Enable colorimetric normalization of JPEG image data during decode

src/ImageSharp/Advanced/AotCompilerTools.cs

@@ -277,11 +277,11 @@ private static void AotCompileImageDecoders<TPixel>()
     private static void AotCompileSpectralConverter<TPixel>()
         where TPixel : unmanaged, IPixel<TPixel>
     {
-        default(SpectralConverter<TPixel>).GetPixelBuffer(default);
-        default(GrayJpegSpectralConverter<TPixel>).GetPixelBuffer(default);
-        default(RgbJpegSpectralConverter<TPixel>).GetPixelBuffer(default);
-        default(TiffJpegSpectralConverter<TPixel>).GetPixelBuffer(default);
-        default(TiffOldJpegSpectralConverter<TPixel>).GetPixelBuffer(default);
+        default(SpectralConverter<TPixel>).GetPixelBuffer(default, default);
+        default(GrayJpegSpectralConverter<TPixel>).GetPixelBuffer(default, default);
+        default(RgbJpegSpectralConverter<TPixel>).GetPixelBuffer(default, default);
+        default(TiffJpegSpectralConverter<TPixel>).GetPixelBuffer(default, default);
+        default(TiffOldJpegSpectralConverter<TPixel>).GetPixelBuffer(default, default);
     }
 
     /// <summary>

src/ImageSharp/ColorProfiles/ColorConversionOptions.cs

@@ -14,15 +14,15 @@ namespace SixLabors.ImageSharp.ColorProfiles;
 public class ColorConversionOptions
 {
     private Matrix4x4 adaptationMatrix;
-    private YCbCrMatrix yCbCrMatrix;
+    private YCbCrTransform yCbCrTransform;
 
     /// <summary>
     /// Initializes a new instance of the <see cref="ColorConversionOptions"/> class.
     /// </summary>
     public ColorConversionOptions()
     {
         this.AdaptationMatrix = KnownChromaticAdaptationMatrices.Bradford;
-        this.YCbCrMatrix = KnownYCbCrMatrices.BT601;
+        this.YCbCrTransform = KnownYCbCrMatrices.BT601;
     }
 
     /// <summary>
@@ -53,13 +53,13 @@ public ColorConversionOptions()
     /// <summary>
     /// Gets the YCbCr matrix to used to perform conversions from/to RGB.
     /// </summary>
-    public YCbCrMatrix YCbCrMatrix
+    public YCbCrTransform YCbCrTransform
     {
-        get => this.yCbCrMatrix;
+        get => this.yCbCrTransform;
         init
         {
-            this.yCbCrMatrix = value;
-            this.TransposedYCbCrMatrix = value.Transpose();
+            this.yCbCrTransform = value;
+            this.TransposedYCbCrTransform = value.Transpose();
         }
     }
 
@@ -88,7 +88,7 @@ public Matrix4x4 AdaptationMatrix
         }
     }
 
-    internal YCbCrMatrix TransposedYCbCrMatrix { get; private set; }
+    internal YCbCrTransform TransposedYCbCrTransform { get; private set; }
 
     internal Matrix4x4 InverseAdaptationMatrix { get; private set; }
 }

src/ImageSharp/ColorProfiles/Icc/SrgbV4Profile.Generated.cs → src/ImageSharp/ColorProfiles/Icc/CompactSrgbV4Profile.cs

@@ -1,17 +1,17 @@
 // Copyright (c) Six Labors.
 // Licensed under the Six Labors Split License.
 
