Add color factory, update decoder methods and tests

src/ImageSharp/Formats/Tiff/TiffEncoderCore.cs

@@ -9,7 +9,7 @@ using System.Threading;
 using SixLabors.ImageSharp.Advanced;
 using SixLabors.ImageSharp.Compression.Zlib;
 using SixLabors.ImageSharp.Formats.Experimental.Tiff.Constants;
-using SixLabors.ImageSharp.Formats.Experimental.Tiff.Utils;
+using SixLabors.ImageSharp.Formats.Experimental.Tiff.Writers;
 using SixLabors.ImageSharp.Memory;
 using SixLabors.ImageSharp.Metadata;
 using SixLabors.ImageSharp.Metadata.Profiles.Exif;
@@ -122,7 +122,7 @@ namespace SixLabors.ImageSharp.Formats.Experimental.Tiff
 
             this.SetPhotometricInterpretation();
 
-            using (var writer = new TiffWriter(stream, this.memoryAllocator, this.configuration))
+            using (var writer = new TiffStreamWriter(stream))
             {
                 long firstIfdMarker = this.WriteHeader(writer);
 
@@ -134,9 +134,11 @@ namespace SixLabors.ImageSharp.Formats.Experimental.Tiff
         /// <summary>
         /// Writes the TIFF file header.
         /// </summary>
-        /// <param name="writer">The <see cref="TiffWriter"/> to write data to.</param>
+        /// <param name="writer">The <see cref="TiffStreamWriter" /> to write data to.</param>
-        /// <returns>The marker to write the first IFD offset.</returns>
+        /// <returns>
-        public long WriteHeader(TiffWriter writer)
+        /// The marker to write the first IFD offset.
+        /// </returns>
+        public long WriteHeader(TiffStreamWriter writer)
         {
             writer.Write(ByteOrderMarker);
             writer.Write(TiffConstants.HeaderMagicNumber);
@@ -153,29 +155,17 @@ namespace SixLabors.ImageSharp.Formats.Experimental.Tiff
         /// <param name="image">The <see cref="Image{TPixel}"/> to encode from.</param>
         /// <param name="ifdOffset">The marker to write this IFD offset.</param>
         /// <returns>The marker to write the next IFD offset (if present).</returns>
-        public long WriteImage<TPixel>(TiffWriter writer, Image<TPixel> image, long ifdOffset)
+        public long WriteImage<TPixel>(TiffStreamWriter writer, Image<TPixel> image, long ifdOffset)
             where TPixel : unmanaged, IPixel<TPixel>
         {
             var entriesCollector = new TiffEncoderEntriesCollector();
 
             // Write the image bytes to the steam.
             var imageDataStart = (uint)writer.Position;
-            int imageDataBytes;
+
-            switch (this.Mode)
+            TiffBaseColorWriter colorWriter = TiffColorWriterFactory.Create(this.Mode, writer, this.memoryAllocator, this.configuration, entriesCollector);
-            {
+
-                case TiffEncodingMode.ColorPalette:
+            int imageDataBytes = colorWriter.Write(image, this.quantizer, this.CompressionType, this.compressionLevel, this.UseHorizontalPredictor);
-                    imageDataBytes = writer.WritePalettedRgb(image, this.quantizer, this.CompressionType, this.compressionLevel, this.UseHorizontalPredictor, entriesCollector);
-                    break;
-                case TiffEncodingMode.Gray:
-                    imageDataBytes = writer.WriteGray(image, this.CompressionType, this.compressionLevel, this.UseHorizontalPredictor);
-                    break;
-                case TiffEncodingMode.BiColor:
-                    imageDataBytes = writer.WriteBiColor(image, this.CompressionType, this.compressionLevel);
-                    break;
-                default:
-                    imageDataBytes = writer.WriteRgb(image, this.CompressionType, this.compressionLevel, this.UseHorizontalPredictor);
-                    break;
-            }
 
