Merge pull request #1457 from IldarKhayrutdinov/tiff-format

#12 Tiff specific fixes for LZW
SixLabors · Dec 3, 2020 · d386a9f · d386a9f
2 parents a1aec8c + 239cc2f
commit d386a9f
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Showing 3 changed files with 13 additions and 7 deletions.
diff --git a/src/ImageSharp/Formats/Tiff/Utils/TiffLzwDecoder.cs b/src/ImageSharp/Formats/Tiff/Utils/TiffLzwDecoder.cs
@@ -168,14 +168,12 @@ public void DecodePixels(int length, int dataSize, Span<byte> pixels)
 
                     pixelStack[top++] = suffix[code];
 
-                    // Fix for Gifs that have "deferred clear code" as per here :
-                    // https://bugzilla.mozilla.org/show_bug.cgi?id=55918
                     if (availableCode < MaxStackSize)
                     {
                         prefix[availableCode] = oldCode;
                         suffix[availableCode] = first;
                         availableCode++;
-                        if (availableCode == codeMask + 1 && availableCode < MaxStackSize)
+                        if (availableCode > codeMask - 1 && availableCode < MaxStackSize)
                         {
                             codeSize++;
                             codeMask = (1 << codeSize) - 1;

diff --git a/tests/ImageSharp.Tests/Formats/Tiff/TiffDecoderTests.cs b/tests/ImageSharp.Tests/Formats/Tiff/TiffDecoderTests.cs
@@ -59,8 +59,8 @@ public void Identify(string imagePath, int expectedPixelSize, int expectedWidth,
         }
 
         [Theory]
-        [InlineData(TestImages.Tiff.RgbLzwNoPredictorMultistrip, TiffByteOrder.LittleEndian)]
-        [InlineData(TestImages.Tiff.RgbLzwNoPredictorMultistripMotorola, TiffByteOrder.BigEndian)]
+        [InlineData(RgbLzwNoPredictorMultistrip, TiffByteOrder.LittleEndian)]
+        [InlineData(RgbLzwNoPredictorMultistripMotorola, TiffByteOrder.BigEndian)]
         public void ByteOrder(string imagePath, TiffByteOrder expectedByteOrder)
         {
             var testFile = TestFile.Create(imagePath);
@@ -91,6 +91,7 @@ public void TiffDecoder_CanDecode_Uncompressed<TPixel>(TestImageProvider<TPixel>
 
         [Theory]
         [WithFile(Calliphora_PaletteUncompressed, PixelTypes.Rgba32)]
+        [WithFile(PaletteDeflateMultistrip, PixelTypes.Rgba32)]
         [WithFile(RgbPalette, PixelTypes.Rgba32)]
         [WithFile(RgbPaletteDeflate, PixelTypes.Rgba32)]
         [WithFile(PaletteUncompressed, PixelTypes.Rgba32)]
@@ -101,11 +102,14 @@ public void TiffDecoder_CanDecode_WithPalette<TPixel>(TestImageProvider<TPixel>
         }
 
         [Theory]
+        [WithFile(GrayscaleDeflateMultistrip, PixelTypes.Rgba32)]
+        [WithFile(RgbDeflateMultistrip, PixelTypes.Rgba32)]
         [WithFile(Calliphora_GrayscaleDeflate, PixelTypes.Rgba32)]
         [WithFile(Calliphora_GrayscaleDeflate_Predictor, PixelTypes.Rgba32)]
         [WithFile(Calliphora_RgbDeflate_Predictor, PixelTypes.Rgba32)]
         [WithFile(RgbDeflate, PixelTypes.Rgba32)]
         [WithFile(RgbDeflatePredictor, PixelTypes.Rgba32)]
+        [WithFile(SmallRgbDeflate, PixelTypes.Rgba32)]
         public void TiffDecoder_CanDecode_DeflateCompressed<TPixel>(TestImageProvider<TPixel> provider)
             where TPixel : unmanaged, IPixel<TPixel>
         {
@@ -115,6 +119,9 @@ public void TiffDecoder_CanDecode_DeflateCompressed<TPixel>(TestImageProvider<TP
         [Theory]
         [WithFile(RgbLzwPredictor, PixelTypes.Rgba32)]
         [WithFile(RgbLzwNoPredictor, PixelTypes.Rgba32)]
+        [WithFile(RgbLzwNoPredictorSinglestripMotorola, PixelTypes.Rgba32)]
+        [WithFile(RgbLzwNoPredictorMultistripMotorola, PixelTypes.Rgba32)]
+        [WithFile(RgbLzwMultistripPredictor, PixelTypes.Rgba32)]
         [WithFile(Calliphora_RgbLzw_Predictor, PixelTypes.Rgba32)]
         [WithFile(SmallRgbLzw, PixelTypes.Rgba32)]
         public void TiffDecoder_CanDecode_LzwCompressed<TPixel>(TestImageProvider<TPixel> provider)
@@ -147,6 +154,7 @@ public void TiffDecoder_CanDecode_Fax3Compressed<TPixel>(TestImageProvider<TPixe
         [Theory]
         [WithFile(Calliphora_RgbPackbits, PixelTypes.Rgba32)]
         [WithFile(RgbPackbits, PixelTypes.Rgba32)]
+        [WithFile(RgbPackbitsMultistrip, PixelTypes.Rgba32)]
         public void TiffDecoder_CanDecode_PackBitsCompressed<TPixel>(TestImageProvider<TPixel> provider)
             where TPixel : unmanaged, IPixel<TPixel>
         {

diff --git a/tests/ImageSharp.Tests/TestImages.cs b/tests/ImageSharp.Tests/TestImages.cs
@@ -558,11 +558,11 @@ public static class Tiff
 
             public const string SampleMetadata = "Tiff/metadata_sample.tiff";
 
-            public static readonly string[] Multiframes = { MultiframeDeflateWithPreview /*MultiframeLzw_Predictor, MultiFrameDifferentSize, MultiframeDifferentSizeTiled, MultiFrameDifferentVariants,*/ };
+            public static readonly string[] Multiframes = { MultiframeDeflateWithPreview, MultiframeLzwPredictor /*, MultiFrameDifferentSize, MultiframeDifferentSizeTiled, MultiFrameDifferentVariants,*/ };
 
             public static readonly string[] Metadata = { SampleMetadata };
 
-            public static readonly string[] NotSupported = { Calliphora_RgbJpeg, RgbLzwMultistripPredictor, RgbJpeg, RgbUncompressedTiled, MultiframeLzwPredictor, MultiframeDifferentSize, MultiframeDifferentVariants };
+            public static readonly string[] NotSupported = { Calliphora_RgbJpeg, RgbJpeg, RgbUncompressedTiled, MultiframeDifferentSize, MultiframeDifferentVariants };
         }
     }
 }