Add RGB support.

Author: JimBobSquarePants

src/ImageSharp/Formats/DecoderOptions.cs

@@ -78,12 +78,12 @@ internal bool TryGetIccProfileForColorConversion(IccProfile? profile, [NotNullWh
             return false;
         }
 
-        if (profile.IsCanonicalSrgbMatrixTrc())
+        if (this.ColorProfileHandling == ColorProfileHandling.Preserve)
         {
             return false;
         }
 
-        if (this.ColorProfileHandling == ColorProfileHandling.Preserve)
+        if (profile.IsCanonicalSrgbMatrixTrc())
         {
             return false;
         }
@@ -99,11 +99,11 @@ internal bool CanRemoveIccProfile(IccProfile? profile)
             return false;
         }
 
-        if (this.ColorProfileHandling == ColorProfileHandling.Compact && profile.IsCanonicalSrgbMatrixTrc())
+        if (this.ColorProfileHandling == ColorProfileHandling.Convert)
         {
             return true;
         }
 
-        return this.ColorProfileHandling == ColorProfileHandling.Convert;
+        return this.ColorProfileHandling == ColorProfileHandling.Compact && profile.IsCanonicalSrgbMatrixTrc();
     }
 }

src/ImageSharp/Formats/ImageDecoder.cs

@@ -328,6 +328,14 @@ private static void HandleIccProfile(DecoderOptions options, Image image)
         {
             image.Metadata.IccProfile = null;
         }
+
+        foreach (ImageFrame frame in image.Frames)
+        {
+            if (options.CanRemoveIccProfile(frame.Metadata.IccProfile))
+            {
+                frame.Metadata.IccProfile = null;
+            }
+        }
     }
 
     private static void HandleIccProfile(DecoderOptions options, ImageInfo image)
@@ -336,5 +344,13 @@ private static void HandleIccProfile(DecoderOptions options, ImageInfo image)
         {
             image.Metadata.IccProfile = null;
         }
+
+        foreach (ImageFrameMetadata frame in image.FrameMetadataCollection)
+        {
+            if (options.CanRemoveIccProfile(frame.IccProfile))
+            {
+                frame.IccProfile = null;
+            }
+        }
     }
 }

src/ImageSharp/Formats/ImageDecoderCore.cs

@@ -5,6 +5,7 @@
 using SixLabors.ImageSharp.ColorProfiles.Icc;
 using SixLabors.ImageSharp.IO;
 using SixLabors.ImageSharp.Memory;
+using SixLabors.ImageSharp.Metadata;
 using SixLabors.ImageSharp.Metadata.Profiles.Icc;
 using SixLabors.ImageSharp.PixelFormats;
 
@@ -164,4 +165,56 @@ protected bool TryConvertIccProfile<TPixel>(Image<TPixel> image)
         converter.Convert(image);
         return true;
     }
+
+    /// <summary>
+    /// Converts the ICC color profile of the specified image frame to the compact sRGB v4 profile if a source profile is
+    /// available.
+    /// </summary>
+    /// <remarks>
+    /// This method should only be used by decoders that gurantee that the encoded image data is in a color space
+    /// compatible with sRGB (e.g. standard RGB, Adobe RGB, ProPhoto RGB).
+    /// <br/>
+    /// If the image does not have a valid ICC profile for color conversion, no changes are made.
+    /// This operation may affect the color appearance of the image to ensure consistency with the sRGB color
+    /// space.
+    /// </remarks>
+    /// <typeparam name="TPixel">The pixel format.</typeparam>
+    /// <param name="frame">The image frame whose ICC profile will be converted to the compact sRGB v4 profile.</param>
+    /// <returns>
+    /// <see langword="true"/> if the conversion was performed; otherwise, <see langword="false"/>.
+    /// </returns>
+    protected bool TryConvertIccProfile<TPixel>(ImageFrame<TPixel> frame)
+        where TPixel : unmanaged, IPixel<TPixel>
+    {
+        if (!this.Options.TryGetIccProfileForColorConversion(frame.Metadata.IccProfile, out IccProfile? profile))
+        {
+            return false;
+        }
+
+        ColorConversionOptions options = new()
+        {
+            SourceIccProfile = profile,
+            TargetIccProfile = CompactSrgbV4Profile.Profile,
+            MemoryAllocator = frame.Configuration.MemoryAllocator,
+        };
+
+        ColorProfileConverter converter = new(options);
+
+        ImageMetadata metadata = new()
+        {
+            IccProfile = frame.Metadata.IccProfile
+        };
+
+        IMemoryGroup<TPixel> m = frame.PixelBuffer.MemoryGroup;
+
+        // Safe: ToArray only materializes the Memory<TPixel> segment list, not the underlying pixel buffers,
+        // and Wrap(Memory<T>[]) creates a Consumed MemoryGroup that does not own the buffers (Dispose just
+        // invalidates the view). This means no pixel data is cloned and disposing the temporary image will
+        // not dispose or leak the frame's pixel buffer.
+        MemoryGroup<TPixel> memorySource = MemoryGroup<TPixel>.Wrap(m.ToArray());
+
+        using Image<TPixel> image = new(frame.Configuration, memorySource, frame.Width, frame.Height, metadata);
+        converter.Convert(image);
+        return true;
+    }
 }

src/ImageSharp/Formats/Tiff/PhotometricInterpretation/TiffColorDecoderFactory{TPixel}.cs

