Merge branch 'master' into bp/tiff12bit

src/ImageSharp/Image.cs

@@ -3,6 +3,7 @@
 
 using System;
 using System.IO;
+using System.Runtime.CompilerServices;
 using System.Threading;
 using System.Threading.Tasks;
 using SixLabors.ImageSharp.Advanced;
@@ -19,6 +20,8 @@ namespace SixLabors.ImageSharp
     /// </summary>
     public abstract partial class Image : IImage, IConfigurationProvider
     {
+        private bool isDisposed;
+
         private Size size;
         private readonly Configuration configuration;
 
@@ -80,8 +83,15 @@ namespace SixLabors.ImageSharp
         /// <inheritdoc />
         public void Dispose()
         {
+            if (this.isDisposed)
+            {
+                return;
+            }
+
             this.Dispose(true);
             GC.SuppressFinalize(this);
+
+            this.isDisposed = true;
         }
 
         /// <summary>
@@ -89,7 +99,7 @@ namespace SixLabors.ImageSharp
         /// </summary>
         /// <param name="stream">The stream to save the image to.</param>
         /// <param name="encoder">The encoder to save the image with.</param>
-        /// <exception cref="System.ArgumentNullException">Thrown if the stream or encoder is null.</exception>
+        /// <exception cref="ArgumentNullException">Thrown if the stream or encoder is null.</exception>
         public void Save(Stream stream, IImageEncoder encoder)
         {
             Guard.NotNull(stream, nameof(stream));
@@ -148,7 +158,13 @@ namespace SixLabors.ImageSharp
         /// <summary>
         /// Throws <see cref="ObjectDisposedException"/> if the image is disposed.
         /// </summary>
-        internal abstract void EnsureNotDisposed();
+        internal void EnsureNotDisposed()
+        {
+            if (this.isDisposed)
+            {
+                ThrowObjectDisposedException(this.GetType());
+            }
+        }
 
         /// <summary>
         /// Accepts a <see cref="IImageVisitor"/>.
@@ -167,6 +183,9 @@ namespace SixLabors.ImageSharp
         /// <param name="cancellationToken">The token to monitor for cancellation requests.</param>
         internal abstract Task AcceptAsync(IImageVisitorAsync visitor, CancellationToken cancellationToken);
 
+        [MethodImpl(InliningOptions.ColdPath)]
+        private static void ThrowObjectDisposedException(Type type) => throw new ObjectDisposedException(type.Name);
+
         private class EncodeVisitor : IImageVisitor, IImageVisitorAsync
         {
             private readonly IImageEncoder encoder;

src/ImageSharp/ImageFrameCollection.cs

@@ -4,6 +4,7 @@
 using System;
 using System.Collections;
 using System.Collections.Generic;
+using System.Runtime.CompilerServices;
 
 namespace SixLabors.ImageSharp
 {
@@ -11,8 +12,10 @@ namespace SixLabors.ImageSharp
     /// Encapsulates a pixel-agnostic collection of <see cref="ImageFrame"/> instances
     /// that make up an <see cref="Image"/>.
     /// </summary>
-    public abstract class ImageFrameCollection : IEnumerable<ImageFrame>
+    public abstract class ImageFrameCollection : IDisposable, IEnumerable<ImageFrame>
     {
+        private bool isDisposed;
+
         /// <summary>
         /// Gets the number of frames.
         /// </summary>
@@ -21,7 +24,15 @@ namespace SixLabors.ImageSharp
         /// <summary>
         /// Gets the root frame.
         /// </summary>
-        public ImageFrame RootFrame => this.NonGenericRootFrame;
+        public ImageFrame RootFrame
+        {
+            get
+            {
+                this.EnsureNotDisposed();
+
+                return this.NonGenericRootFrame;
+            }
+        }
 
         /// <summary>
         /// Gets the root frame. (Implements <see cref="RootFrame"/>.)
@@ -36,7 +47,15 @@ namespace SixLabors.ImageSharp
         /// </value>
         /// <param name="index">The index.</param>
         /// <returns>The <see cref="ImageFrame"/> at the specified index.</returns>
-        public ImageFrame this[int index] => this.NonGenericGetFrame(index);
+        public ImageFrame this[int index]
+        {
+            get
+            {
+                this.EnsureNotDisposed();
+
+                return this.NonGenericGetFrame(index);
+            }
+        }
 
