull(source, nameof(source));
         Guard.NotNull(target, nameof(target));
         Guard.IsTrue(source.IsValid, nameof(source), "Source group must be valid.");
         Guard.IsTrue(target.IsValid, nameof(target), "Target group must be valid.");
-        Guard.MustBeLessThanOrEqualTo(source.TotalLength, target.TotalLength, "Destination buffer too short!");
+        Guard.MustBeGreaterThanOrEqualTo(width, 0, nameof(width));
+        Guard.MustBeGreaterThanOrEqualTo(height, 0, nameof(height));
+        Guard.MustBeGreaterThanOrEqualTo(sourceStride, width, nameof(sourceStride));
+        Guard.MustBeGreaterThanOrEqualTo(targetStride, width, nameof(targetStride));
 
-        if (source.IsEmpty())
+        long sourceRequired = height == 0 ? 0 : checked(((long)(height - 1) * sourceStride) + width);
+        long targetRequired = height == 0 ? 0 : checked(((long)(height - 1) * targetStride) + width);
+        Guard.MustBeGreaterThanOrEqualTo(source.TotalLength, sourceRequired, nameof(source));
+        Guard.MustBeGreaterThanOrEqualTo(target.TotalLength, targetRequired, nameof(target));
+
+        if (width == 0 || height == 0)
         {
             return;
         }
 
-        long position = 0;
-        MemoryGroupCursor<T> srcCur = new(source);
-        MemoryGroupCursor<T> trgCur = new(target);
+        MemoryGroupCursor<T> sourceCursor = new(source);
+        MemoryGroupCursor<T> targetCursor = new(target);
+        int sourceSkip = sourceStride - width;
+        int targetSkip = targetStride - width;
 
-        while (position < source.TotalLength)
+        for (int y = 0; y < height; y++)
         {
-            int fwd = Math.Min(srcCur.LookAhead(), trgCur.LookAhead());
-            Span<T> srcSpan = srcCur.GetSpan(fwd);
-            Span<T> trgSpan = trgCur.GetSpan(fwd);
-            srcSpan.CopyTo(trgSpan);
-
-            srcCur.Forward(fwd);
-            trgCur.Forward(fwd);
-            position += fwd;
+            CopyFromCursorToCursor(ref sourceCursor, ref targetCursor, width);
+
+            // Trailing padding after the last row is optional, so only skip between rows.
+            if (y < height - 1)
+            {
+                ForwardCursor(ref sourceCursor, sourceSkip);
+                ForwardCursor(ref targetCursor, targetSkip);
+            }
         }
     }
 
-    internal static void TransformTo<TSource, TTarget>(
-        this IMemoryGroup<TSource> source,
-        IMemoryGroup<TTarget> target,
-        TransformItemsDelegate<TSource, TTarget> transform)
-        where TSource : struct
-        where TTarget : struct
+    private static void CopyFromCursorToCursor<T>(
+        ref MemoryGroupCursor<T> source,
+        ref MemoryGroupCursor<T> target,
+        int count)
+        where T : struct
     {
-        Guard.NotNull(source, nameof(source));
-        Guard.NotNull(target, nameof(target));
-        Guard.NotNull(transform, nameof(transform));
-        Guard.IsTrue(source.IsValid, nameof(source), "Source group must be valid.");
-        Guard.IsTrue(target.IsValid, nameof(target), "Target group must be valid.");
-        Guard.MustBeLessThanOrEqualTo(source.TotalLength, target.TotalLength, "Destination buffer too short!");
-
-        if (source.IsEmpty())
+        int remaining = count;
+        while (remaining > 0)
         {
-            return;
+            int fwd = Math.Min(remaining, Math.Min(source.LookAhead(), target.LookAhead()));
+            source.GetSpan(fwd).CopyTo(target.GetSpan(fwd));
+            source.Forward(fwd);
+            target.Forward(fwd);
+            remaining -= fwd;
         }
+    }
 
-        long position = 0;
-        MemoryGroupCursor<TSource> srcCur = new(source);
-        MemoryGroupCursor<TTarget> trgCur = new(target);
-
-        while (position < source.TotalLength)
+    private static void CopyFromCursorToSpan<T>(ref MemoryGroupCursor<T> source, Span<T> target)
+        where T : struct
+    {
+        int remaining = target.Length;
+        while (remaining > 0)
         {
-            int fwd = Math.Min(srcCur.LookAhead(), trgCur.LookAhead());
-            Span<TSource> srcSpan = srcCur.GetSpan(fwd);
-            Span<TTarget> trgSpan = trgCur.GetSpan(fwd);
-            transform(srcSpan, trgSpan);
-
-            srcCur.Forward(fwd);
-            trgCur.Forward(fwd);
-            position += fwd;
+            int copied = target.Length - remaining;
+            int fwd = Math.Min(remaining, source.LookAhead());
+            source.GetSpan(fwd).CopyTo(target[copied..]);
+            source.Forward(fwd);
+            remaining -= fwd;
         }
     }
 
-    internal static void TransformInplace<T>(
-        this IMemoryGroup<T> memoryGroup,
-        TransformItemsInplaceDelegate<T> transform)
+    private static void ForwardCursor<T>(ref MemoryGroupCursor<T> cursor, int steps)
         where T : struct
     {
-        foreach (Memory<T> memory in memoryGroup)
+        int remaining = steps;
+        while (remaining > 0)
         {
-            transform(memory.Span);
+            int fwd = Math.Min(remaining, cursor.LookAhead());
+            cursor.Forward(fwd);
+            remaining -= fwd;
         }
     }
 
