Add Tiff encoder Tests

src/ImageSharp/Formats/Tiff/TiffEncoder.cs

@@ -19,6 +19,11 @@ namespace SixLabors.ImageSharp.Formats.Tiff
         /// </summary>
         public TiffBitsPerPixel? BitsPerPixel { get; set; }
 
+        /// <summary>
+        /// Gets or sets a value indicating which compression to use.
+        /// </summary>
+        public TiffEncoderCompression Compression { get; set; } = TiffEncoderCompression.None;
+
         /// <inheritdoc/>
         public void Encode<TPixel>(Image<TPixel> image, Stream stream)
             where TPixel : unmanaged, IPixel<TPixel>

src/ImageSharp/Formats/Tiff/TiffEncoderCompression.cs

@@ -0,0 +1,16 @@
+// Copyright (c) Six Labors.
+// Licensed under the Apache License, Version 2.0.
+
+namespace SixLabors.ImageSharp.Formats.Tiff
+{
+    /// <summary>
+    /// Indicates which tiff compression is used.
+    /// </summary>
+    public enum TiffEncoderCompression
+    {
+        /// <summary>
+        /// No compression is used.
+        /// </summary>
+        None,
+    }
+}

src/ImageSharp/Formats/Tiff/TiffEncoderCore.cs

@@ -47,21 +47,12 @@ namespace SixLabors.ImageSharp.Formats.Tiff
         public TiffEncoderCore(ITiffEncoderOptions options, MemoryAllocator memoryAllocator)
         {
             this.memoryAllocator = memoryAllocator;
-
-            if (options.BitsPerPixel == TiffBitsPerPixel.Pixel8)
-            {
-                this.PhotometricInterpretation = TiffPhotometricInterpretation.BlackIsZero;
-            }
-            else
-            {
-                this.PhotometricInterpretation = TiffPhotometricInterpretation.Rgb;
-            }
         }
 
         /// <summary>
         /// Gets the photometric interpretation implementation to use when encoding the image.
         /// </summary>
-        private TiffPhotometricInterpretation PhotometricInterpretation { get; }
+        private TiffPhotometricInterpretation PhotometricInterpretation { get; set; }
 
         /// <summary>
         /// Gets or sets the compression implementation to use when encoding the image.
@@ -85,6 +76,7 @@ namespace SixLabors.ImageSharp.Formats.Tiff
             ImageMetadata metadata = image.Metadata;
             TiffMetadata tiffMetadata = metadata.GetTiffMetadata();
             this.bitsPerPixel ??= tiffMetadata.BitsPerPixel;
+            this.PhotometricInterpretation = this.bitsPerPixel == TiffBitsPerPixel.Pixel8 ? TiffPhotometricInterpretation.BlackIsZero : TiffPhotometricInterpretation.Rgb;
 
             short bpp = (short)this.bitsPerPixel;
             int bytesPerLine = 4 * (((image.Width * bpp) + 31) / 32);
@@ -132,15 +124,7 @@ namespace SixLabors.ImageSharp.Formats.Tiff
 
             // Write the image bytes to the steam.
             var imageDataStart = (uint)writer.Position;
-            int imageDataBytes;
+            int imageDataBytes = this.PhotometricInterpretation == TiffPhotometricInterpretation.Rgb ? writer.WriteRgbImageData(image, this.padding) : writer.WriteGrayImageData(image, this.padding);
-            if (this.PhotometricInterpretation == TiffPhotometricInterpretation.Rgb)
-            {
-                imageDataBytes = writer.WriteRgbImageData(image, this.padding);
-            }
-            else
-            {
-                imageDataBytes = writer.WriteGrayImageData(image, this.padding);
-            }
 
             // Write info's about the image to the stream.
             this.AddImageFormat(image, ifdEntries, imageDataStart, imageDataBytes);

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

@@ -20,7 +20,7 @@ namespace SixLabors.ImageSharp.Tests.Formats.Tiff
         {
             using (Stream stream = CreateCompressedStream(data))
             {
-                byte[] buffer = new byte[data.Length];
+                var buffer = new byte[data.Length];
 
                 new LzwTiffCompression(Configuration.Default.MemoryAllocator).Decompress(stream, (int)stream.Length, buffer);
 

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

@@ -16,7 +16,7 @@ namespace SixLabors.ImageSharp.Tests.Formats.Tiff
         public void Decompress_ReadsData(byte[] inputData, int byteCount, byte[] expectedResult)
         {
             Stream stream = new MemoryStream(inputData);
-            byte[] buffer = new byte[expectedResult.Length];
+            var buffer = new byte[expectedResult.Length];
 
             new NoneTiffCompression(null).Decompress(stream, byteCount, buffer);
 