@@ -429,7 +429,6 @@ public static TiffBaseColorDecoder<TPixel> Create(
         }
     }
 
-#pragma warning disable IDE0060 // Remove unused parameter
     public static TiffBasePlanarColorDecoder<TPixel> CreatePlanar(
         ImageFrameMetadata metadata,
         DecoderOptions options,

src/ImageSharp/Formats/Tiff/TiffDecoderCore.cs

@@ -52,11 +52,6 @@ internal class TiffDecoderCore : ImageDecoderCore
     /// </summary>
     private ByteOrder byteOrder;
 
-    /// <summary>
-    /// Indicating whether is BigTiff format.
-    /// </summary>
-    private bool isBigTiff;
-
     /// <summary>
     /// Initializes a new instance of the <see cref="TiffDecoderCore" /> class.
     /// </summary>
@@ -167,7 +162,6 @@ protected override Image<TPixel> Decode<TPixel>(BufferedReadStream stream, Cance
 
             IList<ExifProfile> directories = reader.Read();
             this.byteOrder = reader.ByteOrder;
-            this.isBigTiff = reader.IsBigTiff;
 
             Size? size = null;
             uint frameCount = 0;
@@ -273,6 +267,15 @@ private ImageFrame<TPixel> DecodeFrame<TPixel>(ExifProfile tags, Size? size, Can
             this.DecodeImageWithStrips(tags, frame, width, height, cancellationToken);
         }
 
+        // Only RGB-compatible color types can be converted here because the TPixel-based ICC profile conversion
+        // expects RGB-like pixel data; other photometric interpretations (YCbCr, CMYK, Lab, etc.) would require
+        // dedicated transforms. We do this once at the frame level to avoid duplicating conversion logic
+        // across all color decoders and to keep their decode paths focused on raw pixel unpacking.
+        if (this.ColorType is >= TiffColorType.PaletteColor and <= TiffColorType.Rgba32323232Planar)
+        {
+            _ = this.TryConvertIccProfile(frame);
+        }
+
         return frame;
     }
 

tests/ImageSharp.Tests/Formats/Tiff/TiffDecoderTests.cs

@@ -23,7 +23,7 @@ public class TiffDecoderTests : TiffDecoderBaseTester
     public static readonly string[] MultiframeTestImages = Multiframes;
 
     [Theory]
-    // [WithFile(MultiframeDifferentVariants, PixelTypes.Rgba32)]
+    [WithFile(MultiframeDifferentVariants, PixelTypes.Rgba32)]
     [WithFile(Cmyk64BitDeflate, PixelTypes.Rgba32)]
     public void ThrowsNotSupported<TPixel>(TestImageProvider<TPixel> provider)
         where TPixel : unmanaged, IPixel<TPixel> => Assert.Throws<NotSupportedException>(() => provider.GetImage(TiffDecoder.Instance));
@@ -355,6 +355,8 @@ public void TiffDecoder_CanDecode_Cmyk<TPixel>(TestImageProvider<TPixel> provide
     [Theory]
     [WithFile(Icc.PerceptualCmyk, PixelTypes.Rgba32)]
     [WithFile(Icc.PerceptualCieLab, PixelTypes.Rgba32)]
+    [WithFile(Icc.PerceptualRgb8, PixelTypes.Rgba32)]
+    [WithFile(Icc.PerceptualRgb16, PixelTypes.Rgba32)]
     public void Decode_WhenColorProfileHandlingIsConvert_ApplyIccProfile<TPixel>(TestImageProvider<TPixel> provider)
         where TPixel : unmanaged, IPixel<TPixel>
     {

tests/ImageSharp.Tests/TestImages.cs

@@ -1199,6 +1199,8 @@ public static class Icc
         {
             public const string PerceptualCmyk = "Tiff/icc-profiles/Perceptual_CMYK.tiff";
             public const string PerceptualCieLab = "Tiff/icc-profiles/Perceptual_CIELAB.tiff";
+            public const string PerceptualRgb8 = "Tiff/icc-profiles/Perceptual_RGB8.tiff";
+            public const string PerceptualRgb16 = "Tiff/icc-profiles/Perceptual_RGB16.tiff";
         }
     }
 

tests/Images/External/ReferenceOutput/TiffDecoderTests/Decode_WhenColorProfileHandlingIsConvert_ApplyIccProfile_Rgba32_Perceptual_RGB16.png

@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:3b0e89ac971c23c12c9edff6f9e9dd066fe99f36e28e89972343d50562dd7dbd
+size 65260