             this.AddStripTags(image, entriesCollector, imageDataStart, imageDataBytes);
             entriesCollector.ProcessImageFormat(this);
@@ -193,7 +183,7 @@ namespace SixLabors.ImageSharp.Formats.Experimental.Tiff
         /// <param name="writer">The <see cref="BinaryWriter"/> to write data to.</param>
         /// <param name="entries">The IFD entries to write to the file.</param>
         /// <returns>The marker to write the next IFD offset (if present).</returns>
-        public long WriteIfd(TiffWriter writer, List<IExifValue> entries)
+        public long WriteIfd(TiffStreamWriter writer, List<IExifValue> entries)
         {
             if (entries.Count == 0)
             {

src/ImageSharp/Formats/Tiff/Writers/TiffBaseColorWriter.cs

@@ -0,0 +1,44 @@
+// Copyright (c) Six Labors.
+// Licensed under the Apache License, Version 2.0.
+
+using System;
+using System.IO;
+using SixLabors.ImageSharp.Compression.Zlib;
+using SixLabors.ImageSharp.Memory;
+using SixLabors.ImageSharp.PixelFormats;
+using SixLabors.ImageSharp.Processing.Processors.Quantization;
+
+namespace SixLabors.ImageSharp.Formats.Experimental.Tiff.Writers
+{
+    /// <summary>
+    /// Utility class for writing TIFF data to a <see cref="Stream"/>.
+    /// </summary>
+    internal abstract class TiffBaseColorWriter
+    {
+        /// <summary>
+        /// Initializes a new instance of the <see cref="TiffBaseColorWriter" /> class.
+        /// </summary>
+        /// <param name="output">The output stream.</param>
+        /// <param name="memoryAllocator">The memory allocator.</param>
+        /// <param name="configuration">The configuration.</param>
+        /// <param name="entriesCollector">The entries collector.</param>
+        public TiffBaseColorWriter(TiffStreamWriter output, MemoryAllocator memoryAllocator, Configuration configuration, TiffEncoderEntriesCollector entriesCollector)
+        {
+            this.Output = output;
+            this.MemoryAllocator = memoryAllocator;
+            this.Configuration = configuration;
+            this.EntriesCollector = entriesCollector;
+        }
+
+        protected TiffStreamWriter Output { get; }
+
+        protected MemoryAllocator MemoryAllocator { get; }
+
+        protected Configuration Configuration { get; }
+
+        protected TiffEncoderEntriesCollector EntriesCollector { get; }
+
+        public abstract int Write<TPixel>(Image<TPixel> image, IQuantizer quantizer, TiffEncoderCompression compression, DeflateCompressionLevel compressionLevel, bool useHorizontalPredictor)
+            where TPixel : unmanaged, IPixel<TPixel>;
+    }
+}

src/ImageSharp/Formats/Tiff/Writers/TiffBiColorWriter.cs

@@ -11,16 +11,17 @@ using SixLabors.ImageSharp.Memory;
 using SixLabors.ImageSharp.PixelFormats;
 using SixLabors.ImageSharp.Processing;
 using SixLabors.ImageSharp.Processing.Processors.Dithering;
+using SixLabors.ImageSharp.Processing.Processors.Quantization;
 
-namespace SixLabors.ImageSharp.Formats.Experimental.Tiff.Utils
+namespace SixLabors.ImageSharp.Formats.Experimental.Tiff.Writers
 {
     /// <summary>
     /// Utility class for writing TIFF data to a <see cref="Stream"/>.
     /// </summary>
-    internal class TiffBiColorWriter : TiffWriter
+    internal class TiffBiColorWriter : TiffBaseColorWriter
     {
-        public TiffBiColorWriter(Stream output, MemoryAllocator memoryAllocator, Configuration configuration)
+        public TiffBiColorWriter(TiffStreamWriter output, MemoryAllocator memoryAllocator, Configuration configuration, TiffEncoderEntriesCollector entriesCollector)
-            : base(output, memoryAllocator, configuration)
+            : base(output, memoryAllocator, configuration, entriesCollector)
         {
         }
 
