Merge branch 'main' into icc-color-conversion

src/ImageSharp/Color/Color.cs

@@ -1,6 +1,5 @@
 // Copyright (c) Six Labors.
 // Licensed under the Six Labors Split License.
-#nullable disable
 
 using System.Numerics;
 using System.Runtime.CompilerServices;
@@ -20,7 +19,7 @@ namespace SixLabors.ImageSharp;
 public readonly partial struct Color : IEquatable<Color>
 {
     private readonly Rgba64 data;
-    private readonly IPixel boxedHighPrecisionPixel;
+    private readonly IPixel? boxedHighPrecisionPixel;
 
     [MethodImpl(InliningOptions.ShortMethod)]
     private Color(byte r, byte g, byte b, byte a)
@@ -317,7 +316,7 @@ public readonly partial struct Color : IEquatable<Color>
     }
 
     /// <inheritdoc />
-    public override bool Equals(object obj) => obj is Color other && this.Equals(other);
+    public override bool Equals(object? obj) => obj is Color other && this.Equals(other);
 
     /// <inheritdoc />
     [MethodImpl(InliningOptions.ShortMethod)]

src/ImageSharp/ColorSpaces/Conversion/ColorSpaceConverter.Adapt.cs

@@ -32,7 +32,8 @@ public partial class ColorSpaceConverter
             return color;
         }
 
-        return this.chromaticAdaptation.Transform(color, sourceWhitePoint, targetWhitePoint);
+        // We know that chromaticAdaption is not null because performChromaticAdaption is checked
+        return this.chromaticAdaptation!.Transform(color, sourceWhitePoint, targetWhitePoint);
     }
 
     /// <summary>
@@ -128,11 +129,12 @@ public partial class ColorSpaceConverter
         }
 
         // Conversion to XYZ
-        LinearRgbToCieXyzConverter converterToXYZ = this.GetLinearRgbToCieXyzConverter(color.WorkingSpace);
+        LinearRgbToCieXyzConverter converterToXYZ = GetLinearRgbToCieXyzConverter(color.WorkingSpace);
         CieXyz unadapted = converterToXYZ.Convert(color);
 
         // Adaptation
-        CieXyz adapted = this.chromaticAdaptation.Transform(unadapted, color.WorkingSpace.WhitePoint, this.targetRgbWorkingSpace.WhitePoint);
+        // We know that chromaticAdaption is not null because performChromaticAdaption is checked
+        CieXyz adapted = this.chromaticAdaptation!.Transform(unadapted, color.WorkingSpace.WhitePoint, this.targetRgbWorkingSpace.WhitePoint);
 
         // Conversion back to RGB
         return this.cieXyzToLinearRgbConverter.Convert(adapted);

src/ImageSharp/ColorSpaces/Conversion/ColorSpaceConverter.CieXyz.cs

@@ -1,6 +1,7 @@
 // Copyright (c) Six Labors.
 // Licensed under the Six Labors Split License.
 
+using System.Collections.Concurrent;
 using System.Runtime.CompilerServices;
 using System.Runtime.InteropServices;
 
@@ -11,9 +12,7 @@ namespace SixLabors.ImageSharp.ColorSpaces.Conversion;
 /// </content>
 public partial class ColorSpaceConverter
 {
-    private static readonly HunterLabToCieXyzConverter HunterLabToCieXyzConverter = new();
-
-    private LinearRgbToCieXyzConverter linearRgbToCieXyzConverter;
+    private static readonly ConcurrentDictionary<RgbWorkingSpace, LinearRgbToCieXyzConverter> ConverterCache = new();
 
     /// <summary>
     /// Converts a <see cref="CieLab"/> into a <see cref="CieXyz"/>.
@@ -327,7 +326,7 @@ public partial class ColorSpaceConverter
     public CieXyz ToCieXyz(in LinearRgb color)
     {
         // Conversion
-        LinearRgbToCieXyzConverter converter = this.GetLinearRgbToCieXyzConverter(color.WorkingSpace);
+        LinearRgbToCieXyzConverter converter = GetLinearRgbToCieXyzConverter(color.WorkingSpace);
         CieXyz unadapted = converter.Convert(color);
 
         return this.Adapt(unadapted, color.WorkingSpace.WhitePoint);
@@ -454,13 +453,6 @@ public partial class ColorSpaceConverter
     /// </summary>
     /// <param name="workingSpace">The source working space</param>
     /// <returns>The <see cref="LinearRgbToCieXyzConverter"/></returns>
-    private LinearRgbToCieXyzConverter GetLinearRgbToCieXyzConverter(RgbWorkingSpace workingSpace)
-    {
-        if (this.linearRgbToCieXyzConverter?.SourceWorkingSpace.Equals(workingSpace) == true)
-        {
-            return this.linearRgbToCieXyzConverter;
-        }
-
-        return this.linearRgbToCieXyzConverter = new LinearRgbToCieXyzConverter(workingSpace);
-    }
+    private static LinearRgbToCieXyzConverter GetLinearRgbToCieXyzConverter(RgbWorkingSpace workingSpace)
+        => ConverterCache.GetOrAdd(workingSpace, (key) => new LinearRgbToCieXyzConverter(key));
 }

src/ImageSharp/ColorSpaces/Conversion/ColorSpaceConverter.cs

@@ -1,6 +1,5 @@
 // Copyright (c) Six Labors.
 // Licensed under the Six Labors Split License.
-#nullable disable
 
 using System.Numerics;
 
@@ -12,14 +11,14 @@ namespace SixLabors.ImageSharp.ColorSpaces.Conversion;
 public partial class ColorSpaceConverter
 {
     // Options.
-    private static readonly ColorSpaceConverterOptions DefaultOptions = new ColorSpaceConverterOptions();
+    private static readonly ColorSpaceConverterOptions DefaultOptions = new();
     private readonly Matrix4x4 lmsAdaptationMatrix;
     private readonly CieXyz whitePoint;
     private readonly CieXyz targetLuvWhitePoint;
     private readonly CieXyz targetLabWhitePoint;
     private readonly CieXyz targetHunterLabWhitePoint;
     private readonly RgbWorkingSpace targetRgbWorkingSpace;
-    private readonly IChromaticAdaptation chromaticAdaptation;
+    private readonly IChromaticAdaptation? chromaticAdaptation;
     private readonly bool performChromaticAdaptation;
     private readonly CieXyzAndLmsConverter cieXyzAndLmsConverter;
     private readonly CieXyzToCieLabConverter cieXyzToCieLabConverter;

src/ImageSharp/ColorSpaces/Conversion/ColorSpaceConverterOptions.cs

@@ -44,7 +44,7 @@ public class ColorSpaceConverterOptions
     /// <summary>
     /// Gets or sets the chromatic adaptation method used. When <value>null</value>, no adaptation will be performed.
     /// </summary>
-    public IChromaticAdaptation ChromaticAdaptation { get; set; } = new VonKriesChromaticAdaptation();
+    public IChromaticAdaptation? ChromaticAdaptation { get; set; } = new VonKriesChromaticAdaptation();
 
     /// <summary>
     /// Gets or sets transformation matrix used in conversion to and from <see cref="Lms"/>.

src/ImageSharp/ColorSpaces/Conversion/Implementation/WorkingSpaces/RgbWorkingSpace.cs

@@ -75,7 +75,5 @@ public abstract class RgbWorkingSpace
 
     /// <inheritdoc/>
     public override int GetHashCode()
-    {
-        return HashCode.Combine(this.WhitePoint, this.ChromaticityCoordinates);
-    }
+        => HashCode.Combine(this.WhitePoint, this.ChromaticityCoordinates);
 }

src/ImageSharp/Common/Helpers/UnitConverter.cs

@@ -91,10 +91,13 @@ internal static class UnitConverter
     [MethodImpl(InliningOptions.ShortMethod)]
     public static PixelResolutionUnit ExifProfileToResolutionUnit(ExifProfile profile)
     {
-        IExifValue<ushort> resolution = profile.GetValue(ExifTag.ResolutionUnit);
+        if (profile.TryGetValue(ExifTag.ResolutionUnit, out IExifValue<ushort>? resolution))
+        {
+            // EXIF is 1, 2, 3 so we minus "1" off the result.
+            return (PixelResolutionUnit)(byte)(resolution.Value - 1);
+        }
 
-        // EXIF is 1, 2, 3 so we minus "1" off the result.
-        return resolution is null ? DefaultResolutionUnit : (PixelResolutionUnit)(byte)(resolution.Value - 1);
+        return DefaultResolutionUnit;
     }
 
     /// <summary>

src/ImageSharp/Compression/Zlib/DeflateThrowHelper.cs

@@ -1,23 +1,33 @@
 // Copyright (c) Six Labors.
 // Licensed under the Six Labors Split License.
 
+using System.Diagnostics.CodeAnalysis;
+
 namespace SixLabors.ImageSharp.Compression.Zlib;
 
 internal static class DeflateThrowHelper
 {
+    [DoesNotReturn]
     public static void ThrowAlreadyFinished() => throw new InvalidOperationException("Finish() already called.");
 
+    [DoesNotReturn]
     public static void ThrowAlreadyClosed() => throw new InvalidOperationException("Deflator already closed.");
 
+    [DoesNotReturn]
     public static void ThrowUnknownCompression() => throw new InvalidOperationException("Unknown compression function.");
 
+    [DoesNotReturn]
     public static void ThrowNotProcessed() => throw new InvalidOperationException("Old input was not completely processed.");
 
+    [DoesNotReturn]
     public static void ThrowNull(string name) => throw new ArgumentNullException(name);
 
+    [DoesNotReturn]
     public static void ThrowOutOfRange(string name) => throw new ArgumentOutOfRangeException(name);
 
+    [DoesNotReturn]
     public static void ThrowHeapViolated() => throw new InvalidOperationException("Huffman heap invariant violated.");
 
+    [DoesNotReturn]
     public static void ThrowNoDeflate() => throw new ImageFormatException("Cannot deflate all input.");
 }

src/ImageSharp/Compression/Zlib/Deflater.cs

@@ -1,6 +1,5 @@
 // Copyright (c) Six Labors.
 // Licensed under the Six Labors Split License.
-#nullable disable
 
 using System.Runtime.CompilerServices;
 using SixLabors.ImageSharp.Memory;
@@ -285,7 +284,6 @@ internal sealed class Deflater : IDisposable
         if (!this.isDisposed)
         {
             this.engine.Dispose();
-            this.engine = null;
             this.isDisposed = true;
         }
     }

src/ImageSharp/Compression/Zlib/DeflaterEngine.cs

@@ -1,6 +1,5 @@
 // Copyright (c) Six Labors.
 // Licensed under the Six Labors Split License.
-#nullable disable
 
 using System.Buffers;
 using System.Runtime.CompilerServices;
@@ -87,7 +86,7 @@ internal sealed unsafe class DeflaterEngine : IDisposable
     /// <summary>
     /// The input data for compression.
     /// </summary>
-    private byte[] inputBuf;
+    private byte[]? inputBuf;
 
     /// <summary>
     /// The offset into inputBuf, where input data starts.
@@ -222,7 +221,7 @@ internal sealed unsafe class DeflaterEngine : IDisposable
     /// <param name="buffer">The buffer containing input data.</param>
     /// <param name="offset">The offset of the first byte of data.</param>
     /// <param name="count">The number of bytes of data to use as input.</param>
-    public void SetInput(byte[] buffer, int offset, int count)
+    public void SetInput(byte[]? buffer, int offset, int count)
     {
         if (buffer is null)
         {
@@ -362,6 +361,8 @@ internal sealed unsafe class DeflaterEngine : IDisposable
                 more = this.inputEnd - this.inputOff;
             }
 
+            ArgumentNullException.ThrowIfNull(this.inputBuf);
+
             Unsafe.CopyBlockUnaligned(
                 ref this.window.Span[this.strstart + this.lookahead],
                 ref this.inputBuf[this.inputOff],
@@ -393,11 +394,6 @@ internal sealed unsafe class DeflaterEngine : IDisposable
             this.prevMemoryHandle.Dispose();
             this.prevMemoryOwner.Dispose();
 
-            this.windowMemoryOwner = null;
-            this.headMemoryOwner = null;
-            this.prevMemoryOwner = null;
-            this.huffman = null;
-
             this.isDisposed = true;
         }
     }

src/ImageSharp/Compression/Zlib/DeflaterHuffman.cs

@@ -1,6 +1,5 @@
 // Copyright (c) Six Labors.
 // Licensed under the Six Labors Split License.
-#nullable disable
 
 using System.Buffers;
 using System.Runtime.CompilerServices;
@@ -427,10 +426,6 @@ internal sealed unsafe class DeflaterHuffman : IDisposable
             this.blTree.Dispose();
             this.distTree.Dispose();
 
-            this.Pending = null;
-            this.literalTree = null;
-            this.blTree = null;
-            this.distTree = null;
             this.isDisposed = true;
         }
     }
@@ -977,10 +972,6 @@ internal sealed unsafe class DeflaterHuffman : IDisposable
                 this.codesMemoryHandle.Dispose();
                 this.codesMemoryOwner.Dispose();
 
-                this.frequenciesMemoryOwner = null;
-                this.lengthsMemoryOwner = null;
-                this.codesMemoryOwner = null;
-
                 this.isDisposed = true;
             }
         }

src/ImageSharp/Compression/Zlib/DeflaterOutputStream.cs

@@ -1,6 +1,5 @@
 // Copyright (c) Six Labors.
 // Licensed under the Six Labors Split License.
-#nullable disable
 
 using System.Buffers;
 using SixLabors.ImageSharp.Memory;
@@ -137,8 +136,6 @@ internal sealed class DeflaterOutputStream : Stream
                 this.memoryOwner.Dispose();
             }
 
-            this.deflater = null;
-            this.memoryOwner = null;
             this.isDisposed = true;
             base.Dispose(disposing);
         }

src/ImageSharp/Compression/Zlib/DeflaterPendingBuffer.cs

@@ -1,6 +1,5 @@
 // Copyright (c) Six Labors.
 // Licensed under the Six Labors Split License.
-#nullable disable
 
 using System.Buffers;
 using System.Runtime.CompilerServices;
@@ -180,7 +179,6 @@ internal sealed unsafe class DeflaterPendingBuffer : IDisposable
         {
             this.bufferMemoryHandle.Dispose();
             this.bufferMemoryOwner.Dispose();
-            this.bufferMemoryOwner = null;
             this.isDisposed = true;
         }
     }

src/ImageSharp/Compression/Zlib/ZlibDeflateStream.cs

@@ -1,6 +1,5 @@
 // Copyright (c) Six Labors.
 // Licensed under the Six Labors Split License.
-#nullable disable
 
 using System.Runtime.CompilerServices;
 using SixLabors.ImageSharp.Formats.Png;
@@ -172,8 +171,6 @@ internal sealed class ZlibDeflateStream : Stream
             this.rawStream.WriteByte((byte)(crc & 0xFF));
         }
 
-        this.deflateStream = null;
-
         base.Dispose(disposing);
         this.isDisposed = true;
     }

src/ImageSharp/Compression/Zlib/ZlibInflateStream.cs

@@ -1,7 +1,7 @@
 // Copyright (c) Six Labors.
 // Licensed under the Six Labors Split License.
-#nullable disable
 
+using System.Diagnostics.CodeAnalysis;
 using System.IO.Compression;
 using SixLabors.ImageSharp.IO;
 
@@ -90,7 +90,7 @@ internal sealed class ZlibInflateStream : Stream
     /// <summary>
     /// Gets the compressed stream over the deframed inner stream.
     /// </summary>
-    public DeflateStream CompressedStream { get; private set; }
+    public DeflateStream? CompressedStream { get; private set; }
 
