Begin migrating TiffMetadata

src/ImageSharp/Formats/Bmp/BmpMetadata.cs

@@ -50,15 +50,18 @@ public class BmpMetadata : IFormatMetadata<BmpMetadata>, IFormatFrameMetadata<Bm
             <= 8 => new BmpMetadata { BitsPerPixel = BmpBitsPerPixel.Pixel8 },
             <= 16 => new BmpMetadata
             {
-                BitsPerPixel = BmpBitsPerPixel.Pixel16, InfoHeaderType = BmpInfoHeaderType.WinVersion3
+                BitsPerPixel = BmpBitsPerPixel.Pixel16,
+                InfoHeaderType = BmpInfoHeaderType.WinVersion3
             },
             <= 24 => new BmpMetadata
             {
-                BitsPerPixel = BmpBitsPerPixel.Pixel24, InfoHeaderType = BmpInfoHeaderType.WinVersion4
+                BitsPerPixel = BmpBitsPerPixel.Pixel24,
+                InfoHeaderType = BmpInfoHeaderType.WinVersion4
             },
             _ => new BmpMetadata
             {
-                BitsPerPixel = BmpBitsPerPixel.Pixel32, InfoHeaderType = BmpInfoHeaderType.WinVersion5
+                BitsPerPixel = BmpBitsPerPixel.Pixel32,
+                InfoHeaderType = BmpInfoHeaderType.WinVersion5
             }
         };
     }
@@ -68,7 +71,7 @@ public class BmpMetadata : IFormatMetadata<BmpMetadata>, IFormatFrameMetadata<Bm
         => new();
 
     /// <inheritdoc/>
-    public FormatConnectingMetadata ToFormatConnectingMetadata()
+    public PixelTypeInfo GetPixelTypeInfo()
     {
         int bpp = (int)this.BitsPerPixel;
 
@@ -122,17 +125,21 @@ public class BmpMetadata : IFormatMetadata<BmpMetadata>, IFormatFrameMetadata<Bm
                 break;
         }
 
-        return new()
+        return new PixelTypeInfo(bpp)
         {
-            PixelTypeInfo = new PixelTypeInfo(bpp)
-            {
-                AlphaRepresentation = alpha,
-                ComponentInfo = info,
-                ColorType = color
-            }
+            AlphaRepresentation = alpha,
+            ComponentInfo = info,
+            ColorType = color
         };
     }
 
+    /// <inheritdoc/>
+    public FormatConnectingMetadata ToFormatConnectingMetadata()
+        => new()
+        {
+            PixelTypeInfo = this.GetPixelTypeInfo()
+        };
+
     /// <inheritdoc/>
     public FormatConnectingFrameMetadata ToFormatConnectingFrameMetadata()
         => new();

src/ImageSharp/Formats/Gif/GifMetadata.cs

@@ -126,6 +126,20 @@ public class GifMetadata : IFormatMetadata<GifMetadata>
         };
     }
 
+    /// <inheritdoc/>
+    public PixelTypeInfo GetPixelTypeInfo()
+    {
+        int bpp = this.GlobalColorTable.HasValue
+            ? Numerics.Clamp(ColorNumerics.GetBitsNeededForColorDepth(this.GlobalColorTable.Value.Length), 1, 8)
+            : 8;
+
+        return new PixelTypeInfo(bpp)
+        {
+            ColorType = PixelColorType.Indexed,
+            ComponentInfo = PixelComponentInfo.Create(1, bpp, bpp),
+        };
+    }
+
     /// <inheritdoc/>
     public FormatConnectingMetadata ToFormatConnectingMetadata()
     {
@@ -133,21 +147,13 @@ public class GifMetadata : IFormatMetadata<GifMetadata>
             ? this.GlobalColorTable.Value.Span[this.BackgroundColorIndex]
             : Color.Transparent;
 
-        int bpp = this.GlobalColorTable.HasValue
-            ? Numerics.Clamp(ColorNumerics.GetBitsNeededForColorDepth(this.GlobalColorTable.Value.Length), 1, 8)
-            : 8;
-
         return new()
         {
             AnimateRootFrame = true,
             BackgroundColor = color,
             ColorTable = this.GlobalColorTable,
             ColorTableMode = this.ColorTableMode,
-            PixelTypeInfo = new PixelTypeInfo(bpp)
-            {
-                ColorType = PixelColorType.Indexed,
-                ComponentInfo = PixelComponentInfo.Create(1, bpp, bpp),
-            },
+            PixelTypeInfo = this.GetPixelTypeInfo(),
             RepeatCount = this.RepeatCount,
         };
     }

src/ImageSharp/Formats/IFormatMetadata.cs

@@ -1,6 +1,8 @@
 // Copyright (c) Six Labors.
 // Licensed under the Six Labors Split License.
 
