diff --git a/src/ImageSharp/Formats/Png/PngDecoderCore.cs b/src/ImageSharp/Formats/Png/PngDecoderCore.cs index 12770bc521..f46b5058a1 100644 --- a/src/ImageSharp/Formats/Png/PngDecoderCore.cs +++ b/src/ImageSharp/Formats/Png/PngDecoderCore.cs @@ -19,6 +19,7 @@ using SixLabors.ImageSharp.IO; using SixLabors.ImageSharp.Memory; using SixLabors.ImageSharp.Metadata; using SixLabors.ImageSharp.Metadata.Profiles.Exif; +using SixLabors.ImageSharp.Metadata.Profiles.Icc; using SixLabors.ImageSharp.Metadata.Profiles.Xmp; using SixLabors.ImageSharp.PixelFormats; @@ -205,6 +206,9 @@ namespace SixLabors.ImageSharp.Formats.Png this.MergeOrSetExifProfile(metadata, new ExifProfile(exifData), replaceExistingKeys: true); } + break; + case PngChunkType.EmbeddedColorProfile: + this.ReadColorProfileChunk(metadata, chunk.Data.GetSpan()); break; case PngChunkType.End: goto EOF; @@ -1174,6 +1178,76 @@ namespace SixLabors.ImageSharp.Formats.Png return true; } + /// + /// Reads the color profile chunk. The data is stored similar to the zTXt chunk. + /// + /// The metadata. + /// The bytes containing the profile. + private void ReadColorProfileChunk(ImageMetadata metadata, ReadOnlySpan data) + { + int zeroIndex = data.IndexOf((byte)0); + if (zeroIndex is < PngConstants.MinTextKeywordLength or > PngConstants.MaxTextKeywordLength) + { + return; + } + + byte compressionMethod = data[zeroIndex + 1]; + if (compressionMethod != 0) + { + // Only compression method 0 is supported (zlib datastream with deflate compression). + return; + } + + ReadOnlySpan keywordBytes = data.Slice(0, zeroIndex); + if (!this.TryReadTextKeyword(keywordBytes, out string name)) + { + return; + } + + ReadOnlySpan compressedData = data.Slice(zeroIndex + 2); + + if (this.TryUncompressZlibData(compressedData, out byte[] iccpProfileBytes)) + { + metadata.IccProfile = new IccProfile(iccpProfileBytes); + } + } + + /// + /// Tries to un-compress zlib compressed data. + /// + /// The compressed data. + /// The uncompressed bytes array. + /// True, if de-compressing was successful. + private unsafe bool TryUncompressZlibData(ReadOnlySpan compressedData, out byte[] uncompressedBytesArray) + { + fixed (byte* compressedDataBase = compressedData) + { + using (IMemoryOwner destBuffer = this.memoryAllocator.Allocate(this.Configuration.StreamProcessingBufferSize)) + using (var memoryStreamOutput = new MemoryStream(compressedData.Length)) + using (var memoryStreamInput = new UnmanagedMemoryStream(compressedDataBase, compressedData.Length)) + using (var bufferedStream = new BufferedReadStream(this.Configuration, memoryStreamInput)) + using (var inflateStream = new ZlibInflateStream(bufferedStream)) + { + Span destUncompressedData = destBuffer.GetSpan(); + if (!inflateStream.AllocateNewBytes(compressedData.Length, false)) + { + uncompressedBytesArray = Array.Empty(); + return false; + } + + int bytesRead = inflateStream.CompressedStream.Read(destUncompressedData, 0, destUncompressedData.Length); + while (bytesRead != 0) + { + memoryStreamOutput.Write(destUncompressedData.Slice(0, bytesRead)); + bytesRead = inflateStream.CompressedStream.Read(destUncompressedData, 0, destUncompressedData.Length); + } + + uncompressedBytesArray = memoryStreamOutput.ToArray(); + return true; + } + } + } + /// /// Compares two ReadOnlySpan<char>s in a case-insensitive method. /// This is only needed