-// <auto-generated />
-
 using SixLabors.ImageSharp.Metadata.Profiles.Icc;
 
-namespace SixLabors.ImageSharp.ColorProfiles.Conversion.Icc;
+namespace SixLabors.ImageSharp.ColorProfiles.Icc;
 
-internal static class SrgbV4Profile
+internal static class CompactSrgbV4Profile
 {
+    private static readonly Lazy<IccProfile> LazyIccProfile = new(GetIccProfile);
+
     // Generated using the sRGB-v4.icc profile found at https://github.com/saucecontrol/Compact-ICC-Profiles
-    private static ReadOnlySpan<byte> Data => new byte[]
-    {
+    private static ReadOnlySpan<byte> Data =>
+    [
         0, 0, 1, 224, 108, 99, 109, 115, 4, 32, 0, 0, 109, 110, 116, 114, 82, 71, 66, 32, 88, 89, 90, 32, 7, 226, 0, 3, 0,
         20, 0, 9, 0, 14, 0, 29, 97, 99, 115, 112, 77, 83, 70, 84, 0, 0, 0, 0, 115, 97, 119, 115, 99, 116, 114, 108, 0, 0,
         0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 246, 214, 0, 1, 0, 0, 0, 0, 211, 45, 104, 97, 110, 100, 163, 178, 171,
@@ -29,11 +29,9 @@ internal static class SrgbV4Profile
         3, 143, 88, 89, 90, 32, 0, 0, 0, 0, 0, 0, 98, 150, 0, 0, 183, 137, 0, 0, 24, 218, 88, 89, 90, 32, 0, 0, 0,
         0, 0, 0, 36, 160, 0, 0, 15, 133, 0, 0, 182, 196, 112, 97, 114, 97, 0, 0, 0, 0, 0, 3, 0, 0, 0, 2, 102, 105,
         0, 0, 242, 167, 0, 0, 13, 89, 0, 0, 19, 208, 0, 0, 10, 91,
-    };
+    ];
 
-    private static readonly Lazy<IccProfile> LazyIccProfile = new(() => GetIccProfile());
-
-    public static IccProfile GetProfile() => LazyIccProfile.Value;
+    public static IccProfile Profile => LazyIccProfile.Value;
 
     private static IccProfile GetIccProfile()
     {
@@ -42,4 +40,3 @@ private static IccProfile GetIccProfile()
         return new IccProfile(buffer);
     }
 }
-

src/ImageSharp/ColorProfiles/KnownYCbCrMatrices.cs

@@ -15,7 +15,7 @@ public static class KnownYCbCrMatrices
     /// <summary>
     /// ITU-R BT.601 (SD video standard).
     /// </summary>
-    public static readonly YCbCrMatrix BT601 = new(
+    public static readonly YCbCrTransform BT601 = new(
         new Matrix4x4(
             0.299000F, 0.587000F, 0.114000F, 0F,
            -0.168736F, -0.331264F, 0.500000F, 0F,
@@ -31,7 +31,7 @@ public static class KnownYCbCrMatrices
     /// <summary>
     /// ITU-R BT.709 (HD video, sRGB standard).
     /// </summary>
-    public static readonly YCbCrMatrix BT709 = new(
+    public static readonly YCbCrTransform BT709 = new(
         new Matrix4x4(
             0.212600F, 0.715200F, 0.072200F, 0F,
            -0.114572F, -0.385428F, 0.500000F, 0F,
@@ -47,7 +47,7 @@ public static class KnownYCbCrMatrices
     /// <summary>
     /// ITU-R BT.2020 (UHD/4K video standard).
     /// </summary>
-    public static readonly YCbCrMatrix BT2020 = new(
+    public static readonly YCbCrTransform BT2020 = new(
         new Matrix4x4(
             0.262700F, 0.678000F, 0.059300F, 0F,
            -0.139630F, -0.360370F, 0.500000F, 0F,

src/ImageSharp/ColorProfiles/Rgb.cs

@@ -98,7 +98,7 @@ public static Rgb FromScaledVector4(Vector4 source)
     /// <returns>The <see cref="Vector4"/>.</returns>
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     public Vector4 ToScaledVector4()
-        => new(this.ToScaledVector3(), 1F);
+        => new(this.AsVector3Unsafe(), 1F);
 
     /// <inheritdoc/>
     public static void ToScaledVector4(ReadOnlySpan<Rgb> source, Span<Vector4> destination)
@@ -154,7 +154,7 @@ public CieXyz ToProfileConnectingSpace(ColorConversionOptions options)
         Rgb linear = FromScaledVector4(options.SourceRgbWorkingSpace.Expand(this.ToScaledVector4()));
 