@@ -29,11 +30,14 @@ namespace SixLabors.ImageSharp.Formats.Experimental.Tiff.Utils
         /// </summary>
         /// <typeparam name="TPixel">The pixel data.</typeparam>
         /// <param name="image">The image to write to the stream.</param>
+        /// <param name="quantizer">The quantizer.</param>
         /// <param name="compression">The compression to use.</param>
         /// <param name="compressionLevel">The compression level for deflate compression.</param>
-        /// <returns>The number of bytes written.</returns>
+        /// <param name="useHorizontalPredictor">if set to <c>true</c> [use horizontal predictor].</param>
-        public int WriteBiColor<TPixel>(Image<TPixel> image, TiffEncoderCompression compression, DeflateCompressionLevel compressionLevel)
+        /// <returns>
-            where TPixel : unmanaged, IPixel<TPixel>
+        /// The number of bytes written.
+        /// </returns>
+        public override int Write<TPixel>(Image<TPixel> image, IQuantizer quantizer, TiffEncoderCompression compression, DeflateCompressionLevel compressionLevel, bool useHorizontalPredictor)
         {
             int padding = image.Width % 8 == 0 ? 0 : 1;
             int bytesPerRow = (image.Width / 8) + padding;
@@ -60,13 +64,13 @@ namespace SixLabors.ImageSharp.Formats.Experimental.Tiff.Utils
             if (compression == TiffEncoderCompression.CcittGroup3Fax)
             {
                 var bitWriter = new T4BitWriter(this.MemoryAllocator, this.Configuration);
-                return bitWriter.CompressImage(imageBlackWhite, pixelRowAsGraySpan, this.Output);
+                return bitWriter.CompressImage(imageBlackWhite, pixelRowAsGraySpan, this.Output.BaseStream);
             }
 
             if (compression == TiffEncoderCompression.ModifiedHuffman)
             {
                 var bitWriter = new T4BitWriter(this.MemoryAllocator, this.Configuration, useModifiedHuffman: true);
-                return bitWriter.CompressImage(imageBlackWhite, pixelRowAsGraySpan, this.Output);
+                return bitWriter.CompressImage(imageBlackWhite, pixelRowAsGraySpan, this.Output.BaseStream);
             }
 
             // Write image uncompressed.
@@ -93,10 +97,10 @@ namespace SixLabors.ImageSharp.Formats.Experimental.Tiff.Utils
                     }
                 }
 
-                this.Output.Write(row);
+                this.Output.Write(outputRow);
-                bytesWritten += row.Length();
+                bytesWritten += outputRow.Length;
 
-                row.Clear();
+                outputRow.Clear();
             }
 
             return bytesWritten;

src/ImageSharp/Formats/Tiff/Writers/TiffColorWriterFactory.cs

@@ -0,0 +1,25 @@
+// Copyright (c) Six Labors.
+// Licensed under the Apache License, Version 2.0.
+
+using SixLabors.ImageSharp.Memory;
+
+namespace SixLabors.ImageSharp.Formats.Experimental.Tiff.Writers
+{
+    internal static class TiffColorWriterFactory
+    {
+        public static TiffBaseColorWriter Create(TiffEncodingMode mode, TiffStreamWriter output, MemoryAllocator memoryAllocator, Configuration configuration, TiffEncoderEntriesCollector entriesCollector)
+        {
+            switch (mode)
+            {
+                case TiffEncodingMode.ColorPalette:
+                    return new TiffPaletteWriter(output, memoryAllocator, configuration, entriesCollector);
+                case TiffEncodingMode.Gray:
+                    return new TiffGrayWriter(output, memoryAllocator, configuration, entriesCollector);
+                case TiffEncodingMode.BiColor:
+                    return new TiffBiColorWriter(output, memoryAllocator, configuration, entriesCollector);
+                default:
+                    return new TiffRgbWriter(output, memoryAllocator, configuration, entriesCollector);
+            }
+        }
+    }
+}

src/ImageSharp/Formats/Tiff/Writers/TiffGrayWriter.cs

@@ -7,19 +7,21 @@ using System.IO;
 
 using SixLabors.ImageSharp.Compression.Zlib;
 using SixLabors.ImageSharp.Formats.Experimental.Tiff.Compression;
+using SixLabors.ImageSharp.Formats.Experimental.Tiff.Utils;
 using SixLabors.ImageSharp.Formats.Tiff.Compression;
 using SixLabors.ImageSharp.Memory;
 using SixLabors.ImageSharp.PixelFormats;
+using SixLabors.ImageSharp.Processing.Processors.Quantization;
 
