spectral testing

src/ImageSharp/Formats/Jpeg/Common/Block8x8.cs

@@ -164,5 +164,16 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.Common
             return (this[0] * 31) + this[1];
         }
 
+        public static long TotalDifference(ref Block8x8 a, ref Block8x8 b)
+        {
+            long result = 0;
+            for (int i = 0; i < Size; i++)
+            {
+                int d = a[i] - b[i];
+                result += Math.Abs(d);
+            }
+
+            return result;
+        }
     }
 }

src/ImageSharp/Formats/Jpeg/GolangPort/OldJpegDecoderCore.cs

@@ -197,7 +197,7 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.GolangPort
         public Image<TPixel> Decode<TPixel>(Stream stream)
             where TPixel : struct, IPixel<TPixel>
         {
-            this.ParseStream(stream, false);
+            this.ParseStream(stream);
             this.ProcessBlocksIntoJpegImageChannels<TPixel>();
             Image<TPixel> image = this.ConvertJpegPixelsToImagePixels<TPixel>();
 
@@ -260,7 +260,7 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.GolangPort
         /// </summary>
         /// <param name="stream">The stream</param>
         /// <param name="metadataOnly">Whether to decode metadata only.</param>
-        public void ParseStream(Stream stream, bool metadataOnly)
+        public void ParseStream(Stream stream, bool metadataOnly = false)
         {
             this.MetaData = new ImageMetaData();
             this.InputStream = stream;

tests/ImageSharp.Tests/Formats/Jpg/Block8x8Tests.cs

@@ -125,5 +125,20 @@ namespace SixLabors.ImageSharp.Tests
 
             Assert.Equal(42, value);
         }
+
+        [Fact]
+        public void TotalDifference()
+        {
+            short[] data = Create8x8ShortData();
+            var block1 = new Block8x8(data);
+            var block2 = new Block8x8(data);
+
+            block2[10] += 7;
+            block2[63] += 8;
+
+            long d = Block8x8.TotalDifference(ref block1, ref block2);
+
+            Assert.Equal(15, d);
+        }
     }
 }

tests/ImageSharp.Tests/Formats/Jpg/JpegDecoderTests.cs

@@ -294,8 +294,8 @@ namespace SixLabors.ImageSharp.Tests
                 ImageSimilarityReport originalReport = comparer.CompareImagesOrFrames(expectedImage, pdfJsOriginalResult);
                 ImageSimilarityReport portReport = comparer.CompareImagesOrFrames(expectedImage, pdfJsPortResult);
                 
-                this.Output.WriteLine($"Difference for PDF.js ORIGINAL: {originalReport.DifferencePercentage}");
-                this.Output.WriteLine($"Difference for PORT: {portReport.DifferencePercentage}");
+                this.Output.WriteLine($"Difference for PDF.js ORIGINAL: {originalReport.DifferencePercentageString}");
+                this.Output.WriteLine($"Difference for PORT: {portReport.DifferencePercentageString}");
             }
         }
     }

tests/ImageSharp.Tests/Formats/Jpg/LibJpegTools.cs

@@ -9,8 +9,11 @@ namespace SixLabors.ImageSharp.Tests
     using BitMiracle.LibJpeg.Classic;
 
     using SixLabors.ImageSharp.Formats.Jpeg.Common;
+    using SixLabors.ImageSharp.Formats.Jpeg.GolangPort;
+    using SixLabors.ImageSharp.Formats.Jpeg.GolangPort.Components.Decoder;
     using SixLabors.ImageSharp.Formats.Jpeg.PdfJsPort;
     using SixLabors.ImageSharp.Formats.Jpeg.PdfJsPort.Components;
+    using SixLabors.ImageSharp.Memory;
     using SixLabors.ImageSharp.PixelFormats;
     using SixLabors.Primitives;
 