because older frameworks are missing the extension method. @@ -1306,7 +1380,7 @@ namespace SixLabors.ImageSharp.Formats.Png } else if (this.IsXmpTextData(keywordBytes)) { - XmpProfile xmpProfile = new XmpProfile(data.Slice(dataStartIdx).ToArray()); + var xmpProfile = new XmpProfile(data.Slice(dataStartIdx).ToArray()); metadata.XmpProfile = xmpProfile; } else @@ -1325,29 +1399,14 @@ namespace SixLabors.ImageSharp.Formats.Png /// The . private bool TryUncompressTextData(ReadOnlySpan compressedData, Encoding encoding, out string value) { - using (var memoryStream = new MemoryStream(compressedData.ToArray())) - using (var bufferedStream = new BufferedReadStream(this.Configuration, memoryStream)) - using (var inflateStream = new ZlibInflateStream(bufferedStream)) + if (this.TryUncompressZlibData(compressedData, out byte[] uncompressedData)) { - if (!inflateStream.AllocateNewBytes(compressedData.Length, false)) - { - value = null; - return false; - } - - var uncompressedBytes = new List(); - - // Note: this uses a buffer which is only 4 bytes long to read the stream, maybe allocating a larger buffer makes sense here. - int bytesRead = inflateStream.CompressedStream.Read(this.buffer, 0, this.buffer.Length); - while (bytesRead != 0) - { - uncompressedBytes.AddRange(this.buffer.AsSpan(0, bytesRead).ToArray()); - bytesRead = inflateStream.CompressedStream.Read(this.buffer, 0, this.buffer.Length); - } - - value = encoding.GetString(uncompressedBytes.ToArray()); + value = encoding.GetString(uncompressedData); return true; } + + value = null; + return false; } /// diff --git a/src/ImageSharp/Formats/Png/PngEncoderCore.cs b/src/ImageSharp/Formats/Png/PngEncoderCore.cs index c443c0fcf1..ad16c80374 100644 --- a/src/ImageSharp/Formats/Png/PngEncoderCore.cs +++ b/src/ImageSharp/Formats/Png/PngEncoderCore.cs @@ -87,6 +87,11 @@ namespace SixLabors.ImageSharp.Formats.Png /// private IMemoryOwner currentScanline; + /// + /// The color profile name. + /// + private const string ColorProfileName = "ICC Profile"; + /// /// Initializes a new instance of the class. /// @@ -134,6 +139,7 @@ namespace SixLabors.ImageSharp.Formats.Png this.WriteHeaderChunk(stream); this.WriteGammaChunk(stream); + this.WriteColorProfileChunk(stream, metadata); this.WritePaletteChunk(stream, quantized); this.WriteTransparencyChunk(stream, pngMetadata); this.WritePhysicalChunk(stream, metadata); @@ -656,7 +662,7 @@ namespace SixLabors.ImageSharp.Formats.Png } /// - /// Writes an iTXT chunk, containing the XMP metdata to the stream, if such profile is present in the metadata. + /// Writes an iTXT chunk, containing the XMP metadata to the stream, if such profile is present in the metadata. /// /// The containing image data. /// The image metadata. @@ -673,7 +679,7 @@ namespace SixLabors.ImageSharp.Formats.Png return; } - var xmpData = meta.XmpProfile.Data; + byte[] xmpData = meta.XmpProfile.Data; if (xmpData.Length == 0) { @@ -687,19 +693,49 @@ namespace SixLabors.ImageSharp.Formats.Png PngConstants.XmpKeyword.CopyTo(payload); int bytesWritten = PngConstants.XmpKeyword.Length; - // Write the iTxt header (all zeros in this case) - payload[bytesWritten++] = 0; - payload[bytesWritten++] = 0; - payload[bytesWritten++] = 0; - payload[bytesWritten++] = 0; - payload[bytesWritten++] = 0; + // Write the iTxt header (all zeros in this case). + Span iTxtHeader = payload.Slice(bytesWritten); + iTxtHeader[4] = 0; + iTxtHeader[3] = 0; + iTxtHeader[2] = 0; + iTxtHeader[1] = 0; + iTxtHeader[0] = 0; + bytesWritten += 5; - // And the XMP data itself + // And the XMP data itself. xmpData.CopyTo(payload.Slice(bytesWritten)); this.WriteChunk(stream, PngChunkType.InternationalText, payload); } } + /// + /// Writes the color profile chunk. + /// + /// The stream to write to. + /// The image meta data. + private void WriteColorProfileChunk(Stream stream, ImageMetadata metaData) + { + if (metaData.IccProfile is null) + { + return; + } + + byte[] iccProfileBytes = metaData.IccProfile.ToByteArray(); + + byte[] compressedData = this.GetZlibCompressedBytes(iccProfileBytes); + int payloadLength = ColorProfileName.Length + compressedData.Length + 2; + using (IMemoryOwner owner = this.memoryAllocator.Allocate(payloadLength)) + { + Span outputBytes = owner.GetSpan(); + PngConstants.Encoding.GetBytes(ColorProfileName).CopyTo(outputBytes); + int bytesWritten = ColorProfileName.Length; + outputBytes[bytesWritten++] = 0; // Null separator. + outputBytes[bytesWritten++] = 0; // Compression. + compressedData.CopyTo(outputBytes.Slice(bytesWritten)); + this.WriteChunk(stream, PngChunkType.EmbeddedColorProfile, outputBytes); + } + } + /// /// Writes a text chunk to the stream. Can be either a tTXt, iTXt or zTXt chunk, /// depending whether the text contains any latin characters or should be compressed. @@ -727,13 +763,12 @@ namespace SixLabors.ImageSharp.Formats.Png } } - if (hasUnicodeCharacters || (!string.IsNullOrWhiteSpace(textData.LanguageTag) || - !string.IsNullOrWhiteSpace(textData.TranslatedKeyword))) + if (hasUnicodeCharacters || (!string.IsNullOrWhiteSpace(textData.LanguageTag) || !string.IsNullOrWhiteSpace(textData.TranslatedKeyword))) { // Write iTXt chunk. byte[] keywordBytes = PngConstants.Encoding.GetBytes(textData.Keyword); byte[] textBytes = textData.Value.Length > this.options.TextCompressionThreshold - ? this.GetCompressedTextBytes(PngConstants.TranslatedEncoding.GetBytes(textData.Value)) + ? this.GetZlibCompressedBytes(PngConstants.TranslatedEncoding.GetBytes(textData.Value)) : PngConstants.TranslatedEncoding.GetBytes(textData.Value); byte[] translatedKeyword = PngConstants.TranslatedEncoding.GetBytes(textData.TranslatedKeyword); @@ -772,18 +807,17 @@ namespace SixLabors.ImageSharp.Formats.Png if (textData.Value.Length > this.options.TextCompressionThreshold) { // Write zTXt chunk. - byte[] compressedData = - this.GetCompressedTextBytes(PngConstants.Encoding.GetBytes(textData.Value)); + byte[] compressedData = this.GetZlibCompressedBytes(PngConstants.Encoding.GetBytes(textData.Value)); int payloadLength = textData.Keyword.Length + compressedData.Length + 2; using (IMemoryOwner owner = this.memoryAllocator.Allocate(payloadLength)) { Span outputBytes = owner.GetSpan(); PngConstants.Encoding.GetBytes(textData.Keyword).CopyTo(outputBytes); int bytesWritten = textData.Keyword.Length; - outputBytes[bytesWritten++] = 0; - outputBytes[bytesWritten++] = 0; + outputBytes[bytesWritten++] = 0; // Null separator. + outputBytes[bytesWritten++] = 0; // Compression. compressedData.CopyTo(outputBytes.Slice(bytesWritten)); - this.WriteChunk(stream, PngChunkType.CompressedText, outputBytes.ToArray()); + this.WriteChunk(stream, PngChunkType.CompressedText, outputBytes); } } else @@ -796,9 +830,8 @@ namespace SixLabors.ImageSharp.Formats.Png PngConstants.Encoding.GetBytes(textData.Keyword).CopyTo(outputBytes); int bytesWritten = textData.Keyword.Length; outputBytes[bytesWritten++] = 0; - PngConstants.Encoding.GetBytes(textData.Value) - .CopyTo(outputBytes.Slice(bytesWritten)); - this.WriteChunk(stream, PngChunkType.Text, outputBytes.ToArray()); + PngConstants.Encoding.GetBytes(textData.Value).CopyTo(outputBytes.Slice(bytesWritten)); + this.WriteChunk(stream, PngChunkType.Text, outputBytes); } } } @@ -808,15 +841,15 @@ namespace SixLabors.ImageSharp.Formats.Png /// /// Compresses a given text using Zlib compression. /// - /// The text bytes to compress. - /// The compressed text byte array. - private byte[] GetCompressedTextBytes(byte[] textBytes) + /// The bytes to compress. + /// The compressed byte array. + private byte[] GetZlibCompressedBytes(byte[] dataBytes) { using (var memoryStream = new MemoryStream()) { using (var deflateStream = new ZlibDeflateStream(this.memoryAllocator, memoryStream, this.options.CompressionLevel)) { - deflateStream.Write(textBytes); + deflateStream.Write(dataBytes); } return memoryStream.ToArray(); diff --git a/tests/ImageSharp.Tests/Formats/Png/PngEncoderTests.Chunks.cs b/tests/ImageSharp.Tests/Formats/Png/PngEncoderTests.Chunks.cs index 30a6847029..ede4ec1ccc 100644 --- a/tests/ImageSharp.Tests/Formats/Png/PngEncoderTests.Chunks.cs +++ b/tests/ImageSharp.Tests/Formats/Png/PngEncoderTests.Chunks.cs @@ -302,6 +302,7 @@ namespace SixLabors.ImageSharp.Tests.Formats.Png { PngChunkType.Header, PngChunkType.Gamma, + PngChunkType.EmbeddedColorProfile, PngChunkType.Palette, PngChunkType.InternationalText, PngChunkType.Text, diff --git a/tests/ImageSharp.Tests/Formats/Png/PngMetadataTests.cs b/tests/ImageSharp.Tests/Formats/Png/PngMetadataTests.cs index fd39a828f9..d0ae61fd4c 100644 --- a/tests/ImageSharp.Tests/Formats/Png/PngMetadataTests.cs +++ b/tests/ImageSharp.Tests/Formats/Png/PngMetadataTests.cs @@ -17,7 +17,7 @@ namespace SixLabors.ImageSharp.Tests.Formats.Png public class PngMetadataTests { public static readonly TheoryData RatioFiles = - new TheoryData + new() { { TestImages.Png.Splash, 11810, 11810, PixelResolutionUnit.PixelsPerMeter }, { TestImages.Png.Ratio1x4, 1, 4, PixelResolutionUnit.AspectRatio }, @@ -222,6 +222,33 @@ namespace SixLabors.ImageSharp.Tests.Formats.Png } } + [Theory] + [WithFile(TestImages.Png.PngWithMetadata, PixelTypes.Rgba32)] + public void Encode_PreservesColorProfile(TestImageProvider provider) + where TPixel : unmanaged, IPixel + { + using (Image input = provider.GetImage(new PngDecoder())) + { + ImageSharp.Metadata.Profiles.Icc.IccProfile expectedProfile = input.Metadata.IccProfile; + byte[] expectedProfileBytes = expectedProfile.ToByteArray(); + + using (var memStream = new MemoryStream()) + { + input.Save(memStream, new PngEncoder()); + + memStream.Position = 0; + using (var output = Image.Load(memStream)) + { + ImageSharp.Metadata.Profiles.Icc.IccProfile actualProfile = output.Metadata.IccProfile; + byte[] actualProfileBytes = actualProfile.ToByteArray(); + + Assert.NotNull(actualProfile); + Assert.Equal(expectedProfileBytes, actualProfileBytes); + } + } + } + } + [Theory] [MemberData(nameof(RatioFiles))] public void Identify_VerifyRatio(string imagePath, int xResolution, int yResolution, PixelResolutionUnit resolutionUnit)