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

@@ -1,172 +0,0 @@
-// Copyright (c) Six Labors.
-// Licensed under the Apache License, Version 2.0.
-
-using System;
-using System.IO;
-using System.Threading.Tasks;
-using SixLabors.ImageSharp.Formats;
-using SixLabors.ImageSharp.Formats.Tiff;
-using SixLabors.ImageSharp.PixelFormats;
-using Xunit;
-
-namespace SixLabors.ImageSharp.Tests.Formats.Tiff
-{
-    [Trait("Category", "Tiff.BlackBox.Encoder")]
-    [Trait("Category", "Tiff")]
-    public class ImageExtensionsTest
-    {
-        [Theory]
-        [WithFile(TestImages.Tiff.RgbUncompressed, PixelTypes.Rgba32)]
-        public void ThrowsSavingNotImplemented<TPixel>(TestImageProvider<TPixel> provider)
-            where TPixel : unmanaged, IPixel<TPixel>
-        {
-            Assert.Throws<NotImplementedException>(() =>
-            {
-                string dir = TestEnvironment.CreateOutputDirectory(nameof(ImageExtensionsTest));
-                string file = Path.Combine(dir, "SaveAsTiff_Path.tiff");
-                using var image = provider.GetImage(new TiffDecoder());
-                image.SaveAsTiff(file);
-            });
-        }
-
-        [Fact(Skip = "Saving not implemented")]
-        public void SaveAsTiff_Path()
-        {
-            string dir = TestEnvironment.CreateOutputDirectory(nameof(ImageExtensionsTest));
-            string file = Path.Combine(dir, "SaveAsTiff_Path.tiff");
-
-            using (var image = new Image<Rgba32>(10, 10))
-            {
-                image.SaveAsTiff(file);
-            }
-
-            using (Image.Load(file, out IImageFormat mime))
-            {
-                Assert.Equal("image/tiff", mime.DefaultMimeType);
-            }
-        }
-
-        [Fact(Skip = "Saving not implemented")]
-        public async Task SaveAsTiffAsync_Path()
-        {
-            string dir = TestEnvironment.CreateOutputDirectory(nameof(ImageExtensionsTest));
-            string file = Path.Combine(dir, "SaveAsTiffAsync_Path.tiff");
-
-            using (var image = new Image<Rgba32>(10, 10))
-            {
-                await image.SaveAsTiffAsync(file);
-            }
-
-            using (Image.Load(file, out IImageFormat mime))
-            {
-                Assert.Equal("image/tiff", mime.DefaultMimeType);
-            }
-        }
-
-        [Fact(Skip = "Saving not implemented")]
-        public void SaveAsTiff_Path_Encoder()
-        {
-            string dir = TestEnvironment.CreateOutputDirectory(nameof(ImageExtensions));
-            string file = Path.Combine(dir, "SaveAsTiff_Path_Encoder.tiff");
-
-            using (var image = new Image<Rgba32>(10, 10))
-            {
-                image.SaveAsTiff(file, new TiffEncoder());
-            }
-
-            using (Image.Load(file, out IImageFormat mime))
-            {
-                Assert.Equal("image/tiff", mime.DefaultMimeType);
-            }
-        }
-
-        [Fact(Skip = "Saving not implemented")]
-        public async Task SaveAsTiffAsync_Path_Encoder()
-        {
-            string dir = TestEnvironment.CreateOutputDirectory(nameof(ImageExtensions));
-            string file = Path.Combine(dir, "SaveAsTiffAsync_Path_Encoder.tiff");
-
-            using (var image = new Image<Rgba32>(10, 10))
-            {
-                await image.SaveAsTiffAsync(file, new TiffEncoder());
-            }
-
-            using (Image.Load(file, out IImageFormat mime))
-            {
-                Assert.Equal("image/tiff", mime.DefaultMimeType);
-            }
-        }
-
-        [Fact(Skip = "Saving not implemented")]
-        public void SaveAsTiff_Stream()
-        {
-            using var memoryStream = new MemoryStream();
-
-            using (var image = new Image<Rgba32>(10, 10))
-            {
-                image.SaveAsTiff(memoryStream);
-            }
-
-            memoryStream.Position = 0;
-
-            using (Image.Load(memoryStream, out IImageFormat mime))
-            {
-                Assert.Equal("image/tiff", mime.DefaultMimeType);
-            }
-        }
-
-        [Fact(Skip = "Saving not implemented")]
-        public async Task SaveAsTiffAsync_StreamAsync()
-        {
-            using var memoryStream = new MemoryStream();
-
-            using (var image = new Image<Rgba32>(10, 10))
-            {
-                await image.SaveAsTiffAsync(memoryStream);
-            }
-
-            memoryStream.Position = 0;
-
-            using (Image.Load(memoryStream, out IImageFormat mime))
-            {
-                Assert.Equal("image/tiff", mime.DefaultMimeType);
-            }
-        }
-
-        [Fact(Skip = "Saving not implemented")]
-        public void SaveAsTiff_Stream_Encoder()
-        {
-            using var memoryStream = new MemoryStream();
-
-            using (var image = new Image<Rgba32>(10, 10))
-            {
-                image.SaveAsTiff(memoryStream, new TiffEncoder());
-            }
-
-            memoryStream.Position = 0;
-
-            using (Image.Load(memoryStream, out IImageFormat mime))
-            {
-                Assert.Equal("image/tiff", mime.DefaultMimeType);
-            }
-        }
-
-        [Fact(Skip = "Saving not implemented")]
-        public async Task SaveAsTiffAsync_Stream_Encoder()
-        {
-            using var memoryStream = new MemoryStream();
-
-            using (var image = new Image<Rgba32>(10, 10))
-            {
-                await image.SaveAsTiffAsync(memoryStream, new TiffEncoder());
-            }
-
-            memoryStream.Position = 0;
-
-            using (Image.Load(memoryStream, out IImageFormat mime))
-            {
-                Assert.Equal("image/tiff", mime.DefaultMimeType);
-            }
-        }
-    }
-}