         /// <summary>
         /// Determines the index of a specific <paramref name="frame"/> in the <seealso cref="ImageFrameCollection"/>.
@@ -52,14 +71,24 @@ namespace SixLabors.ImageSharp
         /// <param name="source">The <seealso cref="ImageFrame"/> to clone and insert into the <seealso cref="ImageFrameCollection"/>.</param>
         /// <exception cref="ArgumentException">Frame must have the same dimensions as the image.</exception>
         /// <returns>The cloned <see cref="ImageFrame"/>.</returns>
-        public ImageFrame InsertFrame(int index, ImageFrame source) => this.NonGenericInsertFrame(index, source);
+        public ImageFrame InsertFrame(int index, ImageFrame source)
+        {
+            this.EnsureNotDisposed();
+
+            return this.NonGenericInsertFrame(index, source);
+        }
 
         /// <summary>
         /// Clones the <paramref name="source"/> frame and appends the clone to the end of the collection.
         /// </summary>
         /// <param name="source">The raw pixel data to generate the <seealso cref="ImageFrame{TPixel}"/> from.</param>
         /// <returns>The cloned <see cref="ImageFrame{TPixel}"/>.</returns>
-        public ImageFrame AddFrame(ImageFrame source) => this.NonGenericAddFrame(source);
+        public ImageFrame AddFrame(ImageFrame source)
+        {
+            this.EnsureNotDisposed();
+
+            return this.NonGenericAddFrame(source);
+        }
 
         /// <summary>
         /// Removes the frame at the specified index and frees all freeable resources associated with it.
@@ -91,7 +120,12 @@ namespace SixLabors.ImageSharp
         /// <param name="index">The zero-based index of the frame to export.</param>
         /// <exception cref="InvalidOperationException">Cannot remove last frame.</exception>
         /// <returns>The new <see cref="Image{TPixel}"/> with the specified frame.</returns>
-        public Image ExportFrame(int index) => this.NonGenericExportFrame(index);
+        public Image ExportFrame(int index)
+        {
+            this.EnsureNotDisposed();
+
+            return this.NonGenericExportFrame(index);
+        }
 
         /// <summary>
         /// Creates an <see cref="Image{T}"/> with only the frame at the specified index
@@ -99,7 +133,12 @@ namespace SixLabors.ImageSharp
         /// </summary>
         /// <param name="index">The zero-based index of the frame to clone.</param>
         /// <returns>The new <see cref="Image{TPixel}"/> with the specified frame.</returns>
-        public Image CloneFrame(int index) => this.NonGenericCloneFrame(index);
+        public Image CloneFrame(int index)
+        {
+            this.EnsureNotDisposed();
+
+            return this.NonGenericCloneFrame(index);
+        }
 
         /// <summary>
         /// Creates a new <seealso cref="ImageFrame{TPixel}" /> and appends it to the end of the collection.
@@ -107,7 +146,12 @@ namespace SixLabors.ImageSharp
         /// <returns>
         /// The new <see cref="ImageFrame{TPixel}" />.
         /// </returns>
-        public ImageFrame CreateFrame() => this.NonGenericCreateFrame();
+        public ImageFrame CreateFrame()
+        {
+            this.EnsureNotDisposed();
+
+            return this.NonGenericCreateFrame();
+        }
 
         /// <summary>
         /// Creates a new <seealso cref="ImageFrame{TPixel}" /> and appends it to the end of the collection.
@@ -116,14 +160,55 @@ namespace SixLabors.ImageSharp
         /// <returns>
         /// The new <see cref="ImageFrame{TPixel}" />.
         /// </returns>
-        public ImageFrame CreateFrame(Color backgroundColor) => this.NonGenericCreateFrame(backgroundColor);
+        public ImageFrame CreateFrame(Color backgroundColor)
+        {
+            this.EnsureNotDisposed();
+
+            return this.NonGenericCreateFrame(backgroundColor);
+        }
 