@@ -105,7 +108,14 @@ namespace SixLabors.ImageSharp.Tests
             public static SpectralData LoadFromImageSharpDecoder(JpegDecoderCore decoder)
             {
                 FrameComponent[] srcComponents = decoder.Frame.Components;
+                ComponentData[] destComponents = srcComponents.Select(ComponentData.Load).ToArray();
+
+                return new SpectralData(destComponents);
+            }
 
+            public static SpectralData LoadFromImageSharpDecoder(OldJpegDecoderCore decoder)
+            {
+                OldComponent[] srcComponents = decoder.Components;
                 ComponentData[] destComponents = srcComponents.Select(ComponentData.Load).ToArray();
 
                 return new SpectralData(destComponents);
@@ -124,11 +134,11 @@ namespace SixLabors.ImageSharp.Tests
                     return null;
                 }
 
-                Image<Rgba32> result = new Image<Rgba32>(c0.XCount * 8, c0.YCount * 8);
+                Image<Rgba32> result = new Image<Rgba32>(c0.BlockCountX * 8, c0.BlockCountY * 8);
 
-                for (int by = 0; by < c0.YCount; by++)
+                for (int by = 0; by < c0.BlockCountY; by++)
                 {
-                    for (int bx = 0; bx < c0.XCount; bx++)
+                    for (int bx = 0; bx < c0.BlockCountX; bx++)
                     {
                         this.WriteToImage(bx, by, result);
                     }
@@ -142,9 +152,9 @@ namespace SixLabors.ImageSharp.Tests
                 ComponentData c1 = this.Components[1];
                 ComponentData c2 = this.Components[2];
 
-                Block8x8 block0 = c0.Blocks[by, bx];
-                Block8x8 block1 = c1.Blocks[by, bx];
-                Block8x8 block2 = c2.Blocks[by, bx];
+                Block8x8 block0 = c0.Blocks[bx, by];
+                Block8x8 block1 = c1.Blocks[bx, by];
+                Block8x8 block2 = c2.Blocks[bx, by];
 
                 float d0 = (c0.MaxVal - c0.MinVal);
                 float d1 = (c1.MaxVal - c1.MinVal);
@@ -216,28 +226,28 @@ namespace SixLabors.ImageSharp.Tests
 
         public class ComponentData : IEquatable<ComponentData>
         {
-            public ComponentData(int yCount, int xCount, int index)
+            public ComponentData(int blockCountY, int blockCountX, int index)
             {
-                this.YCount = yCount;
-                this.XCount = xCount;
+                this.BlockCountY = blockCountY;
+                this.BlockCountX = blockCountX;
                 this.Index = index;
-                this.Blocks = new Block8x8[this.YCount, this.XCount];
+                this.Blocks = new Buffer2D<Block8x8>(this.BlockCountX, this.BlockCountY);
             }
 
-            public Size Size => new Size(this.XCount, this.YCount);
+            public Size Size => new Size(this.BlockCountX, this.BlockCountY);
 
             public int Index { get; }
 
-            public int YCount { get; }
+            public int BlockCountY { get; }
 
-            public int XCount { get; }
+            public int BlockCountX { get; }
 
-            public Block8x8[,] Blocks { get; private set; }
+            public Buffer2D<Block8x8> Blocks { get; private set; }
 
             public short MinVal { get; private set; } = short.MaxValue;
 
             public short MaxVal { get; private set; } = short.MinValue;
-
+            
             public static ComponentData Load(Array bloxSource, int index)
             {
                 int yCount = bloxSource.Length;
@@ -266,39 +276,56 @@ namespace SixLabors.ImageSharp.Tests
             {
                 this.MinVal = Math.Min(this.MinVal, data.Min());
                 this.MaxVal = Math.Max(this.MaxVal, data.Max());
-                this.Blocks[y, x] = new Block8x8(data);
+                this.Blocks[x, y] = new Block8x8(data);
             }
 