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

@@ -13,12 +13,13 @@ namespace SixLabors.ImageSharp.Tests.Formats.Tiff
     {
         private static readonly MemoryAllocator MemoryAllocator = new ArrayPoolMemoryAllocator();
         private static readonly Configuration Configuration = Configuration.Default;
+        private static readonly ITiffEncoderOptions Options = new TiffEncoder();
 
         [Fact]
         public void WriteHeader_WritesValidHeader()
         {
-            var stream = new MemoryStream();
+            using var stream = new MemoryStream();
-            var encoder = new TiffEncoderCore(null, MemoryAllocator);
+            var encoder = new TiffEncoderCore(Options, MemoryAllocator);
 
             using (var writer = new TiffWriter(stream, MemoryAllocator, Configuration))
             {
@@ -31,8 +32,8 @@ namespace SixLabors.ImageSharp.Tests.Formats.Tiff
         [Fact]
         public void WriteHeader_ReturnsFirstIfdMarker()
         {
-            var stream = new MemoryStream();
+            using var stream = new MemoryStream();
-            var encoder = new TiffEncoderCore(null, MemoryAllocator);
+            var encoder = new TiffEncoderCore(Options, MemoryAllocator);
 
             using (var writer = new TiffWriter(stream, MemoryAllocator, Configuration))
             {