         // Then convert to xyz
-        return new CieXyz(Vector3.Transform(linear.ToScaledVector3(), GetRgbToCieXyzMatrix(options.SourceRgbWorkingSpace)));
+        return new CieXyz(Vector3.Transform(linear.AsVector3Unsafe(), GetRgbToCieXyzMatrix(options.SourceRgbWorkingSpace)));
     }
 
     /// <inheritdoc/>
@@ -171,7 +171,7 @@ public static void ToProfileConnectionSpace(ColorConversionOptions options, Read
             Rgb linear = FromScaledVector4(options.SourceRgbWorkingSpace.Expand(rgb.ToScaledVector4()));
 
             // Then convert to xyz
-            destination[i] = new CieXyz(Vector3.Transform(linear.ToScaledVector3(), matrix));
+            destination[i] = new CieXyz(Vector3.Transform(linear.AsVector3Unsafe(), matrix));
         }
     }
 

src/ImageSharp/ColorProfiles/Y.cs

@@ -90,8 +90,8 @@ public Rgb ToProfileConnectingSpace(ColorConversionOptions options)
     /// <inheritdoc/>
     public static Y FromProfileConnectingSpace(ColorConversionOptions options, in Rgb source)
     {
-        Matrix4x4 m = options.YCbCrMatrix.Forward;
-        float offset = options.YCbCrMatrix.Offset.X;
+        Matrix4x4 m = options.YCbCrTransform.Forward;
+        float offset = options.YCbCrTransform.Offset.X;
         return new(Vector3.Dot(source.AsVector3Unsafe(), new Vector3(m.M11, m.M12, m.M13)) + offset);
     }
 

src/ImageSharp/ColorProfiles/YCbCr.cs

@@ -130,8 +130,8 @@ public static void FromScaledVector4(ReadOnlySpan<Vector4> source, Span<YCbCr> d
     public static YCbCr FromProfileConnectingSpace(ColorConversionOptions options, in Rgb source)
     {
         Vector3 rgb = source.AsVector3Unsafe();
-        Matrix4x4 m = options.TransposedYCbCrMatrix.Forward;
-        Vector3 offset = options.TransposedYCbCrMatrix.Offset;
+        Matrix4x4 m = options.TransposedYCbCrTransform.Forward;
+        Vector3 offset = options.TransposedYCbCrTransform.Offset;
 
         return new YCbCr(Vector3.Transform(rgb, m) + offset, true);
     }
@@ -152,8 +152,8 @@ public static void FromProfileConnectionSpace(ColorConversionOptions options, Re
     /// <inheritdoc/>
     public Rgb ToProfileConnectingSpace(ColorConversionOptions options)
     {
-        Matrix4x4 m = options.TransposedYCbCrMatrix.Inverse;
-        Vector3 offset = options.TransposedYCbCrMatrix.Offset;
+        Matrix4x4 m = options.TransposedYCbCrTransform.Inverse;
+        Vector3 offset = options.TransposedYCbCrTransform.Offset;
         Vector3 normalized = this.AsVector3Unsafe() - offset;
 
         return Rgb.FromScaledVector3(Vector3.Transform(normalized, m));

src/ImageSharp/ColorProfiles/YcbCrMatrix.cs → src/ImageSharp/ColorProfiles/YCbCrTransform.cs

@@ -8,7 +8,7 @@ namespace SixLabors.ImageSharp.ColorProfiles;
 