-namespace SixLabors.ImageSharp.Formats.Experimental.Tiff.Utils
+namespace SixLabors.ImageSharp.Formats.Experimental.Tiff.Writers
 {
     /// <summary>
     /// Utility class for writing TIFF data to a <see cref="Stream"/>.
     /// </summary>
-    internal class TiffGrayWriter : TiffWriter
+    internal class TiffGrayWriter : TiffBaseColorWriter
     {
-        public TiffGrayWriter(Stream output, MemoryAllocator memoryMemoryAllocator, Configuration configuration)
+        public TiffGrayWriter(TiffStreamWriter output, MemoryAllocator memoryAllocator, Configuration configuration, TiffEncoderEntriesCollector entriesCollector)
-            : base(output, memoryMemoryAllocator, configuration)
+            : base(output, memoryAllocator, configuration, entriesCollector)
         {
         }
 
@@ -28,12 +30,14 @@ namespace SixLabors.ImageSharp.Formats.Experimental.Tiff.Utils
         /// </summary>
         /// <typeparam name="TPixel">The pixel data.</typeparam>
         /// <param name="image">The image to write to the stream.</param>
+        /// <param name="quantizer">The quantizer.</param>
         /// <param name="compression">The compression to use.</param>
         /// <param name="compressionLevel">The compression level for deflate compression.</param>
         /// <param name="useHorizontalPredictor">Indicates if horizontal prediction should be used. Should only be used with deflate or lzw compression.</param>
-        /// <returns>The number of bytes written.</returns>
+        /// <returns>
-        public int WriteGray<TPixel>(Image<TPixel> image, TiffEncoderCompression compression, DeflateCompressionLevel compressionLevel, bool useHorizontalPredictor)
+        /// The number of bytes written.
-        where TPixel : unmanaged, IPixel<TPixel>
+        /// </returns>
+        public override int Write<TPixel>(Image<TPixel> image, IQuantizer quantizer, TiffEncoderCompression compression, DeflateCompressionLevel compressionLevel, bool useHorizontalPredictor)
         {
             using IManagedByteBuffer row = this.MemoryAllocator.AllocateManagedByteBuffer(image.Width);
             Span<byte> rowSpan = row.GetSpan();

src/ImageSharp/Formats/Tiff/Writers/TiffPaletteWriter.cs

@@ -8,27 +8,29 @@ using System.Runtime.InteropServices;
 
 using SixLabors.ImageSharp.Compression.Zlib;
 using SixLabors.ImageSharp.Formats.Experimental.Tiff.Compression;
+using SixLabors.ImageSharp.Formats.Experimental.Tiff.Utils;
 using SixLabors.ImageSharp.Formats.Tiff.Compression;
 using SixLabors.ImageSharp.Memory;
 using SixLabors.ImageSharp.Metadata.Profiles.Exif;
 using SixLabors.ImageSharp.PixelFormats;
 using SixLabors.ImageSharp.Processing.Processors.Quantization;
 
-namespace SixLabors.ImageSharp.Formats.Experimental.Tiff.Utils
+namespace SixLabors.ImageSharp.Formats.Experimental.Tiff.Writers
 {
     /// <summary>
     /// Utility class for writing TIFF data to a <see cref="Stream"/>.
     /// </summary>
-    internal class TiffPaletteWriter : TiffWriter
+    internal class TiffPaletteWriter : TiffBaseColorWriter
     {
         /// <summary>
-        /// Initializes a new instance of the <see cref="TiffPaletteWriter"/> class.
+        /// Initializes a new instance of the <see cref="TiffPaletteWriter" /> class.
         /// </summary>
         /// <param name="output">The output stream.</param>
-        /// <param name="memoryMemoryAllocator">The memory allocator.</param>
+        /// <param name="memoryAllocator">The memory allocator.</param>
         /// <param name="configuration">The configuration.</param>
-        public TiffPaletteWriter(Stream output, MemoryAllocator memoryMemoryAllocator, Configuration configuration)
+        /// <param name="entriesCollector">The entries collector.</param>
-             : base(output, memoryMemoryAllocator, configuration)
+        public TiffPaletteWriter(TiffStreamWriter output, MemoryAllocator memoryAllocator, Configuration configuration, TiffEncoderEntriesCollector entriesCollector)
+             : base(output, memoryAllocator, configuration, entriesCollector)
         {
         }
 