-    internal static bool IsEmpty<T>(this IMemoryGroup<T> group)
-        where T : struct
-        => group.Count == 0;
-
     private struct MemoryGroupCursor<T>
         where T : struct
     {

src/ImageSharp/Memory/MemoryAllocatorExtensions.cs

@@ -29,6 +29,9 @@ public static class MemoryAllocatorExtensions
         AllocationOptions options = AllocationOptions.None)
         where T : struct
     {
+        Guard.MustBeGreaterThan(width, 0, nameof(width));
+        Guard.MustBeGreaterThan(height, 0, nameof(height));
+
         long groupLength = (long)width * height;
         MemoryGroup<T> memoryGroup;
         if (preferContiguosImageBuffers && groupLength < int.MaxValue)
@@ -104,6 +107,9 @@ public static class MemoryAllocatorExtensions
         AllocationOptions options = AllocationOptions.None)
         where T : struct
     {
+        Guard.MustBeGreaterThan(width, 0, nameof(width));
+        Guard.MustBeGreaterThan(height, 0, nameof(height));
+
         long groupLength = (long)width * height;
         MemoryGroup<T> memoryGroup = memoryAllocator.AllocateGroup<T>(
             groupLength,

src/ImageSharp/Memory/TransformItemsDelegate{TSource, TTarget}.cs

@@ -1,8 +0,0 @@
-// Copyright (c) Six Labors.
-// Licensed under the Six Labors Split License.
-
-namespace SixLabors.ImageSharp.Memory;
-
-#pragma warning disable SA1649 // File name should match first type name
-internal delegate void TransformItemsDelegate<TSource, TTarget>(ReadOnlySpan<TSource> source, Span<TTarget> target);
-#pragma warning restore SA1649 // File name should match first type name

src/ImageSharp/Memory/TransformItemsInplaceDelegate.cs

@@ -1,6 +0,0 @@
-// Copyright (c) Six Labors.
-// Licensed under the Six Labors Split License.
-
-namespace SixLabors.ImageSharp.Memory;
-
-internal delegate void TransformItemsInplaceDelegate<T>(Span<T> data);

src/ImageSharp/Processing/Processors/Transforms/CropProcessor{TPixel}.cs

@@ -53,7 +53,7 @@ internal class CropProcessor<TPixel> : TransformProcessor<TPixel>
             && this.SourceRectangle == this.cropRectangle)
         {
             // the cloned will be blank here copy all the pixel data over
-            source.GetPixelMemoryGroup().CopyTo(destination.GetPixelMemoryGroup());
+            source.PixelBuffer.CopyTo(destination.PixelBuffer);
             return;
         }
 

src/ImageSharp/Processing/Processors/Transforms/Linear/RotateProcessor{TPixel}.cs

@@ -97,7 +97,7 @@ internal class RotateProcessor<TPixel> : AffineTransformProcessor<TPixel>
         if (MathF.Abs(degrees) < Constants.Epsilon)
         {
             // The destination will be blank here so copy all the pixel data over
-            source.GetPixelMemoryGroup().CopyTo(destination.GetPixelMemoryGroup());
+            source.PixelBuffer.CopyTo(destination.PixelBuffer);
             return true;
         }
 

src/ImageSharp/Processing/Processors/Transforms/Resize/ResizeProcessor{TPixel}.cs

@@ -91,7 +91,7 @@ internal class ResizeProcessor<TPixel> : TransformProcessor<TPixel>, IResampling
                 ImageFrame<TPixel> destinationFrame = destination.Frames[i];
 
                 // The cloned will be blank here copy all the pixel data over
-                sourceFrame.GetPixelMemoryGroup().CopyTo(destinationFrame.GetPixelMemoryGroup());
+                sourceFrame.PixelBuffer.CopyTo(destinationFrame.PixelBuffer);
             }
 
             return;

tests/ImageSharp.Tests/Image/ImageFrameCollectionTests.Generic.cs

@@ -64,7 +64,7 @@ public abstract partial class ImageFrameCollectionTests
                     using ImageFrame<Rgba32> addedFrame = this.Collection.AddFrame(Array.Empty<Rgba32>());
                 });
 
-            Assert.StartsWith($"Parameter \"data\" ({typeof(int)}) must be greater than or equal to {100}, was {0}", ex.Message);
+            Assert.StartsWith($"Parameter \"data\" ({typeof(long)}) must be greater than or equal to {100}, was {0}", ex.Message);
         }
 
         [Fact]

