- Seal tiff writer

- TiffStreamWriter Write byte uses WriteByte method from base stream
- Deflate compress strip: remove duplicate Dispose

src/ImageSharp/Common/ByteOrder.cs

@@ -4,7 +4,7 @@
 namespace SixLabors.ImageSharp
 {
     /// <summary>
-    /// The tiff data stream byte order enum.
+    /// The byte order of the data stream.
     /// </summary>
     public enum ByteOrder
     {

src/ImageSharp/Formats/Tiff/Compression/Compressors/DeflateCompressor.cs

@@ -31,17 +31,16 @@ namespace SixLabors.ImageSharp.Formats.Experimental.Tiff.Compression.Compressors
         public override void CompressStrip(Span<byte> rows, int height)
         {
             this.memoryStream.Seek(0, SeekOrigin.Begin);
-            using var stream = new ZlibDeflateStream(this.Allocator, this.memoryStream, this.compressionLevel);
-
-            if (this.Predictor == TiffPredictor.Horizontal)
+            using (var stream = new ZlibDeflateStream(this.Allocator, this.memoryStream, this.compressionLevel))
             {
-                HorizontalPredictor.ApplyHorizontalPrediction(rows, this.BytesPerRow, this.BitsPerPixel);
-            }
+                if (this.Predictor == TiffPredictor.Horizontal)
+                {
+                    HorizontalPredictor.ApplyHorizontalPrediction(rows, this.BytesPerRow, this.BitsPerPixel);
+                }
 
-            stream.Write(rows);
-
-            stream.Flush();
-            stream.Dispose();
+                stream.Write(rows);
+                stream.Flush();
+            }
 
             int size = (int)this.memoryStream.Position;
 

src/ImageSharp/Formats/Tiff/TiffEncoderCore.cs

@@ -26,8 +26,6 @@ namespace SixLabors.ImageSharp.Formats.Experimental.Tiff
     {
         public const int DefaultStripSize = 8 * 1024;
 
-        public static readonly ByteOrder ByteOrder = BitConverter.IsLittleEndian ? ByteOrder.LittleEndian : ByteOrder.BigEndian;
-
         private static readonly ushort ByteOrderMarker = BitConverter.IsLittleEndian
                 ? TiffConstants.ByteOrderLittleEndianShort
                 : TiffConstants.ByteOrderBigEndianShort;

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

@@ -12,7 +12,7 @@ using SixLabors.ImageSharp.Processing;
 
 namespace SixLabors.ImageSharp.Formats.Experimental.Tiff.Writers
 {
-    internal class TiffBiColorWriter<TPixel> : TiffBaseColorWriter<TPixel>
+    internal sealed class TiffBiColorWriter<TPixel> : TiffBaseColorWriter<TPixel>
         where TPixel : unmanaged, IPixel<TPixel>
     {
         private readonly Image<TPixel> imageBlackWhite;
@@ -25,7 +25,6 @@ namespace SixLabors.ImageSharp.Formats.Experimental.Tiff.Writers
             : base(image, memoryAllocator, configuration, entriesCollector)
         {
             // Convert image to black and white.
-            // TODO: Should we allow to skip this by the user, if its known to be black and white already?
             this.imageBlackWhite = new Image<TPixel>(configuration, new ImageMetadata(), new[] { image.Clone() });
             this.imageBlackWhite.Mutate(img => img.BinaryDither(KnownDitherings.FloydSteinberg));
         }

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

@@ -7,7 +7,7 @@ using SixLabors.ImageSharp.PixelFormats;
 
 namespace SixLabors.ImageSharp.Formats.Experimental.Tiff.Writers
 {
-    internal class TiffGrayWriter<TPixel> : TiffCompositeColorWriter<TPixel>
+    internal sealed class TiffGrayWriter<TPixel> : TiffCompositeColorWriter<TPixel>
         where TPixel : unmanaged, IPixel<TPixel>
     {
         public TiffGrayWriter(ImageFrame<TPixel> image, MemoryAllocator memoryAllocator, Configuration configuration, TiffEncoderEntriesCollector entriesCollector)

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

@@ -13,7 +13,7 @@ using SixLabors.ImageSharp.Processing.Processors.Quantization;
 
 namespace SixLabors.ImageSharp.Formats.Experimental.Tiff.Writers
 {
-    internal class TiffPaletteWriter<TPixel> : TiffBaseColorWriter<TPixel>
+    internal sealed class TiffPaletteWriter<TPixel> : TiffBaseColorWriter<TPixel>
         where TPixel : unmanaged, IPixel<TPixel>
     {
         private const int ColorsPerChannel = 256;

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

@@ -7,7 +7,7 @@ using SixLabors.ImageSharp.PixelFormats;
 
 namespace SixLabors.ImageSharp.Formats.Experimental.Tiff.Writers
 {
-    internal class TiffRgbWriter<TPixel> : TiffCompositeColorWriter<TPixel>
+    internal sealed class TiffRgbWriter<TPixel> : TiffCompositeColorWriter<TPixel>
         where TPixel : unmanaged, IPixel<TPixel>
     {
         public TiffRgbWriter(ImageFrame<TPixel> image, MemoryAllocator memoryAllocator, Configuration configuration, TiffEncoderEntriesCollector entriesCollector)

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

@@ -61,7 +61,7 @@ namespace SixLabors.ImageSharp.Formats.Experimental.Tiff.Writers
         /// Writes a byte to the current stream.
         /// </summary>
         /// <param name="value">The byte to write.</param>
-        public void Write(byte value) => this.BaseStream.Write(new byte[] { value }, 0, 1);
+        public void Write(byte value) => this.BaseStream.WriteByte(value);
 
         /// <summary>
         /// Writes a two-byte unsigned integer to the current stream.