         /// <inheritdoc />
-        public IEnumerator<ImageFrame> GetEnumerator() => this.NonGenericGetEnumerator();
+        public void Dispose()
+        {
+            if (this.isDisposed)
+            {
+                return;
+            }
+
+            this.Dispose(true);
+            GC.SuppressFinalize(this);
+
+            this.isDisposed = true;
+        }
+
+        /// <inheritdoc />
+        public IEnumerator<ImageFrame> GetEnumerator()
+        {
+            this.EnsureNotDisposed();
+
+            return this.NonGenericGetEnumerator();
+        }
 
         /// <inheritdoc/>
         IEnumerator IEnumerable.GetEnumerator() => this.GetEnumerator();
 
+        /// <summary>
+        /// Throws <see cref="ObjectDisposedException"/> if the image frame is disposed.
+        /// </summary>
+        protected void EnsureNotDisposed()
+        {
+            if (this.isDisposed)
+            {
+                ThrowObjectDisposedException(this.GetType());
+            }
+        }
+
+        /// <summary>
+        /// Disposes the object and frees resources for the Garbage Collector.
+        /// </summary>
+        /// <param name="disposing">Whether to dispose of managed and unmanaged objects.</param>
+        protected abstract void Dispose(bool disposing);
+
         /// <summary>
         /// Implements <see cref="GetEnumerator"/>.
         /// </summary>
@@ -178,5 +263,8 @@ namespace SixLabors.ImageSharp
         /// <param name="backgroundColor">The background color.</param>
         /// <returns>The new frame.</returns>
         protected abstract ImageFrame NonGenericCreateFrame(Color backgroundColor);
+
+        [MethodImpl(InliningOptions.ColdPath)]
+        private static void ThrowObjectDisposedException(Type type) => throw new ObjectDisposedException(type.Name);
     }
 }

src/ImageSharp/ImageFrameCollection{TPixel}.cs

@@ -67,7 +67,26 @@ namespace SixLabors.ImageSharp
         /// <summary>
         /// Gets the root frame.
         /// </summary>
-        public new ImageFrame<TPixel> RootFrame => this.frames.Count > 0 ? this.frames[0] : null;
+        public new ImageFrame<TPixel> RootFrame
+        {
+            get
+            {
+                this.EnsureNotDisposed();
+
+                // frame collection would always contain at least 1 frame
+                // the only exception is when collection is disposed what is checked via EnsureNotDisposed() call
+                return this.frames[0];
+            }
+        }
+
+        /// <summary>
+        /// Gets root frame accessor in unsafe manner without any checks.
+        /// </summary>
+        /// <remarks>
+        /// This property is most likely to be called from <see cref="Image{TPixel}"/> for indexing pixels.
+        /// <see cref="Image{TPixel}"/> already checks if it was disposed before querying for root frame.
+        /// </remarks>
+        internal ImageFrame<TPixel> RootFrameUnsafe => this.frames[0];
 
         /// <inheritdoc />
         protected override ImageFrame NonGenericRootFrame => this.RootFrame;
@@ -80,12 +99,22 @@ namespace SixLabors.ImageSharp
         /// </value>
         /// <param name="index">The index.</param>
         /// <returns>The <see cref="ImageFrame{TPixel}"/> at the specified index.</returns>
-        public new ImageFrame<TPixel> this[int index] => this.frames[index];
+        public new ImageFrame<TPixel> this[int index]
+        {
+            get
+            {
+                this.EnsureNotDisposed();
+
+                return this.frames[index];
+            }
+        }
 
         /// <inheritdoc />
         public override int IndexOf(ImageFrame frame)
         {
-            return frame is ImageFrame<TPixel> specific ? this.IndexOf(specific) : -1;
+            this.EnsureNotDisposed();
+
+            return frame is ImageFrame<TPixel> specific ? this.frames.IndexOf(specific) : -1;
         }
 
         /// <summary>
@@ -93,7 +122,12 @@ namespace SixLabors.ImageSharp
         /// </summary>
         /// <param name="frame">The <seealso cref="ImageFrame{TPixel}"/> to locate in the <seealso cref="ImageFrameCollection{TPixel}"/>.</param>
         /// <returns>The index of item if found in the list; otherwise, -1.</returns>
-        public int IndexOf(ImageFrame<TPixel> frame) => this.frames.IndexOf(frame);
+        public int IndexOf(ImageFrame<TPixel> frame)
+        {
+            this.EnsureNotDisposed();
+
+            return this.frames.IndexOf(frame);
+        }
 