tests/ImageSharp.Tests/Image/ImageTests.LoadPixelData.cs

@@ -52,5 +52,79 @@ public partial class ImageTests
             Assert.Equal(Color.White, Color.FromPixel(img[1, 0]));
             Assert.Equal(Color.Black, Color.FromPixel(img[1, 1]));
         }
+
+        [Fact]
+        public void FromPixels_WithRowStride()
+        {
+            Rgba32[] data =
+            [
+                Color.Black.ToPixel<Rgba32>(),
+                Color.White.ToPixel<Rgba32>(),
+                Color.Red.ToPixel<Rgba32>(), // padding
+                Color.White.ToPixel<Rgba32>(),
+                Color.Black.ToPixel<Rgba32>(),
+                Color.Red.ToPixel<Rgba32>() // padding
+            ];
+
+            using Image<Rgba32> img = Image.LoadPixelData<Rgba32>(data.AsSpan(), width: 2, height: 2, rowStride: 3);
+            Assert.NotNull(img);
+            Assert.Equal(Color.Black, Color.FromPixel(img[0, 0]));
+            Assert.Equal(Color.White, Color.FromPixel(img[0, 1]));
+            Assert.Equal(Color.White, Color.FromPixel(img[1, 0]));
+            Assert.Equal(Color.Black, Color.FromPixel(img[1, 1]));
+        }
+
+        [Fact]
+        public void FromBytes_WithRowStrideInBytes()
+        {
+            byte[] data =
+            [
+                0, 0, 0, 255, // 0,0
+                255, 255, 255, 255, // 0,1
+                255, 0, 0, 255, // padding
+                255, 255, 255, 255, // 1,0
+                0, 0, 0, 255, // 1,1
+                255, 0, 0, 255 // padding
+            ];
+
+            using Image<Rgba32> img = Image.LoadPixelData<Rgba32>(data.AsSpan(), width: 2, height: 2, rowStrideInBytes: 12);
+            Assert.NotNull(img);
+            Assert.Equal(Color.Black, Color.FromPixel(img[0, 0]));
+            Assert.Equal(Color.White, Color.FromPixel(img[0, 1]));
+            Assert.Equal(Color.White, Color.FromPixel(img[1, 0]));
+            Assert.Equal(Color.Black, Color.FromPixel(img[1, 1]));
+        }
+
+        [Fact]
+        public void FromPixels_WithRowStride_InvalidStride_Throws()
+        {
+            Rgba32[] data = new Rgba32[6];
+            Assert.ThrowsAny<ArgumentOutOfRangeException>(
+                () => Image.LoadPixelData<Rgba32>(data.AsSpan(), width: 2, height: 2, rowStride: 1));
+        }
+
+        [Fact]
+        public void FromPixels_WithRowStride_InvalidLength_Throws()
+        {
+            Rgba32[] data = new Rgba32[4];
+            Assert.ThrowsAny<ArgumentException>(
+                () => Image.LoadPixelData<Rgba32>(data.AsSpan(), width: 2, height: 2, rowStride: 3));
+        }
+
+        [Fact]
+        public void FromBytes_WithRowStrideInBytes_InvalidStride_Throws()
+        {
+            byte[] data = new byte[24];
+            Assert.ThrowsAny<ArgumentException>(
+                () => Image.LoadPixelData<Rgba32>(data.AsSpan(), width: 2, height: 2, rowStrideInBytes: 10));
+        }
+
+        [Fact]
+        public void FromBytes_WithRowStrideInBytes_InvalidLength_Throws()
+        {
+            byte[] data = new byte[19];
+            Assert.ThrowsAny<ArgumentException>(
+                () => Image.LoadPixelData<Rgba32>(data.AsSpan(), width: 2, height: 2, rowStrideInBytes: 12));
+        }
     }
 }

