Add setters for tiff metadata properties

src/ImageSharp/Formats/Tiff/Constants/TiffCompression.cs

@@ -45,7 +45,7 @@ namespace SixLabors.ImageSharp.Formats.Experimental.Tiff.Constants
         /// JPEG compression - obsolete (see Section 22 of the TIFF 6.0 specification).
         ///
         /// Note: The TIFF encoder does not support this compression and will default to use no compression instead,
-        /// if this is choosen.
+        /// if this is chosen.
         /// </summary>
         OldJpeg = 6,
 
@@ -53,7 +53,7 @@ namespace SixLabors.ImageSharp.Formats.Experimental.Tiff.Constants
         /// JPEG compression (see TIFF Specification, supplement 2).
         ///
         /// Note: The TIFF encoder does not yet support this compression and will default to use no compression instead,
-        /// if this is choosen.
+        /// if this is chosen.
         /// </summary>
         Jpeg = 7,
 
@@ -66,7 +66,7 @@ namespace SixLabors.ImageSharp.Formats.Experimental.Tiff.Constants
         /// Deflate compression - old.
         ///
         /// Note: The TIFF encoder does not support this compression and will default to use no compression instead,
-        /// if this is choosen.
+        /// if this is chosen.
         /// </summary>
         OldDeflate = 32946,
 
@@ -74,7 +74,7 @@ namespace SixLabors.ImageSharp.Formats.Experimental.Tiff.Constants
         /// ITU-T Rec. T.82 coding, applying ITU-T Rec. T.85 (JBIG) (see RFC2301).
         ///
         /// Note: The TIFF encoder does not yet support this compression and will default to use no compression instead,
-        /// if this is choosen.
+        /// if this is chosen.
         /// </summary>
         ItuTRecT82 = 9,
 
@@ -82,7 +82,7 @@ namespace SixLabors.ImageSharp.Formats.Experimental.Tiff.Constants
         /// ITU-T Rec. T.43 representation, using ITU-T Rec. T.82 (JBIG) (see RFC2301).
         ///
         /// Note: The TIFF encoder does not yet support this compression and will default to use no compression instead,
-        /// if this is choosen.
+        /// if this is chosen.
         /// </summary>
         ItuTRecT43 = 10
     }

src/ImageSharp/Formats/Tiff/Constants/TiffPhotometricInterpretation.cs

@@ -19,12 +19,12 @@ namespace SixLabors.ImageSharp.Formats.Experimental.Tiff.Constants
         BlackIsZero = 1,
 
         /// <summary>
-        /// RGB
+        /// RGB image.
         /// </summary>
         Rgb = 2,
 
         /// <summary>
-        /// Palette Color
+        /// Palette Color.
         /// </summary>
         PaletteColor = 3,
 

src/ImageSharp/Formats/Tiff/ITiffEncoderOptions.cs

@@ -13,9 +13,9 @@ namespace SixLabors.ImageSharp.Formats.Experimental.Tiff
     internal interface ITiffEncoderOptions
     {
         /// <summary>
-        /// Gets or sets the number of bits per pixel.
+        /// Gets the number of bits per pixel.
         /// </summary>
-        TiffBitsPerPixel? BitsPerPixel { get; set; }
+        TiffBitsPerPixel? BitsPerPixel { get; }
 
         /// <summary>
         /// Gets the compression type to use.

src/ImageSharp/Formats/Tiff/TiffEncoderCore.cs

@@ -293,10 +293,10 @@ namespace SixLabors.ImageSharp.Formats.Experimental.Tiff
                 }
             }
 
-            if (this.Mode == TiffEncodingMode.Default)
+            if (this.Mode == TiffEncodingMode.Default && this.BitsPerPixel != null)
             {
-                // Preserve input bits per pixel, if no mode was specified.
+                // Preserve input bits per pixel, if no encoding mode was specified.
-                switch (tiffMetadata.BitsPerPixel)
+                switch (this.BitsPerPixel)
                 {
                     case TiffBitsPerPixel.Bit1:
                         this.Mode = TiffEncodingMode.BiColor;

src/ImageSharp/Formats/Tiff/TiffMetadata.cs

@@ -33,24 +33,25 @@ namespace SixLabors.ImageSharp.Formats.Experimental.Tiff
         }
 