         /// <summary>
         /// Clones and inserts the <paramref name="source"/> into the <seealso cref="ImageFrameCollection{TPixel}"/> at the specified <paramref name="index"/>.
@@ -104,6 +138,8 @@ namespace SixLabors.ImageSharp
         /// <returns>The cloned <see cref="ImageFrame{TPixel}"/>.</returns>
         public ImageFrame<TPixel> InsertFrame(int index, ImageFrame<TPixel> source)
         {
+            this.EnsureNotDisposed();
+
             this.ValidateFrame(source);
             ImageFrame<TPixel> clonedFrame = source.Clone(this.parent.GetConfiguration());
             this.frames.Insert(index, clonedFrame);
@@ -117,6 +153,8 @@ namespace SixLabors.ImageSharp
         /// <returns>The cloned <see cref="ImageFrame{TPixel}"/>.</returns>
         public ImageFrame<TPixel> AddFrame(ImageFrame<TPixel> source)
         {
+            this.EnsureNotDisposed();
+
             this.ValidateFrame(source);
             ImageFrame<TPixel> clonedFrame = source.Clone(this.parent.GetConfiguration());
             this.frames.Add(clonedFrame);
@@ -131,6 +169,8 @@ namespace SixLabors.ImageSharp
         /// <returns>The new <see cref="ImageFrame{TPixel}"/>.</returns>
         public ImageFrame<TPixel> AddFrame(ReadOnlySpan<TPixel> source)
         {
+            this.EnsureNotDisposed();
+
             var frame = ImageFrame.LoadPixelData(
                 this.parent.GetConfiguration(),
                 source,
@@ -149,6 +189,7 @@ namespace SixLabors.ImageSharp
         public ImageFrame<TPixel> AddFrame(TPixel[] source)
         {
             Guard.NotNull(source, nameof(source));
+
             return this.AddFrame(source.AsSpan());
         }
 
@@ -159,6 +200,8 @@ namespace SixLabors.ImageSharp
         /// <exception cref="InvalidOperationException">Cannot remove last frame.</exception>
         public override void RemoveFrame(int index)
         {
+            this.EnsureNotDisposed();
+
             if (index == 0 && this.Count == 1)
             {
                 throw new InvalidOperationException("Cannot remove last frame.");
@@ -170,8 +213,12 @@ namespace SixLabors.ImageSharp
         }
 
         /// <inheritdoc />
-        public override bool Contains(ImageFrame frame) =>
-            frame is ImageFrame<TPixel> specific && this.Contains(specific);
+        public override bool Contains(ImageFrame frame)
+        {
+            this.EnsureNotDisposed();
+
+            return frame is ImageFrame<TPixel> specific && this.frames.Contains(specific);
+        }
 
         /// <summary>
         /// Determines whether the <seealso cref="ImageFrameCollection{TPixel}"/> contains the <paramref name="frame"/>.
@@ -180,7 +227,12 @@ namespace SixLabors.ImageSharp
         /// <returns>
         ///   <c>true</c> if the <seealso cref="ImageFrameCollection{TPixel}"/> contains the specified frame; otherwise, <c>false</c>.
         /// </returns>
-        public bool Contains(ImageFrame<TPixel> frame) => this.frames.Contains(frame);
+        public bool Contains(ImageFrame<TPixel> frame)
+        {
+            this.EnsureNotDisposed();
+
+            return this.frames.Contains(frame);
+        }
 
         /// <summary>
         /// Moves an <seealso cref="ImageFrame{TPixel}"/> from <paramref name="sourceIndex"/> to <paramref name="destinationIndex"/>.
@@ -189,6 +241,8 @@ namespace SixLabors.ImageSharp
         /// <param name="destinationIndex">The index to move the frame to.</param>
         public override void MoveFrame(int sourceIndex, int destinationIndex)
         {
+            this.EnsureNotDisposed();
+
             if (sourceIndex == destinationIndex)
             {
                 return;
@@ -208,6 +262,8 @@ namespace SixLabors.ImageSharp
         /// <returns>The new <see cref="Image{TPixel}"/> with the specified frame.</returns>
         public new Image<TPixel> ExportFrame(int index)
         {
+            this.EnsureNotDisposed();
+
             ImageFrame<TPixel> frame = this[index];
 
