diff --git a/src/ImageSharp/Formats/Png/PngDecoderCore.cs b/src/ImageSharp/Formats/Png/PngDecoderCore.cs index 12770bc521..3dc6d0bf42 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 +1178,58 @@ 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 < PngConstants.MinTextKeywordLength || zeroIndex > 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); + + using (var memoryStream = new MemoryStream(compressedData.ToArray())) + using (var bufferedStream = new BufferedReadStream(this.Configuration, memoryStream)) + using (var inflateStream = new ZlibInflateStream(bufferedStream)) + { + if (!inflateStream.AllocateNewBytes(compressedData.Length, false)) + { + return; + } + + 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); + } + + byte[] iccpProfileBytes = uncompressedBytes.ToArray(); + metadata.IccProfile = new IccProfile(iccpProfileBytes); + } + } + /// /// Compares two ReadOnlySpan<char>s in a case-insensitive method. /// This is only needed because older frameworks are missing the extension method.