diff --git a/src/ImageSharp/Formats/Jpeg/Components/Decoder/QualityEvaluator.cs b/src/ImageSharp/Formats/Jpeg/Components/Decoder/QualityEvaluator.cs new file mode 100644 index 000000000..4e11568c8 --- /dev/null +++ b/src/ImageSharp/Formats/Jpeg/Components/Decoder/QualityEvaluator.cs @@ -0,0 +1,140 @@ +// Copyright (c) Six Labors and contributors. +// Licensed under the Apache License, Version 2.0. + +namespace SixLabors.ImageSharp.Formats.Jpeg.Components.Decoder +{ + /// + /// Provides methods to evaluate the quality of an image. + /// Ported from + /// + internal static class QualityEvaluator + { + private static readonly int[] Hash = new int[101] + { + 1020, 1015, 932, 848, 780, 735, 702, 679, 660, 645, + 632, 623, 613, 607, 600, 594, 589, 585, 581, 571, + 555, 542, 529, 514, 494, 474, 457, 439, 424, 410, + 397, 386, 373, 364, 351, 341, 334, 324, 317, 309, + 299, 294, 287, 279, 274, 267, 262, 257, 251, 247, + 243, 237, 232, 227, 222, 217, 213, 207, 202, 198, + 192, 188, 183, 177, 173, 168, 163, 157, 153, 148, + 143, 139, 132, 128, 125, 119, 115, 108, 104, 99, + 94, 90, 84, 79, 74, 70, 64, 59, 55, 49, + 45, 40, 34, 30, 25, 20, 15, 11, 6, 4, + 0 + }; + + private static readonly int[] Sums = new int[101] + { + 32640, 32635, 32266, 31495, 30665, 29804, 29146, 28599, 28104, + 27670, 27225, 26725, 26210, 25716, 25240, 24789, 24373, 23946, + 23572, 22846, 21801, 20842, 19949, 19121, 18386, 17651, 16998, + 16349, 15800, 15247, 14783, 14321, 13859, 13535, 13081, 12702, + 12423, 12056, 11779, 11513, 11135, 10955, 10676, 10392, 10208, + 9928, 9747, 9564, 9369, 9193, 9017, 8822, 8639, 8458, + 8270, 8084, 7896, 7710, 7527, 7347, 7156, 6977, 6788, + 6607, 6422, 6236, 6054, 5867, 5684, 5495, 5305, 5128, + 4945, 4751, 4638, 4442, 4248, 4065, 3888, 3698, 3509, + 3326, 3139, 2957, 2775, 2586, 2405, 2216, 2037, 1846, + 1666, 1483, 1297, 1109, 927, 735, 554, 375, 201, + 128, 0 + }; + + private static readonly int[] Hash1 = new int[101] + { + 510, 505, 422, 380, 355, 338, 326, 318, 311, 305, + 300, 297, 293, 291, 288, 286, 284, 283, 281, 280, + 279, 278, 277, 273, 262, 251, 243, 233, 225, 218, + 211, 205, 198, 193, 186, 181, 177, 172, 168, 164, + 158, 156, 152, 148, 145, 142, 139, 136, 133, 131, + 129, 126, 123, 120, 118, 115, 113, 110, 107, 105, + 102, 100, 97, 94, 92, 89, 87, 83, 81, 79, + 76, 74, 70, 68, 66, 63, 61, 57, 55, 52, + 50, 48, 44, 42, 39, 37, 34, 31, 29, 26, + 24, 21, 18, 16, 13, 11, 8, 6, 3, 2, + 0 + }; + + private static readonly int[] Sums1 = new int[101] + { + 16320, 16315, 15946, 15277, 14655, 14073, 13623, 13230, 12859, + 12560, 12240, 11861, 11456, 11081, 10714, 10360, 10027, 9679, + 9368, 9056, 8680, 8331, 7995, 7668, 7376, 7084, 6823, + 6562, 6345, 6125, 5939, 5756, 5571, 5421, 5240, 5086, + 4976, 4829, 4719, 4616, 4463, 4393, 4280, 4166, 4092, + 3980, 3909, 3835, 3755, 3688, 3621, 3541, 3467, 3396, + 3323, 3247, 3170, 3096, 3021, 2952, 2874, 2804, 2727, + 2657, 2583, 2509, 2437, 2362, 2290, 2211, 2136, 2068, + 1996, 1915, 1858, 1773, 1692, 1620, 1552, 1477, 1398, + 1326, 1251, 1179, 1109, 1031, 961, 884, 814, 736, + 667, 592, 518, 441, 369, 292, 