@@ -41,10 +43,10 @@ namespace SixLabors.ImageSharp.Formats.Experimental.Tiff.Utils
         /// <param name="compression">The compression to use.</param>
         /// <param name="compressionLevel">The compression level for deflate compression.</param>
         /// <param name="useHorizontalPredictor">Indicates if horizontal prediction should be used. Should only be used in combination with deflate or LZW compression.</param>
-        /// <param name="entriesCollector">The entries collector.</param>
+        /// <returns>
-        /// <returns>The number of bytes written.</returns>
+        /// The number of bytes written.
-        public int WritePalettedRgb<TPixel>(Image<TPixel> image, IQuantizer quantizer, TiffEncoderCompression compression, DeflateCompressionLevel compressionLevel, bool useHorizontalPredictor, TiffEncoderEntriesCollector entriesCollector)
+        /// </returns>
-            where TPixel : unmanaged, IPixel<TPixel>
+        public override int Write<TPixel>(Image<TPixel> image, IQuantizer quantizer, TiffEncoderCompression compression, DeflateCompressionLevel compressionLevel, bool useHorizontalPredictor)
         {
             int colorsPerChannel = 256;
             int colorPaletteSize = colorsPerChannel * 3;
@@ -93,7 +95,7 @@ namespace SixLabors.ImageSharp.Formats.Experimental.Tiff.Utils
                 Value = palette
             };
 
-            entriesCollector.Add(colorMap);
+            this.EntriesCollector.Add(colorMap);
 
             if (compression == TiffEncoderCompression.Deflate)
             {

src/ImageSharp/Formats/Tiff/Writers/TiffRgbWriter.cs

@@ -7,19 +7,21 @@ using System.IO;
 
 using SixLabors.ImageSharp.Compression.Zlib;
 using SixLabors.ImageSharp.Formats.Experimental.Tiff.Compression;
+using SixLabors.ImageSharp.Formats.Experimental.Tiff.Utils;
 using SixLabors.ImageSharp.Formats.Tiff.Compression;
 using SixLabors.ImageSharp.Memory;
 using SixLabors.ImageSharp.PixelFormats;
+using SixLabors.ImageSharp.Processing.Processors.Quantization;
 
-namespace SixLabors.ImageSharp.Formats.Experimental.Tiff.Utils
+namespace SixLabors.ImageSharp.Formats.Experimental.Tiff.Writers
 {
     /// <summary>
     /// Utility class for writing TIFF data to a <see cref="Stream"/>.
     /// </summary>
-    internal class TiffRgbWriter : TiffWriter
+    internal class TiffRgbWriter : TiffBaseColorWriter
     {
-        public TiffRgbWriter(Stream output, MemoryAllocator memoryMemoryAllocator, Configuration configuration)
+        public TiffRgbWriter(TiffStreamWriter output, MemoryAllocator memoryAllocator, Configuration configuration, TiffEncoderEntriesCollector entriesCollector)
-            : base(output, memoryMemoryAllocator, configuration)
+            : base(output, memoryAllocator, configuration, entriesCollector)
         {
         }
 