     /// <summary>
     /// Adds new bytes from a frame found in the original stream.
@@ -98,6 +98,7 @@ internal sealed class ZlibInflateStream : Stream
     /// <param name="bytes">The current remaining data according to the chunk length.</param>
     /// <param name="isCriticalChunk">Whether the chunk to be inflated is a critical chunk.</param>
     /// <returns>The <see cref="bool"/>.</returns>
+    [MemberNotNullWhen(true, nameof(CompressedStream))]
     public bool AllocateNewBytes(int bytes, bool isCriticalChunk)
     {
         this.currentDataRemaining = bytes;
@@ -210,6 +211,7 @@ internal sealed class ZlibInflateStream : Stream
         this.isDisposed = true;
     }
 
+    [MemberNotNullWhen(true, nameof(CompressedStream))]
     private bool InitializeInflateStream(bool isCriticalChunk)
     {
         // Read the zlib header : http://tools.ietf.org/html/rfc1950

src/ImageSharp/Diagnostics/MemoryDiagnostics.cs

@@ -1,6 +1,5 @@
 // Copyright (c) Six Labors.
 // Licensed under the Six Labors Split License.
-#nullable disable
 
 namespace SixLabors.ImageSharp.Diagnostics;
 
@@ -17,7 +16,7 @@ public static class MemoryDiagnostics
 {
     private static int totalUndisposedAllocationCount;
 
-    private static UndisposedAllocationDelegate undisposedAllocation;
+    private static UndisposedAllocationDelegate? undisposedAllocation;
     private static int undisposedAllocationSubscriptionCounter;
     private static readonly object SyncRoot = new();
 
@@ -50,12 +49,12 @@ public static class MemoryDiagnostics
     /// <summary>
     /// Fires when ImageSharp allocates memory from a MemoryAllocator
     /// </summary>
-    internal static event Action MemoryAllocated;
+    internal static event Action? MemoryAllocated;
 
     /// <summary>
     /// Fires when ImageSharp releases memory allocated from a MemoryAllocator
     /// </summary>
-    internal static event Action MemoryReleased;
+    internal static event Action? MemoryReleased;
 
     /// <summary>
     /// Gets a value indicating the total number of memory resource objects leaked to the finalizer.

src/ImageSharp/Formats/Gif/GifEncoderCore.cs

@@ -171,7 +171,10 @@ internal sealed class GifEncoderCore : IImageEncoderInternals
             quantized = null;
         }
 
-        paletteQuantizer.Dispose();
+        if (hasPaletteQuantizer)
+        {
+            paletteQuantizer.Dispose();
+        }
     }
 
     private void EncodeFrame<TPixel>(

src/ImageSharp/Formats/Jpeg/Components/Decoder/JFifMarker.cs

@@ -26,16 +26,6 @@ internal readonly struct JFifMarker : IEquatable<JFifMarker>
     /// <param name="yDensity">The vertical pixel density.</param>
     private JFifMarker(byte majorVersion, byte minorVersion, byte densityUnits, short xDensity, short yDensity)
     {
-        if (xDensity <= 0)
-        {
-            JpegThrowHelper.ThrowInvalidImageContentException($"X-Density {xDensity} must be greater than 0.");
-        }
-
-        if (yDensity <= 0)
-        {
-            JpegThrowHelper.ThrowInvalidImageContentException($"Y-Density {yDensity} must be greater than 0.");
-        }
-
         this.MajorVersion = majorVersion;
         this.MinorVersion = minorVersion;
 
@@ -64,12 +54,12 @@ internal readonly struct JFifMarker : IEquatable<JFifMarker>
     public PixelResolutionUnit DensityUnits { get; }
 
     /// <summary>
-    /// Gets the horizontal pixel density. Must not be zero.
+    /// Gets the horizontal pixel density.
     /// </summary>
     public short XDensity { get; }
 
     /// <summary>
-    /// Gets the vertical pixel density. Must not be zero.
+    /// Gets the vertical pixel density.
     /// </summary>
     public short YDensity { get; }
 
@@ -88,12 +78,8 @@ internal readonly struct JFifMarker : IEquatable<JFifMarker>
             byte densityUnits = bytes[7];
             short xDensity = (short)((bytes[8] << 8) | bytes[9]);
             short yDensity = (short)((bytes[10] << 8) | bytes[11]);
-
-            if (xDensity > 0 && yDensity > 0)
-            {
-                marker = new JFifMarker(majorVersion, minorVersion, densityUnits, xDensity, yDensity);
-                return true;
-            }
+            marker = new JFifMarker(majorVersion, minorVersion, densityUnits, xDensity, yDensity);
+            return true;
         }
 
         marker = default;

src/ImageSharp/Formats/Jpeg/Components/Decoder/SpectralConverter.cs

@@ -121,4 +121,10 @@ internal abstract class SpectralConverter
 
         return size;
     }
+
+    /// <summary>
+    /// Gets a value indicating whether the converter has a pixel buffer.
+    /// </summary>
+    /// <returns><see langword="true"/> if the converter has a pixel buffer; otherwise, <see langword="false"/>.</returns>
+    public abstract bool HasPixelBuffer();
 }

src/ImageSharp/Formats/Jpeg/Components/Decoder/SpectralConverter{TPixel}.cs

@@ -85,6 +85,12 @@ internal class SpectralConverter<TPixel> : SpectralConverter, IDisposable
     /// </summary>
     public Configuration Configuration { get; }
 
+    /// <summary>
+    /// Gets a value indicating whether the converter has a pixel buffer.
+    /// </summary>
+    /// <returns><see langword="true"/> if the converter has a pixel buffer; otherwise, <see langword="false"/>.</returns>
+    public override bool HasPixelBuffer() => this.pixelBuffer is not null;
+
     /// <summary>
     /// Gets converted pixel buffer.
     /// </summary>

src/ImageSharp/Formats/Jpeg/JpegDecoderCore.cs

@@ -356,6 +356,18 @@ internal sealed class JpegDecoderCore : IRawJpegData, IImageDecoderInternals
                 // to uint to avoid sign extension.
                 if (stream.RemainingBytes < (uint)markerContentByteSize)
                 {
+                    if (metadataOnly && this.Metadata != null && this.Frame != null)
+                    {
+                        // We have enough data to decode the image, so we can stop parsing.
+                        return;
+                    }
+
+                    if (this.Metadata != null && this.Frame != null && spectralConverter.HasPixelBuffer())
+                    {
+                        // We have enough data to decode the image, so we can stop parsing.
+                        return;
+                    }
+
                     JpegThrowHelper.ThrowNotEnoughBytesForMarker(fileMarker.Marker);
                 }
 
@@ -705,9 +717,12 @@ internal sealed class JpegDecoderCore : IRawJpegData, IImageDecoderInternals
 
     private double GetExifResolutionValue(ExifTag<Rational> tag)
     {
-        IExifValue<Rational> resolution = this.Metadata.ExifProfile.GetValue(tag);
+        if (this.Metadata.ExifProfile.TryGetValue(tag, out IExifValue<Rational> resolution))
+        {
+            return resolution.Value.ToDouble();
+        }
 
-        return resolution is null ? 0 : resolution.Value.ToDouble();
+        return 0;
     }
 
     /// <summary>

src/ImageSharp/Formats/Tiff/Compression/Decompressors/DeflateTiffCompression.cs

@@ -50,19 +50,21 @@ internal sealed class DeflateTiffCompression : TiffBaseDecompressor
                 return left > 0 ? left : 0;
             }))
         {
-            deframeStream.AllocateNewBytes(byteCount, true);
-            DeflateStream dataStream = deframeStream.CompressedStream;
-
-            int totalRead = 0;
-            while (totalRead < buffer.Length)
+            if (deframeStream.AllocateNewBytes(byteCount, true))
             {
-                int bytesRead = dataStream.Read(buffer, totalRead, buffer.Length - totalRead);
-                if (bytesRead <= 0)
+                DeflateStream? dataStream = deframeStream.CompressedStream;
+
+                int totalRead = 0;
+                while (totalRead < buffer.Length)
                 {
-                    break;
-                }
+                    int bytesRead = dataStream.Read(buffer, totalRead, buffer.Length - totalRead);
+                    if (bytesRead <= 0)
+                    {
+                        break;
+                    }
 
-                totalRead += bytesRead;
+                    totalRead += bytesRead;
+                }
             }
         }
 

src/ImageSharp/Formats/Tiff/Compression/HorizontalPredictor.cs

@@ -67,6 +67,11 @@ internal static class HorizontalPredictor
         {
             ApplyHorizontalPrediction8Bit(rows, width);
         }
+        else if (bitsPerPixel == 16)
+        {
+            // Assume rows are L16 grayscale since that's currently the only way 16 bits is supported by encoder
+            ApplyHorizontalPrediction16Bit(rows, width);
+        }
         else if (bitsPerPixel == 24)
         {
             ApplyHorizontalPrediction24Bit(rows, width);
@@ -102,6 +107,32 @@ internal static class HorizontalPredictor
         }
     }
 
+    /// <summary>
+    /// Applies a horizontal predictor to the L16 row.
+    /// Make use of the fact that many continuous-tone images rarely vary much in pixel value from one pixel to the next.
+    /// In such images, if we replace the pixel values by differences between consecutive pixels, many of the differences should be 0, plus
+    /// or minus 1, and so on.This reduces the apparent information content and allows LZW to encode the data more compactly.
+    /// </summary>
+    /// <param name="rows">The L16 pixel rows.</param>
+    /// <param name="width">The width.</param>
+    [MethodImpl(InliningOptions.ShortMethod)]
+    private static void ApplyHorizontalPrediction16Bit(Span<byte> rows, int width)
+    {
+        DebugGuard.IsTrue(rows.Length % width == 0, "Values must be equals");
+        int height = rows.Length / width;
+        for (int y = 0; y < height; y++)
+        {
+            Span<byte> rowSpan = rows.Slice(y * width, width);
+            Span<L16> rowL16 = MemoryMarshal.Cast<byte, L16>(rowSpan);
+
+            for (int x = rowL16.Length - 1; x >= 1; x--)
+            {
+                ushort val = (ushort)(rowL16[x].PackedValue - rowL16[x - 1].PackedValue);
+                rowL16[x].PackedValue = val;
+            }
+        }
+    }
+
     /// <summary>
     /// Applies a horizontal predictor to a gray pixel row.
     /// </summary>

src/ImageSharp/Formats/Tiff/Constants/TiffConstants.cs

@@ -73,6 +73,11 @@ internal static class TiffConstants
     /// </summary>
     public static readonly TiffBitsPerSample BitsPerSample8Bit = new TiffBitsPerSample(8, 0, 0);
 
+    /// <summary>
+    /// The bits per sample for 16-bit grayscale images.
+    /// </summary>
+    public static readonly TiffBitsPerSample BitsPerSample16Bit = new TiffBitsPerSample(16, 0, 0);
+
     /// <summary>
     /// The bits per sample for color images with 8 bits for each color channel.
     /// </summary>

src/ImageSharp/Formats/Tiff/TiffBitsPerPixel.cs

@@ -54,7 +54,7 @@ public enum TiffBitsPerPixel
     /// <summary>
     /// 16 bits per pixel, for gray images.
     ///
-    /// Note: The TiffEncoder does not yet support 16 bits per color channel and will default to 24 bits per pixel instead.
+    /// Note: The TiffEncoder does not yet support 16 bits per color channel and will default to 16 bits grayscale instead.
     /// </summary>
     Bit16 = 16,
 

src/ImageSharp/Formats/Tiff/TiffBitsPerSample.cs

@@ -82,7 +82,7 @@ public readonly struct TiffBitsPerSample : IEquatable<TiffBitsPerSample>
     /// <param name="value">The value to parse.</param>
     /// <param name="sample">The tiff bits per sample.</param>
     /// <returns>True, if the value could be parsed.</returns>
-    public static bool TryParse(ushort[] value, out TiffBitsPerSample sample)
+    public static bool TryParse(ushort[]? value, out TiffBitsPerSample sample)
     {
         if (value is null || value.Length == 0)
         {

src/ImageSharp/Formats/Tiff/TiffDecoderCore.cs

@@ -276,9 +276,15 @@ internal class TiffDecoderCore : IImageDecoderInternals
     private void DecodeImageWithStrips<TPixel>(ExifProfile tags, ImageFrame<TPixel> frame, CancellationToken cancellationToken)
         where TPixel : unmanaged, IPixel<TPixel>
     {
-        int rowsPerStrip = tags.GetValue(ExifTag.RowsPerStrip) != null
-            ? (int)tags.GetValue(ExifTag.RowsPerStrip).Value
-            : TiffConstants.RowsPerStripInfinity;
+        int rowsPerStrip;
+        if (tags.TryGetValue(ExifTag.RowsPerStrip, out IExifValue<Number> value))
+        {
+            rowsPerStrip = (int)value.Value;
+        }
+        else
+        {
+            rowsPerStrip = TiffConstants.RowsPerStripInfinity;
+        }
 
         Array stripOffsetsArray = (Array)tags.GetValueInternal(ExifTag.StripOffsets).GetValue();
         Array stripByteCountsArray = (Array)tags.GetValueInternal(ExifTag.StripByteCounts).GetValue();
@@ -320,8 +326,18 @@ internal class TiffDecoderCore : IImageDecoderInternals
         int width = pixels.Width;
         int height = pixels.Height;
 
-        int tileWidth = (int)tags.GetValue(ExifTag.TileWidth).Value;
-        int tileLength = (int)tags.GetValue(ExifTag.TileLength).Value;
+        if (!tags.TryGetValue(ExifTag.TileWidth, out IExifValue<Number> valueWidth))
+        {
+            ArgumentNullException.ThrowIfNull(valueWidth);
+        }
+
+        if (!tags.TryGetValue(ExifTag.TileWidth, out IExifValue<Number> valueLength))
+        {
+            ArgumentNullException.ThrowIfNull(valueLength);
+        }
+
+        int tileWidth = (int)valueWidth.Value;
+        int tileLength = (int)valueLength.Value;
         int tilesAcross = (width + tileWidth - 1) / tileWidth;
         int tilesDown = (height + tileLength - 1) / tileLength;
 
@@ -775,10 +791,9 @@ internal class TiffDecoderCore : IImageDecoderInternals
     /// <returns>The image width.</returns>
     private static int GetImageWidth(ExifProfile exifProfile)
     {
-        IExifValue<Number> width = exifProfile.GetValue(ExifTag.ImageWidth);
-        if (width == null)
+        if (!exifProfile.TryGetValue(ExifTag.ImageWidth, out IExifValue<Number> width))
         {
-            TiffThrowHelper.ThrowImageFormatException("The TIFF image frame is missing the ImageWidth");
+            TiffThrowHelper.ThrowInvalidImageContentException("The TIFF image frame is missing the ImageWidth");
         }
 
         DebugGuard.MustBeLessThanOrEqualTo((ulong)width.Value, (ulong)int.MaxValue, nameof(ExifTag.ImageWidth));
@@ -793,8 +808,7 @@ internal class TiffDecoderCore : IImageDecoderInternals
     /// <returns>The image height.</returns>
     private static int GetImageHeight(ExifProfile exifProfile)
     {
-        IExifValue<Number> height = exifProfile.GetValue(ExifTag.ImageLength);
-        if (height == null)
+        if (!exifProfile.TryGetValue(ExifTag.ImageLength, out IExifValue<Number> height))
         {
             TiffThrowHelper.ThrowImageFormatException("The TIFF image frame is missing the ImageLength");
         }

src/ImageSharp/Formats/Tiff/TiffDecoderMetadataCreator.cs

@@ -38,14 +38,12 @@ internal static class TiffDecoderMetadataCreator
                     frameMetaData.IptcProfile = new IptcProfile(iptcBytes);
                 }
 