             if (this.Count == 1 && this.frames.Contains(frame))
@@ -228,6 +284,8 @@ namespace SixLabors.ImageSharp
         /// <returns>The new <see cref="Image{TPixel}"/> with the specified frame.</returns>
         public new Image<TPixel> CloneFrame(int index)
         {
+            this.EnsureNotDisposed();
+
             ImageFrame<TPixel> frame = this[index];
             ImageFrame<TPixel> clonedFrame = frame.Clone();
             return new Image<TPixel>(this.parent.GetConfiguration(), this.parent.Metadata.DeepClone(), new[] { clonedFrame });
@@ -241,6 +299,8 @@ namespace SixLabors.ImageSharp
         /// </returns>
         public new ImageFrame<TPixel> CreateFrame()
         {
+            this.EnsureNotDisposed();
+
             var frame = new ImageFrame<TPixel>(
                 this.parent.GetConfiguration(),
                 this.RootFrame.Width,
@@ -335,14 +395,18 @@ namespace SixLabors.ImageSharp
             }
         }
 
-        internal void Dispose()
+        /// <inheritdoc/>
+        protected override void Dispose(bool disposing)
         {
-            foreach (ImageFrame<TPixel> f in this.frames)
+            if (disposing)
             {
-                f.Dispose();
-            }
+                foreach (ImageFrame<TPixel> f in this.frames)
+                {
+                    f.Dispose();
+                }
 
-            this.frames.Clear();
+                this.frames.Clear();
+            }
         }
 
         private ImageFrame<TPixel> CopyNonCompatibleFrame(ImageFrame source)

src/ImageSharp/Image{TPixel}.cs

@@ -23,7 +23,7 @@ namespace SixLabors.ImageSharp
     public sealed class Image<TPixel> : Image
         where TPixel : unmanaged, IPixel<TPixel>
     {
-        private bool isDisposed;
+        private readonly ImageFrameCollection<TPixel> frames;
 
         /// <summary>
         /// Initializes a new instance of the <see cref="Image{TPixel}"/> class
@@ -84,7 +84,7 @@ namespace SixLabors.ImageSharp
         internal Image(Configuration configuration, int width, int height, ImageMetadata metadata)
             : base(configuration, PixelTypeInfo.Create<TPixel>(), metadata, width, height)
         {
-            this.Frames = new ImageFrameCollection<TPixel>(this, width, height, default(TPixel));
+            this.frames = new ImageFrameCollection<TPixel>(this, width, height, default(TPixel));
         }
 
         /// <summary>
@@ -104,7 +104,7 @@ namespace SixLabors.ImageSharp
             ImageMetadata metadata)
             : base(configuration, PixelTypeInfo.Create<TPixel>(), metadata, width, height)
         {
-            this.Frames = new ImageFrameCollection<TPixel>(this, width, height, memoryGroup);
+            this.frames = new ImageFrameCollection<TPixel>(this, width, height, memoryGroup);
         }
 
         /// <summary>
@@ -124,7 +124,7 @@ namespace SixLabors.ImageSharp
             ImageMetadata metadata)
             : base(configuration, PixelTypeInfo.Create<TPixel>(), metadata, width, height)
         {
-            this.Frames = new ImageFrameCollection<TPixel>(this, width, height, backgroundColor);
+            this.frames = new ImageFrameCollection<TPixel>(this, width, height, backgroundColor);
         }
 
         /// <summary>
@@ -137,7 +137,7 @@ namespace SixLabors.ImageSharp
         internal Image(Configuration configuration, ImageMetadata metadata, IEnumerable<ImageFrame<TPixel>> frames)
             : base(configuration, PixelTypeInfo.Create<TPixel>(), metadata, ValidateFramesAndGetSize(frames))
         {
-            this.Frames = new ImageFrameCollection<TPixel>(this, frames);
+            this.frames = new ImageFrameCollection<TPixel>(this, frames);
         }
 
         /// <inheritdoc />
@@ -146,12 +146,19 @@ namespace SixLabors.ImageSharp
         /// <summary>
         /// Gets the collection of image frames.
         /// </summary>
-        public new ImageFrameCollection<TPixel> Frames { get; }
+        public new ImageFrameCollection<TPixel> Frames
+        {
+            get
+            {
+                this.EnsureNotDisposed();
+                return this.frames;
+            }
+        }
 