@@ -28,12 +30,14 @@ namespace SixLabors.ImageSharp.Formats.Experimental.Tiff.Utils
         /// </summary>
         /// <typeparam name="TPixel">The pixel data.</typeparam>
         /// <param name="image">The image to write to the stream.</param>
+        /// <param name="quantizer">The quantizer.</param>
         /// <param name="compression">The compression to use.</param>
         /// <param name="compressionLevel">The compression level for deflate compression.</param>
         /// <param name="useHorizontalPredictor">Indicates if horizontal prediction should be used. Should only be used with deflate compression.</param>
-        /// <returns>The number of bytes written.</returns>
+        /// <returns>
-        public int WriteRgb<TPixel>(Image<TPixel> image, TiffEncoderCompression compression, DeflateCompressionLevel compressionLevel, bool useHorizontalPredictor)
+        /// The number of bytes written.
-            where TPixel : unmanaged, IPixel<TPixel>
+        /// </returns>
+        public override int Write<TPixel>(Image<TPixel> image, IQuantizer quantizer, TiffEncoderCompression compression, DeflateCompressionLevel compressionLevel, bool useHorizontalPredictor)
         {
             using IManagedByteBuffer row = this.MemoryAllocator.AllocateManagedByteBuffer(image.Width * 3);
             Span<byte> rowSpan = row.GetSpan();

src/ImageSharp/Formats/Tiff/Utils/TiffWriter.cs → src/ImageSharp/Formats/Tiff/Writers/TiffStreamWriter.cs

@@ -5,27 +5,20 @@ using System;
 using System.IO;
 using SixLabors.ImageSharp.Memory;
 
-namespace SixLabors.ImageSharp.Formats.Experimental.Tiff.Utils
+namespace SixLabors.ImageSharp.Formats.Experimental.Tiff.Writers
 {
     /// <summary>
     /// Utility class for writing TIFF data to a <see cref="Stream"/>.
     /// </summary>
-    internal class TiffWriter : IDisposable
+    internal class TiffStreamWriter : IDisposable
     {
         private static readonly byte[] PaddingBytes = new byte[4];
 
         /// <summary>
-        /// Initializes a new instance of the <see cref="TiffWriter"/> class.
+        /// Initializes a new instance of the <see cref="TiffStreamWriter"/> class.
         /// </summary>
         /// <param name="output">The output stream.</param>
-        /// <param name="memoryAllocator">The memory allocator.</param>
+        public TiffStreamWriter(Stream output) => this.BaseStream = output;
-        /// <param name="configuration">The configuration.</param>
-        public TiffWriter(Stream output, MemoryAllocator memoryAllocator, Configuration configuration)
-        {
-            this.Output = output;
-            this.MemoryAllocator = memoryAllocator;
-            this.Configuration = configuration;
-        }
 
         /// <summary>
         /// Gets a value indicating whether the architecture is little-endian.
@@ -35,9 +28,9 @@ namespace SixLabors.ImageSharp.Formats.Experimental.Tiff.Utils
         /// <summary>
         /// Gets the current position within the stream.
         /// </summary>
-        public long Position => this.Output.Position;
+        public long Position => this.BaseStream.Position;
 
-        protected Stream Output { get; }
+        public Stream BaseStream { get; }
 
         protected MemoryAllocator MemoryAllocator { get; }
 
@@ -49,7 +42,7 @@ namespace SixLabors.ImageSharp.Formats.Experimental.Tiff.Utils
         /// <returns>The offset to be written later</returns>
         public long PlaceMarker()
         {
-            long offset = this.Output.Position;
+            long offset = this.BaseStream.Position;
             this.Write(0u);
             return offset;
         }
@@ -58,13 +51,15 @@ namespace SixLabors.ImageSharp.Formats.Experimental.Tiff.Utils
         /// Writes an array of bytes to the current stream.
         /// </summary>
         /// <param name="value">The bytes to write.</param>
-        public void Write(byte[] value) => this.Output.Write(value, 0, value.Length);
+        public void Write(byte[] value) => this.BaseStream.Write(value, 0, value.Length);
+
+        public void Write(ReadOnlySpan<byte> value) => this.BaseStream.Write(value);
 
         /// <summary>
         /// Writes a byte to the current stream.
         /// </summary>
         /// <param name="value">The byte to write.</param>
-        public void Write(byte value) => this.Output.Write(new byte[] { value }, 0, 1);
+        public void Write(byte value) => this.BaseStream.Write(new byte[] { value }, 0, 1);
 