-                IExifValue<byte[]> xmpProfileBytes = frameMetaData.ExifProfile.GetValue(ExifTag.XMP);
-                if (xmpProfileBytes != null)
+                if (frameMetaData.ExifProfile.TryGetValue(ExifTag.XMP, out IExifValue<byte[]> xmpProfileBytes))
                 {
                     frameMetaData.XmpProfile = new XmpProfile(xmpProfileBytes.Value);
                 }
 
-                IExifValue<byte[]> iccProfileBytes = frameMetaData.ExifProfile.GetValue(ExifTag.IccProfile);
-                if (iccProfileBytes != null)
+                if (frameMetaData.ExifProfile.TryGetValue(ExifTag.IccProfile, out IExifValue<byte[]> iccProfileBytes))
                 {
                     frameMetaData.IccProfile = new IccProfile(iccProfileBytes.Value);
                 }
@@ -70,16 +68,20 @@ internal static class TiffDecoderMetadataCreator
     private static void SetResolution(ImageMetadata imageMetaData, ExifProfile exifProfile)
     {
         imageMetaData.ResolutionUnits = exifProfile != null ? UnitConverter.ExifProfileToResolutionUnit(exifProfile) : PixelResolutionUnit.PixelsPerInch;
-        double? horizontalResolution = exifProfile?.GetValue(ExifTag.XResolution)?.Value.ToDouble();
-        if (horizontalResolution != null)
+
+        if (exifProfile is null)
+        {
+            return;
+        }
+
+        if (exifProfile.TryGetValue(ExifTag.XResolution, out IExifValue<Rational> horizontalResolution))
         {
-            imageMetaData.HorizontalResolution = horizontalResolution.Value;
+            imageMetaData.HorizontalResolution = horizontalResolution.Value.ToDouble();
         }
 
-        double? verticalResolution = exifProfile?.GetValue(ExifTag.YResolution)?.Value.ToDouble();
-        if (verticalResolution != null)
+        if (exifProfile.TryGetValue(ExifTag.YResolution, out IExifValue<Rational> verticalResolution))
         {
-            imageMetaData.VerticalResolution = verticalResolution.Value;
+            imageMetaData.VerticalResolution = verticalResolution.Value.ToDouble();
         }
     }
 

src/ImageSharp/Formats/Tiff/TiffDecoderOptionsParser.cs

@@ -42,7 +42,16 @@ internal static class TiffDecoderOptionsParser
             }
         }
 
-        TiffFillOrder fillOrder = (TiffFillOrder?)exifProfile.GetValue(ExifTag.FillOrder)?.Value ?? TiffFillOrder.MostSignificantBitFirst;
+        TiffFillOrder fillOrder;
+        if (exifProfile.TryGetValue(ExifTag.FillOrder, out IExifValue<ushort> value))
+        {
+            fillOrder = (TiffFillOrder)value.Value;
+        }
+        else
+        {
+            fillOrder = TiffFillOrder.MostSignificantBitFirst;
+        }
+
         if (fillOrder == TiffFillOrder.LeastSignificantBitFirst && frameMetadata.BitsPerPixel != TiffBitsPerPixel.Bit1)
         {
             TiffThrowHelper.ThrowNotSupported("The lower-order bits of the byte FillOrder is only supported in combination with 1bit per pixel bicolor tiff's.");
@@ -53,10 +62,10 @@ internal static class TiffDecoderOptionsParser
             TiffThrowHelper.ThrowNotSupported("TIFF images with FloatingPoint horizontal predictor are not supported.");
         }
 
-        TiffSampleFormat[] sampleFormats = exifProfile.GetValue(ExifTag.SampleFormat)?.Value?.Select(a => (TiffSampleFormat)a).ToArray();
         TiffSampleFormat? sampleFormat = null;
-        if (sampleFormats != null)
+        if (exifProfile.TryGetValue(ExifTag.SampleFormat, out var formatValue))
         {
+            TiffSampleFormat[] sampleFormats = formatValue.Value.Select(a => (TiffSampleFormat)a).ToArray();
             sampleFormat = sampleFormats[0];
             foreach (TiffSampleFormat format in sampleFormats)
             {
@@ -67,7 +76,12 @@ internal static class TiffDecoderOptionsParser
             }
         }
 
-        ushort[] ycbcrSubSampling = exifProfile.GetValue(ExifTag.YCbCrSubsampling)?.Value;
+        ushort[] ycbcrSubSampling = null;
+        if (exifProfile.TryGetValue(ExifTag.YCbCrSubsampling, out IExifValue<ushort[]> subSamplingValue))
+        {
+            ycbcrSubSampling = subSamplingValue.Value;
+        }
+
         if (ycbcrSubSampling != null && ycbcrSubSampling.Length != 2)
         {
             TiffThrowHelper.ThrowImageFormatException("Invalid YCbCrSubsampling, expected 2 values.");
@@ -78,23 +92,52 @@ internal static class TiffDecoderOptionsParser
             TiffThrowHelper.ThrowImageFormatException("ChromaSubsampleVert shall always be less than or equal to ChromaSubsampleHoriz.");
         }
 
-        if (exifProfile.GetValue(ExifTag.StripRowCounts)?.Value != null)
+        if (exifProfile.TryGetValue(ExifTag.StripRowCounts, out _))
         {
             TiffThrowHelper.ThrowNotSupported("Variable-sized strips are not supported.");
         }
 
-        options.PlanarConfiguration = (TiffPlanarConfiguration?)exifProfile.GetValue(ExifTag.PlanarConfiguration)?.Value ?? DefaultPlanarConfiguration;
+        if (exifProfile.TryGetValue(ExifTag.PlanarConfiguration, out IExifValue<ushort> planarValue))
+        {
+            options.PlanarConfiguration = (TiffPlanarConfiguration)planarValue.Value;
+        }
+        else
+        {
+            options.PlanarConfiguration = DefaultPlanarConfiguration;
+        }
+
         options.Predictor = frameMetadata.Predictor ?? TiffPredictor.None;
         options.PhotometricInterpretation = frameMetadata.PhotometricInterpretation ?? TiffPhotometricInterpretation.Rgb;
         options.SampleFormat = sampleFormat ?? TiffSampleFormat.UnsignedInteger;
         options.BitsPerPixel = frameMetadata.BitsPerPixel != null ? (int)frameMetadata.BitsPerPixel.Value : (int)TiffBitsPerPixel.Bit24;
         options.BitsPerSample = frameMetadata.BitsPerSample ?? new TiffBitsPerSample(0, 0, 0);
-        options.ReferenceBlackAndWhite = exifProfile.GetValue(ExifTag.ReferenceBlackWhite)?.Value;
-        options.YcbcrCoefficients = exifProfile.GetValue(ExifTag.YCbCrCoefficients)?.Value;
-        options.YcbcrSubSampling = exifProfile.GetValue(ExifTag.YCbCrSubsampling)?.Value;
+
+        if (exifProfile.TryGetValue(ExifTag.ReferenceBlackWhite, out IExifValue<Rational[]> blackWhiteValue))
+        {
+            options.ReferenceBlackAndWhite = blackWhiteValue.Value;
+        }
+
+        if (exifProfile.TryGetValue(ExifTag.YCbCrCoefficients, out IExifValue<Rational[]> coefficientsValue))
+        {
+            options.YcbcrCoefficients = coefficientsValue.Value;
+        }
+
+        if (exifProfile.TryGetValue(ExifTag.YCbCrSubsampling, out IExifValue<ushort[]> ycbrSubSamplingValue))
+        {
+            options.YcbcrSubSampling = ycbrSubSamplingValue.Value;
+        }
+
         options.FillOrder = fillOrder;
-        options.JpegTables = exifProfile.GetValue(ExifTag.JPEGTables)?.Value;
-        options.OldJpegCompressionStartOfImageMarker = exifProfile.GetValue(ExifTag.JPEGInterchangeFormat)?.Value;
+
+        if (exifProfile.TryGetValue(ExifTag.JPEGTables, out IExifValue<byte[]> jpegTablesValue))
+        {
+            options.JpegTables = jpegTablesValue.Value;
+        }
+
+        if (exifProfile.TryGetValue(ExifTag.JPEGInterchangeFormat, out IExifValue<uint> jpegInterchangeFormatValue))
+        {
+            options.OldJpegCompressionStartOfImageMarker = jpegInterchangeFormatValue.Value;
+        }
 
         options.ParseColorType(exifProfile);
         options.ParseCompression(frameMetadata.Compression, exifProfile);
@@ -394,9 +437,9 @@ internal static class TiffDecoderOptionsParser
 
             case TiffPhotometricInterpretation.PaletteColor:
             {
-                options.ColorMap = exifProfile.GetValue(ExifTag.ColorMap)?.Value;
-                if (options.ColorMap != null)
+                if (exifProfile.TryGetValue(ExifTag.ColorMap, out IExifValue<ushort[]> value))
                 {
+                    options.ColorMap = value.Value;
                     if (options.BitsPerSample.Channels != 1)
                     {
                         TiffThrowHelper.ThrowNotSupported("The number of samples in the TIFF BitsPerSample entry is not supported.");
@@ -414,7 +457,11 @@ internal static class TiffDecoderOptionsParser
 
             case TiffPhotometricInterpretation.YCbCr:
             {
-                options.ColorMap = exifProfile.GetValue(ExifTag.ColorMap)?.Value;
+                if (exifProfile.TryGetValue(ExifTag.ColorMap, out IExifValue<ushort[]> value))
+                {
+                    options.ColorMap = value.Value;
+                }
+
                 if (options.BitsPerSample.Channels != 3)
                 {
                     TiffThrowHelper.ThrowNotSupported("The number of samples in the TIFF BitsPerSample entry is not supported for YCbCr images.");
@@ -508,7 +555,15 @@ internal static class TiffDecoderOptionsParser
             case TiffCompression.CcittGroup3Fax:
             {
                 options.CompressionType = TiffDecoderCompressionType.T4;
-                options.FaxCompressionOptions = exifProfile.GetValue(ExifTag.T4Options) != null ? (FaxCompressionOptions)exifProfile.GetValue(ExifTag.T4Options).Value : FaxCompressionOptions.None;
+
+                if (exifProfile.TryGetValue(ExifTag.T4Options, out IExifValue<uint> t4OptionsValue))
+                {
+                    options.FaxCompressionOptions = (FaxCompressionOptions)t4OptionsValue.Value;
+                }
+                else
+                {
+                    options.FaxCompressionOptions = FaxCompressionOptions.None;
+                }
 
                 break;
             }
@@ -516,7 +571,14 @@ internal static class TiffDecoderOptionsParser
             case TiffCompression.CcittGroup4Fax:
             {
                 options.CompressionType = TiffDecoderCompressionType.T6;
-                options.FaxCompressionOptions = exifProfile.GetValue(ExifTag.T4Options) != null ? (FaxCompressionOptions)exifProfile.GetValue(ExifTag.T4Options).Value : FaxCompressionOptions.None;
+                if (exifProfile.TryGetValue(ExifTag.T4Options, out IExifValue<uint> t4OptionsValue))
+                {
+                    options.FaxCompressionOptions = (FaxCompressionOptions)t4OptionsValue.Value;
+                }
+                else
+                {
+                    options.FaxCompressionOptions = FaxCompressionOptions.None;
+                }
 
                 break;
             }

src/ImageSharp/Formats/Tiff/TiffEncoderCore.cs

@@ -164,8 +164,6 @@ internal sealed class TiffEncoderCore : IImageEncoderInternals
         {
             cancellationToken.ThrowIfCancellationRequested();
 
-            TiffNewSubfileType subfileType = (TiffNewSubfileType)(frame.Metadata.ExifProfile?.GetValue(ExifTag.SubfileType)?.Value ?? (int)TiffNewSubfileType.FullImage);
-
             ifdMarker = this.WriteFrame(writer, frame, image.Metadata, metadataImage, ifdMarker);
             metadataImage = null;
         }
@@ -378,11 +376,14 @@ internal sealed class TiffEncoderCore : IImageEncoderInternals
                 case TiffBitsPerPixel.Bit8:
                     this.SetEncoderOptions(bitsPerPixel, photometricInterpretation ?? TiffPhotometricInterpretation.BlackIsZero, compression, predictor);
                     break;
+                case TiffBitsPerPixel.Bit16:
+                    // Assume desire to encode as L16 grayscale
+                    this.SetEncoderOptions(bitsPerPixel, TiffPhotometricInterpretation.BlackIsZero, compression, predictor);
+                    break;
                 case TiffBitsPerPixel.Bit6:
                 case TiffBitsPerPixel.Bit10:
                 case TiffBitsPerPixel.Bit12:
                 case TiffBitsPerPixel.Bit14:
-                case TiffBitsPerPixel.Bit16:
                 case TiffBitsPerPixel.Bit30:
                 case TiffBitsPerPixel.Bit36:
                 case TiffBitsPerPixel.Bit42:
@@ -415,13 +416,20 @@ internal sealed class TiffEncoderCore : IImageEncoderInternals
                 return;
             }
 
-            // At the moment only 8 and 32 bits per pixel can be preserved by the tiff encoder.
+            // At the moment only 8, 16 and 32 bits per pixel can be preserved by the tiff encoder.
             if (inputBitsPerPixel == 8)
             {
                 this.SetEncoderOptions(TiffBitsPerPixel.Bit8, TiffPhotometricInterpretation.BlackIsZero, compression, predictor);
                 return;
             }
 
+            if (inputBitsPerPixel == 16)
+            {
+                // Assume desire to encode as L16 grayscale
+                this.SetEncoderOptions(TiffBitsPerPixel.Bit16, TiffPhotometricInterpretation.BlackIsZero, compression, predictor);
+                return;
+            }
+
             this.SetEncoderOptions(TiffBitsPerPixel.Bit24, TiffPhotometricInterpretation.Rgb, compression, predictor);
             return;
         }
@@ -436,6 +444,12 @@ internal sealed class TiffEncoderCore : IImageEncoderInternals
                     return;
                 }
 