 /// <summary>
 /// <para>
-/// Represents a YCbCr color matrix containing forward and inverse transformation matrices,
+/// Represents a YCbCr color transform containing forward and inverse transformation matrices,
 /// and the chrominance offsets to apply for full-range encoding
 /// </para>
 /// <para>
@@ -17,10 +17,10 @@ namespace SixLabors.ImageSharp.ColorProfiles;
 /// working spaces will produce incorrect conversions.
 /// </para>
 /// </summary>
-public readonly struct YCbCrMatrix
+public readonly struct YCbCrTransform
 {
     /// <summary>
-    /// Initializes a new instance of the <see cref="YCbCrMatrix"/> struct.
+    /// Initializes a new instance of the <see cref="YCbCrTransform"/> struct.
     /// </summary>
     /// <param name="forward">
     /// The forward transformation matrix from RGB to YCbCr. The matrix must include the
@@ -34,7 +34,7 @@ public readonly struct YCbCrMatrix
     /// The chrominance offsets to be added after the forward conversion,
     /// and subtracted before the inverse conversion. Usually <c>(0, 0.5, 0.5)</c>.
     /// </param>
-    public YCbCrMatrix(Matrix4x4 forward, Matrix4x4 inverse, Vector3 offset)
+    public YCbCrTransform(Matrix4x4 forward, Matrix4x4 inverse, Vector3 offset)
     {
         this.Forward = forward;
         this.Inverse = inverse;
@@ -56,6 +56,6 @@ public YCbCrMatrix(Matrix4x4 forward, Matrix4x4 inverse, Vector3 offset)
     /// </summary>
     public Vector3 Offset { get; }
 
-    internal YCbCrMatrix Transpose()
+    internal YCbCrTransform Transpose()
         => new(Matrix4x4.Transpose(this.Forward), Matrix4x4.Transpose(this.Inverse), this.Offset);
 }

src/ImageSharp/ColorProfiles/YccK.cs

@@ -131,8 +131,8 @@ public static void FromScaledVector4(ReadOnlySpan<Vector4> source, Span<YccK> de
     /// <inheritdoc/>
     public Rgb ToProfileConnectingSpace(ColorConversionOptions options)
     {
-        Matrix4x4 m = options.TransposedYCbCrMatrix.Inverse;
-        Vector3 offset = options.TransposedYCbCrMatrix.Offset;
+        Matrix4x4 m = options.TransposedYCbCrTransform.Inverse;
+        Vector3 offset = options.TransposedYCbCrTransform.Offset;
         Vector3 normalized = this.AsVector3Unsafe() - offset;
 
         return Rgb.FromScaledVector3(Vector3.Transform(normalized, m) * (1F - this.K));
@@ -141,8 +141,8 @@ public Rgb ToProfileConnectingSpace(ColorConversionOptions options)
     /// <inheritdoc/>
     public static YccK FromProfileConnectingSpace(ColorConversionOptions options, in Rgb source)
     {
-        Matrix4x4 m = options.TransposedYCbCrMatrix.Forward;
-        Vector3 offset = options.TransposedYCbCrMatrix.Offset;
+        Matrix4x4 m = options.TransposedYCbCrTransform.Forward;
+        Vector3 offset = options.TransposedYCbCrTransform.Offset;
 
         Vector3 rgb = source.AsVector3Unsafe();
         float k = 1F - MathF.Max(rgb.X, MathF.Max(rgb.Y, rgb.Z));

src/ImageSharp/Formats/ColorProfileHandling.cs

@@ -13,9 +13,14 @@ public enum ColorProfileHandling
     /// </summary>
     Preserve,
 
+    /// <summary>
+    /// Removes any embedded Standard sRGB ICC color profiles without transforming the pixels of the image.
+    /// </summary>
+    Compact,
+
     /// <summary>
     /// Transforms the pixels of the image based on the conversion of any embedded ICC color profiles to sRGB V4 profile.
-    /// The original profile is then replaced.
+    /// The original profile is then removed.
     /// </summary>
     Convert
 }

src/ImageSharp/Formats/DecoderOptions.cs

@@ -1,6 +1,8 @@
 // Copyright (c) Six Labors.
 // Licensed under the Six Labors Split License.
 