         /// <summary>
         /// Gets the root frame.
         /// </summary>
-        private IPixelSource<TPixel> PixelSource => this.Frames?.RootFrame ?? throw new ObjectDisposedException(nameof(Image<TPixel>));
+        private IPixelSource<TPixel> PixelSourceUnsafe => this.frames.RootFrameUnsafe;
 
         /// <summary>
         /// Gets or sets the pixel at the specified position.
@@ -165,15 +172,19 @@ namespace SixLabors.ImageSharp
             [MethodImpl(InliningOptions.ShortMethod)]
             get
             {
+                this.EnsureNotDisposed();
+
                 this.VerifyCoords(x, y);
-                return this.PixelSource.PixelBuffer.GetElementUnsafe(x, y);
+                return this.PixelSourceUnsafe.PixelBuffer.GetElementUnsafe(x, y);
             }
 
             [MethodImpl(InliningOptions.ShortMethod)]
             set
             {
+                this.EnsureNotDisposed();
+
                 this.VerifyCoords(x, y);
-                this.PixelSource.PixelBuffer.GetElementUnsafe(x, y) = value;
+                this.PixelSourceUnsafe.PixelBuffer.GetElementUnsafe(x, y) = value;
             }
         }
 
@@ -189,7 +200,9 @@ namespace SixLabors.ImageSharp
             Guard.MustBeGreaterThanOrEqualTo(rowIndex, 0, nameof(rowIndex));
             Guard.MustBeLessThan(rowIndex, this.Height, nameof(rowIndex));
 
-            return this.PixelSource.PixelBuffer.GetRowSpan(rowIndex);
+            this.EnsureNotDisposed();
+
+            return this.PixelSourceUnsafe.PixelBuffer.GetRowSpan(rowIndex);
         }
 
         /// <summary>
@@ -226,10 +239,10 @@ namespace SixLabors.ImageSharp
         {
             this.EnsureNotDisposed();
 
-            var clonedFrames = new ImageFrame<TPixel>[this.Frames.Count];
+            var clonedFrames = new ImageFrame<TPixel>[this.frames.Count];
             for (int i = 0; i < clonedFrames.Length; i++)
             {
-                clonedFrames[i] = this.Frames[i].Clone(configuration);
+                clonedFrames[i] = this.frames[i].Clone(configuration);
             }
 
             return new Image<TPixel>(configuration, this.Metadata.DeepClone(), clonedFrames);
@@ -245,10 +258,10 @@ namespace SixLabors.ImageSharp
         {
             this.EnsureNotDisposed();
 
-            var clonedFrames = new ImageFrame<TPixel2>[this.Frames.Count];
+            var clonedFrames = new ImageFrame<TPixel2>[this.frames.Count];
             for (int i = 0; i < clonedFrames.Length; i++)
             {
-                clonedFrames[i] = this.Frames[i].CloneAs<TPixel2>(configuration);
+                clonedFrames[i] = this.frames[i].CloneAs<TPixel2>(configuration);
             }
 
             return new Image<TPixel2>(configuration, this.Metadata.DeepClone(), clonedFrames);
@@ -257,25 +270,9 @@ namespace SixLabors.ImageSharp
         /// <inheritdoc/>
         protected override void Dispose(bool disposing)
         {
-            if (this.isDisposed)
-            {
-                return;
-            }
-
             if (disposing)
             {
-                this.Frames.Dispose();
-            }
-
-            this.isDisposed = true;
-        }
-
-        /// <inheritdoc/>
-        internal override void EnsureNotDisposed()
-        {
-            if (this.isDisposed)
-            {
-                throw new ObjectDisposedException("Trying to execute an operation on a disposed image.");
+                this.frames.Dispose();
             }
         }
 
@@ -306,9 +303,12 @@ namespace SixLabors.ImageSharp
         {
             Guard.NotNull(pixelSource, nameof(pixelSource));
 
-            for (int i = 0; i < this.Frames.Count; i++)
+            this.EnsureNotDisposed();
+
+            ImageFrameCollection<TPixel> sourceFrames = pixelSource.Frames;
+            for (int i = 0; i < this.frames.Count; i++)
             {
-                this.Frames[i].SwapOrCopyPixelsBufferFrom(pixelSource.Frames[i]);
+                this.frames[i].SwapOrCopyPixelsBufferFrom(sourceFrames[i]);
             }
 
             this.UpdateSize(pixelSource.Size());