tests/ImageSharp.Tests/Image/ImageTests.WrapMemory.cs

@@ -141,6 +141,103 @@ public partial class ImageTests
             }
         }
 
+        [Fact]
+        public void WrapMemory_MemoryOfT_Strided_CreatedImageIsCorrect()
+        {
+            Rgba32[] source =
+            [
+                new Rgba32(1, 1, 1, 255),
+                new Rgba32(2, 2, 2, 255),
+                new Rgba32(3, 3, 3, 255),
+                new Rgba32(90, 90, 90, 255),
+                new Rgba32(4, 4, 4, 255),
+                new Rgba32(5, 5, 5, 255),
+                new Rgba32(6, 6, 6, 255),
+                new Rgba32(91, 91, 91, 255)
+            ];
+
+            using Image<Rgba32> image = Image.WrapMemory(source.AsMemory(), width: 3, height: 2, rowStride: 4);
+
+            Assert.Equal(4, image.Frames.RootFrame.PixelBuffer.RowStride);
+            Assert.False(image.DangerousTryGetSinglePixelMemory(out Memory<Rgba32> _));
+            Assert.Equal(source[0], image[0, 0]);
+            Assert.Equal(source[2], image[2, 0]);
+            Assert.Equal(source[4], image[0, 1]);
+            Assert.Equal(source[6], image[2, 1]);
+        }
+
+        [Fact]
+        public void WrapMemory_MemoryOfT_Strided_CopyPixelDataTo_UsesRowStrideLayout()
+        {
+            Rgba32[] source =
+            [
+                new Rgba32(1, 1, 1, 255),
+                new Rgba32(2, 2, 2, 255),
+                new Rgba32(3, 3, 3, 255),
+                new Rgba32(90, 90, 90, 255),
+                new Rgba32(4, 4, 4, 255),
+                new Rgba32(5, 5, 5, 255),
+                new Rgba32(6, 6, 6, 255),
+                new Rgba32(91, 91, 91, 255)
+            ];
+
+            using Image<Rgba32> image = Image.WrapMemory(source.AsMemory(), width: 3, height: 2, rowStride: 4);
+
+            Rgba32 sentinel = new(250, 1, 1, 255);
+            Rgba32[] destination = [sentinel, sentinel, sentinel, sentinel, sentinel, sentinel, sentinel];
+            image.CopyPixelDataTo(destination);
+
+            Assert.Equal(source[0], destination[0]);
+            Assert.Equal(source[1], destination[1]);
+            Assert.Equal(source[2], destination[2]);
+            Assert.Equal(sentinel, destination[3]);
+            Assert.Equal(source[4], destination[4]);
+            Assert.Equal(source[5], destination[5]);
+            Assert.Equal(source[6], destination[6]);
+            Assert.ThrowsAny<ArgumentOutOfRangeException>(() => image.CopyPixelDataTo(new Rgba32[6]));
+        }
+
+        [Fact]
+        public void WrapMemory_MemoryOfByte_Strided_CreatedImageIsCorrect()
+        {
+            int pixelSize = Unsafe.SizeOf<Rgba32>();
+            byte[] sourceBytes = new byte[8 * pixelSize];
+            Span<Rgba32> source = MemoryMarshal.Cast<byte, Rgba32>(sourceBytes.AsSpan());
+
+            source[0] = new Rgba32(1, 1, 1, 255);
+            source[1] = new Rgba32(2, 2, 2, 255);
+            source[2] = new Rgba32(3, 3, 3, 255);
+            source[4] = new Rgba32(4, 4, 4, 255);
+            source[5] = new Rgba32(5, 5, 5, 255);
+            source[6] = new Rgba32(6, 6, 6, 255);
+
+            using Image<Rgba32> image = Image.WrapMemory<Rgba32>(
+                sourceBytes.AsMemory(),
+                width: 3,
+                height: 2,
+                rowStrideInBytes: 4 * pixelSize);
+
+            Assert.Equal(4, image.Frames.RootFrame.PixelBuffer.RowStride);
+            Assert.False(image.DangerousTryGetSinglePixelMemory(out Memory<Rgba32> _));
+            Assert.Equal(source[0], image[0, 0]);
+            Assert.Equal(source[2], image[2, 0]);
+            Assert.Equal(source[4], image[0, 1]);
+            Assert.Equal(source[6], image[2, 1]);
+        }
+
+        [Fact]
+        public void WrapMemory_Strided_InvalidStride_Throws()
+        {
+            Rgba32[] pixelSource = new Rgba32[8];
+            byte[] byteSource = new byte[8 * Unsafe.SizeOf<Rgba32>()];
+
+            Assert.ThrowsAny<ArgumentOutOfRangeException>(() => Image.WrapMemory(pixelSource.AsMemory(), width: 3, height: 2, rowStride: 2));
+            Assert.ThrowsAny<ArgumentException>(() => Image.WrapMemory(pixelSource.AsMemory(0, 6), width: 3, height: 2, rowStride: 4));
+
+            Assert.ThrowsAny<ArgumentException>(() => Image.WrapMemory<Rgba32>(byteSource.AsMemory(), width: 3, height: 2, rowStrideInBytes: (4 * Unsafe.SizeOf<Rgba32>()) - 1));
+            Assert.ThrowsAny<ArgumentException>(() => Image.WrapMemory<Rgba32>(byteSource.AsMemory(0, 6 * Unsafe.SizeOf<Rgba32>()), width: 3, height: 2, rowStrideInBytes: 4 * Unsafe.SizeOf<Rgba32>()));
+        }
+
         [Fact]
         public void WrapSystemDrawingBitmap_WhenObserved()
         {

tests/ImageSharp.Tests/Memory/Buffer2DTests.CopyTo.cs

@@ -0,0 +1,43 @@
+// Copyright (c) Six Labors.
+// Licensed under the Six Labors Split License.
+
+using SixLabors.ImageSharp.Memory;
+
+namespace SixLabors.ImageSharp.Tests.Memory;
+
+public partial class Buffer2DTests
+{
+    [Fact]
+    public void CopyToSpan_StridedSource_WritesDestinationUsingSourceStride()
+    {
+        int[] source = [1, 2, 3, 777, 4, 5, 6, 888];
+        int[] destination = [-1, -1, -1, -1, -1, -1, -1];
+
+        using Buffer2D<int> buffer = Buffer2D<int>.WrapMemory(source.AsMemory(), width: 3, height: 2, stride: 4);
+        buffer.CopyTo(destination);
+
+        Assert.Equal(new[] { 1, 2, 3, -1, 4, 5, 6 }, destination);
+    }
+
+    [Fact]
+    public void CopyToSpan_PackedSource_WritesPackedDestination()
+    {
+        int[] source = [1, 2, 3, 4, 5, 6];
+        int[] destination = new int[6];
+
+        using Buffer2D<int> buffer = Buffer2D<int>.WrapMemory(source.AsMemory(), width: 3, height: 2);
+        buffer.CopyTo(destination);
+
+        Assert.Equal(new[] { 1, 2, 3, 4, 5, 6 }, destination);
+    }
+
+    [Fact]
+    public void CopyToSpan_StridedSource_ThrowsWhenDestinationTooShort()
+    {
+        int[] source = [1, 2, 3, 777, 4, 5, 6, 888];
+        int[] destination = new int[6];
+
+        using Buffer2D<int> buffer = Buffer2D<int>.WrapMemory(source.AsMemory(), width: 3, height: 2, stride: 4);
+        Assert.Throws<ArgumentOutOfRangeException>(() => buffer.CopyTo(destination));
+    }
+}