221, 151, 86, + 64, 0 + }; + + /// + /// Returns an estimated quality of the image based on the quantization tables. + /// + /// The quantization tables. + /// The . + public static int EstimateQuality(Block8x8F[] quantizationTables) + { + int quality = 75; + float sum = 0; + + for (int i = 0; i < quantizationTables.Length; i++) + { + ref Block8x8F qTable = ref quantizationTables[i]; + for (int j = 0; j < Block8x8F.Size; j++) + { + sum += qTable[j]; + } + } + + ref Block8x8F qTable0 = ref quantizationTables[0]; + ref Block8x8F qTable1 = ref quantizationTables[1]; + + if (!qTable0.Equals(default)) + { + if (!qTable1.Equals(default)) + { + quality = (int)(qTable0[2] + + qTable0[53] + + qTable1[0] + + qTable1[Block8x8F.Size - 1]); + + for (int i = 0; i < 100; i++) + { + if (quality < Hash[i] && sum < Sums[i]) + { + continue; + } + + if (((quality <= Hash[i]) && (sum <= Sums[i])) || (i >= 50)) + { + return i + 1; + } + } + } + else + { + quality = (int)(qTable0[2] + qTable0[53]); + + for (int i = 0; i < 100; i++) + { + if (quality < Hash1[i] && sum < Sums1[i]) + { + continue; + } + + if (((quality <= Hash1[i]) && (sum <= Sums1[i])) || (i >= 50)) + { + return i + 1; + } + } + } + } + + return quality; + } + } +} \ No newline at end of file diff --git a/src/ImageSharp/Formats/Jpeg/IJpegEncoderOptions.cs b/src/ImageSharp/Formats/Jpeg/IJpegEncoderOptions.cs index 4076b7da8..53108de93 100644 --- a/src/ImageSharp/Formats/Jpeg/IJpegEncoderOptions.cs +++ b/src/ImageSharp/Formats/Jpeg/IJpegEncoderOptions.cs @@ -8,17 +8,12 @@ namespace SixLabors.ImageSharp.Formats.Jpeg /// internal interface IJpegEncoderOptions { - /// - /// Gets a value indicating whether the metadata should be ignored when the image is being decoded. - /// - bool IgnoreMetadata { get; } - /// /// Gets the quality, that will be used to encode the image. Quality /// index must be between 0 and 100 (compression from max to min). /// /// The quality of the jpg image from 0 to 100. - int Quality { get; } + int? Quality { get; } /// /// Gets the subsample ration, that will be used to encode the image. diff --git a/src/ImageSharp/Formats/Jpeg/JpegDecoderCore.cs b/src/ImageSharp/Formats/Jpeg/JpegDecoderCore.cs index 3ea24809d..011b6100d 100644 --- a/src/ImageSharp/Formats/Jpeg/JpegDecoderCore.cs +++ b/src/ImageSharp/Formats/Jpeg/JpegDecoderCore.cs @@ -259,11 +259,11 @@ namespace SixLabors.ImageSharp.Formats.Jpeg this.InputStream.Read(this.markerBuffer, 0, 2); byte marker = this.markerBuffer[1]; fileMarker = new JpegFileMarker(marker, (int)this.InputStream.Position - 2); + this.QuantizationTables = new Block8x8F[4]; // Only assign what we need if (!metadataOnly) { - this.QuantizationTables = new Block8x8F[4]; this.dcHuffmanTables = new HuffmanTables(); this.acHuffmanTables = new HuffmanTables(); this.fastACTables = new FastACTables(this.configuration.MemoryAllocator); @@ -314,15 +314,7 @@ namespace SixLabors.ImageSharp.Formats.Jpeg break; case JpegConstants.Markers.DQT: - if (metadataOnly) - { - this.InputStream.Skip(remaining); - } - else - { - this.ProcessDefineQuantizationTablesMarker(remaining); - } - + this.ProcessDefineQuantizationTablesMarker(remaining); break; case