+using SixLabors.ImageSharp.PixelFormats;
+
 namespace SixLabors.ImageSharp.Formats;
 
 /// <summary>
@@ -8,6 +10,12 @@ namespace SixLabors.ImageSharp.Formats;
 /// </summary>
 public interface IFormatMetadata : IDeepCloneable
 {
+    /// <summary>
+    /// Converts the metadata to a <see cref="PixelTypeInfo"/> instance.
+    /// </summary>
+    /// <returns>The pixel type info.</returns>
+    PixelTypeInfo GetPixelTypeInfo();
+
     /// <summary>
     /// Converts the metadata to a <see cref="FormatConnectingMetadata"/> instance.
     /// </summary>

src/ImageSharp/Formats/Jpeg/JpegMetadata.cs

@@ -139,7 +139,7 @@ public class JpegMetadata : IFormatMetadata<JpegMetadata>
     }
 
     /// <inheritdoc/>
-    public FormatConnectingMetadata ToFormatConnectingMetadata()
+    public PixelTypeInfo GetPixelTypeInfo()
     {
         int bpp;
         PixelColorType colorType;
@@ -173,18 +173,22 @@ public class JpegMetadata : IFormatMetadata<JpegMetadata>
                 break;
         }
 
-        return new FormatConnectingMetadata
+        return new PixelTypeInfo(bpp)
         {
-            PixelTypeInfo = new PixelTypeInfo(bpp)
-            {
-                AlphaRepresentation = PixelAlphaRepresentation.None,
-                ColorType = colorType,
-                ComponentInfo = info,
-            },
-            Quality = this.Quality,
+            AlphaRepresentation = PixelAlphaRepresentation.None,
+            ColorType = colorType,
+            ComponentInfo = info,
         };
     }
 
+    /// <inheritdoc/>
+    public FormatConnectingMetadata ToFormatConnectingMetadata()
+        => new()
+        {
+            PixelTypeInfo = this.GetPixelTypeInfo(),
+            Quality = this.Quality,
+        };
+
     /// <inheritdoc/>
     IDeepCloneable IDeepCloneable.DeepClone() => this.DeepClone();
 

src/ImageSharp/Formats/Pbm/PbmMetadata.cs

@@ -85,7 +85,7 @@ public class PbmMetadata : IFormatMetadata<PbmMetadata>
     }
 
     /// <inheritdoc/>
-    public FormatConnectingMetadata ToFormatConnectingMetadata()
+    public PixelTypeInfo GetPixelTypeInfo()
     {
         int bpp;
         PixelColorType colorType;
@@ -114,17 +114,21 @@ public class PbmMetadata : IFormatMetadata<PbmMetadata>
                 break;
         }
 
-        return new FormatConnectingMetadata
+        return new PixelTypeInfo(bpp)
         {
-            PixelTypeInfo = new PixelTypeInfo(bpp)
-            {
-                AlphaRepresentation = PixelAlphaRepresentation.None,
-                ColorType = colorType,
-                ComponentInfo = info,
-            },
+            AlphaRepresentation = PixelAlphaRepresentation.None,
+            ColorType = colorType,
+            ComponentInfo = info,
         };
     }
 
+    /// <inheritdoc/>
+    public FormatConnectingMetadata ToFormatConnectingMetadata()
+        => new()
+        {
+            PixelTypeInfo = this.GetPixelTypeInfo(),
+        };
+
     /// <inheritdoc/>
     IDeepCloneable IDeepCloneable.DeepClone() => this.DeepClone();
 

src/ImageSharp/Formats/Png/PngMetadata.cs

@@ -191,7 +191,7 @@ public class PngMetadata : IFormatMetadata<PngMetadata>
     }
 
     /// <inheritdoc/>
-    public FormatConnectingMetadata ToFormatConnectingMetadata()
+    public PixelTypeInfo GetPixelTypeInfo()
     {
         int bpp;
         PixelColorType colorType;
@@ -262,19 +262,23 @@ public class PngMetadata : IFormatMetadata<PngMetadata>
                 break;
         }
 
-        return new()
+        return new PixelTypeInfo(bpp)
+        {
+            AlphaRepresentation = alpha,
+            ColorType = colorType,
+            ComponentInfo = info,
+        };
+    }
+
+    /// <inheritdoc/>
+    public FormatConnectingMetadata ToFormatConnectingMetadata()
+        => new()
         {
             ColorTable = this.ColorTable,
             ColorTableMode = FrameColorTableMode.Global,
-            PixelTypeInfo = new PixelTypeInfo(bpp)
-            {
-                AlphaRepresentation = alpha,
-                ColorType = colorType,
-                ComponentInfo = info,
-            },
+            PixelTypeInfo = this.GetPixelTypeInfo(),
             RepeatCount = (ushort)Numerics.Clamp(this.RepeatCount, 0, ushort.MaxValue),
         };
-    }
 
     /// <inheritdoc/>
     IDeepCloneable IDeepCloneable.DeepClone() => this.DeepClone();

src/ImageSharp/Formats/Qoi/QoiMetadata.cs

@@ -51,7 +51,7 @@ public class QoiMetadata : IFormatMetadata<QoiMetadata>
     }
 
     /// <inheritdoc/>
-    public FormatConnectingMetadata ToFormatConnectingMetadata()
+    public PixelTypeInfo GetPixelTypeInfo()
     {
         int bpp;
         PixelColorType colorType;
@@ -73,17 +73,21 @@ public class QoiMetadata : IFormatMetadata<QoiMetadata>
                 break;
         }
 