tests/ImageSharp.Tests/Memory/Buffer2DTests.SwapOrCopyContent.cs

@@ -152,5 +152,74 @@ public partial class Buffer2DTests
             Assert.Equal(color, source.MemoryGroup[0].Span[10]);
             Assert.NotEqual(color, dest.MemoryGroup[0].Span[10]);
         }
+
+        [Fact]
+        public void WhenDestIsNotMemoryOwner_DifferentSizeSameTotal_PackedLayout_ShouldCopy()
+        {
+            int[] data = new int[6];
+            using TestMemoryManager<int> destOwner = new(data);
+            using Buffer2D<int> dest = new(MemoryGroup<int>.Wrap(destOwner.Memory), 2, 3);
+            using Buffer2D<int> source = this.memoryAllocator.Allocate2D<int>(3, 2, AllocationOptions.Clean);
+
+            source[0, 0] = 1;
+            source[1, 0] = 2;
+            source[2, 0] = 3;
+            source[0, 1] = 4;
+            source[1, 1] = 5;
+            source[2, 1] = 6;
+
+            bool swap = Buffer2D<int>.SwapOrCopyContent(dest, source);
+
+            Assert.False(swap);
+            Assert.Equal(new Size(3, 2), dest.Size());
+            Assert.Equal(6, dest[2, 1]);
+        }
+
+        [Fact]
+        public void WhenDestIsNotMemoryOwner_DifferentSizeSameTotal_StridedLayout_ShouldCopy()
+        {
+            int[] data = new int[5];
+            using Buffer2D<int> dest = Buffer2D<int>.WrapMemory(data.AsMemory(), width: 2, height: 2, stride: 3);
+            using Buffer2D<int> source = this.memoryAllocator.Allocate2D<int>(1, 5, AllocationOptions.Clean);
+
+            source[0, 0] = 1;
+            source[0, 1] = 2;
+            source[0, 2] = 3;
+            source[0, 3] = 4;
+            source[0, 4] = 5;
+
+            bool swap = Buffer2D<int>.SwapOrCopyContent(dest, source);
+
+            Assert.False(swap);
+            Assert.Equal(new Size(1, 5), dest.Size());
+            Assert.Equal(1, dest[0, 0]);
+            Assert.Equal(2, dest[0, 1]);
+            Assert.Equal(3, dest[0, 2]);
+            Assert.Equal(4, dest[0, 3]);
+            Assert.Equal(5, dest[0, 4]);
+        }
+
+        [Fact]
+        public void WhenDestIsNotMemoryOwner_DifferentSizeDifferentTotal_ButBothLayoutsFit_ShouldCopy()
+        {
+            int[] data = new int[5];
+            using TestMemoryManager<int> destOwner = new(data);
+            using Buffer2D<int> dest = new(MemoryGroup<int>.Wrap(destOwner.Memory), 1, 3);
+            using Buffer2D<int> source = this.memoryAllocator.Allocate2D<int>(2, 2, AllocationOptions.Clean);
+
+            source[0, 0] = 1;
+            source[1, 0] = 2;
+            source[0, 1] = 3;
+            source[1, 1] = 4;
+
+            bool swap = Buffer2D<int>.SwapOrCopyContent(dest, source);
+
+            Assert.False(swap);
+            Assert.Equal(new Size(2, 2), dest.Size());
+            Assert.Equal(1, dest[0, 0]);
+            Assert.Equal(2, dest[1, 0]);
+            Assert.Equal(3, dest[0, 1]);
+            Assert.Equal(4, dest[1, 1]);
+        }
     }
 }

tests/ImageSharp.Tests/Memory/Buffer2DTests.WrapMemory.cs

@@ -0,0 +1,91 @@
+// Copyright (c) Six Labors.
+// Licensed under the Six Labors Split License.
+
+using System.Runtime.CompilerServices;
+using SixLabors.ImageSharp.Memory;
+
+namespace SixLabors.ImageSharp.Tests.Memory;
+
+public partial class Buffer2DTests
+{
+    [Fact]
+    public void WrapMemory_Packed_DangerousTryGetSinglePixelMemory_ReturnsTrue()
+    {
+        int[] data = [1, 2, 3, 4, 5, 6];
+
+        using Buffer2D<int> buffer = Buffer2D<int>.WrapMemory(data.AsMemory(), width: 3, height: 2, stride: 3);
+
+        Assert.True(buffer.DangerousTryGetSingleMemory(out Memory<int> memory));
+        Assert.Equal(3, buffer.RowStride);
+        Assert.Equal(6, memory.Length);
+        Assert.True(Unsafe.AreSame(ref data[0], ref memory.Span[0]));
+        Assert.SpanPointsTo(buffer.DangerousGetRowSpan(1), data.AsMemory(), bufferOffset: 3);
+    }
+
+    [Fact]
+    public void WrapMemory_Strided_DangerousTryGetSinglePixelMemory_ReturnsFalse()
+    {
+        int[] data = [1, 2, 3, 777, 4, 5, 6, 888];
+
+        using Buffer2D<int> buffer = Buffer2D<int>.WrapMemory(data.AsMemory(), width: 3, height: 2, stride: 4);
+
+        Assert.False(buffer.DangerousTryGetSingleMemory(out Memory<int> _));
+        Assert.Equal(4, buffer.RowStride);
+        Assert.Equal(4, new Buffer2DRegion<int>(buffer).Stride);
+
+        Span<int> row0 = buffer.DangerousGetRowSpan(0);
+        Span<int> row1 = buffer.DangerousGetRowSpan(1);
+
+        Assert.Equal(3, row0.Length);
+        Assert.Equal(3, row1.Length);
+        Assert.Equal(1, row0[0]);
+        Assert.Equal(3, row0[2]);
+        Assert.Equal(4, row1[0]);
+        Assert.Equal(6, row1[2]);
+
+        Assert.SpanPointsTo(row0, data.AsMemory(), bufferOffset: 0);
+        Assert.SpanPointsTo(row1, data.AsMemory(), bufferOffset: 4);
+    }
+
+    [Fact]
+    public void WrapMemory_Packed_WithTrailingData_DangerousTryGetSinglePixelMemory_IsLogicalSize()
+    {
+        int[] data = [1, 2, 3, 4, 5, 6, 777, 888];
+
+        using Buffer2D<int> buffer = Buffer2D<int>.WrapMemory(data.AsMemory(), width: 3, height: 2, stride: 3);
+
+        Assert.True(buffer.DangerousTryGetSingleMemory(out Memory<int> memory));
+        Assert.Equal(6, memory.Length);
+        Assert.True(Unsafe.AreSame(ref data[0], ref memory.Span[0]));
+    }
+
+    [Fact]
+    public void WrapMemory_Strided_ThrowsWhenStrideIsLessThanWidth()
+    {
+        int[] data = new int[10];
+
+        Assert.Throws<ArgumentOutOfRangeException>(() => Buffer2D<int>.WrapMemory(data.AsMemory(), width: 3, height: 2, stride: 2));
+    }
+
+    [Fact]
+    public void WrapMemory_Strided_ThrowsWhenInputMemoryTooSmall()
+    {
+        int[] data = new int[6];
+
+        Assert.Throws<ArgumentException>(() => Buffer2D<int>.WrapMemory(data.AsMemory(), width: 3, height: 2, stride: 4));
+    }
+
+    [Theory]
+    [InlineData(0, 1)]
+    [InlineData(1, 0)]
+    [InlineData(0, 0)]
+    [InlineData(-1, 1)]
+    [InlineData(1, -1)]
+    public void WrapMemory_ThrowsWhenWidthOrHeightIsNotPositive(int width, int height)
+    {
+        int[] data = new int[16];
+
+        Assert.Throws<ArgumentOutOfRangeException>(() => Buffer2D<int>.WrapMemory(data.AsMemory(), width, height));
+        Assert.Throws<ArgumentOutOfRangeException>(() => Buffer2D<int>.WrapMemory(data.AsMemory(), width, height, stride: 4));
+    }
+}