-            public static ComponentData Load(FrameComponent sc, int index)
+            public static ComponentData Load(FrameComponent c, int index)
             {
                 var result = new ComponentData(
-                    sc.BlocksPerColumnForMcu,
-                    sc.BlocksPerLineForMcu,
+                    c.BlocksPerColumnForMcu,
+                    c.BlocksPerLineForMcu,
                     index
                     );
-                result.Init(sc);
+
+                for (int y = 0; y < result.BlockCountY; y++)
+                {
+                    for (int x = 0; x < result.BlockCountX; x++)
+                    {
+                        short[] data = c.GetBlockBuffer(y, x).ToArray();
+                        result.MakeBlock(data, y, x);
+                    }
+                }
+
                 return result;
             }
 
-            private void Init(FrameComponent sc)
+            public static ComponentData Load(OldComponent c)
             {
-                for (int y = 0; y < this.YCount; y++)
+                var result = new ComponentData(
+                    c.BlockCountY,
+                    c.BlockCountX,
+                    c.Index
+                );
+
+                for (int y = 0; y < result.BlockCountY; y++)
                 {
-                    for (int x = 0; x < this.XCount; x++)
+                    for (int x = 0; x < result.BlockCountX; x++)
                     {
-                        short[] data = sc.GetBlockBuffer(y, x).ToArray();
-                        this.MakeBlock(data, y, x);
+                        short[] data = c.GetBlockReference(x, y).ToArray();
+                        result.MakeBlock(data, y, x);
                     }
                 }
+
+                return result;
             }
 
             public Image<Rgba32> CreateGrayScaleImage()
             {
-                Image<Rgba32> result = new Image<Rgba32>(this.XCount * 8, this.YCount * 8);
+                Image<Rgba32> result = new Image<Rgba32>(this.BlockCountX * 8, this.BlockCountY * 8);
                 
-                for (int by = 0; by < this.YCount; by++)
+                for (int by = 0; by < this.BlockCountY; by++)
                 {
-                    for (int bx = 0; bx < this.XCount; bx++)
+                    for (int bx = 0; bx < this.BlockCountX; bx++)
                     {
                         this.WriteToImage(bx, by, result);
                     }
@@ -308,7 +335,7 @@ namespace SixLabors.ImageSharp.Tests
 
             internal void WriteToImage(int bx, int by, Image<Rgba32> image)
             {
-                Block8x8 block = this.Blocks[by, bx];
+                Block8x8 block = this.Blocks[bx, by];
                 
                 for (int y = 0; y < 8; y++)
                 {
@@ -340,17 +367,18 @@ namespace SixLabors.ImageSharp.Tests
             {
                 if (ReferenceEquals(null, other)) return false;
                 if (ReferenceEquals(this, other)) return true;
-                bool ok = this.Index == other.Index && this.YCount == other.YCount && this.XCount == other.XCount
-                       && this.MinVal == other.MinVal
-                       && this.MaxVal == other.MaxVal;
+                bool ok = this.Index == other.Index && this.BlockCountY == other.BlockCountY
+                          && this.BlockCountX == other.BlockCountX;
+                       //&& this.MinVal == other.MinVal
+                       //&& this.MaxVal == other.MaxVal;
                 if (!ok) return false;
 
-                for (int i = 0; i < this.YCount; i++)
+                for (int y = 0; y < this.BlockCountY; y++)
                 {
-                    for (int j = 0; j < this.XCount; j++)
+                    for (int x = 0; x < this.BlockCountX; x++)
                     {
-                        Block8x8 a = this.Blocks[i, j];
-                        Block8x8 b = other.Blocks[i, j];
+                        Block8x8 a = this.Blocks[x, y];
+                        Block8x8 b = other.Blocks[x, y];
                         if (!a.Equals(b)) return false;
                     }
                 }
@@ -370,8 +398,8 @@ namespace SixLabors.ImageSharp.Tests
                 unchecked
                 {
                     var hashCode = this.Index;
-                    hashCode = (hashCode * 397) ^ this.YCount;
-                    hashCode = (hashCode * 397) ^ this.XCount;
+                    hashCode = (hashCode * 397) ^ this.BlockCountY;
+                    hashCode = (hashCode * 397) ^ this.BlockCountX;
                     hashCode = (hashCode * 397) ^ this.MinVal.GetHashCode();
                     hashCode = (hashCode * 397) ^ this.MaxVal.GetHashCode();
                     return hashCode;
@@ -387,6 +415,8 @@ namespace SixLabors.ImageSharp.Tests
             {
                 return !Equals(left, right);
             }
+
+            
         }
 