         /// <summary>
-        /// Gets the byte order.
+        /// Gets or sets the byte order.
         /// </summary>
-        public ByteOrder ByteOrder { get; internal set; }
+        public ByteOrder ByteOrder { get; set; }
 
         /// <summary>
-        /// Gets the number of bits per pixel.
+        /// Gets or sets the number of bits per pixel.
         /// </summary>
-        public TiffBitsPerPixel BitsPerPixel { get; internal set; } = TiffBitsPerPixel.Bit24;
+        public TiffBitsPerPixel? BitsPerPixel { get; set; }
 
         /// <summary>
-        /// Gets the compression used to create the TIFF file.
+        /// Gets or sets the compression used to create the TIFF file.
+        /// Defaults to None.
         /// </summary>
-        public TiffCompression Compression { get; internal set; } = TiffCompression.None;
+        public TiffCompression Compression { get; set; } = TiffCompression.None;
 
         /// <summary>
-        /// Gets the photometric interpretation which indicates how the pixels are to be interpreted, e.g. if the image is bicolor, RGB, color paletted etc.
+        /// Gets or sets the photometric interpretation which indicates how the pixels are to be interpreted, e.g. if the image is bicolor, RGB, color paletted etc.
         /// </summary>
-        public TiffPhotometricInterpretation PhotometricInterpretation { get; internal set; }
+        public TiffPhotometricInterpretation PhotometricInterpretation { get; set; }
 
         /// <summary>
         /// Gets or sets the XMP profile.