tests/ImageSharp.Tests/Memory/Buffer2DTests.cs

@@ -50,17 +50,11 @@ public partial class Buffer2DTests
     [InlineData(Big, 1, 0)]
     [InlineData(60, 42, 0)]
     [InlineData(3, 0, 0)]
-    public unsafe void Construct_Empty(int bufferCapacity, int width, int height)
+    public unsafe void Construct_Empty_Throws(int bufferCapacity, int width, int height)
     {
         this.MemoryAllocator.BufferCapacityInBytes = sizeof(TestStructs.Foo) * bufferCapacity;
 
-        using (Buffer2D<TestStructs.Foo> buffer = this.MemoryAllocator.Allocate2D<TestStructs.Foo>(width, height))
-        {
-            Assert.Equal(width, buffer.Width);
-            Assert.Equal(height, buffer.Height);
-            Assert.Equal(0, buffer.FastMemoryGroup.TotalLength);
-            Assert.Equal(0, buffer.DangerousGetSingleSpan().Length);
-        }
+        Assert.Throws<ArgumentOutOfRangeException>(() => this.MemoryAllocator.Allocate2D<TestStructs.Foo>(width, height));
     }
 
     [Theory]
@@ -339,25 +333,47 @@ public partial class Buffer2DTests
         Assert.NotSame(mgBefore, buffer1.MemoryGroup);
     }
 
-    public static TheoryData<Size> InvalidLengths { get; set; } = new()
+    public static TheoryData<Size> InvalidDimensions { get; set; } = new()
     {
         { new Size(-1, -1) },
+        { new Size(0, 1) },
+        { new Size(1, 0) },
+        { new Size(0, 0) }
+    };
+
+    public static TheoryData<Size> OverflowDimensions { get; set; } = new()
+    {
         { new Size(32768, 32769) },
         { new Size(32769, 32768) }
     };
 
     [Theory]
-    [MemberData(nameof(InvalidLengths))]
-    public void Allocate_IncorrectAmount_ThrowsCorrect_InvalidMemoryOperationException(Size size)
+    [MemberData(nameof(InvalidDimensions))]
+    public void Allocate_InvalidDimensions_ThrowsArgumentOutOfRangeException(Size size)
+        => Assert.Throws<ArgumentOutOfRangeException>(() => this.MemoryAllocator.Allocate2D<Rgba32>(size.Width, size.Height));
+
+    [Theory]
+    [MemberData(nameof(InvalidDimensions))]
+    public void Allocate_InvalidDimensions_SizeOverload_ThrowsArgumentOutOfRangeException(Size size)
+        => Assert.Throws<ArgumentOutOfRangeException>(() => this.MemoryAllocator.Allocate2D<Rgba32>(new Size(size)));
+
+    [Theory]
+    [MemberData(nameof(InvalidDimensions))]
+    public void Allocate_InvalidDimensions_OverAligned_ThrowsArgumentOutOfRangeException(Size size)
+        => Assert.Throws<ArgumentOutOfRangeException>(() => this.MemoryAllocator.Allocate2DOveraligned<Rgba32>(size.Width, size.Height, 1));
+
+    [Theory]
+    [MemberData(nameof(OverflowDimensions))]
+    public void Allocate_OverflowDimensions_ThrowsInvalidMemoryOperationException(Size size)
         => Assert.Throws<InvalidMemoryOperationException>(() => this.MemoryAllocator.Allocate2D<Rgba32>(size.Width, size.Height));
 
     [Theory]
-    [MemberData(nameof(InvalidLengths))]
-    public void Allocate_IncorrectAmount_ThrowsCorrect_InvalidMemoryOperationException_Size(Size size)
+    [MemberData(nameof(OverflowDimensions))]
+    public void Allocate_OverflowDimensions_SizeOverload_ThrowsInvalidMemoryOperationException(Size size)
         => Assert.Throws<InvalidMemoryOperationException>(() => this.MemoryAllocator.Allocate2D<Rgba32>(new Size(size)));
 