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

@@ -339,6 +339,48 @@ namespace SixLabors.ImageSharp.Tests
                 using var frame = new ImageFrame<Rgba32>(Configuration.Default, 10, 10);
                 Assert.False(this.Image.Frames.Contains(frame));
             }
+
+            [Fact]
+            public void DisposeCall_NoThrowIfCalledMultiple()
+            {
+                var image = new Image<Rgba32>(Configuration.Default, 10, 10);
+                var frameCollection = image.Frames as ImageFrameCollection;
+
+                image.Dispose(); // this should invalidate underlying collection as well
+                frameCollection.Dispose();
+            }
+
+            [Fact]
+            public void PublicProperties_ThrowIfDisposed()
+            {
+                var image = new Image<Rgba32>(Configuration.Default, 10, 10);
+                var frameCollection = image.Frames as ImageFrameCollection;
+
+                image.Dispose(); // this should invalidate underlying collection as well
+
+                Assert.Throws<ObjectDisposedException>(() => { var prop = frameCollection.RootFrame; });
+            }
+
+            [Fact]
+            public void PublicMethods_ThrowIfDisposed()
+            {
+                var image = new Image<Rgba32>(Configuration.Default, 10, 10);
+                var frameCollection = image.Frames as ImageFrameCollection;
+
+                image.Dispose(); // this should invalidate underlying collection as well
+
+                Assert.Throws<ObjectDisposedException>(() => { var res = frameCollection.AddFrame(default); });
+                Assert.Throws<ObjectDisposedException>(() => { var res = frameCollection.CloneFrame(default); });
+                Assert.Throws<ObjectDisposedException>(() => { var res = frameCollection.Contains(default); });
+                Assert.Throws<ObjectDisposedException>(() => { var res = frameCollection.CreateFrame(); });
+                Assert.Throws<ObjectDisposedException>(() => { var res = frameCollection.CreateFrame(default); });
+                Assert.Throws<ObjectDisposedException>(() => { var res = frameCollection.ExportFrame(default); });
+                Assert.Throws<ObjectDisposedException>(() => { var res = frameCollection.GetEnumerator(); });
+                Assert.Throws<ObjectDisposedException>(() => { var prop = frameCollection.IndexOf(default); });
+                Assert.Throws<ObjectDisposedException>(() => { var prop = frameCollection.InsertFrame(default, default); });
+                Assert.Throws<ObjectDisposedException>(() => { frameCollection.RemoveFrame(default); });
+                Assert.Throws<ObjectDisposedException>(() => { frameCollection.MoveFrame(default, default); });
+            }
         }
     }
 }

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

@@ -263,6 +263,42 @@ namespace SixLabors.ImageSharp.Tests
                 Assert.False(this.Image.Frames.Contains(frame));
             }
 
+            [Fact]
+            public void PublicProperties_ThrowIfDisposed()
+            {
+                var image = new Image<Rgba32>(Configuration.Default, 10, 10);
+                var frameCollection = image.Frames;
+
+                image.Dispose(); // this should invalidate underlying collection as well
+
+                Assert.Throws<ObjectDisposedException>(() => { var prop = frameCollection.RootFrame; });
+            }
+
+            [Fact]
+            public void PublicMethods_ThrowIfDisposed()
+            {
+                var image = new Image<Rgba32>(Configuration.Default, 10, 10);
+                var frameCollection = image.Frames;
+                var rgba32Array = new Rgba32[0];
+
+                image.Dispose(); // this should invalidate underlying collection as well
+
+                Assert.Throws<ObjectDisposedException>(() => { var res = frameCollection.AddFrame((ImageFrame)null); });
+                Assert.Throws<ObjectDisposedException>(() => { var res = frameCollection.AddFrame(rgba32Array); });
+                Assert.Throws<ObjectDisposedException>(() => { var res = frameCollection.AddFrame((ImageFrame<Rgba32>)null); });
+                Assert.Throws<ObjectDisposedException>(() => { var res = frameCollection.AddFrame(rgba32Array.AsSpan()); });
+                Assert.Throws<ObjectDisposedException>(() => { var res = frameCollection.CloneFrame(default); });
+                Assert.Throws<ObjectDisposedException>(() => { var res = frameCollection.Contains(default); });
+                Assert.Throws<ObjectDisposedException>(() => { var res = frameCollection.CreateFrame(); });
+                Assert.Throws<ObjectDisposedException>(() => { var res = frameCollection.CreateFrame(default); });
+                Assert.Throws<ObjectDisposedException>(() => { var res = frameCollection.ExportFrame(default); });
+                Assert.Throws<ObjectDisposedException>(() => { var res = frameCollection.GetEnumerator(); });
+                Assert.Throws<ObjectDisposedException>(() => { var prop = frameCollection.IndexOf(default); });
+                Assert.Throws<ObjectDisposedException>(() => { var prop = frameCollection.InsertFrame(default, default); });
+                Assert.Throws<ObjectDisposedException>(() => { frameCollection.RemoveFrame(default); });
+                Assert.Throws<ObjectDisposedException>(() => { frameCollection.MoveFrame(default, default); });
+            }
+
             /// <summary>
             /// Integration test for end-to end API validation.
             /// </summary>