         internal static FieldInfo GetNonPublicField(object obj, string fieldName)
@@ -400,5 +430,28 @@ namespace SixLabors.ImageSharp.Tests
             FieldInfo fi = GetNonPublicField(obj, fieldName);
             return fi.GetValue(obj);
         }
+
+        public static double CalculateAverageDifference(ComponentData a, ComponentData b)
+        {
+            BigInteger totalDiff = 0;
+            if (a.Size != b.Size)
+            {
+                throw new Exception("a.Size != b.Size");
+            }
+
+            int count = a.Blocks.Length;
+
+            for (int i = 0; i < count; i++)
+            {
+                Block8x8 aa = a.Blocks[i];
+                Block8x8 bb = b.Blocks[i];
+
+                long diff = Block8x8.TotalDifference(ref aa, ref bb);
+                totalDiff += diff;
+            }
+
+            double result = (double)totalDiff;
+            return result / (count * Block8x8.Size);
+        }
     }
 }

tests/ImageSharp.Tests/Formats/Jpg/SpectralJpegTests.cs

@@ -1,12 +1,14 @@
 // ReSharper disable InconsistentNaming
 namespace SixLabors.ImageSharp.Tests
 {
+    using System;
     using System.Collections.Generic;
     using System.IO;
     using System.Linq;
 
     using SixLabors.ImageSharp.Formats;
     using SixLabors.ImageSharp.Formats.Jpeg;
+    using SixLabors.ImageSharp.Formats.Jpeg.GolangPort;
     using SixLabors.ImageSharp.Formats.Jpeg.PdfJsPort;
     using SixLabors.ImageSharp.PixelFormats;
     using SixLabors.ImageSharp.Tests.TestUtilities.ImageComparison;
@@ -58,7 +60,7 @@ namespace SixLabors.ImageSharp.Tests
         }
 
         [Theory]
-        [WithFileCollection(nameof(BaselineTestJpegs), PixelTypes.Rgba32)]
+        [WithFileCollection(nameof(AllTestJpegs), PixelTypes.Rgba32)]
         public void PdfJsDecoder_ParseStream_SaveSpectralResult<TPixel>(TestImageProvider<TPixel> provider)
             where TPixel : struct, IPixel<TPixel>
         {
@@ -77,7 +79,63 @@ namespace SixLabors.ImageSharp.Tests
 