     [Theory]
-    [MemberData(nameof(InvalidLengths))]
-    public void Allocate_IncorrectAmount_ThrowsCorrect_InvalidMemoryOperationException_OverAligned(Size size)
+    [MemberData(nameof(OverflowDimensions))]
+    public void Allocate_OverflowDimensions_OverAligned_ThrowsInvalidMemoryOperationException(Size size)
         => Assert.Throws<InvalidMemoryOperationException>(() => this.MemoryAllocator.Allocate2DOveraligned<Rgba32>(size.Width, size.Height, 1));
 }

tests/ImageSharp.Tests/Memory/DiscontiguousBuffers/MemoryGroupTests.CopyTo.cs

@@ -9,100 +9,74 @@ public partial class MemoryGroupTests
 {
     public class CopyTo : MemoryGroupTestsBase
     {
-        public static readonly TheoryData<int, int, int, int> WhenSourceBufferIsShorterOrEqual_Data =
-            CopyAndTransformData;
-
-        [Theory]
-        [MemberData(nameof(WhenSourceBufferIsShorterOrEqual_Data))]
-        public void WhenSourceBufferIsShorterOrEqual(int srcTotal, int srcBufLen, int trgTotal, int trgBufLen)
+        [Fact]
+        public void GroupToSpan_StridedSource_DoesNotRequireTrailingPadding()
         {
-            using MemoryGroup<int> src = this.CreateTestGroup(srcTotal, srcBufLen, true);
-            using MemoryGroup<int> trg = this.CreateTestGroup(trgTotal, trgBufLen, false);
-
-            src.CopyTo(trg);
+            using MemoryGroup<int> src = this.CreateTestGroup(totalLength: 7, bufferLength: 4, fillSequence: true);
+            int[] trg = new int[6];
 
-            int pos = 0;
-            MemoryGroupIndex i = src.MinIndex();
-            MemoryGroupIndex j = trg.MinIndex();
-            for (; i < src.MaxIndex(); i += 1, j += 1, pos++)
-            {
-                int a = src.GetElementAt(i);
-                int b = trg.GetElementAt(j);
+            src.CopyTo(
+                sourceStride: 4,
+                trg,
+                targetStride: 3,
+                width: 3,
+                height: 2);
 
-                Assert.True(a == b, $"Mismatch @ {pos} Expected: {a} Actual: {b}");
-            }
+            Assert.Equal(new[] { 1, 2, 3, 5, 6, 7 }, trg);
         }
 
         [Fact]
-        public void WhenTargetBufferTooShort_Throws()
+        public void GroupToGroup_StridedCopy_DoesNotRequireTrailingPadding()
         {
-            using MemoryGroup<int> src = this.CreateTestGroup(10, 20, true);
-            using MemoryGroup<int> trg = this.CreateTestGroup(5, 20, false);
-
-            Assert.Throws<ArgumentOutOfRangeException>(() => src.CopyTo(trg));
+            using MemoryGroup<int> src = this.CreateTestGroup(totalLength: 11, bufferLength: 5, fillSequence: true);
+            using MemoryGroup<int> trg = this.CreateTestGroup(totalLength: 13, bufferLength: 6, fillSequence: false);
+
+            src.CopyTo(
+                sourceStride: 4,
+                trg,
+                targetStride: 5,
+                width: 3,
+                height: 3);
+
+            Assert.Equal(1, GetElementAtLinearIndex(trg, 0));
+            Assert.Equal(2, GetElementAtLinearIndex(trg, 1));
+            Assert.Equal(3, GetElementAtLinearIndex(trg, 2));
+            Assert.Equal(5, GetElementAtLinearIndex(trg, 5));
+            Assert.Equal(6, GetElementAtLinearIndex(trg, 6));
+            Assert.Equal(7, GetElementAtLinearIndex(trg, 7));
+            Assert.Equal(9, GetElementAtLinearIndex(trg, 10));
+            Assert.Equal(10, GetElementAtLinearIndex(trg, 11));
+            Assert.Equal(11, GetElementAtLinearIndex(trg, 12));
         }
 
-        [Theory]
-        [InlineData(30, 10, 40)]
-        [InlineData(42, 23, 42)]
-        [InlineData(1, 3, 10)]
-        [InlineData(0, 4, 0)]
-        public void GroupToSpan_Success(long totalLength, int bufferLength, int spanLength)
+        [Fact]
+        public void GroupToSpan_StridedSource_HeightOne()
         {
-            using MemoryGroup<int> src = this.CreateTestGroup(totalLength, bufferLength, true);
-            int[] trg = new int[spanLength];
-            src.CopyTo(trg);
+            using MemoryGroup<int> src = this.CreateTestGroup(totalLength: 3, bufferLength: 2, fillSequence: true);
+            int[] trg = new int[3];
 
-            int expected = 1;
-            foreach (int val in trg.AsSpan().Slice(0, (int)totalLength))
-            {
-                Assert.Equal(expected, val);
-                expected++;
-            }
-        }
+            src.CopyTo(
+                sourceStride: 8,
+                trg,
+                targetStride: 3,
+                width: 3,
+                height: 1);
 
-        [Theory]
-        [InlineData(20, 7, 19)]
-        [InlineData(2, 1, 1)]
-        public void GroupToSpan_OutOfRange(long totalLength, int bufferLength, int spanLength)
-        {
-            using MemoryGroup<int> src = this.CreateTestGroup(totalLength, bufferLength, true);
-            int[] trg = new int[spanLength];
-            Assert.ThrowsAny<ArgumentOutOfRangeException>(() => src.CopyTo(trg));
+            Assert.Equal(new[] { 1, 2, 3 }, trg);
         }
 