+                if (inputBitsPerPixel == 16)
+                {
+                    this.SetEncoderOptions(TiffBitsPerPixel.Bit16, photometricInterpretation, compression, predictor);
+                    return;
+                }
+
                 this.SetEncoderOptions(TiffBitsPerPixel.Bit8, photometricInterpretation, compression, predictor);
                 return;
 

src/ImageSharp/Formats/Tiff/TiffEncoderEntriesCollector.cs

@@ -343,20 +343,20 @@ internal class TiffEncoderEntriesCollector
                     return TiffConstants.BitsPerSampleRgb8Bit.ToArray();
 
                 case TiffPhotometricInterpretation.WhiteIsZero:
-                    if (encoder.BitsPerPixel == TiffBitsPerPixel.Bit1)
+                    return encoder.BitsPerPixel switch
                     {
-                        return TiffConstants.BitsPerSample1Bit.ToArray();
-                    }
-
-                    return TiffConstants.BitsPerSample8Bit.ToArray();
+                        TiffBitsPerPixel.Bit1 => TiffConstants.BitsPerSample1Bit.ToArray(),
+                        TiffBitsPerPixel.Bit16 => TiffConstants.BitsPerSample16Bit.ToArray(),
+                        _ => TiffConstants.BitsPerSample8Bit.ToArray()
+                    };
 
                 case TiffPhotometricInterpretation.BlackIsZero:
-                    if (encoder.BitsPerPixel == TiffBitsPerPixel.Bit1)
+                    return encoder.BitsPerPixel switch
                     {
-                        return TiffConstants.BitsPerSample1Bit.ToArray();
-                    }
-
-                    return TiffConstants.BitsPerSample8Bit.ToArray();
+                        TiffBitsPerPixel.Bit1 => TiffConstants.BitsPerSample1Bit.ToArray(),
+                        TiffBitsPerPixel.Bit16 => TiffConstants.BitsPerSample16Bit.ToArray(),
+                        _ => TiffConstants.BitsPerSample8Bit.ToArray()
+                    };
 
                 default:
                     return TiffConstants.BitsPerSampleRgb8Bit.ToArray();

src/ImageSharp/Formats/Tiff/TiffFrameMetadata.cs

@@ -1,6 +1,5 @@
 // Copyright (c) Six Labors.
 // Licensed under the Six Labors Split License.
-#nullable disable
 
 using SixLabors.ImageSharp.Formats.Tiff.Constants;
 using SixLabors.ImageSharp.Metadata.Profiles.Exif;
@@ -78,15 +77,30 @@ public class TiffFrameMetadata : IDeepCloneable
     {
         if (profile != null)
         {
-            if (TiffBitsPerSample.TryParse(profile.GetValue(ExifTag.BitsPerSample)?.Value, out TiffBitsPerSample bitsPerSample))
+            if (profile.TryGetValue(ExifTag.BitsPerSample, out IExifValue<ushort[]>? bitsPerSampleValue))
             {
-                meta.BitsPerSample = bitsPerSample;
+                if (TiffBitsPerSample.TryParse(bitsPerSampleValue.Value, out TiffBitsPerSample bitsPerSample))
+                {
+                    meta.BitsPerSample = bitsPerSample;
+                }
             }
 
             meta.BitsPerPixel = meta.BitsPerSample?.BitsPerPixel();
-            meta.Compression = (TiffCompression?)profile.GetValue(ExifTag.Compression)?.Value;
-            meta.PhotometricInterpretation = (TiffPhotometricInterpretation?)profile.GetValue(ExifTag.PhotometricInterpretation)?.Value;
-            meta.Predictor = (TiffPredictor?)profile.GetValue(ExifTag.Predictor)?.Value;
+
+            if (profile.TryGetValue(ExifTag.Compression, out IExifValue<ushort>? compressionValue))
+            {
+                meta.Compression = (TiffCompression)compressionValue.Value;
+            }
+
+            if (profile.TryGetValue(ExifTag.PhotometricInterpretation, out IExifValue<ushort>? photometricInterpretationValue))
+            {
+                meta.PhotometricInterpretation = (TiffPhotometricInterpretation)photometricInterpretationValue.Value;
+            }
+
+            if (profile.TryGetValue(ExifTag.Predictor, out IExifValue<ushort>? predictorValue))
+            {
+                meta.Predictor = (TiffPredictor)predictorValue.Value;
+            }
 
             profile.RemoveValue(ExifTag.BitsPerSample);
             profile.RemoveValue(ExifTag.Compression);

src/ImageSharp/Formats/Tiff/TiffThrowHelper.cs

@@ -1,21 +1,33 @@
 // Copyright (c) Six Labors.
 // Licensed under the Six Labors Split License.
 
+using System.Diagnostics.CodeAnalysis;
+
 namespace SixLabors.ImageSharp.Formats.Tiff;
 
 internal static class TiffThrowHelper
 {
+    [DoesNotReturn]
     public static Exception ThrowImageFormatException(string errorMessage) => throw new ImageFormatException(errorMessage);
 
+    [DoesNotReturn]
+    public static Exception ThrowInvalidImageContentException(string errorMessage) => throw new InvalidImageContentException(errorMessage);
+
+    [DoesNotReturn]
     public static Exception NotSupportedDecompressor(string compressionType) => throw new NotSupportedException($"Not supported decoder compression method: {compressionType}");
 
+    [DoesNotReturn]
     public static Exception NotSupportedCompressor(string compressionType) => throw new NotSupportedException($"Not supported encoder compression method: {compressionType}");
 
+    [DoesNotReturn]
     public static Exception InvalidColorType(string colorType) => throw new NotSupportedException($"Invalid color type: {colorType}");
 
+    [DoesNotReturn]
     public static Exception ThrowInvalidHeader() => throw new ImageFormatException("Invalid TIFF file header.");
 
+    [DoesNotReturn]
     public static void ThrowNotSupported(string message) => throw new NotSupportedException(message);
 
+    [DoesNotReturn]
     public static void ThrowArgumentException(string message) => throw new ArgumentException(message);
 }

src/ImageSharp/Formats/Tiff/Writers/TiffColorWriterFactory.cs

@@ -27,12 +27,13 @@ internal static class TiffColorWriterFactory
                 return new TiffPaletteWriter<TPixel>(image, quantizer, pixelSamplingStrategy, memoryAllocator, configuration, entriesCollector, bitsPerPixel);
             case TiffPhotometricInterpretation.BlackIsZero:
             case TiffPhotometricInterpretation.WhiteIsZero:
-                if (bitsPerPixel == 1)
+                return bitsPerPixel switch
                 {
-                    return new TiffBiColorWriter<TPixel>(image, memoryAllocator, configuration, entriesCollector);
-                }
+                    1 => new TiffBiColorWriter<TPixel>(image, memoryAllocator, configuration, entriesCollector),
+                    16 => new TiffGrayL16Writer<TPixel>(image, memoryAllocator, configuration, entriesCollector),
+                    _ => new TiffGrayWriter<TPixel>(image, memoryAllocator, configuration, entriesCollector)
+                };
 
-                return new TiffGrayWriter<TPixel>(image, memoryAllocator, configuration, entriesCollector);
             default:
                 return new TiffRgbWriter<TPixel>(image, memoryAllocator, configuration, entriesCollector);
         }

src/ImageSharp/Formats/Tiff/Writers/TiffGrayL16Writer{TPixel}.cs

@@ -0,0 +1,22 @@
+// Copyright (c) Six Labors.
+// Licensed under the Six Labors Split License.
+
+using SixLabors.ImageSharp.Memory;
+using SixLabors.ImageSharp.PixelFormats;
+
+namespace SixLabors.ImageSharp.Formats.Tiff.Writers;
+
+internal sealed class TiffGrayL16Writer<TPixel> : TiffCompositeColorWriter<TPixel>
+    where TPixel : unmanaged, IPixel<TPixel>
+{
+    public TiffGrayL16Writer(ImageFrame<TPixel> image, MemoryAllocator memoryAllocator, Configuration configuration, TiffEncoderEntriesCollector entriesCollector)
+        : base(image, memoryAllocator, configuration, entriesCollector)
+    {
+    }
+
+    /// <inheritdoc />
+    public override int BitsPerPixel => 16;
+
+    /// <inheritdoc />
+    protected override void EncodePixels(Span<TPixel> pixels, Span<byte> buffer) => PixelOperations<TPixel>.Instance.ToL16Bytes(this.Configuration, pixels, buffer, pixels.Length);
+}

src/ImageSharp/Memory/Allocators/Internals/Gen2GcCallback.cs

@@ -1,6 +1,5 @@
 // Copyright (c) Six Labors.
 // Licensed under the Six Labors Split License.
-#nullable disable
 
 // Port of BCL internal utility:
 // https://github.com/dotnet/runtime/blob/57bfe474518ab5b7cfe6bf7424a79ce3af9d6657/src/libraries/System.Private.CoreLib/src/System/Gen2GcCallback.cs
@@ -15,8 +14,8 @@ namespace SixLabors.ImageSharp.Memory.Internals;
 /// </summary>
 internal sealed class Gen2GcCallback : CriticalFinalizerObject
 {
-    private readonly Func<bool> callback0;
-    private readonly Func<object, bool> callback1;
+    private readonly Func<bool>? callback0;
+    private readonly Func<object, bool>? callback1;
     private GCHandle weakTargetObj;
 
     private Gen2GcCallback(Func<bool> callback) => this.callback0 = callback;
@@ -32,7 +31,7 @@ internal sealed class Gen2GcCallback : CriticalFinalizerObject
         if (this.weakTargetObj.IsAllocated)
         {
             // Check to see if the target object is still alive.
-            object targetObj = this.weakTargetObj.Target;
+            object? targetObj = this.weakTargetObj.Target;
             if (targetObj == null)
             {
                 // The target object is dead, so this callback object is no longer needed.
@@ -43,7 +42,7 @@ internal sealed class Gen2GcCallback : CriticalFinalizerObject
             // Execute the callback method.
             try
             {
-                if (!this.callback1(targetObj))
+                if (!this.callback1!(targetObj))
                 {
                     // If the callback returns false, this callback object is no longer needed.
                     this.weakTargetObj.Free();
@@ -64,7 +63,7 @@ internal sealed class Gen2GcCallback : CriticalFinalizerObject
             // Execute the callback method.
             try
             {
-                if (!this.callback0())
+                if (!this.callback0!())
                 {
                     // If the callback returns false, this callback object is no longer needed.
                     return;

src/ImageSharp/Memory/Allocators/Internals/RefCountedMemoryLifetimeGuard.cs

@@ -1,6 +1,5 @@
 // Copyright (c) Six Labors.
 // Licensed under the Six Labors Split License.
-#nullable disable
 
 using SixLabors.ImageSharp.Diagnostics;
 
@@ -15,7 +14,7 @@ internal abstract class RefCountedMemoryLifetimeGuard : IDisposable
     private int refCount = 1;
     private int disposed;
     private int released;
-    private string allocationStackTrace;
+    private string? allocationStackTrace;
 
     protected RefCountedMemoryLifetimeGuard()
     {

src/ImageSharp/Memory/Allocators/Internals/SharedArrayPoolBuffer{T}.cs

@@ -1,9 +1,9 @@
 // Copyright (c) Six Labors.
 // Licensed under the Six Labors Split License.
-#nullable disable
 
 using System.Buffers;
 using System.Diagnostics;
+using System.Diagnostics.CodeAnalysis;
 using System.Runtime.CompilerServices;
 using System.Runtime.InteropServices;
 
@@ -22,7 +22,7 @@ internal class SharedArrayPoolBuffer<T> : ManagedBufferBase<T>, IRefCounted
         this.lifetimeGuard = new LifetimeGuard(this.Array);
     }
 
-    public byte[] Array { get; private set; }
+    public byte[]? Array { get; private set; }
 
     protected override void Dispose(bool disposing)
     {
@@ -41,7 +41,11 @@ internal class SharedArrayPoolBuffer<T> : ManagedBufferBase<T>, IRefCounted
         return MemoryMarshal.Cast<byte, T>(this.Array.AsSpan(0, this.lengthInBytes));
     }
 
-    protected override object GetPinnableObject() => this.Array;
+    protected override object GetPinnableObject()
+    {
+        this.CheckDisposed();
+        return this.Array;
+    }
 
     public void AddRef()
     {
@@ -52,6 +56,7 @@ internal class SharedArrayPoolBuffer<T> : ManagedBufferBase<T>, IRefCounted
     public void ReleaseRef() => this.lifetimeGuard.ReleaseRef();
 
     [Conditional("DEBUG")]
+    [MemberNotNull(nameof(Array))]
     private void CheckDisposed()
     {
         if (this.Array == null)
@@ -62,7 +67,7 @@ internal class SharedArrayPoolBuffer<T> : ManagedBufferBase<T>, IRefCounted
 
     private sealed class LifetimeGuard : RefCountedMemoryLifetimeGuard
     {
-        private byte[] array;
+        private byte[]? array;
 
         public LifetimeGuard(byte[] array) => this.array = array;
 
@@ -73,7 +78,7 @@ internal class SharedArrayPoolBuffer<T> : ManagedBufferBase<T>, IRefCounted
             // This is not ideal, but subsequent leaks will end up returning arrays to per-cpu buckets,
             // meaning likely a different bucket than it was rented from,
             // but this is PROBABLY better than not returning the arrays at all.
-            ArrayPool<byte>.Shared.Return(this.array);
+            ArrayPool<byte>.Shared.Return(this.array!);
             this.array = null;
         }
     }

src/ImageSharp/Memory/Allocators/Internals/UniformUnmanagedMemoryPool.cs

@@ -1,6 +1,5 @@
 // Copyright (c) Six Labors.
 // Licensed under the Six Labors Split License.
-#nullable disable
 
 using System.Diagnostics;
 
@@ -13,7 +12,7 @@ internal partial class UniformUnmanagedMemoryPool : System.Runtime.ConstrainedEx
 {
     private static int minTrimPeriodMilliseconds = int.MaxValue;
     private static readonly List<WeakReference<UniformUnmanagedMemoryPool>> AllPools = new();
-    private static Timer trimTimer;
+    private static Timer? trimTimer;
 
     private static readonly Stopwatch Stopwatch = Stopwatch.StartNew();
 
@@ -97,7 +96,7 @@ internal partial class UniformUnmanagedMemoryPool : System.Runtime.ConstrainedEx
     /// <summary>
     /// Rent <paramref name="bufferCount"/> buffers or return 'null' if the pool is full.
     /// </summary>
-    public UnmanagedMemoryHandle[] Rent(int bufferCount)
+    public UnmanagedMemoryHandle[]? Rent(int bufferCount)
     {
         UnmanagedMemoryHandle[] buffersLocal = this.buffers;
 
@@ -248,7 +247,7 @@ internal partial class UniformUnmanagedMemoryPool : System.Runtime.ConstrainedEx
 
             foreach (WeakReference<UniformUnmanagedMemoryPool> weakPoolRef in AllPools)
             {
-                if (weakPoolRef.TryGetTarget(out UniformUnmanagedMemoryPool pool))
+                if (weakPoolRef.TryGetTarget(out UniformUnmanagedMemoryPool? pool))
                 {
                     pool.Trim();
                 }

src/ImageSharp/Memory/Allocators/Internals/UnmanagedMemoryHandle.cs

@@ -1,6 +1,5 @@
 // Copyright (c) Six Labors.
 // Licensed under the Six Labors Split License.
-#nullable disable
 
 using System.Runtime.InteropServices;
 
@@ -20,7 +19,7 @@ internal struct UnmanagedMemoryHandle : IEquatable<UnmanagedMemoryHandle>
     private static long totalOomRetries;
 
     // A Monitor to wait/signal when we are low on memory.
-    private static object lowMemoryMonitor;
+    private static object? lowMemoryMonitor;
 
     public static readonly UnmanagedMemoryHandle NullHandle;
 
@@ -114,9 +113,9 @@ internal struct UnmanagedMemoryHandle : IEquatable<UnmanagedMemoryHandle>
         if (Volatile.Read(ref lowMemoryMonitor) != null)
         {
             // We are low on memory. Signal all threads waiting in AllocateHandle().
-            Monitor.Enter(lowMemoryMonitor);
-            Monitor.PulseAll(lowMemoryMonitor);
-            Monitor.Exit(lowMemoryMonitor);
+            Monitor.Enter(lowMemoryMonitor!);
+            Monitor.PulseAll(lowMemoryMonitor!);
+            Monitor.Exit(lowMemoryMonitor!);
         }
 
         this.lengthInBytes = 0;
@@ -124,7 +123,7 @@ internal struct UnmanagedMemoryHandle : IEquatable<UnmanagedMemoryHandle>
 
     public bool Equals(UnmanagedMemoryHandle other) => this.handle.Equals(other.handle);
 
-    public override bool Equals(object obj) => obj is UnmanagedMemoryHandle other && this.Equals(other);
+    public override bool Equals(object? obj) => obj is UnmanagedMemoryHandle other && this.Equals(other);
 
     public override int GetHashCode() => this.handle.GetHashCode();
 }

src/ImageSharp/Memory/Allocators/UniformUnmanagedMemoryPoolMemoryAllocator.cs

@@ -135,7 +135,7 @@ internal sealed class UniformUnmanagedMemoryPoolMemoryAllocator : MemoryAllocato
         }
 
         // Attempt to rent the whole group from the pool, allocate a group of unmanaged buffers if the attempt fails:
-        if (MemoryGroup<T>.TryAllocate(this.pool, totalLength, bufferAlignment, options, out MemoryGroup<T> poolGroup))
+        if (MemoryGroup<T>.TryAllocate(this.pool, totalLength, bufferAlignment, options, out MemoryGroup<T>? poolGroup))
         {
             return poolGroup;
         }

src/ImageSharp/Memory/DiscontiguousBuffers/MemoryGroupExtensions.cs

@@ -106,7 +106,7 @@ internal static class MemoryGroupExtensions
         }
     }
 