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

@@ -0,0 +1,70 @@
+// Copyright (c) Six Labors.
+// Licensed under the Apache License, Version 2.0.
+
+using System.IO;
+
+using SixLabors.ImageSharp.Formats.Tiff;
+using SixLabors.ImageSharp.PixelFormats;
+
+using Xunit;
+
+namespace SixLabors.ImageSharp.Tests.Formats.Tiff
+{
+    public class TiffEncoderTests
+    {
+        public static readonly TheoryData<string, TiffBitsPerPixel> TiffBitsPerPixelFiles =
+            new TheoryData<string, TiffBitsPerPixel>
+            {
+                { TestImages.Tiff.GrayscaleUncompressed, TiffBitsPerPixel.Pixel8 },
+                { TestImages.Tiff.RgbUncompressed, TiffBitsPerPixel.Pixel24 },
+            };
+
+        [Theory]
+        [MemberData(nameof(TiffBitsPerPixelFiles))]
+        public void TiffEncoder_PreserveBitsPerPixel(string imagePath, TiffBitsPerPixel expectedBitsPerPixel)
+        {
+            // arrange
+            var tiffEncoder = new TiffEncoder();
+            var testFile = TestFile.Create(imagePath);
+            using Image<Rgba32> input = testFile.CreateRgba32Image();
+            using var memStream = new MemoryStream();
+
+            // act
+            input.Save(memStream, tiffEncoder);
+
+            // assert
+            memStream.Position = 0;
+            using var output = Image.Load<Rgba32>(memStream);
+            TiffMetadata meta = output.Metadata.GetTiffMetadata();
+            Assert.Equal(expectedBitsPerPixel, meta.BitsPerPixel);
+        }
+
+        [Theory]
+        [WithFile(TestImages.Tiff.RgbUncompressed, PixelTypes.Rgba32)]
+        public void TiffEncoder_EncodeRgb_Works<TPixel>(TestImageProvider<TPixel> provider, TiffBitsPerPixel bitsPerPixel = TiffBitsPerPixel.Pixel24)
+            where TPixel : unmanaged, IPixel<TPixel> => TestTiffEncoderCore(provider, bitsPerPixel);
+
+        [Theory]
+        [WithFile(TestImages.Tiff.RgbUncompressed, PixelTypes.Rgba32)]
+        public void TiffEncoder_EncodeGray_Works<TPixel>(TestImageProvider<TPixel> provider, TiffBitsPerPixel bitsPerPixel = TiffBitsPerPixel.Pixel8)
+            where TPixel : unmanaged, IPixel<TPixel> => TestTiffEncoderCore(provider, bitsPerPixel);
+
+        private static void TestTiffEncoderCore<TPixel>(
+            TestImageProvider<TPixel> provider,
+            TiffBitsPerPixel bitsPerPixel,
+            TiffEncoderCompression compression = TiffEncoderCompression.None,
+            bool useExactComparer = true,
+            float compareTolerance = 0.01f)
+            where TPixel : unmanaged, IPixel<TPixel>
+        {
+            using Image<TPixel> image = provider.GetImage();
+            var encoder = new TiffEncoder { BitsPerPixel = bitsPerPixel, Compression = compression };
+
+            using var memStream = new MemoryStream();
+            image.Save(memStream, encoder);
+            memStream.Position = 0;
+            using var encodedImage = (Image<TPixel>)Image.Load(memStream);
+            TiffTestUtils.CompareWithReferenceDecoder(provider, encodedImage, useExactComparer, compareTolerance);
+        }
+    }
+}

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

@@ -0,0 +1,63 @@
+// Copyright (c) Six Labors.
+// Licensed under the Apache License, Version 2.0.
+
+using System;
+using System.IO;
+using ImageMagick;
+
+using SixLabors.ImageSharp.PixelFormats;
+using SixLabors.ImageSharp.Tests.TestUtilities.ImageComparison;
+
+using Xunit;
+
+namespace SixLabors.ImageSharp.Tests.Formats.Tiff
+{
+    public class TiffTestUtils
+    {
+        public static void CompareWithReferenceDecoder<TPixel>(
+            TestImageProvider<TPixel> provider,
+            Image<TPixel> image,
+            bool useExactComparer = true,
+            float compareTolerance = 0.01f)
+            where TPixel : unmanaged, ImageSharp.PixelFormats.IPixel<TPixel>
+        {
+            string path = TestImageProvider<TPixel>.GetFilePathOrNull(provider);
+            if (path == null)
+            {
+                throw new InvalidOperationException("CompareToOriginal() works only with file providers!");
+            }
+
+            var testFile = TestFile.Create(path);
+            Image<Rgba32> magickImage = DecodeWithMagick<Rgba32>(Configuration.Default, new FileInfo(testFile.FullPath));
+            if (useExactComparer)
+            {
+                ImageComparer.Exact.VerifySimilarity(magickImage, image);
+            }
+            else
+            {
+                ImageComparer.Tolerant(compareTolerance).VerifySimilarity(magickImage, image);
+            }
+        }
+
+        public static Image<TPixel> DecodeWithMagick<TPixel>(Configuration configuration, FileInfo fileInfo)
+            where TPixel : unmanaged, ImageSharp.PixelFormats.IPixel<TPixel>
+        {
+            using var magickImage = new MagickImage(fileInfo);
+            magickImage.AutoOrient();
+            var result = new Image<TPixel>(configuration, magickImage.Width, magickImage.Height);
+
+            Assert.True(result.TryGetSinglePixelSpan(out Span<TPixel> resultPixels));
+
+            using IUnsafePixelCollection<ushort> pixels = magickImage.GetPixelsUnsafe();
+            byte[] data = pixels.ToByteArray(PixelMapping.RGBA);
+
+            PixelOperations<TPixel>.Instance.FromRgba32Bytes(
+                configuration,
+                data,
+                resultPixels,
+                resultPixels.Length);
+
+            return result;
+        }
+    }
+}