-        [Theory]
-        [InlineData(30, 35, 10)]
-        [InlineData(42, 23, 42)]
-        [InlineData(10, 3, 1)]
-        [InlineData(0, 3, 0)]
-        public void SpanToGroup_Success(long totalLength, int bufferLength, int spanLength)
+        private static int GetElementAtLinearIndex(MemoryGroup<int> group, int index)
         {
-            int[] src = new int[spanLength];
-            for (int i = 0; i < src.Length; i++)
-            {
-                src[i] = i + 1;
-            }
-
-            using MemoryGroup<int> trg = this.CreateTestGroup(totalLength, bufferLength);
-            src.AsSpan().CopyTo(trg);
-
-            int position = 0;
-            for (MemoryGroupIndex i = trg.MinIndex(); position < spanLength; i += 1, position++)
+            int pos = 0;
+            for (MemoryGroupIndex i = group.MinIndex(); i < group.MaxIndex(); i += 1, pos++)
             {
-                int expected = position + 1;
-                Assert.Equal(expected, trg.GetElementAt(i));
+                if (pos == index)
+                {
+                    return group.GetElementAt(i);
+                }
             }
-        }
 
-        [Theory]
-        [InlineData(10, 3, 11)]
-        [InlineData(0, 3, 1)]
-        public void SpanToGroup_OutOfRange(long totalLength, int bufferLength, int spanLength)
-        {
-            int[] src = new int[spanLength];
-            using MemoryGroup<int> trg = this.CreateTestGroup(totalLength, bufferLength, true);
-            Assert.ThrowsAny<ArgumentOutOfRangeException>(() => src.AsSpan().CopyTo(trg));
+            throw new ArgumentOutOfRangeException(nameof(index));
         }
     }
 }

tests/ImageSharp.Tests/Memory/DiscontiguousBuffers/MemoryGroupTests.cs

@@ -26,76 +26,6 @@ public partial class MemoryGroupTests : MemoryGroupTestsBase
         Assert.False(g.IsValid);
     }
 
-#pragma warning disable SA1509
-    private static readonly TheoryData<int, int, int, int> CopyAndTransformData =
-        new()
-        {
-            { 20, 10, 20, 10 },
-            { 20, 5, 20, 4 },
-            { 20, 4, 20, 5 },
-            { 18, 6, 20, 5 },
-            { 19, 10, 20, 10 },
-            { 21, 10, 22, 2 },
-            { 1, 5, 5, 4 },
-
-            { 30, 12, 40, 5 },
-            { 30, 5, 40, 12 },
-        };
-
-    public class TransformTo : MemoryGroupTestsBase
-    {
-        public static readonly TheoryData<int, int, int, int> WhenSourceBufferIsShorterOrEqual_Data =
-            CopyAndTransformData;
-
-        [Theory]
-        [MemberData(nameof(WhenSourceBufferIsShorterOrEqual_Data))]
-        public void WhenSourceBufferIsShorterOrEqual(int srcTotal, int srcBufLen, int trgTotal, int trgBufLen)
-        {
-            using MemoryGroup<int> src = this.CreateTestGroup(srcTotal, srcBufLen, true);
-            using MemoryGroup<int> trg = this.CreateTestGroup(trgTotal, trgBufLen, false);
-
-            src.TransformTo(trg, MultiplyAllBy2);
-
-            int pos = 0;
-            MemoryGroupIndex i = src.MinIndex();
-            MemoryGroupIndex j = trg.MinIndex();
-            for (; i < src.MaxIndex(); i += 1, j += 1, pos++)
-            {
-                int a = src.GetElementAt(i);
-                int b = trg.GetElementAt(j);
-
-                Assert.True(b == 2 * a, $"Mismatch @ {pos} Expected: {a} Actual: {b}");
-            }
-        }
-
-        [Fact]
-        public void WhenTargetBufferTooShort_Throws()
-        {
-            using MemoryGroup<int> src = this.CreateTestGroup(10, 20, true);
-            using MemoryGroup<int> trg = this.CreateTestGroup(5, 20, false);
-
-            Assert.Throws<ArgumentOutOfRangeException>(() => src.TransformTo(trg, MultiplyAllBy2));
-        }
-    }
-
-    [Theory]
-    [InlineData(100, 5)]
-    [InlineData(100, 101)]
-    public void TransformInplace(int totalLength, int bufferLength)
-    {
-        using MemoryGroup<int> src = this.CreateTestGroup(10, 20, true);
-
-        src.TransformInplace(s => MultiplyAllBy2(s, s));
-
-        int cnt = 1;
-        for (MemoryGroupIndex i = src.MinIndex(); i < src.MaxIndex(); i += 1)
-        {
-            int val = src.GetElementAt(i);
-            Assert.Equal(expected: cnt * 2, val);
-            cnt++;
-        }
-    }
-
     [Fact]
     public void Wrap()
     {
@@ -224,12 +154,4 @@ public partial class MemoryGroupTests : MemoryGroupTestsBase
         }
     }
 
-    private static void MultiplyAllBy2(ReadOnlySpan<int> source, Span<int> target)
-    {
-        Assert.Equal(source.Length, target.Length);
-        for (int k = 0; k < source.Length; k++)
-        {
-            target[k] = source[k] * 2;
-        }
-    }
 }