Do not ignore tileHeight when undoing horizontal predictor

Author: brianpopow

src/ImageSharp/Formats/Tiff/Compression/Decompressors/DeflateTiffCompression.cs

@@ -26,6 +26,8 @@ internal sealed class DeflateTiffCompression : TiffBaseDecompressor
 
     private readonly int tileWidth;
 
+    private readonly int tileHeight;
+
     /// <summary>
     /// Initializes a new instance of the <see cref="DeflateTiffCompression" /> class.
     /// </summary>
@@ -37,13 +39,15 @@ internal sealed class DeflateTiffCompression : TiffBaseDecompressor
     /// <param name="isBigEndian">if set to <c>true</c> decodes the pixel data as big endian, otherwise as little endian.</param>
     /// <param name="isTiled">Flag indicates, if the image is a tiled image.</param>
     /// <param name="tileWidth">Number of pixels in a tile row.</param>
-    public DeflateTiffCompression(MemoryAllocator memoryAllocator, int width, int bitsPerPixel, TiffColorType colorType, TiffPredictor predictor, bool isBigEndian, bool isTiled, int tileWidth)
+    /// <param name="tileHeight">Number of rows in a tile.</param>
+    public DeflateTiffCompression(MemoryAllocator memoryAllocator, int width, int bitsPerPixel, TiffColorType colorType, TiffPredictor predictor, bool isBigEndian, bool isTiled, int tileWidth, int tileHeight)
         : base(memoryAllocator, width, bitsPerPixel, predictor)
     {
         this.colorType = colorType;
         this.isBigEndian = isBigEndian;
         this.isTiled = isTiled;
         this.tileWidth = tileWidth;
+        this.tileHeight = tileHeight;
     }
 
     /// <inheritdoc/>
@@ -81,7 +85,7 @@ protected override void Decompress(BufferedReadStream stream, int byteCount, int
             if (this.isTiled)
             {
                 // When the image is tiled, undoing the horizontal predictor will be done for each tile row.
-                HorizontalPredictor.UndoTile(buffer, this.tileWidth, this.colorType, this.isBigEndian);
+                HorizontalPredictor.UndoTile(buffer, this.tileWidth, this.tileHeight, this.colorType, this.isBigEndian);
             }
             else
             {

src/ImageSharp/Formats/Tiff/Compression/Decompressors/LzwTiffCompression.cs

@@ -21,6 +21,8 @@ internal sealed class LzwTiffCompression : TiffBaseDecompressor
 
     private readonly int tileWidth;
 
+    private readonly int tileHeight;
+
     /// <summary>
     /// Initializes a new instance of the <see cref="LzwTiffCompression" /> class.
     /// </summary>
@@ -32,13 +34,15 @@ internal sealed class LzwTiffCompression : TiffBaseDecompressor
     /// <param name="isBigEndian">if set to <c>true</c> decodes the pixel data as big endian, otherwise as little endian.</param>
     /// <param name="isTiled">Flag indicates, if the image is a tiled image.</param>
     /// <param name="tileWidth">Number of pixels in a tile row.</param>
-    public LzwTiffCompression(MemoryAllocator memoryAllocator, int width, int bitsPerPixel, TiffColorType colorType, TiffPredictor predictor, bool isBigEndian, bool isTiled, int tileWidth)
+    /// <param name="tileHeight">Number of rows in a tile.</param>
+    public LzwTiffCompression(MemoryAllocator memoryAllocator, int width, int bitsPerPixel, TiffColorType colorType, TiffPredictor predictor, bool isBigEndian, bool isTiled, int tileWidth, int tileHeight)
         : base(memoryAllocator, width, bitsPerPixel, predictor)
     {
         this.colorType = colorType;
         this.isBigEndian = isBigEndian;
         this.isTiled = isTiled;
         this.tileWidth = tileWidth;
+        this.tileHeight = tileHeight;
     }
 
     /// <inheritdoc/>
@@ -52,7 +56,7 @@ protected override void Decompress(BufferedReadStream stream, int byteCount, int
             if (this.isTiled)
             {
                 // When the image is tiled, undoing the horizontal predictor will be done for each tile row.
-                HorizontalPredictor.UndoTile(buffer, this.tileWidth, this.colorType, this.isBigEndian);
+                HorizontalPredictor.UndoTile(buffer, this.tileWidth, this.tileHeight, this.colorType, this.isBigEndian);
             }
             else
             {

src/ImageSharp/Formats/Tiff/Compression/HorizontalPredictor.cs

@@ -66,12 +66,13 @@ public static void Undo(Span<byte> pixelBytes, int width, TiffColorType colorTyp
     /// Inverts the horizontal predictor for each tile row.
     /// </summary>
     /// <param name="pixelBytes">Buffer with decompressed pixel data for a tile.</param>
-    /// <param name="tileWidth">Tile with in pixels.</param>
+    /// <param name="tileWidth">Tile width in pixels.</param>
+    /// <param name="tileHeight">Tile height in pixels.</param>
     /// <param name="colorType">The color type of the pixel data.</param>
     /// <param name="isBigEndian">If set to <c>true</c> decodes the pixel data as big endian, otherwise as little endian.</param>
-    public static void UndoTile(Span<byte> pixelBytes, int tileWidth, TiffColorType colorType, bool isBigEndian)
+    public static void UndoTile(Span<byte> pixelBytes, int tileWidth, int tileHeight, TiffColorType colorType, bool isBigEndian)
     {
-        for (int y = 0; y < tileWidth; y++)
+        for (int y = 0; y < tileHeight; y++)
         {
             UndoRow(pixelBytes, tileWidth, y, colorType, isBigEndian);
         }