-    internal static void CopyTo<T>(this IMemoryGroup<T> source, IMemoryGroup<T> target)
+    internal static void CopyTo<T>(this IMemoryGroup<T>? source, IMemoryGroup<T>? target)
         where T : struct
     {
         Guard.NotNull(source, nameof(source));

src/ImageSharp/Memory/DiscontiguousBuffers/MemoryGroupSpanCache.cs

@@ -13,7 +13,7 @@ namespace SixLabors.ImageSharp.Memory;
 internal unsafe struct MemoryGroupSpanCache
 {
     public SpanCacheMode Mode;
-    public byte[] SingleArray;
+    public byte[]? SingleArray;
     public void* SinglePointer;
     public void*[] MultiPointer;
 

src/ImageSharp/Memory/DiscontiguousBuffers/MemoryGroupView{T}.cs

@@ -1,9 +1,9 @@
 // Copyright (c) Six Labors.
 // Licensed under the Six Labors Split License.
-#nullable disable
 
 using System.Buffers;
 using System.Collections;
+using System.Diagnostics.CodeAnalysis;
 using System.Runtime.CompilerServices;
 
 namespace SixLabors.ImageSharp.Memory;
@@ -21,7 +21,7 @@ namespace SixLabors.ImageSharp.Memory;
 internal class MemoryGroupView<T> : IMemoryGroup<T>
     where T : struct
 {
-    private MemoryGroup<T> owner;
+    private MemoryGroup<T>? owner;
     private readonly MemoryOwnerWrapper[] memoryWrappers;
 
     public MemoryGroupView(MemoryGroup<T> owner)
@@ -63,6 +63,7 @@ internal class MemoryGroupView<T> : IMemoryGroup<T>
         }
     }
 
+    [MemberNotNullWhen(true, nameof(owner))]
     public bool IsValid => this.owner != null;
 
     public Memory<T> this[int index]
@@ -99,6 +100,7 @@ internal class MemoryGroupView<T> : IMemoryGroup<T>
         this.owner = null;
     }
 
+    [MemberNotNull(nameof(owner))]
     private void EnsureIsValid()
     {
         if (!this.IsValid)

src/ImageSharp/Memory/DiscontiguousBuffers/MemoryGroup{T}.Owned.cs

@@ -1,8 +1,8 @@
 // Copyright (c) Six Labors.
 // Licensed under the Six Labors Split License.
-#nullable disable
 
 using System.Buffers;
+using System.Diagnostics.CodeAnalysis;
 using System.Runtime.CompilerServices;
 using SixLabors.ImageSharp.Memory.Internals;
 
@@ -15,8 +15,8 @@ internal abstract partial class MemoryGroup<T>
     /// </summary>
     public sealed class Owned : MemoryGroup<T>, IEnumerable<Memory<T>>
     {
-        private IMemoryOwner<T>[] memoryOwners;
-        private RefCountedMemoryLifetimeGuard groupLifetimeGuard;
+        private IMemoryOwner<T>[]? memoryOwners;
+        private RefCountedMemoryLifetimeGuard? groupLifetimeGuard;
 
         public Owned(IMemoryOwner<T>[] memoryOwners, int bufferLength, long totalLength, bool swappable)
             : base(bufferLength, totalLength)
@@ -149,7 +149,7 @@ internal abstract partial class MemoryGroup<T>
             }
             else
             {
-                foreach (IMemoryOwner<T> memoryOwner in this.memoryOwners)
+                foreach (IMemoryOwner<T> memoryOwner in this.memoryOwners!)
                 {
                     memoryOwner.Dispose();
                 }
@@ -161,6 +161,7 @@ internal abstract partial class MemoryGroup<T>
         }
 
         [MethodImpl(InliningOptions.ShortMethod)]
+        [MemberNotNull(nameof(memoryOwners))]
         private void EnsureNotDisposed()
         {
             if (this.memoryOwners is null)
@@ -170,6 +171,7 @@ internal abstract partial class MemoryGroup<T>
         }
 
         [MethodImpl(MethodImplOptions.NoInlining)]
+        [DoesNotReturn]
         private static void ThrowObjectDisposedException() => throw new ObjectDisposedException(nameof(MemoryGroup<T>));
 
         // When the MemoryGroup points to multiple buffers via `groupLifetimeGuard`,

src/ImageSharp/Memory/DiscontiguousBuffers/MemoryGroup{T}.cs

@@ -1,9 +1,9 @@
 // Copyright (c) Six Labors.
 // Licensed under the Six Labors Split License.
-#nullable disable
 
 using System.Buffers;
 using System.Collections;
+using System.Diagnostics.CodeAnalysis;
 using System.Runtime.CompilerServices;
 using System.Runtime.InteropServices;
 using SixLabors.ImageSharp.Memory.Internals;
@@ -41,7 +41,7 @@ internal abstract partial class MemoryGroup<T> : IMemoryGroup<T>, IDisposable
     /// <inheritdoc />
     public bool IsValid { get; private set; } = true;
 
-    public MemoryGroupView<T> View { get; private set; }
+    public MemoryGroupView<T> View { get; private set; } = null!;
 
     /// <inheritdoc />
     public abstract Memory<T> this[int index] { get; }
@@ -150,7 +150,7 @@ internal abstract partial class MemoryGroup<T> : IMemoryGroup<T>, IDisposable
         long totalLengthInElements,
         int bufferAlignmentInElements,
         AllocationOptions options,
-        out MemoryGroup<T> memoryGroup)
+        [NotNullWhen(true)] out MemoryGroup<T>? memoryGroup)
     {
         Guard.NotNull(pool, nameof(pool));
         Guard.MustBeGreaterThanOrEqualTo(totalLengthInElements, 0, nameof(totalLengthInElements));
@@ -188,7 +188,7 @@ internal abstract partial class MemoryGroup<T> : IMemoryGroup<T>, IDisposable
             bufferCount++;
         }
 
-        UnmanagedMemoryHandle[] arrays = pool.Rent(bufferCount);
+        UnmanagedMemoryHandle[]? arrays = pool.Rent(bufferCount);
 
         if (arrays == null)
         {

src/ImageSharp/Metadata/Profiles/Exif/ExifEncodedStringHelpers.cs

@@ -1,6 +1,5 @@
 // Copyright (c) Six Labors.
 // Licensed under the Six Labors Split License.
-#nullable disable
 
 using System.Buffers.Binary;
 using System.Text;
@@ -27,7 +26,14 @@ internal static class ExifEncodedStringHelpers
 
     // 20932 EUC-JP Japanese (JIS 0208-1990 and 0212-1990)
     // https://docs.microsoft.com/en-us/dotnet/api/system.text.encoding?view=net-6.0
-    private static Encoding JIS0208Encoding => CodePagesEncodingProvider.Instance.GetEncoding(20932);
+    private static Encoding JIS0208Encoding
+    {
+        get
+        {
+            Encoding.RegisterProvider(CodePagesEncodingProvider.Instance);
+            return Encoding.GetEncoding(20932);
+        }
+    }
 
     public static bool IsEncodedString(ExifTagValue tag) => tag switch
     {

src/ImageSharp/Metadata/Profiles/Exif/ExifProfile.cs

@@ -1,7 +1,7 @@
 // Copyright (c) Six Labors.
 // Licensed under the Six Labors Split License.
-#nullable disable
 
+using System.Diagnostics.CodeAnalysis;
 using SixLabors.ImageSharp.PixelFormats;
 
 namespace SixLabors.ImageSharp.Metadata.Profiles.Exif;
@@ -14,12 +14,12 @@ public sealed class ExifProfile : IDeepCloneable<ExifProfile>
     /// <summary>
     /// The byte array to read the EXIF profile from.
     /// </summary>
-    private readonly byte[] data;
+    private readonly byte[]? data;
 
     /// <summary>
     /// The collection of EXIF values
     /// </summary>
-    private List<IExifValue> values;
+    private List<IExifValue>? values;
 
     /// <summary>
     /// The thumbnail offset position in the byte stream
@@ -35,7 +35,7 @@ public sealed class ExifProfile : IDeepCloneable<ExifProfile>
     /// Initializes a new instance of the <see cref="ExifProfile"/> class.
     /// </summary>
     public ExifProfile()
-        : this((byte[])null)
+        : this((byte[]?)null)
     {
     }
 
@@ -43,7 +43,7 @@ public sealed class ExifProfile : IDeepCloneable<ExifProfile>
     /// Initializes a new instance of the <see cref="ExifProfile"/> class.
     /// </summary>
     /// <param name="data">The byte array to read the EXIF profile from.</param>
-    public ExifProfile(byte[] data)
+    public ExifProfile(byte[]? data)
     {
         this.Parts = ExifParts.All;
         this.data = data;
@@ -78,7 +78,7 @@ public sealed class ExifProfile : IDeepCloneable<ExifProfile>
 
         this.InvalidTags = other.InvalidTags.Count > 0
             ? new List<ExifTag>(other.InvalidTags)
-            : (IReadOnlyList<ExifTag>)Array.Empty<ExifTag>();
+            : Array.Empty<ExifTag>();
 
         if (other.values != null)
         {
@@ -110,6 +110,7 @@ public sealed class ExifProfile : IDeepCloneable<ExifProfile>
     /// <summary>
     /// Gets the values of this EXIF profile.
     /// </summary>
+    [MemberNotNull(nameof(values))]
     public IReadOnlyList<IExifValue> Values
     {
         get
@@ -122,36 +123,47 @@ public sealed class ExifProfile : IDeepCloneable<ExifProfile>
     /// <summary>
     /// Returns the thumbnail in the EXIF profile when available.
     /// </summary>
+    /// <param name="image">The thumbnail</param>
     /// <returns>
-    /// The <see cref="Image"/>.
+    /// True, if there is a thumbnail otherwise false.
     /// </returns>
-    public Image CreateThumbnail() => this.CreateThumbnail<Rgba32>();
+    public bool TryCreateThumbnail([NotNullWhen(true)] out Image? image)
+    {
+        if (this.TryCreateThumbnail(out Image<Rgba32>? innerimage))
+        {
+            image = innerimage;
+            return true;
+        }
+
+        image = null;
+        return false;
+    }
 
     /// <summary>
     /// Returns the thumbnail in the EXIF profile when available.
     /// </summary>
     /// <typeparam name="TPixel">The pixel format.</typeparam>
-    /// <returns>
-    /// The <see cref="Image{TPixel}"/>.
-    /// </returns>
-    public Image<TPixel> CreateThumbnail<TPixel>()
+    /// <param name="image">The thumbnail.</param>
+    /// <returns>True, if there is a thumbnail otherwise false.</returns>
+    public bool TryCreateThumbnail<TPixel>([NotNullWhen(true)] out Image<TPixel>? image)
         where TPixel : unmanaged, IPixel<TPixel>
     {
         this.InitializeValues();
-
+        image = null;
         if (this.thumbnailOffset == 0 || this.thumbnailLength == 0)
         {
-            return null;
+            return false;
         }
 
         if (this.data is null || this.data.Length < (this.thumbnailOffset + this.thumbnailLength))
         {
-            return null;
+            return false;
         }
 
-        using (var memStream = new MemoryStream(this.data, this.thumbnailOffset, this.thumbnailLength))
+        using (MemoryStream memStream = new(this.data, this.thumbnailOffset, this.thumbnailLength))
         {
-            return Image.Load<TPixel>(memStream);
+            image = Image.Load<TPixel>(memStream);
+            return true;
         }
     }
 
@@ -159,12 +171,21 @@ public sealed class ExifProfile : IDeepCloneable<ExifProfile>
     /// Returns the value with the specified tag.
     /// </summary>
     /// <param name="tag">The tag of the exif value.</param>
-    /// <returns>The value with the specified tag.</returns>
+    /// <param name="exifValue">The value with the specified tag.</param>
+    /// <returns>True when found, otherwise false</returns>
     /// <typeparam name="TValueType">The data type of the tag.</typeparam>
-    public IExifValue<TValueType> GetValue<TValueType>(ExifTag<TValueType> tag)
+    public bool TryGetValue<TValueType>(ExifTag<TValueType> tag, [NotNullWhen(true)] out IExifValue<TValueType>? exifValue)
     {
-        IExifValue value = this.GetValueInternal(tag);
-        return value is null ? null : (IExifValue<TValueType>)value;
+        IExifValue? value = this.GetValueInternal(tag);
+
+        if (value is null)
+        {
+            exifValue = null;
+            return false;
+        }
+
+        exifValue = (IExifValue<TValueType>)value;
+        return true;
     }
 
     /// <summary>
@@ -203,7 +224,7 @@ public sealed class ExifProfile : IDeepCloneable<ExifProfile>
     /// Converts this instance to a byte array.
     /// </summary>
     /// <returns>The <see cref="T:byte[]"/></returns>
-    public byte[] ToByteArray()
+    public byte[]? ToByteArray()
     {
         if (this.values is null)
         {
@@ -215,19 +236,19 @@ public sealed class ExifProfile : IDeepCloneable<ExifProfile>
             return Array.Empty<byte>();
         }
 
-        var writer = new ExifWriter(this.values, this.Parts);
+        ExifWriter writer = new(this.values, this.Parts);
         return writer.GetData();
     }
 
     /// <inheritdoc/>
-    public ExifProfile DeepClone() => new ExifProfile(this);
+    public ExifProfile DeepClone() => new(this);
 
     /// <summary>
     /// Returns the value with the specified tag.
     /// </summary>
     /// <param name="tag">The tag of the exif value.</param>
     /// <returns>The value with the specified tag.</returns>
-    internal IExifValue GetValueInternal(ExifTag tag)
+    internal IExifValue? GetValueInternal(ExifTag tag)
     {
         foreach (IExifValue exifValue in this.Values)
         {
@@ -245,7 +266,8 @@ public sealed class ExifProfile : IDeepCloneable<ExifProfile>
     /// </summary>
     /// <param name="tag">The tag of the exif value.</param>
     /// <param name="value">The value.</param>
-    internal void SetValueInternal(ExifTag tag, object value)
+    /// <exception cref="NotSupportedException">Newly created value is null.</exception>
+    internal void SetValueInternal(ExifTag tag, object? value)
     {
         foreach (IExifValue exifValue in this.Values)
         {
@@ -256,10 +278,10 @@ public sealed class ExifProfile : IDeepCloneable<ExifProfile>
             }
         }
 
-        ExifValue newExifValue = ExifValues.Create(tag);
+        ExifValue? newExifValue = ExifValues.Create(tag);
         if (newExifValue is null)
         {
-            throw new NotSupportedException();
+            throw new NotSupportedException($"Newly created value for tag {tag} is null.");
         }
 
         newExifValue.TrySetValue(value);
@@ -278,9 +300,7 @@ public sealed class ExifProfile : IDeepCloneable<ExifProfile>
 
     private void SyncResolution(ExifTag<Rational> tag, double resolution)
     {
-        IExifValue<Rational> value = this.GetValue(tag);
-
-        if (value is null)
+        if (!this.TryGetValue(tag, out IExifValue<Rational>? value))
         {
             return;
         }
@@ -290,10 +310,11 @@ public sealed class ExifProfile : IDeepCloneable<ExifProfile>
             this.RemoveValue(value.Tag);
         }
 
-        var newResolution = new Rational(resolution, false);
+        Rational newResolution = new(resolution, false);
         this.SetValue(tag, newResolution);
     }
 
+    [MemberNotNull(nameof(values))]
     private void InitializeValues()
     {
         if (this.values != null)
@@ -307,13 +328,13 @@ public sealed class ExifProfile : IDeepCloneable<ExifProfile>
             return;
         }
 