tests/ImageSharp.Tests/Image/ImageTests.cs

@@ -2,7 +2,9 @@
 // Licensed under the Apache License, Version 2.0.
 
 using System;
+using System.IO;
 using SixLabors.ImageSharp.Advanced;
+using SixLabors.ImageSharp.Formats.Jpeg;
 using SixLabors.ImageSharp.Memory;
 using SixLabors.ImageSharp.Metadata;
 using SixLabors.ImageSharp.PixelFormats;
@@ -169,5 +171,72 @@ namespace SixLabors.ImageSharp.Tests
                 Assert.Equal("y", ex.ParamName);
             }
         }
+
+        public class Dispose
+        {
+            private readonly Configuration configuration = Configuration.CreateDefaultInstance();
+
+            public void MultipleDisposeCalls()
+            {
+                var image = new Image<Rgba32>(this.configuration, 10, 10);
+                image.Dispose();
+                image.Dispose();
+            }
+
+            [Fact]
+            public void NonPrivateProperties_ObjectDisposedException()
+            {
+                var image = new Image<Rgba32>(this.configuration, 10, 10);
+                var genericImage = (Image)image;
+
+                image.Dispose();
+
+                // Image<TPixel>
+                Assert.Throws<ObjectDisposedException>(() => { var prop = image.Frames; });
+
+                // Image
+                Assert.Throws<ObjectDisposedException>(() => { var prop = genericImage.Frames; });
+            }
+
+            [Fact]
+            public void Save_ObjectDisposedException()
+            {
+                using var stream = new MemoryStream();
+                var image = new Image<Rgba32>(this.configuration, 10, 10);
+                var encoder = new JpegEncoder();
+
+                image.Dispose();
+
+                // Image<TPixel>
+                Assert.Throws<ObjectDisposedException>(() => image.Save(stream, encoder));
+            }
+
+            [Fact]
+            public void AcceptVisitor_ObjectDisposedException()
+            {
+                // This test technically should exist but it's impossible to write proper test case without reflection:
+                // All visitor types are private and can't be created without context of some save/processing operation
+                // Save_ObjectDisposedException test checks this method with AcceptVisitor(EncodeVisitor) anyway
+                return;
+            }
+
+            [Fact]
+            public void NonPrivateMethods_ObjectDisposedException()
+            {
+                var image = new Image<Rgba32>(this.configuration, 10, 10);
+                var genericImage = (Image)image;
+
+                image.Dispose();
+
+                // Image<TPixel>
+                Assert.Throws<ObjectDisposedException>(() => { var res = image.Clone(this.configuration); });
+                Assert.Throws<ObjectDisposedException>(() => { var res = image.CloneAs<Rgba32>(this.configuration); });
+                Assert.Throws<ObjectDisposedException>(() => { var res = image.GetPixelRowSpan(default); });
+                Assert.Throws<ObjectDisposedException>(() => { var res = image.TryGetSinglePixelSpan(out var _); });
+
+                // Image
+                Assert.Throws<ObjectDisposedException>(() => { var res = genericImage.CloneAs<Rgba32>(this.configuration); });
+            }
+        }
     }
 }