         /// <summary>
         /// Writes a two-byte unsigned integer to the current stream.
@@ -73,7 +68,7 @@ namespace SixLabors.ImageSharp.Formats.Experimental.Tiff.Utils
         public void Write(ushort value)
         {
             byte[] bytes = BitConverter.GetBytes(value);
-            this.Output.Write(bytes, 0, 2);
+            this.BaseStream.Write(bytes, 0, 2);
         }
 
         /// <summary>
@@ -83,7 +78,7 @@ namespace SixLabors.ImageSharp.Formats.Experimental.Tiff.Utils
         public void Write(uint value)
         {
             byte[] bytes = BitConverter.GetBytes(value);
-            this.Output.Write(bytes, 0, 4);
+            this.BaseStream.Write(bytes, 0, 4);
         }
 
         /// <summary>
@@ -92,11 +87,11 @@ namespace SixLabors.ImageSharp.Formats.Experimental.Tiff.Utils
         /// <param name="value">The bytes to write.</param>
         public void WritePadded(byte[] value)
         {
-            this.Output.Write(value, 0, value.Length);
+            this.BaseStream.Write(value, 0, value.Length);
 
             if (value.Length < 4)
             {
-                this.Output.Write(PaddingBytes, 0, 4 - value.Length);
+                this.BaseStream.Write(PaddingBytes, 0, 4 - value.Length);
             }
         }
 
@@ -107,15 +102,15 @@ namespace SixLabors.ImageSharp.Formats.Experimental.Tiff.Utils
         /// <param name="value">The four-byte unsigned integer to write.</param>
         public void WriteMarker(long offset, uint value)
         {
-            long currentOffset = this.Output.Position;
+            long currentOffset = this.BaseStream.Position;
-            this.Output.Seek(offset, SeekOrigin.Begin);
+            this.BaseStream.Seek(offset, SeekOrigin.Begin);
             this.Write(value);
-            this.Output.Seek(currentOffset, SeekOrigin.Begin);
+            this.BaseStream.Seek(currentOffset, SeekOrigin.Begin);
         }
 
         /// <summary>
-        /// Disposes <see cref="TiffWriter"/> instance, ensuring any unwritten data is flushed.
+        /// Disposes <see cref="TiffStreamWriter"/> instance, ensuring any unwritten data is flushed.
         /// </summary>
-        public void Dispose() => this.Output.Flush();
+        public void Dispose() => this.BaseStream.Flush();
     }
 }

tests/ImageSharp.Tests/Formats/Tiff/TiffEncoderHeaderTests.cs

@@ -5,6 +5,7 @@ using System.IO;
 
 using SixLabors.ImageSharp.Formats.Experimental.Tiff;
 using SixLabors.ImageSharp.Formats.Experimental.Tiff.Utils;
+using SixLabors.ImageSharp.Formats.Experimental.Tiff.Writers;
 using SixLabors.ImageSharp.Memory;
 
 using Xunit;
@@ -24,7 +25,7 @@ namespace SixLabors.ImageSharp.Tests.Formats.Tiff
             using var stream = new MemoryStream();
             var encoder = new TiffEncoderCore(Options, MemoryAllocator);
 
-            using (var writer = new TiffWriter(stream, MemoryAllocator, Configuration))
+            using (var writer = new TiffStreamWriter(stream))
             {
                 long firstIfdMarker = encoder.WriteHeader(writer);
             }
@@ -38,7 +39,7 @@ namespace SixLabors.ImageSharp.Tests.Formats.Tiff
             using var stream = new MemoryStream();
             var encoder = new TiffEncoderCore(Options, MemoryAllocator);
 