-        var reader = new ExifReader(this.data);
+        ExifReader reader = new(this.data);
 
         this.values = reader.ReadValues();
 
         this.InvalidTags = reader.InvalidTags.Count > 0
             ? new List<ExifTag>(reader.InvalidTags)
-            : (IReadOnlyList<ExifTag>)Array.Empty<ExifTag>();
+            : Array.Empty<ExifTag>();
 
         this.thumbnailOffset = (int)reader.ThumbnailOffset;
         this.thumbnailLength = (int)reader.ThumbnailLength;

src/ImageSharp/Metadata/Profiles/Exif/ExifReader.cs

@@ -1,6 +1,5 @@
 // Copyright (c) Six Labors.
 // Licensed under the Six Labors Split License.
-#nullable disable
 
 using System.Buffers;
 using System.Buffers.Binary;
@@ -20,9 +19,10 @@ internal class ExifReader : BaseExifReader
     {
     }
 
-    public ExifReader(byte[] exifData, MemoryAllocator allocator)
+    public ExifReader(byte[] exifData, MemoryAllocator? allocator)
         : base(new MemoryStream(exifData ?? throw new ArgumentNullException(nameof(exifData))), allocator)
     {
+        // TODO: We never call this constructor passing a non-null allocator.
     }
 
     /// <summary>
@@ -90,13 +90,13 @@ internal abstract class BaseExifReader
     private readonly byte[] buf4 = new byte[4];
     private readonly byte[] buf2 = new byte[2];
 
-    private readonly MemoryAllocator allocator;
+    private readonly MemoryAllocator? allocator;
     private readonly Stream data;
-    private List<ExifTag> invalidTags;
+    private List<ExifTag>? invalidTags;
 
-    private List<ulong> subIfds;
+    private List<ulong>? subIfds;
 
-    protected BaseExifReader(Stream stream, MemoryAllocator allocator)
+    protected BaseExifReader(Stream stream, MemoryAllocator? allocator)
     {
         this.data = stream ?? throw new ArgumentNullException(nameof(stream));
         this.allocator = allocator;
@@ -219,7 +219,7 @@ internal abstract class BaseExifReader
         this.Seek(tag.Offset);
         if (this.TryReadSpan(buffer))
         {
-            object value = this.ConvertValue(tag.DataType, buffer, tag.NumberOfComponents > 1 || tag.Exif.IsArray);
+            object? value = this.ConvertValue(tag.DataType, buffer, tag.NumberOfComponents > 1 || tag.Exif.IsArray);
             this.Add(values, tag.Exif, value);
         }
     }
@@ -255,7 +255,7 @@ internal abstract class BaseExifReader
 
     private static byte ConvertToByte(ReadOnlySpan<byte> buffer) => buffer[0];
 
-    private object ConvertValue(ExifDataType dataType, ReadOnlySpan<byte> buffer, bool isArray)
+    private object? ConvertValue(ExifDataType dataType, ReadOnlySpan<byte> buffer, bool isArray)
     {
         if (buffer.Length == 0)
         {
@@ -390,7 +390,7 @@ internal abstract class BaseExifReader
             numberOfComponents = 4 / ExifDataTypes.GetSize(dataType);
         }
 
-        ExifValue exifValue = ExifValues.Create(tag) ?? ExifValues.Create(tag, dataType, numberOfComponents);
+        ExifValue? exifValue = ExifValues.Create(tag) ?? ExifValues.Create(tag, dataType, numberOfComponents);
 
         if (exifValue is null)
         {
@@ -414,7 +414,7 @@ internal abstract class BaseExifReader
         }
         else
         {
-            object value = this.ConvertValue(dataType, offsetBuffer[..(int)size], numberOfComponents > 1 || exifValue.IsArray);
+            object? value = this.ConvertValue(dataType, offsetBuffer[..(int)size], numberOfComponents > 1 || exifValue.IsArray);
             this.Add(values, exifValue, value);
         }
     }
@@ -443,7 +443,7 @@ internal abstract class BaseExifReader
             numberOfComponents = 8 / ExifDataTypes.GetSize(dataType);
         }
 
-        ExifValue exifValue = tag switch
+        ExifValue? exifValue = tag switch
         {
             ExifTagValue.StripOffsets => new ExifLong8Array(ExifTagValue.StripOffsets),
             ExifTagValue.StripByteCounts => new ExifLong8Array(ExifTagValue.StripByteCounts),
@@ -471,12 +471,12 @@ internal abstract class BaseExifReader
         }
         else
         {
-            object value = this.ConvertValue(dataType, offsetBuffer[..(int)size], numberOfComponents > 1 || exifValue.IsArray);
+            object? value = this.ConvertValue(dataType, offsetBuffer[..(int)size], numberOfComponents > 1 || exifValue.IsArray);
             this.Add(values, exifValue, value);
         }
     }
 
-    private void Add(IList<IExifValue> values, IExifValue exif, object value)
+    private void Add(IList<IExifValue> values, IExifValue exif, object? value)
     {
         if (!exif.TrySetValue(value))
         {
@@ -510,7 +510,7 @@ internal abstract class BaseExifReader
     private void AddInvalidTag(ExifTag tag)
         => (this.invalidTags ??= new List<ExifTag>()).Add(tag);
 
-    private void AddSubIfd(object val)
+    private void AddSubIfd(object? val)
         => (this.subIfds ??= new List<ulong>()).Add(Convert.ToUInt64(val, CultureInfo.InvariantCulture));
 
     private void Seek(ulong pos)

src/ImageSharp/Metadata/Profiles/Exif/ExifTagDescriptionAttribute.cs

@@ -1,7 +1,7 @@
 // Copyright (c) Six Labors.
 // Licensed under the Six Labors Split License.
-#nullable disable
 
+using System.Diagnostics.CodeAnalysis;
 using System.Reflection;
 
 namespace SixLabors.ImageSharp.Metadata.Profiles.Exif;
@@ -26,29 +26,34 @@ internal sealed class ExifTagDescriptionAttribute : Attribute
     /// </summary>
     /// <param name="tag">The tag.</param>
     /// <param name="value">The value.</param>
+    /// <param name="description">The description.</param>
     /// <returns>
-    /// The <see cref="string"/>.
+    /// True when description was found
     /// </returns>
-    public static string GetDescription(ExifTag tag, object value)
+    public static bool TryGetDescription(ExifTag tag, object? value, [NotNullWhen(true)] out string? description)
     {
-        var tagValue = (ExifTagValue)(ushort)tag;
-        FieldInfo field = typeof(ExifTagValue).GetField(tagValue.ToString(), BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Static);
+        ExifTagValue tagValue = (ExifTagValue)(ushort)tag;
+        FieldInfo? field = typeof(ExifTagValue).GetField(tagValue.ToString(), BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Static);
+
+        description = null;
 
         if (field is null)
         {
-            return null;
+            return false;
         }
 
         foreach (CustomAttributeData customAttribute in field.CustomAttributes)
         {
-            object attributeValue = customAttribute.ConstructorArguments[0].Value;
+            object? attributeValue = customAttribute.ConstructorArguments[0].Value;
 
             if (Equals(attributeValue, value))
             {
-                return (string)customAttribute.ConstructorArguments[1].Value;
+                description = (string?)customAttribute.ConstructorArguments[1].Value;
+
+                return description is not null;
             }
         }
 
-        return null;
+        return false;
     }
 }

src/ImageSharp/Metadata/Profiles/Exif/ExifWriter.cs

@@ -1,6 +1,5 @@
 // Copyright (c) Six Labors.
 // Licensed under the Six Labors Split License.
-#nullable disable
 
 using System.Buffers.Binary;
 
@@ -16,7 +15,7 @@ internal sealed class ExifWriter
     /// </summary>
     private readonly ExifParts allowedParts;
     private readonly IList<IExifValue> values;
-    private List<int> dataOffsets;
+    private List<int>? dataOffsets;
     private readonly List<IExifValue> ifdValues;
     private readonly List<IExifValue> exifValues;
     private readonly List<IExifValue> gpsValues;
@@ -45,8 +44,8 @@ internal sealed class ExifWriter
     {
         const uint startIndex = 0;
 
-        IExifValue exifOffset = GetOffsetValue(this.ifdValues, this.exifValues, ExifTag.SubIFDOffset);
-        IExifValue gpsOffset = GetOffsetValue(this.ifdValues, this.gpsValues, ExifTag.GPSIFDOffset);
+        IExifValue? exifOffset = GetOffsetValue(this.ifdValues, this.exifValues, ExifTag.SubIFDOffset);
+        IExifValue? gpsOffset = GetOffsetValue(this.ifdValues, this.gpsValues, ExifTag.GPSIFDOffset);
 
         uint ifdLength = GetLength(this.ifdValues);
         uint exifLength = GetLength(this.exifValues);
@@ -91,7 +90,7 @@ internal sealed class ExifWriter
         if (gpsLength > 0)
         {
             i = this.WriteHeaders(this.gpsValues, result, i);
-            i = this.WriteData(startIndex, this.gpsValues, result, i);
+            this.WriteData(startIndex, this.gpsValues, result, i);
         }
 
         return result;
@@ -160,7 +159,7 @@ internal sealed class ExifWriter
         return offset + 4;
     }
 
-    private static IExifValue GetOffsetValue(List<IExifValue> ifdValues, List<IExifValue> values, ExifTag offset)
+    private static IExifValue? GetOffsetValue(List<IExifValue> ifdValues, List<IExifValue> values, ExifTag offset)
     {
         int index = -1;
 
@@ -179,8 +178,12 @@ internal sealed class ExifWriter
                 return ifdValues[index];
             }
 
-            ExifValue result = ExifValues.Create(offset);
-            ifdValues.Add(result);
+            ExifValue? result = ExifValues.Create(offset);
+
+            if (result is not null)
+            {
+                ifdValues.Add(result);
+            }
 
             return result;
         }
@@ -219,15 +222,14 @@ internal sealed class ExifWriter
 
     private static bool HasValue(IExifValue exifValue)
     {
-        object value = exifValue.GetValue();
+        object? value = exifValue.GetValue();
         if (value is null)
         {
             return false;
         }
 
-        if (exifValue.DataType == ExifDataType.Ascii)
+        if (exifValue.DataType == ExifDataType.Ascii && value is string stringValue)
         {
-            string stringValue = (string)value;
             return stringValue.Length > 0;
         }
 
@@ -270,11 +272,11 @@ internal sealed class ExifWriter
 
     internal static uint GetNumberOfComponents(IExifValue exifValue)
     {
-        object value = exifValue.GetValue();
+        object? value = exifValue.GetValue();
 
         if (ExifUcs2StringHelpers.IsUcs2Tag((ExifTagValue)(ushort)exifValue.Tag))
         {
-            return (uint)ExifUcs2StringHelpers.Ucs2Encoding.GetByteCount((string)value);
+            return (uint)ExifUcs2StringHelpers.Ucs2Encoding.GetByteCount((string?)value!);
         }
 
         if (value is EncodedString encodedString)
@@ -284,7 +286,7 @@ internal sealed class ExifWriter
 
         if (exifValue.DataType == ExifDataType.Ascii)
         {
-            return (uint)ExifConstants.DefaultEncoding.GetByteCount((string)value) + 1;
+            return (uint)ExifConstants.DefaultEncoding.GetByteCount((string?)value!) + 1;
         }
 
         if (value is Array arrayValue)
@@ -298,7 +300,7 @@ internal sealed class ExifWriter
     private static int WriteArray(IExifValue value, Span<byte> destination, int offset)
     {
         int newOffset = offset;
-        foreach (object obj in (Array)value.GetValue())
+        foreach (object obj in (Array)value.GetValue()!)
         {
             newOffset = WriteValue(value.DataType, obj, destination, newOffset);
         }
@@ -308,7 +310,7 @@ internal sealed class ExifWriter
 
     private int WriteData(uint startIndex, List<IExifValue> values, Span<byte> destination, int offset)
     {
-        if (this.dataOffsets.Count == 0)
+        if (this.dataOffsets is null || this.dataOffsets.Count == 0)
         {
             return offset;
         }
@@ -428,7 +430,8 @@ internal sealed class ExifWriter
 
     internal static int WriteValue(IExifValue exifValue, Span<byte> destination, int offset)
     {
-        object value = exifValue.GetValue();
+        object? value = exifValue.GetValue();
+        Guard.NotNull(value);
 
         if (ExifUcs2StringHelpers.IsUcs2Tag((ExifTagValue)(ushort)exifValue.Tag))
         {

src/ImageSharp/Metadata/Profiles/Exif/Values/ExifArrayValue{TValueType}.cs

@@ -1,6 +1,5 @@
 // Copyright (c) Six Labors.
 // Licensed under the Six Labors Split License.
-#nullable disable
 
 namespace SixLabors.ImageSharp.Metadata.Profiles.Exif;
 
@@ -23,11 +22,11 @@ internal abstract class ExifArrayValue<TValueType> : ExifValue, IExifValue<TValu
 
     public override bool IsArray => true;
 
-    public TValueType[] Value { get; set; }
+    public TValueType[]? Value { get; set; }
 
-    public override object GetValue() => this.Value;
+    public override object? GetValue() => this.Value;
 
-    public override bool TrySetValue(object value)
+    public override bool TrySetValue(object? value)
     {
         if (value is null)
         {

src/ImageSharp/Metadata/Profiles/Exif/Values/ExifByte.cs

@@ -20,7 +20,7 @@ internal sealed class ExifByte : ExifValue<byte>
 
     protected override string StringValue => this.Value.ToString("X2", CultureInfo.InvariantCulture);
 
-    public override bool TrySetValue(object value)
+    public override bool TrySetValue(object? value)
     {
         if (base.TrySetValue(value))
         {

src/ImageSharp/Metadata/Profiles/Exif/Values/ExifByteArray.cs

@@ -16,7 +16,7 @@ internal sealed class ExifByteArray : ExifArrayValue<byte>
 
     public override ExifDataType DataType { get; }
 
-    public override bool TrySetValue(object value)
+    public override bool TrySetValue(object? value)
     {
         if (base.TrySetValue(value))
         {

src/ImageSharp/Metadata/Profiles/Exif/Values/ExifDouble.cs

@@ -26,7 +26,7 @@ internal sealed class ExifDouble : ExifValue<double>
 
     protected override string StringValue => this.Value.ToString(CultureInfo.InvariantCulture);
 
-    public override bool TrySetValue(object value)
+    public override bool TrySetValue(object? value)
     {
         if (base.TrySetValue(value))
         {

src/ImageSharp/Metadata/Profiles/Exif/Values/ExifEncodedString.cs

@@ -24,7 +24,7 @@ internal sealed class ExifEncodedString : ExifValue<EncodedString>
 
     protected override string StringValue => this.Value.Text;
 
-    public override bool TrySetValue(object value)
+    public override bool TrySetValue(object? value)
     {
         if (base.TrySetValue(value))
         {

src/ImageSharp/Metadata/Profiles/Exif/Values/ExifFloat.cs

@@ -21,7 +21,7 @@ internal sealed class ExifFloat : ExifValue<float>
 
     protected override string StringValue => this.Value.ToString(CultureInfo.InvariantCulture);
 
-    public override bool TrySetValue(object value)
+    public override bool TrySetValue(object? value)
     {
         if (base.TrySetValue(value))
         {

src/ImageSharp/Metadata/Profiles/Exif/Values/ExifLong.cs

@@ -26,7 +26,7 @@ internal sealed class ExifLong : ExifValue<uint>
 
     protected override string StringValue => this.Value.ToString(CultureInfo.InvariantCulture);
 
-    public override bool TrySetValue(object value)
+    public override bool TrySetValue(object? value)
     {
         if (base.TrySetValue(value))
         {

src/ImageSharp/Metadata/Profiles/Exif/Values/ExifLong8.cs

@@ -26,7 +26,7 @@ internal sealed class ExifLong8 : ExifValue<ulong>
 
     protected override string StringValue => this.Value.ToString(CultureInfo.InvariantCulture);
 