         [Theory]
         [WithFileCollection(nameof(AllTestJpegs), PixelTypes.Rgba32)]
-        public void CompareSpectralResults_PdfJs<TPixel>(TestImageProvider<TPixel> provider)
+        public void OriginalDecoder_ParseStream_SaveSpectralResult<TPixel>(TestImageProvider<TPixel> provider)
+            where TPixel : struct, IPixel<TPixel>
+        {
+            OldJpegDecoderCore decoder = new OldJpegDecoderCore(Configuration.Default, new JpegDecoder());
+
+            byte[] sourceBytes = TestFile.Create(provider.SourceFileOrDescription).Bytes;
+
+            using (var ms = new MemoryStream(sourceBytes))
+            {
+                decoder.ParseStream(ms, false);
+
+                var data = LibJpegTools.SpectralData.LoadFromImageSharpDecoder(decoder);
+                this.SaveSpectralImage(provider, data);
+            }
+        }
+
+        private void VerifySpectralCorrectness<TPixel>(
+            MemoryStream ms,
+            LibJpegTools.SpectralData imageSharpData)
+            where TPixel : struct, IPixel<TPixel>
+        {
+            ms.Seek(0, SeekOrigin.Begin);
+            var libJpegData = LibJpegTools.SpectralData.Load(ms);
+
+            bool equality = libJpegData.Equals(imageSharpData);
+            this.Output.WriteLine("Spectral data equality: " + equality);
+            //if (!equality)
+            //{
+                int componentCount = imageSharpData.ComponentCount;
+                if (libJpegData.ComponentCount != componentCount)
+                {
+                    throw new Exception("libJpegData.ComponentCount != componentCount");
+                }
+
+                double totalDifference = 0;
+                this.Output.WriteLine("*** Differences ***");
+                for (int i = 0; i < componentCount; i++)
+                {
+                    LibJpegTools.ComponentData libJpegComponent = libJpegData.Components[i];
+                    LibJpegTools.ComponentData imageSharpComponent = imageSharpData.Components[i];
+
+                    double d = LibJpegTools.CalculateAverageDifference(libJpegComponent, imageSharpComponent);
+
+                    this.Output.WriteLine($"Component{i}: {d}");
+                    totalDifference += d;
+                }
+                totalDifference /= componentCount;
+                
+                this.Output.WriteLine($"AVERAGE: {totalDifference}");
+            //}
+
+            Assert.Equal(libJpegData, imageSharpData);
+        }
+
+        [Theory]
+        [WithFileCollection(nameof(AllTestJpegs), PixelTypes.Rgba32)]
+        public void VerifySpectralCorrectness_PdfJs<TPixel>(TestImageProvider<TPixel> provider)
             where TPixel : struct, IPixel<TPixel>
         {
             JpegDecoderCore decoder = new JpegDecoderCore(Configuration.Default, new JpegDecoder());
@@ -89,13 +147,25 @@ namespace SixLabors.ImageSharp.Tests
                 decoder.ParseStream(ms);
                 var imageSharpData = LibJpegTools.SpectralData.LoadFromImageSharpDecoder(decoder);
                 
-                ms.Seek(0, SeekOrigin.Begin);
-                var libJpegData = LibJpegTools.SpectralData.Load(ms);
+                this.VerifySpectralCorrectness<TPixel>(ms, imageSharpData);
+            }
+        }
 
-                bool equality = libJpegData.Equals(imageSharpData);
-                this.Output.WriteLine("Spectral data equality: " + equality);
+        [Theory]
+        [WithFileCollection(nameof(AllTestJpegs), PixelTypes.Rgba32)]
+        public void VerifySpectralResults_OriginalDecoder<TPixel>(TestImageProvider<TPixel> provider)
+            where TPixel : struct, IPixel<TPixel>
+        {
+            OldJpegDecoderCore decoder = new OldJpegDecoderCore(Configuration.Default, new JpegDecoder());
+
+            byte[] sourceBytes = TestFile.Create(provider.SourceFileOrDescription).Bytes;
+
+            using (var ms = new MemoryStream(sourceBytes))
+            {
+                decoder.ParseStream(ms);
+                var imageSharpData = LibJpegTools.SpectralData.LoadFromImageSharpDecoder(decoder);
 
-                Assert.Equal(libJpegData, imageSharpData);
+                this.VerifySpectralCorrectness<TPixel>(ms, imageSharpData);
             }
         }
 

tests/ImageSharp.Tests/TestUtilities/ImageComparison/ImageSimilarityReport.cs

@@ -24,7 +24,7 @@
 
         public float? TotalNormalizedDifference { get; }
 
-        public string DifferencePercentage => this.TotalNormalizedDifference.HasValue
+        public string DifferencePercentageString => this.TotalNormalizedDifference.HasValue
                                                   ? $"{this.TotalNormalizedDifference.Value * 100:0.0000}%"
                                                   : "?";
 
@@ -46,7 +46,7 @@
             var sb = new StringBuilder();
             if (this.TotalNormalizedDifference.HasValue)
             {
-                sb.AppendLine($"Total difference: {this.DifferencePercentage}");
+                sb.AppendLine($"Total difference: {this.DifferencePercentageString}");
             }
             int max = Math.Min(5, this.Differences.Length);