JpegConstants.Markers.DRI: @@ -708,6 +700,8 @@ namespace SixLabors.ImageSharp.Formats.Jpeg { throw new ImageFormatException("DQT has wrong length"); } + + this.MetaData.GetFormatMetaData(JpegFormat.Instance).Quality = QualityEvaluator.EstimateQuality(this.QuantizationTables); } /// diff --git a/src/ImageSharp/Formats/Jpeg/JpegEncoder.cs b/src/ImageSharp/Formats/Jpeg/JpegEncoder.cs index 0f389dee0..d649d3041 100644 --- a/src/ImageSharp/Formats/Jpeg/JpegEncoder.cs +++ b/src/ImageSharp/Formats/Jpeg/JpegEncoder.cs @@ -11,17 +11,12 @@ namespace SixLabors.ImageSharp.Formats.Jpeg /// public sealed class JpegEncoder : IImageEncoder, IJpegEncoderOptions { - /// - /// Gets or sets a value indicating whether the metadata should be ignored when the image is being decoded. - /// - public bool IgnoreMetadata { get; set; } - /// /// Gets or sets the quality, that will be used to encode the image. Quality /// index must be between 0 and 100 (compression from max to min). /// Defaults to 75. /// - public int Quality { get; set; } = 75; + public int? Quality { get; set; } /// /// Gets or sets the subsample ration, that will be used to encode the image. diff --git a/src/ImageSharp/Formats/Jpeg/JpegEncoderCore.cs b/src/ImageSharp/Formats/Jpeg/JpegEncoderCore.cs index f7b6fe996..32c50d2a0 100644 --- a/src/ImageSharp/Formats/Jpeg/JpegEncoderCore.cs +++ b/src/ImageSharp/Formats/Jpeg/JpegEncoderCore.cs @@ -123,19 +123,14 @@ namespace SixLabors.ImageSharp.Formats.Jpeg private readonly byte[] huffmanBuffer = new byte[179]; /// - /// Gets or sets a value indicating whether the metadata should be ignored when the image is being decoded. + /// Gets or sets the subsampling method to use. /// - private readonly bool ignoreMetadata; + private JpegSubsample? subsample; /// /// The quality, that will be used to encode the image. /// - private readonly int quality; - - /// - /// Gets or sets the subsampling method to use. - /// - private readonly JpegSubsample? subsample; + private readonly int? quality; /// /// The accumulated bits to write to the stream. @@ -168,11 +163,8 @@ namespace SixLabors.ImageSharp.Formats.Jpeg /// The options public JpegEncoderCore(IJpegEncoderOptions options) { - // System.Drawing produces identical output for jpegs with a quality parameter of 0 and 1. - this.quality = options.Quality.Clamp(1, 100); - this.subsample = options.Subsample ?? (this.quality >= 91 ? JpegSubsample.Ratio444 : JpegSubsample.Ratio420); - - this.ignoreMetadata = options.IgnoreMetadata; + this.quality = options.Quality; + this.subsample = options.Subsample; } /// @@ -195,15 +187,19 @@ namespace SixLabors.ImageSharp.Formats.Jpeg this.outputStream = stream; + // System.Drawing produces identical output for jpegs with a quality parameter of 0 and 1. + int qlty = (this.quality ?? image.MetaData.GetFormatMetaData(JpegFormat.Instance).Quality).Clamp(1, 100); + this.subsample = this.subsample ?? (qlty >= 91 ? JpegSubsample.Ratio444 : JpegSubsample.Ratio420); + // Convert from a quality rating to a scaling factor. int scale; - if (this.quality < 50) + if (qlty < 50) { - scale = 5000 / this.quality; + scale = 5000 / qlty; } else { - scale = 200 - (this.quality * 2); + scale = 200 - (qlty * 2); } // Initialize the quantization tables. @@ -767,11 +763,6 @@ namespace SixLabors.ImageSharp.Formats.Jpeg private void WriteProfiles(Image image) where TPixel : struct, IPixel { - if (this.ignoreMetadata) - { - return; - } - image.MetaData.SyncProfiles(); this.WriteExifProfile(image.MetaData.ExifProfile); this.WriteIccProfile(image.MetaData.IccProfile); diff --git a/src/ImageSharp/Formats/Jpeg/JpegMetaData.cs b/src/ImageSharp/Formats/Jpeg/JpegMetaData.cs index b05f9fa15..bd7232e60 100644 --- a/src/ImageSharp/Formats/Jpeg/JpegMetaData.cs +++ b/src/ImageSharp/Formats/Jpeg/JpegMetaData.cs @@ -8,6 +8,9 @@ namespace SixLabors.ImageSharp.Formats.Jpeg /// public class JpegMetaData { - // TODO: Analyse what properties we would like to preserve. + /// + /// Gets or sets the encoded quality. + /// + public int Quality { get; set; } = 75; } -} +} \ No newline at end of file diff --git a/tests/ImageSharp.Tests/Formats/Jpg/JpegDecoderTests.MetaData.cs b/tests/ImageSharp.Tests/Formats/Jpg/JpegDecoderTests.MetaData.cs index 2e67c06c1..4810985f1 100644 --- a/tests/ImageSharp.Tests/Formats/Jpg/JpegDecoderTests.MetaData.cs +++ b/tests/ImageSharp.Tests/Formats/Jpg/JpegDecoderTests.MetaData.cs @@ -49,6 +49,13 @@ namespace SixLabors.ImageSharp.Tests.Formats.Jpg { TestImages.Jpeg.Baseline.GammaDalaiLamaGray, 72, 72, PixelResolutionUnit.PixelsPerInch } }; + public static readonly TheoryData QualityFiles = + new TheoryData + { + { TestImages.Jpeg.Baseline.Calliphora, 80}, + { TestImages.Jpeg.Progressive.Fb, 75 } + }; + [Theory] [MemberData(nameof(MetaDataTestData))] public void MetaDataIsParsedCorrectly( @@ -101,6 +108,36 @@ namespace SixLabors.ImageSharp.Tests.Formats.Jpg } } + [Theory] + [MemberData(nameof(QualityFiles))] + public void Identify_VerifyQuality(string imagePath, int quality) + { + var testFile = TestFile.Create(imagePath); + using (var stream = new MemoryStream(testFile.Bytes, false)) + { + var decoder = new JpegDecoder(); + IImageInfo image = decoder.Identify(Configuration.Default, stream); + JpegMetaData meta = image.MetaData.GetFormatMetaData(JpegFormat.Instance); + Assert.Equal(quality, meta.Quality); + } + } + + [Theory] + [MemberData(nameof(QualityFiles))] + public void Decode_VerifyQuality(string imagePath, int quality) + { + var testFile = TestFile.Create(imagePath); + using (var stream = new MemoryStream(testFile.Bytes, false)) + { + var decoder = new JpegDecoder(); + using (Image image = decoder.Decode(Configuration.Default, stream)) + { + JpegMetaData meta = image.MetaData.GetFormatMetaData(JpegFormat.Instance); + Assert.Equal(quality, meta.Quality); + } + } + } + private static void TestImageInfo(string imagePath, IImageDecoder decoder, bool useIdentify, Action test) { var testFile = TestFile.Create(imagePath); diff --git a/tests/ImageSharp.Tests/Formats/Jpg/JpegEncoderTests.cs b/tests/ImageSharp.Tests/Formats/Jpg/JpegEncoderTests.cs index a31ae37b7..598d99274 100644 --- a/tests/ImageSharp.Tests/Formats/Jpg/JpegEncoderTests.cs +++ b/tests/ImageSharp.Tests/Formats/Jpg/JpegEncoderTests.cs @@ -14,6 +14,13 @@ namespace SixLabors.ImageSharp.Tests.Formats.Jpg { public class JpegEncoderTests { + public static readonly TheoryData QualityFiles = + new TheoryData + { + { TestImages.Jpeg.Baseline.Calliphora, 80}, + { TestImages.Jpeg.Progressive.Fb, 75 } + }; + public static readonly TheoryData BitsPerPixel_Quality = new TheoryData { @@ -34,6 +41,29 @@ namespace SixLabors.ImageSharp.Tests.Formats.Jpg { TestImages.Jpeg.Baseline.GammaDalaiLamaGray, 72, 72, PixelResolutionUnit.PixelsPerInch } }; + [Theory] + [MemberData(nameof(QualityFiles))] + public void Encode_PreserveQuality(string imagePath, int quality) + { + var options = new JpegEncoder(); + + var testFile = TestFile.Create(imagePath); + using (Image input = testFile.CreateImage()) + { + using (var memStream = new MemoryStream()) + { + input.Save(memStream, options); + + memStream.Position = 0; + using (var output = Image.Load(memStream)) + { + JpegMetaData meta = output.MetaData.GetFormatMetaData(JpegFormat.Instance); + Assert.Equal(quality, meta.Quality); + } + } + } + } + [Theory] [WithFile(TestImages.Png.CalliphoraPartial, nameof(BitsPerPixel_Quality), PixelTypes.Rgba32)] [WithTestPatternImages(nameof(BitsPerPixel_Quality), 73, 71, PixelTypes.Rgba32)] @@ -43,18 +73,12 @@ namespace SixLabors.ImageSharp.Tests.Formats.Jpg [WithSolidFilledImages(nameof(BitsPerPixel_Quality), 1, 1, 255, 100, 50, 255, PixelTypes.Rgba32)] [WithTestPatternImages(nameof(BitsPerPixel_Quality), 7, 5, PixelTypes.Rgba32)] public void EncodeBaseline_WorksWithDifferentSizes(TestImageProvider provider, JpegSubsample subsample, int quality) - where TPixel : struct, IPixel - { - TestJpegEncoderCore(provider, subsample, quality); - } + where TPixel : struct, IPixel => TestJpegEncoderCore(provider, subsample, quality); [Theory] [WithTestPatternImages(nameof(BitsPerPixel_Quality), 48, 48, PixelTypes.Rgba32 | PixelTypes.Bgra32)] public void EncodeBaseline_IsNotBoundToSinglePixelType(TestImageProvider provider, JpegSubsample subsample, int quality) - where TPixel : struct, IPixel - { - TestJpegEncoderCore(provider, subsample, quality); - } + where TPixel : struct, IPixel => TestJpegEncoderCore(provider, subsample, quality); /// /// Anton's SUPER-SCIENTIFIC tolerance threshold calculation @@ -103,38 +127,6 @@ namespace SixLabors.ImageSharp.Tests.Formats.Jpg } } - [Theory] - [InlineData(false)] - [InlineData(true)] - public void IgnoreMetadata_ControlsIfExifProfileIsWritten(bool ignoreMetaData) - { - var encoder = new JpegEncoder() - { - IgnoreMetadata = ignoreMetaData - }; - - using (Image input = TestFile.Create(TestImages.Jpeg.Baseline.Floorplan).CreateImage()) - { - using (var memStream = new MemoryStream()) - { - input.Save(memStream, encoder); - - memStream.Position = 0; - using (var output = Image.Load(memStream)) - { - if (ignoreMetaData) - { - Assert.Null(output.MetaData.ExifProfile); - } - else - { - Assert.NotNull(output.MetaData.ExifProfile); - } - } - } - } - } - [Fact] public void Quality_0_And_1_Are_Identical() {