-    public override bool TrySetValue(object value)
+    public override bool TrySetValue(object? value)
     {
         if (base.TrySetValue(value))
         {

src/ImageSharp/Metadata/Profiles/Exif/Values/ExifLong8Array.cs

@@ -34,7 +34,7 @@ internal sealed class ExifLong8Array : ExifArrayValue<ulong>
         }
     }
 
-    public override bool TrySetValue(object value)
+    public override bool TrySetValue(object? value)
     {
         if (base.TrySetValue(value))
         {

src/ImageSharp/Metadata/Profiles/Exif/Values/ExifNumber.cs

@@ -32,7 +32,7 @@ internal sealed class ExifNumber : ExifValue<Number>
 
     protected override string StringValue => this.Value.ToString(CultureInfo.InvariantCulture);
 
-    public override bool TrySetValue(object value)
+    public override bool TrySetValue(object? value)
     {
         if (base.TrySetValue(value))
         {

src/ImageSharp/Metadata/Profiles/Exif/Values/ExifNumberArray.cs

@@ -34,7 +34,7 @@ internal sealed class ExifNumberArray : ExifArrayValue<Number>
         }
     }
 
-    public override bool TrySetValue(object value)
+    public override bool TrySetValue(object? value)
     {
         if (base.TrySetValue(value))
         {

src/ImageSharp/Metadata/Profiles/Exif/Values/ExifRational.cs

@@ -26,7 +26,7 @@ internal sealed class ExifRational : ExifValue<Rational>
 
     protected override string StringValue => this.Value.ToString(CultureInfo.InvariantCulture);
 
-    public override bool TrySetValue(object value)
+    public override bool TrySetValue(object? value)
     {
         if (base.TrySetValue(value))
         {

src/ImageSharp/Metadata/Profiles/Exif/Values/ExifRationalArray.cs

@@ -22,7 +22,7 @@ internal sealed class ExifRationalArray : ExifArrayValue<Rational>
 
     public override ExifDataType DataType => ExifDataType.Rational;
 
-    public override bool TrySetValue(object value)
+    public override bool TrySetValue(object? value)
     {
         if (base.TrySetValue(value))
         {

src/ImageSharp/Metadata/Profiles/Exif/Values/ExifShort.cs

@@ -26,7 +26,7 @@ internal sealed class ExifShort : ExifValue<ushort>
 
     protected override string StringValue => this.Value.ToString(CultureInfo.InvariantCulture);
 
-    public override bool TrySetValue(object value)
+    public override bool TrySetValue(object? value)
     {
         if (base.TrySetValue(value))
         {

src/ImageSharp/Metadata/Profiles/Exif/Values/ExifShortArray.cs

@@ -22,7 +22,7 @@ internal sealed class ExifShortArray : ExifArrayValue<ushort>
 
     public override ExifDataType DataType => ExifDataType.Short;
 
-    public override bool TrySetValue(object value)
+    public override bool TrySetValue(object? value)
     {
         if (base.TrySetValue(value))
         {

src/ImageSharp/Metadata/Profiles/Exif/Values/ExifSignedByte.cs

@@ -21,7 +21,7 @@ internal sealed class ExifSignedByte : ExifValue<sbyte>
 
     protected override string StringValue => this.Value.ToString("X2", CultureInfo.InvariantCulture);
 
-    public override bool TrySetValue(object value)
+    public override bool TrySetValue(object? value)
     {
         if (base.TrySetValue(value))
         {

src/ImageSharp/Metadata/Profiles/Exif/Values/ExifSignedShort.cs

@@ -21,7 +21,7 @@ internal sealed class ExifSignedShort : ExifValue<short>
 
     protected override string StringValue => this.Value.ToString(CultureInfo.InvariantCulture);
 
-    public override bool TrySetValue(object value)
+    public override bool TrySetValue(object? value)
     {
         if (base.TrySetValue(value))
         {

src/ImageSharp/Metadata/Profiles/Exif/Values/ExifSignedShortArray.cs

@@ -17,7 +17,7 @@ internal sealed class ExifSignedShortArray : ExifArrayValue<short>
 
     public override ExifDataType DataType => ExifDataType.SignedShort;
 
-    public override bool TrySetValue(object value)
+    public override bool TrySetValue(object? value)
     {
         if (base.TrySetValue(value))
         {

src/ImageSharp/Metadata/Profiles/Exif/Values/ExifString.cs

@@ -24,9 +24,9 @@ internal sealed class ExifString : ExifValue<string>
 
     public override ExifDataType DataType => ExifDataType.Ascii;
 
-    protected override string StringValue => this.Value;
+    protected override string? StringValue => this.Value;
 
-    public override bool TrySetValue(object value)
+    public override bool TrySetValue(object? value)
     {
         if (base.TrySetValue(value))
         {

src/ImageSharp/Metadata/Profiles/Exif/Values/ExifUcs2String.cs

@@ -22,11 +22,11 @@ internal sealed class ExifUcs2String : ExifValue<string>
 
     public override ExifDataType DataType => ExifDataType.Byte;
 
-    protected override string StringValue => this.Value;
+    protected override string? StringValue => this.Value;
 
-    public override object GetValue() => this.Value;
+    public override object? GetValue() => this.Value;
 
-    public override bool TrySetValue(object value)
+    public override bool TrySetValue(object? value)
     {
         if (base.TrySetValue(value))
         {

src/ImageSharp/Metadata/Profiles/Exif/Values/ExifValue.cs

@@ -1,6 +1,5 @@
 // Copyright (c) Six Labors.
 // Licensed under the Six Labors Split License.
-#nullable disable
 
 using System.Runtime.CompilerServices;
 
@@ -28,7 +27,7 @@ internal abstract class ExifValue : IExifValue, IEquatable<ExifTag>
         else
         {
             // All array types are value types so Clone() is sufficient here.
-            var array = (Array)other.GetValue();
+            Array? array = (Array?)other.GetValue();
             this.TrySetValue(array?.Clone());
         }
     }
@@ -43,7 +42,7 @@ internal abstract class ExifValue : IExifValue, IEquatable<ExifTag>
 
     public static bool operator !=(ExifValue left, ExifTag right) => !Equals(left, right);
 
-    public override bool Equals(object obj)
+    public override bool Equals(object? obj)
     {
         if (obj is null)
         {
@@ -69,14 +68,14 @@ internal abstract class ExifValue : IExifValue, IEquatable<ExifTag>
     }
 
     [MethodImpl(InliningOptions.ShortMethod)]
-    public bool Equals(ExifTag other) => this.Tag.Equals(other);
+    public bool Equals(ExifTag? other) => this.Tag.Equals(other);
 
     [MethodImpl(InliningOptions.ShortMethod)]
     public override int GetHashCode() => HashCode.Combine(this.Tag, this.GetValue());
 
-    public abstract object GetValue();
+    public abstract object? GetValue();
 
-    public abstract bool TrySetValue(object value);
+    public abstract bool TrySetValue(object? value);
 
     public abstract IExifValue DeepClone();
 }

src/ImageSharp/Metadata/Profiles/Exif/Values/ExifValues.cs

@@ -1,18 +1,17 @@
 // Copyright (c) Six Labors.
 // Licensed under the Six Labors Split License.
-#nullable disable
 
 namespace SixLabors.ImageSharp.Metadata.Profiles.Exif;
 
 internal static partial class ExifValues
 {
-    public static ExifValue Create(ExifTagValue tag) => (ExifValue)CreateValue(tag);
+    public static ExifValue? Create(ExifTagValue tag) => (ExifValue?)CreateValue(tag);
 
-    public static ExifValue Create(ExifTag tag) => (ExifValue)CreateValue((ExifTagValue)(ushort)tag);
+    public static ExifValue? Create(ExifTag tag) => (ExifValue?)CreateValue((ExifTagValue)(ushort)tag);
 
-    public static ExifValue Create(ExifTagValue tag, ExifDataType dataType, ulong numberOfComponents) => Create(tag, dataType, numberOfComponents != 1);
+    public static ExifValue? Create(ExifTagValue tag, ExifDataType dataType, ulong numberOfComponents) => Create(tag, dataType, numberOfComponents != 1);
 
-    public static ExifValue Create(ExifTagValue tag, ExifDataType dataType, bool isArray)
+    public static ExifValue? Create(ExifTagValue tag, ExifDataType dataType, bool isArray)
     {
         switch (dataType)
         {
@@ -49,7 +48,7 @@ internal static partial class ExifValues
         }
     }
 
-    private static object CreateValue(ExifTagValue tag)
+    private static object? CreateValue(ExifTagValue tag)
     {
         switch (tag)
         {

src/ImageSharp/Metadata/Profiles/Exif/Values/ExifValue{TValueType}.cs

@@ -1,6 +1,5 @@
 // Copyright (c) Six Labors.
 // Licensed under the Six Labors Split License.
-#nullable disable
 
 namespace SixLabors.ImageSharp.Metadata.Profiles.Exif;
 
@@ -21,16 +20,16 @@ internal abstract class ExifValue<TValueType> : ExifValue, IExifValue<TValueType
     {
     }
 
-    public TValueType Value { get; set; }
+    public TValueType? Value { get; set; }
 
     /// <summary>
     /// Gets the value of the current instance as a string.
     /// </summary>
-    protected abstract string StringValue { get; }
+    protected abstract string? StringValue { get; }
 
-    public override object GetValue() => this.Value;
+    public override object? GetValue() => this.Value;
 
-    public override bool TrySetValue(object value)
+    public override bool TrySetValue(object? value)
     {
         if (value is null)
         {
@@ -49,14 +48,5 @@ internal abstract class ExifValue<TValueType> : ExifValue, IExifValue<TValueType
         return false;
     }
 
-    public override string ToString()
-    {
-        if (this.Value == null)
-        {
-            return null;
-        }
-
-        string description = ExifTagDescriptionAttribute.GetDescription(this.Tag, this.Value);
-        return description ?? this.StringValue;
-    }
+    public override string? ToString() => ExifTagDescriptionAttribute.TryGetDescription(this.Tag, this.Value, out string? description) ? description : this.StringValue;
 }

src/ImageSharp/Metadata/Profiles/Exif/Values/IExifValue.cs

@@ -27,12 +27,12 @@ public interface IExifValue : IDeepCloneable<IExifValue>
     /// Gets the value of this exif value.
     /// </summary>
     /// <returns>The value of this exif value.</returns>
-    object GetValue();
+    object? GetValue();
 
     /// <summary>
     /// Sets the value of this exif value.
     /// </summary>
     /// <param name="value">The value of this exif value.</param>
     /// <returns>A value indicating whether the value could be set.</returns>
-    bool TrySetValue(object value);
+    bool TrySetValue(object? value);
 }

src/ImageSharp/Metadata/Profiles/Exif/Values/IExifValue{TValueType}.cs

@@ -12,5 +12,5 @@ public interface IExifValue<TValueType> : IExifValue
     /// <summary>
     /// Gets or sets the value.
     /// </summary>
-    TValueType Value { get; set; }
+    TValueType? Value { get; set; }
 }

src/ImageSharp/PixelFormats/PixelImplementations/A8.cs

@@ -1,6 +1,5 @@
 // Copyright (c) Six Labors.
 // Licensed under the Six Labors Split License.
-#nullable disable
 
 using System.Numerics;
 using System.Runtime.CompilerServices;
@@ -140,7 +139,7 @@ public partial struct A8 : IPixel<A8>, IPackedVector<byte>
     /// </summary>
     /// <param name="obj">The object to compare.</param>
     /// <returns>True if the object is equal to the packed vector.</returns>
-    public override readonly bool Equals(object obj) => obj is A8 other && this.Equals(other);
+    public override readonly bool Equals(object? obj) => obj is A8 other && this.Equals(other);
 
     /// <summary>
     /// Compares another A8 packed vector with the packed vector.

src/ImageSharp/PixelFormats/PixelImplementations/Abgr32.cs

@@ -1,6 +1,5 @@
 // Copyright (c) Six Labors.
 // Licensed under the Six Labors Split License.
-#nullable disable
 
 using System.Numerics;
 using System.Runtime.CompilerServices;
@@ -335,7 +334,7 @@ public partial struct Abgr32 : IPixel<Abgr32>, IPackedVector<uint>
     }
 
     /// <inheritdoc/>
-    public override readonly bool Equals(object obj) => obj is Abgr32 abgr32 && this.Equals(abgr32);
+    public override readonly bool Equals(object? obj) => obj is Abgr32 abgr32 && this.Equals(abgr32);
 
     /// <inheritdoc/>
     [MethodImpl(InliningOptions.ShortMethod)]

src/ImageSharp/PixelFormats/PixelImplementations/Argb32.cs

@@ -1,6 +1,5 @@
 // Copyright (c) Six Labors.
 // Licensed under the Six Labors Split License.
-#nullable disable
 
 using System.Numerics;
 using System.Runtime.CompilerServices;
@@ -334,7 +333,7 @@ public partial struct Argb32 : IPixel<Argb32>, IPackedVector<uint>
     }
 
     /// <inheritdoc/>
-    public override readonly bool Equals(object obj) => obj is Argb32 argb32 && this.Equals(argb32);
+    public override readonly bool Equals(object? obj) => obj is Argb32 argb32 && this.Equals(argb32);
 
     /// <inheritdoc/>
     [MethodImpl(InliningOptions.ShortMethod)]

src/ImageSharp/PixelFormats/PixelImplementations/Bgr24.cs

@@ -1,6 +1,5 @@
 // Copyright (c) Six Labors.
 // Licensed under the Six Labors Split License.
-#nullable disable
 
 using System.Numerics;
 using System.Runtime.CompilerServices;
@@ -232,7 +231,7 @@ public partial struct Bgr24 : IPixel<Bgr24>
     public readonly bool Equals(Bgr24 other) => this.R.Equals(other.R) && this.G.Equals(other.G) && this.B.Equals(other.B);
 
     /// <inheritdoc/>
-    public override readonly bool Equals(object obj) => obj is Bgr24 other && this.Equals(other);
+    public override readonly bool Equals(object? obj) => obj is Bgr24 other && this.Equals(other);
 
     /// <inheritdoc />
     public override readonly string ToString() => $"Bgr24({this.B}, {this.G}, {this.R})";

src/ImageSharp/PixelFormats/PixelImplementations/Bgr565.cs

@@ -1,6 +1,5 @@
 // Copyright (c) Six Labors.
 // Licensed under the Six Labors Split License.
-#nullable disable
 
 using System.Numerics;
 using System.Runtime.CompilerServices;
@@ -151,7 +150,7 @@ public partial struct Bgr565 : IPixel<Bgr565>, IPackedVector<ushort>
                    (this.PackedValue & 0x1F) * (1F / 31F));
 
     /// <inheritdoc />
-    public override readonly bool Equals(object obj) => obj is Bgr565 other && this.Equals(other);
+    public override readonly bool Equals(object? obj) => obj is Bgr565 other && this.Equals(other);
 
     /// <inheritdoc />
     [MethodImpl(InliningOptions.ShortMethod)]

src/ImageSharp/PixelFormats/PixelImplementations/Bgra32.cs

@@ -1,6 +1,5 @@
 // Copyright (c) Six Labors.
 // Licensed under the Six Labors Split License.
-#nullable disable
 
 using System.Numerics;
 using System.Runtime.CompilerServices;
@@ -287,7 +286,7 @@ public partial struct Bgra32 : IPixel<Bgra32>, IPackedVector<uint>
     }
 
     /// <inheritdoc/>
-    public override readonly bool Equals(object obj) => obj is Bgra32 other && this.Equals(other);
+    public override readonly bool Equals(object? obj) => obj is Bgra32 other && this.Equals(other);
 