+using System.Diagnostics.CodeAnalysis;
+using SixLabors.ImageSharp.Metadata.Profiles.Icc;
 using SixLabors.ImageSharp.Processing;
 using SixLabors.ImageSharp.Processing.Processors.Transforms;
 
@@ -62,9 +64,46 @@ public sealed class DecoderOptions
 
     /// <summary>
     /// Gets a value that controls how ICC profiles are handled during decode.
-    /// TODO: Implement this.
     /// </summary>
-    internal ColorProfileHandling ColorProfileHandling { get; init; }
+    public ColorProfileHandling ColorProfileHandling { get; init; }
 
     internal void SetConfiguration(Configuration configuration) => this.configuration = configuration;
+
+    internal bool TryGetIccProfileForColorConversion(IccProfile? profile, [NotNullWhen(true)] out IccProfile? value)
+    {
+        value = null;
+
+        if (profile is null)
+        {
+            return false;
+        }
+
+        if (IccProfileHeader.IsLikelySrgb(profile.Header))
+        {
+            return false;
+        }
+
+        if (this.ColorProfileHandling == ColorProfileHandling.Preserve)
+        {
+            return false;
+        }
+
+        value = profile;
+        return true;
+    }
+
+    internal bool CanRemoveIccProfile(IccProfile? profile)
+    {
+        if (profile is null)
+        {
+            return false;
+        }
+
+        if (this.ColorProfileHandling == ColorProfileHandling.Compact && IccProfileHeader.IsLikelySrgb(profile.Header))
+        {
+            return true;
+        }
+
+        return this.ColorProfileHandling == ColorProfileHandling.Convert;
+    }
 }

src/ImageSharp/Formats/ImageDecoder.cs

@@ -24,6 +24,7 @@ public Image<TPixel> Decode<TPixel>(DecoderOptions options, Stream stream)
             s => this.Decode<TPixel>(options, s, default));
 
         this.SetDecoderFormat(options.Configuration, image);
+        HandleIccProfile(options, image);
 
         return image;
     }
@@ -37,6 +38,7 @@ public Image Decode(DecoderOptions options, Stream stream)
             s => this.Decode(options, s, default));
 
         this.SetDecoderFormat(options.Configuration, image);
+        HandleIccProfile(options, image);
 
         return image;
     }
@@ -52,6 +54,7 @@ public async Task<Image<TPixel>> DecodeAsync<TPixel>(DecoderOptions options, Str
             cancellationToken).ConfigureAwait(false);
 
         this.SetDecoderFormat(options.Configuration, image);
+        HandleIccProfile(options, image);
 
         return image;
     }
@@ -66,6 +69,7 @@ public async Task<Image> DecodeAsync(DecoderOptions options, Stream stream, Canc
             cancellationToken).ConfigureAwait(false);
 
         this.SetDecoderFormat(options.Configuration, image);
+        HandleIccProfile(options, image);
 
         return image;
     }
@@ -79,6 +83,7 @@ public ImageInfo Identify(DecoderOptions options, Stream stream)
             s => this.Identify(options, s, default));
 
         this.SetDecoderFormat(options.Configuration, info);
+        HandleIccProfile(options, info);
 
         return info;
     }
@@ -93,6 +98,7 @@ public async Task<ImageInfo> IdentifyAsync(DecoderOptions options, Stream stream
             cancellationToken).ConfigureAwait(false);
 
         this.SetDecoderFormat(options.Configuration, info);
+        HandleIccProfile(options, info);
 
         return info;
     }
@@ -315,4 +321,20 @@ internal void SetDecoderFormat(Configuration configuration, ImageInfo info)
             }
         }
     }
+
+    private static void HandleIccProfile(DecoderOptions options, Image image)
+    {
+        if (options.CanRemoveIccProfile(image.Metadata.IccProfile))
+        {
+            image.Metadata.IccProfile = null;
+        }
+    }
+
+    private static void HandleIccProfile(DecoderOptions options, ImageInfo image)
+    {
+        if (options.CanRemoveIccProfile(image.Metadata.IccProfile))
+        {
+            image.Metadata.IccProfile = null;
+        }
+    }
 }