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

@@ -30,11 +30,53 @@ namespace SixLabors.ImageSharp.Tests.Formats.Tiff
         }
 
         [Theory]
-        [InlineData(TiffEncodingMode.Default, TiffCompression.None, TiffBitsPerPixel.Bit24, TiffCompression.None)]
+        [InlineData(TiffEncodingMode.Default, TiffBitsPerPixel.Bit24)]
-        [InlineData(TiffEncodingMode.Rgb, TiffCompression.None, TiffBitsPerPixel.Bit24, TiffCompression.None)]
+        [InlineData(TiffEncodingMode.Rgb, TiffBitsPerPixel.Bit24)]
-        [InlineData(TiffEncodingMode.ColorPalette, TiffCompression.None, TiffBitsPerPixel.Bit8, TiffCompression.None)]
+        [InlineData(TiffEncodingMode.ColorPalette, TiffBitsPerPixel.Bit8)]
-        [InlineData(TiffEncodingMode.Gray, TiffCompression.None, TiffBitsPerPixel.Bit8, TiffCompression.None)]
+        [InlineData(TiffEncodingMode.Gray, TiffBitsPerPixel.Bit8)]
-        [InlineData(TiffEncodingMode.BiColor, TiffCompression.None, TiffBitsPerPixel.Bit1, TiffCompression.None)]
+        [InlineData(TiffEncodingMode.BiColor, TiffBitsPerPixel.Bit1)]
+        public void EncoderOptions_SetEncodingMode_Works(TiffEncodingMode mode, TiffBitsPerPixel expectedBitsPerPixel)
+        {
+            // arrange
+            var tiffEncoder = new TiffEncoder { Mode = mode };
+            Image input = new Image<Rgb24>(10, 10);
+            using var memStream = new MemoryStream();
+
+            // act
+            input.Save(memStream, tiffEncoder);
+
+            // assert
+            memStream.Position = 0;
+            using var output = Image.Load<Rgba32>(Configuration, memStream);
+            TiffMetadata meta = output.Metadata.GetTiffMetadata();
+            Assert.Equal(expectedBitsPerPixel, meta.BitsPerPixel);
+            Assert.Equal(TiffCompression.None, meta.Compression);
+        }
+
+        [Theory]
+        [InlineData(TiffBitsPerPixel.Bit24)]
+        [InlineData(TiffBitsPerPixel.Bit8)]
+        [InlineData(TiffBitsPerPixel.Bit4)]
+        [InlineData(TiffBitsPerPixel.Bit1)]
+        public void EncoderOptions_SetBitPerPixel_Works(TiffBitsPerPixel bitsPerPixel)
+        {
+            // arrange
+            var tiffEncoder = new TiffEncoder { BitsPerPixel = bitsPerPixel };
+            Image input = new Image<Rgb24>(10, 10);
+            using var memStream = new MemoryStream();
+
+            // act
+            input.Save(memStream, tiffEncoder);
+
+            // assert
+            memStream.Position = 0;
+            using var output = Image.Load<Rgba32>(Configuration, memStream);
+            TiffMetadata meta = output.Metadata.GetTiffMetadata();
+            Assert.Equal(bitsPerPixel, meta.BitsPerPixel);
+            Assert.Equal(TiffCompression.None, meta.Compression);
+        }
+
+        [Theory]
         [InlineData(TiffEncodingMode.Default, TiffCompression.Deflate, TiffBitsPerPixel.Bit24, TiffCompression.Deflate)]
         [InlineData(TiffEncodingMode.Rgb, TiffCompression.Deflate, TiffBitsPerPixel.Bit24, TiffCompression.Deflate)]
         [InlineData(TiffEncodingMode.Gray, TiffCompression.Deflate, TiffBitsPerPixel.Bit8, TiffCompression.Deflate)]
@@ -55,7 +97,7 @@ namespace SixLabors.ImageSharp.Tests.Formats.Tiff
         [InlineData(TiffEncodingMode.Rgb, TiffCompression.Jpeg, TiffBitsPerPixel.Bit24, TiffCompression.None)]
         [InlineData(TiffEncodingMode.Rgb, TiffCompression.OldDeflate, TiffBitsPerPixel.Bit24, TiffCompression.None)]
         [InlineData(TiffEncodingMode.Rgb, TiffCompression.OldJpeg, TiffBitsPerPixel.Bit24, TiffCompression.None)]
-        public void EncoderOptions_Work(TiffEncodingMode mode, TiffCompression compression, TiffBitsPerPixel expectedBitsPerPixel, TiffCompression expectedCompression)
+        public void EncoderOptions_SetEncodingModeAndCompression_Works(TiffEncodingMode mode, TiffCompression compression, TiffBitsPerPixel expectedBitsPerPixel, TiffCompression expectedCompression)
         {
             // arrange
             var tiffEncoder = new TiffEncoder { Mode = mode, Compression = compression };
@@ -80,7 +122,7 @@ namespace SixLabors.ImageSharp.Tests.Formats.Tiff
         [WithFile(Rgb4BitPalette, PixelTypes.Rgba32, TiffBitsPerPixel.Bit4)]
         [WithFile(RgbPalette, PixelTypes.Rgba32, TiffBitsPerPixel.Bit8)]
         [WithFile(Calliphora_PaletteUncompressed, PixelTypes.Rgba32, TiffBitsPerPixel.Bit8)]
-        public void TiffEncoder_PreserveBitsPerPixel<TPixel>(TestImageProvider<TPixel> provider, TiffBitsPerPixel expectedBitsPerPixel)
+        public void TiffEncoder_PreservesBitsPerPixel<TPixel>(TestImageProvider<TPixel> provider, TiffBitsPerPixel expectedBitsPerPixel)
             where TPixel : unmanaged, IPixel<TPixel>
         {
             // arrange

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

@@ -3,7 +3,6 @@
 
 using System.IO;
 using SixLabors.ImageSharp.Formats.Experimental.Tiff.Writers;
-using SixLabors.ImageSharp.Memory;
 
 using Xunit;
 
@@ -12,9 +11,6 @@ namespace SixLabors.ImageSharp.Tests.Formats.Tiff.Utils
     [Trait("Format", "Tiff")]
     public class TiffWriterTests
     {
-        private static readonly MemoryAllocator MemoryAllocator = new ArrayPoolMemoryAllocator();
-        private static readonly Configuration Configuration = Configuration.Default;
-
         [Fact]
         public void IsLittleEndian_IsTrueOnWindows()
         {
@@ -40,7 +36,7 @@ namespace SixLabors.ImageSharp.Tests.Formats.Tiff.Utils
         {
             using var stream = new MemoryStream();
             using var writer = new TiffStreamWriter(stream);
-            writer.Write((byte)42);
+            writer.Write(42);
 
             Assert.Equal(new byte[] { 42 }, stream.ToArray());
         }
@@ -60,7 +56,7 @@ namespace SixLabors.ImageSharp.Tests.Formats.Tiff.Utils
         {
             using var stream = new MemoryStream();
             using var writer = new TiffStreamWriter(stream);
-            writer.Write((ushort)1234);
+            writer.Write(1234);
 
             Assert.Equal(new byte[] { 0xD2, 0x04 }, stream.ToArray());
         }