     /// <inheritdoc/>
     public readonly bool Equals(Bgra32 other) => this.Bgra.Equals(other.Bgra);

src/ImageSharp/PixelFormats/PixelImplementations/Bgra4444.cs

@@ -1,6 +1,5 @@
 // Copyright (c) Six Labors.
 // Licensed under the Six Labors Split License.
-#nullable disable
 
 using System.Numerics;
 using System.Runtime.CompilerServices;
@@ -143,7 +142,7 @@ public partial struct Bgra4444 : IPixel<Bgra4444>, IPackedVector<ushort>
     public void FromRgba64(Rgba64 source) => this.FromScaledVector4(source.ToScaledVector4());
 
     /// <inheritdoc />
-    public override readonly bool Equals(object obj) => obj is Bgra4444 other && this.Equals(other);
+    public override readonly bool Equals(object? obj) => obj is Bgra4444 other && this.Equals(other);
 
     /// <inheritdoc />
     [MethodImpl(InliningOptions.ShortMethod)]

src/ImageSharp/PixelFormats/PixelImplementations/Byte4.cs

@@ -1,6 +1,5 @@
 // Copyright (c) Six Labors.
 // Licensed under the Six Labors Split License.
-#nullable disable
 
 using System.Numerics;
 using System.Runtime.CompilerServices;
@@ -141,7 +140,7 @@ public partial struct Byte4 : IPixel<Byte4>, IPackedVector<uint>
     public void FromRgba64(Rgba64 source) => this.FromScaledVector4(source.ToScaledVector4());
 
     /// <inheritdoc />
-    public override readonly bool Equals(object obj) => obj is Byte4 byte4 && this.Equals(byte4);
+    public override readonly bool Equals(object? obj) => obj is Byte4 byte4 && this.Equals(byte4);
 
     /// <inheritdoc />
     [MethodImpl(InliningOptions.ShortMethod)]

src/ImageSharp/PixelFormats/PixelImplementations/HalfSingle.cs

@@ -1,6 +1,5 @@
 // Copyright (c) Six Labors.
 // Licensed under the Six Labors Split License.
-#nullable disable
 
 using System.Numerics;
 using System.Runtime.CompilerServices;
@@ -140,7 +139,7 @@ public partial struct HalfSingle : IPixel<HalfSingle>, IPackedVector<ushort>
     public readonly float ToSingle() => HalfTypeHelper.Unpack(this.PackedValue);
 
     /// <inheritdoc />
-    public override readonly bool Equals(object obj) => obj is HalfSingle other && this.Equals(other);
+    public override readonly bool Equals(object? obj) => obj is HalfSingle other && this.Equals(other);
 
     /// <inheritdoc />
     [MethodImpl(InliningOptions.ShortMethod)]

src/ImageSharp/PixelFormats/PixelImplementations/HalfVector2.cs

@@ -1,6 +1,5 @@
 // Copyright (c) Six Labors.
 // Licensed under the Six Labors Split License.
-#nullable disable
 
 using System.Numerics;
 using System.Runtime.CompilerServices;
@@ -157,7 +156,7 @@ public partial struct HalfVector2 : IPixel<HalfVector2>, IPackedVector<uint>
     }
 
     /// <inheritdoc />
-    public override readonly bool Equals(object obj) => obj is HalfVector2 other && this.Equals(other);
+    public override readonly bool Equals(object? obj) => obj is HalfVector2 other && this.Equals(other);
 
     /// <inheritdoc />
     [MethodImpl(InliningOptions.ShortMethod)]

src/ImageSharp/PixelFormats/PixelImplementations/HalfVector4.cs

@@ -1,6 +1,5 @@
 // Copyright (c) Six Labors.
 // Licensed under the Six Labors Split License.
-#nullable disable
 
 using System.Numerics;
 using System.Runtime.CompilerServices;
@@ -149,7 +148,7 @@ public partial struct HalfVector4 : IPixel<HalfVector4>, IPackedVector<ulong>
     public void FromRgba64(Rgba64 source) => this.FromScaledVector4(source.ToScaledVector4());
 
     /// <inheritdoc />
-    public override readonly bool Equals(object obj) => obj is HalfVector4 other && this.Equals(other);
+    public override readonly bool Equals(object? obj) => obj is HalfVector4 other && this.Equals(other);
 
     /// <inheritdoc />
     [MethodImpl(InliningOptions.ShortMethod)]

src/ImageSharp/PixelFormats/PixelImplementations/L16.cs

@@ -1,6 +1,5 @@
 // Copyright (c) Six Labors.
 // Licensed under the Six Labors Split License.
-#nullable disable
 
 using System.Numerics;
 using System.Runtime.CompilerServices;
@@ -153,7 +152,7 @@ public partial struct L16 : IPixel<L16>, IPackedVector<ushort>
     public void FromRgba64(Rgba64 source) => this.PackedValue = ColorNumerics.Get16BitBT709Luminance(source.R, source.G, source.B);
 
     /// <inheritdoc />
-    public override readonly bool Equals(object obj) => obj is L16 other && this.Equals(other);
+    public override readonly bool Equals(object? obj) => obj is L16 other && this.Equals(other);
 
     /// <inheritdoc />
     [MethodImpl(InliningOptions.ShortMethod)]

src/ImageSharp/PixelFormats/PixelImplementations/L8.cs

@@ -1,6 +1,5 @@
 // Copyright (c) Six Labors.
 // Licensed under the Six Labors Split License.
-#nullable disable
 
 using System.Numerics;
 using System.Runtime.CompilerServices;
@@ -143,7 +142,7 @@ public partial struct L8 : IPixel<L8>, IPackedVector<byte>
             ColorNumerics.DownScaleFrom16BitTo8Bit(source.B));
 
     /// <inheritdoc />
-    public override readonly bool Equals(object obj) => obj is L8 other && this.Equals(other);
+    public override readonly bool Equals(object? obj) => obj is L8 other && this.Equals(other);
 
     /// <inheritdoc />
     [MethodImpl(InliningOptions.ShortMethod)]

src/ImageSharp/PixelFormats/PixelImplementations/La16.cs

@@ -1,6 +1,5 @@
 // Copyright (c) Six Labors.
 // Licensed under the Six Labors Split License.
-#nullable disable
 
 using System.Numerics;
 using System.Runtime.CompilerServices;
@@ -80,7 +79,7 @@ public partial struct La16 : IPixel<La16>, IPackedVector<ushort>
     public readonly bool Equals(La16 other) => this.PackedValue.Equals(other.PackedValue);
 
     /// <inheritdoc />
-    public override readonly bool Equals(object obj) => obj is La16 other && this.Equals(other);
+    public override readonly bool Equals(object? obj) => obj is La16 other && this.Equals(other);
 
     /// <inheritdoc />
     public override readonly string ToString() => $"La16({this.L}, {this.A})";

src/ImageSharp/PixelFormats/PixelImplementations/La32.cs

@@ -1,6 +1,5 @@
 // Copyright (c) Six Labors.
 // Licensed under the Six Labors Split License.
-#nullable disable
 
 using System.Numerics;
 using System.Runtime.CompilerServices;
@@ -82,7 +81,7 @@ public partial struct La32 : IPixel<La32>, IPackedVector<uint>
     public readonly bool Equals(La32 other) => this.PackedValue.Equals(other.PackedValue);
 
     /// <inheritdoc />
-    public override readonly bool Equals(object obj) => obj is La32 other && this.Equals(other);
+    public override readonly bool Equals(object? obj) => obj is La32 other && this.Equals(other);
 
     /// <inheritdoc />
     public override readonly string ToString() => $"La32({this.L}, {this.A})";

src/ImageSharp/PixelFormats/PixelImplementations/NormalizedByte2.cs

@@ -1,6 +1,5 @@
 // Copyright (c) Six Labors.
 // Licensed under the Six Labors Split License.
-#nullable disable
 
 using System.Numerics;
 using System.Runtime.CompilerServices;
@@ -162,7 +161,7 @@ public partial struct NormalizedByte2 : IPixel<NormalizedByte2>, IPackedVector<u
             (sbyte)((this.PackedValue >> 8) & 0xFF) / MaxPos);
 
     /// <inheritdoc />
-    public override readonly bool Equals(object obj) => obj is NormalizedByte2 other && this.Equals(other);
+    public override readonly bool Equals(object? obj) => obj is NormalizedByte2 other && this.Equals(other);
 
     /// <inheritdoc />
     [MethodImpl(InliningOptions.ShortMethod)]

src/ImageSharp/PixelFormats/PixelImplementations/NormalizedByte4.cs

@@ -1,6 +1,5 @@
 // Copyright (c) Six Labors.
 // Licensed under the Six Labors Split License.
-#nullable disable
 
 using System.Numerics;
 using System.Runtime.CompilerServices;
@@ -154,7 +153,7 @@ public partial struct NormalizedByte4 : IPixel<NormalizedByte4>, IPackedVector<u
     public void FromRgba64(Rgba64 source) => this.FromScaledVector4(source.ToScaledVector4());
 
     /// <inheritdoc />
-    public override readonly bool Equals(object obj) => obj is NormalizedByte4 other && this.Equals(other);
+    public override readonly bool Equals(object? obj) => obj is NormalizedByte4 other && this.Equals(other);
 
     /// <inheritdoc />
     [MethodImpl(InliningOptions.ShortMethod)]

src/ImageSharp/PixelFormats/PixelImplementations/NormalizedShort2.cs

@@ -1,6 +1,5 @@
 // Copyright (c) Six Labors.
 // Licensed under the Six Labors Split License.
-#nullable disable
 
 using System.Numerics;
 using System.Runtime.CompilerServices;
@@ -163,7 +162,7 @@ public partial struct NormalizedShort2 : IPixel<NormalizedShort2>, IPackedVector
             (short)(this.PackedValue >> 0x10) / MaxPos);
 
     /// <inheritdoc />
-    public override readonly bool Equals(object obj) => obj is NormalizedShort2 other && this.Equals(other);
+    public override readonly bool Equals(object? obj) => obj is NormalizedShort2 other && this.Equals(other);
 
     /// <inheritdoc />
     [MethodImpl(InliningOptions.ShortMethod)]

src/ImageSharp/PixelFormats/PixelImplementations/NormalizedShort4.cs

@@ -1,6 +1,5 @@
 // Copyright (c) Six Labors.
 // Licensed under the Six Labors Split License.
-#nullable disable
 
 using System.Numerics;
 using System.Runtime.CompilerServices;
@@ -155,7 +154,7 @@ public partial struct NormalizedShort4 : IPixel<NormalizedShort4>, IPackedVector
     public void FromRgba64(Rgba64 source) => this.FromScaledVector4(source.ToScaledVector4());
 
     /// <inheritdoc />
-    public override readonly bool Equals(object obj) => obj is NormalizedShort4 other && this.Equals(other);
+    public override readonly bool Equals(object? obj) => obj is NormalizedShort4 other && this.Equals(other);
 
     /// <inheritdoc />
     [MethodImpl(InliningOptions.ShortMethod)]

src/ImageSharp/PixelFormats/PixelImplementations/Rg32.cs

@@ -1,6 +1,5 @@
 // Copyright (c) Six Labors.
 // Licensed under the Six Labors Split License.
-#nullable disable
 
 using System.Numerics;
 using System.Runtime.CompilerServices;
@@ -146,7 +145,7 @@ public partial struct Rg32 : IPixel<Rg32>, IPackedVector<uint>
     public readonly Vector2 ToVector2() => new Vector2(this.PackedValue & 0xFFFF, (this.PackedValue >> 16) & 0xFFFF) / Max;
 
     /// <inheritdoc />
-    public override readonly bool Equals(object obj) => obj is Rg32 other && this.Equals(other);
+    public override readonly bool Equals(object? obj) => obj is Rg32 other && this.Equals(other);
 
     /// <inheritdoc />
     [MethodImpl(InliningOptions.ShortMethod)]

src/ImageSharp/PixelFormats/PixelImplementations/Rgb24.cs

@@ -1,6 +1,5 @@
 // Copyright (c) Six Labors.
 // Licensed under the Six Labors Split License.
-#nullable disable
 
 using System.Numerics;
 using System.Runtime.CompilerServices;
@@ -241,7 +240,7 @@ public partial struct Rgb24 : IPixel<Rgb24>
     }
 
     /// <inheritdoc/>
-    public override readonly bool Equals(object obj) => obj is Rgb24 other && this.Equals(other);
+    public override readonly bool Equals(object? obj) => obj is Rgb24 other && this.Equals(other);
 
     /// <inheritdoc/>
     [MethodImpl(InliningOptions.ShortMethod)]

src/ImageSharp/PixelFormats/PixelImplementations/Rgb48.cs

@@ -1,6 +1,5 @@
 // Copyright (c) Six Labors.
 // Licensed under the Six Labors Split License.
-#nullable disable
 
 using System.Numerics;
 using System.Runtime.CompilerServices;
@@ -210,7 +209,7 @@ public partial struct Rgb48 : IPixel<Rgb48>
     public void FromRgb48(Rgb48 source) => this = source;
 
     /// <inheritdoc />
-    public override readonly bool Equals(object obj) => obj is Rgb48 rgb48 && this.Equals(rgb48);
+    public override readonly bool Equals(object? obj) => obj is Rgb48 rgb48 && this.Equals(rgb48);
 
     /// <inheritdoc />
     [MethodImpl(InliningOptions.ShortMethod)]

src/ImageSharp/PixelFormats/PixelImplementations/Rgba1010102.cs

@@ -1,6 +1,5 @@
 // Copyright (c) Six Labors.
 // Licensed under the Six Labors Split License.
-#nullable disable
 
 using System.Numerics;
 using System.Runtime.CompilerServices;
@@ -141,7 +140,7 @@ public partial struct Rgba1010102 : IPixel<Rgba1010102>, IPackedVector<uint>
     public void FromRgba64(Rgba64 source) => this.FromScaledVector4(source.ToScaledVector4());
 
     /// <inheritdoc />
-    public override readonly bool Equals(object obj) => obj is Rgba1010102 other && this.Equals(other);
+    public override readonly bool Equals(object? obj) => obj is Rgba1010102 other && this.Equals(other);
 
     /// <inheritdoc />
     [MethodImpl(InliningOptions.ShortMethod)]

src/ImageSharp/PixelFormats/PixelImplementations/Rgba32.cs

@@ -1,6 +1,5 @@
 // Copyright (c) Six Labors.
 // Licensed under the Six Labors Split License.
-#nullable disable
 
 using System.Buffers.Binary;
 using System.Globalization;
@@ -267,7 +266,7 @@ public partial struct Rgba32 : IPixel<Rgba32>, IPackedVector<uint>
     /// The <see cref="bool"/>.
     /// </returns>
     [MethodImpl(InliningOptions.ShortMethod)]
-    public static bool TryParseHex(string hex, out Rgba32 result)
+    public static bool TryParseHex(string? hex, out Rgba32 result)
     {
         result = default;
         if (string.IsNullOrWhiteSpace(hex))
@@ -437,7 +436,7 @@ public partial struct Rgba32 : IPixel<Rgba32>, IPackedVector<uint>
     }
 
     /// <inheritdoc/>
-    public override readonly bool Equals(object obj) => obj is Rgba32 rgba32 && this.Equals(rgba32);
+    public override readonly bool Equals(object? obj) => obj is Rgba32 rgba32 && this.Equals(rgba32);
 
     /// <inheritdoc/>
     [MethodImpl(InliningOptions.ShortMethod)]
@@ -514,7 +513,7 @@ public partial struct Rgba32 : IPixel<Rgba32>, IPackedVector<uint>
     /// <returns>
     /// A rrggbbaa hex value.
     /// </returns>
-    private static string ToRgbaHex(string hex)
+    private static string? ToRgbaHex(string hex)
     {
         if (hex[0] == '#')
         {