src/ImageSharp/Formats/Tiff/Compression/TiffDecompressorsFactory.cs

@@ -25,7 +25,8 @@ public static TiffBaseDecompressor Create(
         TiffFillOrder fillOrder,
         ByteOrder byteOrder,
         bool isTiled = false,
-        int tileWidth = 0)
+        int tileWidth = 0,
+        int tileHeight = 0)
     {
         switch (method)
         {
@@ -41,11 +42,11 @@ public static TiffBaseDecompressor Create(
 
             case TiffDecoderCompressionType.Deflate:
                 DebugGuard.IsTrue(faxOptions == FaxCompressionOptions.None, "No fax compression options are expected");
-                return new DeflateTiffCompression(allocator, width, bitsPerPixel, colorType, predictor, byteOrder == ByteOrder.BigEndian, isTiled, tileWidth);
+                return new DeflateTiffCompression(allocator, width, bitsPerPixel, colorType, predictor, byteOrder == ByteOrder.BigEndian, isTiled, tileWidth, tileHeight);
 
             case TiffDecoderCompressionType.Lzw:
                 DebugGuard.IsTrue(faxOptions == FaxCompressionOptions.None, "No fax compression options are expected");
-                return new LzwTiffCompression(allocator, width, bitsPerPixel, colorType, predictor, byteOrder == ByteOrder.BigEndian, isTiled, tileWidth);
+                return new LzwTiffCompression(allocator, width, bitsPerPixel, colorType, predictor, byteOrder == ByteOrder.BigEndian, isTiled, tileWidth, tileHeight);
 
             case TiffDecoderCompressionType.T4:
                 DebugGuard.IsTrue(predictor == TiffPredictor.None, "Predictor should only be used with lzw or deflate compression");

src/ImageSharp/Formats/Tiff/TiffDecoderCore.cs

@@ -679,7 +679,7 @@ private void DecodeTilesChunky<TPixel>(
         using IMemoryOwner<byte> tileBuffer = this.memoryAllocator.Allocate<byte>(bytesPerTileRow * tileLength, AllocationOptions.Clean);
         Span<byte> tileBufferSpan = tileBuffer.GetSpan();
 
-        using TiffBaseDecompressor decompressor = this.CreateDecompressor<TPixel>(frame.Width, bitsPerPixel, true, tileWidth);
+        using TiffBaseDecompressor decompressor = this.CreateDecompressor<TPixel>(frame.Width, bitsPerPixel, true, tileWidth, tileLength);
         TiffBaseColorDecoder<TPixel> colorDecoder = this.CreateChunkyColorDecoder<TPixel>();
 
         int tileIndex = 0;
@@ -747,7 +747,7 @@ private TiffBasePlanarColorDecoder<TPixel> CreatePlanarColorDecoder<TPixel>()
             this.YcbcrSubSampling,
             this.byteOrder);
 
-    private TiffBaseDecompressor CreateDecompressor<TPixel>(int frameWidth, int bitsPerPixel, bool isTiled = false, int tileWidth = 0)
+    private TiffBaseDecompressor CreateDecompressor<TPixel>(int frameWidth, int bitsPerPixel, bool isTiled = false, int tileWidth = 0, int tileHeight = 0)
         where TPixel : unmanaged, IPixel<TPixel> =>
         TiffDecompressorsFactory.Create(
             this.Options,
@@ -764,7 +764,8 @@ private TiffBaseDecompressor CreateDecompressor<TPixel>(int frameWidth, int bits
             this.FillOrder,
             this.byteOrder,
             isTiled,
-            tileWidth);
+            tileWidth,
+            tileHeight);
 
     private IMemoryOwner<ulong> ConvertNumbers(Array array, out Span<ulong> span)
     {

tests/ImageSharp.Tests/Formats/Tiff/Compression/DeflateTiffCompressionTests.cs

@@ -23,7 +23,7 @@ public void Compress_Decompress_Roundtrip_Works(byte[] data)
         using BufferedReadStream stream = CreateCompressedStream(data);
         byte[] buffer = new byte[data.Length];
 
-        using var decompressor = new DeflateTiffCompression(Configuration.Default.MemoryAllocator, 10, 8, TiffColorType.BlackIsZero8, TiffPredictor.None, false, false, 0);
+        using var decompressor = new DeflateTiffCompression(Configuration.Default.MemoryAllocator, 10, 8, TiffColorType.BlackIsZero8, TiffPredictor.None, false, false, 0, 0);
 
         decompressor.Decompress(stream, 0, (uint)stream.Length, 1, buffer, default);
 

tests/ImageSharp.Tests/Formats/Tiff/Compression/LzwTiffCompressionTests.cs

@@ -37,7 +37,7 @@ public void Compress_Decompress_Roundtrip_Works(byte[] data)
         using BufferedReadStream stream = CreateCompressedStream(data);
         byte[] buffer = new byte[data.Length];
 
-        using var decompressor = new LzwTiffCompression(Configuration.Default.MemoryAllocator, 10, 8, TiffColorType.BlackIsZero8, TiffPredictor.None, false, false, 0);
+        using var decompressor = new LzwTiffCompression(Configuration.Default.MemoryAllocator, 10, 8, TiffColorType.BlackIsZero8, TiffPredictor.None, false, false, 0, 0);
         decompressor.Decompress(stream, 0, (uint)stream.Length, 1, buffer, default);
 
         Assert.Equal(data, buffer);