-            using (var writer = new TiffWriter(stream, MemoryAllocator, Configuration))
+            using (var writer = new TiffStreamWriter(stream))
             {
                 long firstIfdMarker = encoder.WriteHeader(writer);
                 Assert.Equal(4, firstIfdMarker);

tests/ImageSharp.Tests/Formats/Tiff/Utils/TiffWriterTests.cs

@@ -4,6 +4,7 @@
 using System.IO;
 
 using SixLabors.ImageSharp.Formats.Experimental.Tiff.Utils;
+using SixLabors.ImageSharp.Formats.Experimental.Tiff.Writers;
 using SixLabors.ImageSharp.Memory;
 
 using Xunit;
@@ -20,7 +21,7 @@ namespace SixLabors.ImageSharp.Tests.Formats.Tiff.Utils
         public void IsLittleEndian_IsTrueOnWindows()
         {
             using var stream = new MemoryStream();
-            using var writer = new TiffWriter(stream, MemoryAllocator, Configuration);
+            using var writer = new TiffStreamWriter(stream);
             Assert.True(writer.IsLittleEndian);
         }
 
@@ -31,7 +32,7 @@ namespace SixLabors.ImageSharp.Tests.Formats.Tiff.Utils
         public void Position_EqualsTheStreamPosition(byte[] data, long expectedResult)
         {
             using var stream = new MemoryStream();
-            using var writer = new TiffWriter(stream, MemoryAllocator, Configuration);
+            using var writer = new TiffStreamWriter(stream);
             writer.Write(data);
             Assert.Equal(writer.Position, expectedResult);
         }
@@ -40,7 +41,7 @@ namespace SixLabors.ImageSharp.Tests.Formats.Tiff.Utils
         public void Write_WritesByte()
         {
             using var stream = new MemoryStream();
-            using var writer = new TiffWriter(stream, MemoryAllocator, Configuration);
+            using var writer = new TiffStreamWriter(stream);
             writer.Write((byte)42);
 
             Assert.Equal(new byte[] { 42 }, stream.ToArray());
@@ -50,7 +51,7 @@ namespace SixLabors.ImageSharp.Tests.Formats.Tiff.Utils
         public void Write_WritesByteArray()
         {
             using var stream = new MemoryStream();
-            using var writer = new TiffWriter(stream, MemoryAllocator, Configuration);
+            using var writer = new TiffStreamWriter(stream);
             writer.Write(new byte[] { 2, 4, 6, 8 });
 
             Assert.Equal(new byte[] { 2, 4, 6, 8 }, stream.ToArray());
@@ -60,7 +61,7 @@ namespace SixLabors.ImageSharp.Tests.Formats.Tiff.Utils
         public void Write_WritesUInt16()
         {
             using var stream = new MemoryStream();
-            using var writer = new TiffWriter(stream, MemoryAllocator, Configuration);
+            using var writer = new TiffStreamWriter(stream);
             writer.Write((ushort)1234);
 
             Assert.Equal(new byte[] { 0xD2, 0x04 }, stream.ToArray());
@@ -70,7 +71,7 @@ namespace SixLabors.ImageSharp.Tests.Formats.Tiff.Utils
         public void Write_WritesUInt32()
         {
             using var stream = new MemoryStream();
-            using var writer = new TiffWriter(stream, MemoryAllocator, Configuration);
+            using var writer = new TiffStreamWriter(stream);
             writer.Write(12345678U);
 
             Assert.Equal(new byte[] { 0x4E, 0x61, 0xBC, 0x00 }, stream.ToArray());
@@ -86,7 +87,7 @@ namespace SixLabors.ImageSharp.Tests.Formats.Tiff.Utils
         public void WritePadded_WritesByteArray(byte[] bytes, byte[] expectedResult)
         {
             using var stream = new MemoryStream();
-            using var writer = new TiffWriter(stream, MemoryAllocator, Configuration);
+            using var writer = new TiffStreamWriter(stream);
             writer.WritePadded(bytes);
 
             Assert.Equal(expectedResult, stream.ToArray());
@@ -97,7 +98,7 @@ namespace SixLabors.ImageSharp.Tests.Formats.Tiff.Utils
         {
             using var stream = new MemoryStream();
 
-            using (var writer = new TiffWriter(stream, MemoryAllocator, Configuration))
+            using (var writer = new TiffStreamWriter(stream))
             {
                 writer.Write(0x11111111);
                 long marker = writer.PlaceMarker();