-        return new()
+        return new PixelTypeInfo(bpp)
         {
-            PixelTypeInfo = new PixelTypeInfo(bpp)
-            {
-                AlphaRepresentation = alpha,
-                ColorType = colorType,
-                ComponentInfo = info,
-            }
+            AlphaRepresentation = alpha,
+            ColorType = colorType,
+            ComponentInfo = info,
         };
     }
 
+    /// <inheritdoc/>
+    public FormatConnectingMetadata ToFormatConnectingMetadata()
+        => new()
+        {
+            PixelTypeInfo = this.GetPixelTypeInfo()
+        };
+
     /// <inheritdoc/>
     IDeepCloneable IDeepCloneable.DeepClone() => this.DeepClone();
 

src/ImageSharp/Formats/Tga/TgaMetadata.cs

@@ -49,10 +49,9 @@ public class TgaMetadata : IFormatMetadata<TgaMetadata>
     }
 
     /// <inheritdoc/>
-    public FormatConnectingMetadata ToFormatConnectingMetadata()
+    public PixelTypeInfo GetPixelTypeInfo()
     {
         int bpp = (int)this.BitsPerPixel;
-
         PixelComponentInfo info;
         PixelColorType color;
         PixelAlphaRepresentation alpha;
@@ -80,17 +79,21 @@ public class TgaMetadata : IFormatMetadata<TgaMetadata>
                 break;
         }
 
-        return new()
+        return new PixelTypeInfo(bpp)
         {
-            PixelTypeInfo = new PixelTypeInfo(bpp)
-            {
-                AlphaRepresentation = alpha,
-                ComponentInfo = info,
-                ColorType = color
-            }
+            AlphaRepresentation = alpha,
+            ComponentInfo = info,
+            ColorType = color
         };
     }
 
+    /// <inheritdoc/>
+    public FormatConnectingMetadata ToFormatConnectingMetadata()
+        => new()
+        {
+            PixelTypeInfo = this.GetPixelTypeInfo()
+        };
+
     /// <inheritdoc/>
     IDeepCloneable IDeepCloneable.DeepClone() => this.DeepClone();
 

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

@@ -39,9 +39,9 @@ internal static class TiffConstants
     public const ushort BigTiffHeaderMagicNumber = 43;
 
     /// <summary>
-    /// The big tiff bytesize of offsets value.
+    /// The big tiff byte size of offsets value.
     /// </summary>
-    public const ushort BigTiffBytesize = 8;
+    public const ushort BigTiffByteSize = 8;
 
     /// <summary>
     /// RowsPerStrip default value, which is effectively infinity.
@@ -58,38 +58,63 @@ internal static class TiffConstants
     /// </summary>
     public const int DefaultStripSize = 8 * 1024;
 
+    /// <summary>
+    /// The default predictor is None.
+    /// </summary>
+    public const TiffPredictor DefaultPredictor = TiffPredictor.None;
+
+    /// <summary>
+    /// The default bits per pixel is Bit24.
+    /// </summary>
+    public const TiffBitsPerPixel DefaultBitsPerPixel = TiffBitsPerPixel.Bit24;
+
+    /// <summary>
+    /// The default bits per sample for color images with 8 bits for each color channel.
+    /// </summary>
+    public static readonly TiffBitsPerSample DefaultBitsPerSample = BitsPerSampleRgb8Bit;
+
+    /// <summary>
+    /// The default compression is None.
+    /// </summary>
+    public const TiffCompression DefaultCompression = TiffCompression.None;
+
+    /// <summary>
+    /// The default photometric interpretation is Rgb.
+    /// </summary>
+    public const TiffPhotometricInterpretation DefaultPhotometricInterpretation = TiffPhotometricInterpretation.Rgb;
+
     /// <summary>
     /// The bits per sample for 1 bit bicolor images.
     /// </summary>
-    public static readonly TiffBitsPerSample BitsPerSample1Bit = new TiffBitsPerSample(1, 0, 0);
+    public static readonly TiffBitsPerSample BitsPerSample1Bit = new(1, 0, 0);
 
     /// <summary>
     /// The bits per sample for images with a 4 color palette.
     /// </summary>
-    public static readonly TiffBitsPerSample BitsPerSample4Bit = new TiffBitsPerSample(4, 0, 0);
+    public static readonly TiffBitsPerSample BitsPerSample4Bit = new(4, 0, 0);
 
     /// <summary>
     /// The bits per sample for 8 bit images.
     /// </summary>
-    public static readonly TiffBitsPerSample BitsPerSample8Bit = new TiffBitsPerSample(8, 0, 0);
+    public static readonly TiffBitsPerSample BitsPerSample8Bit = new(8, 0, 0);
 
     /// <summary>
     /// The bits per sample for 16-bit grayscale images.
     /// </summary>
-    public static readonly TiffBitsPerSample BitsPerSample16Bit = new TiffBitsPerSample(16, 0, 0);
+    public static readonly TiffBitsPerSample BitsPerSample16Bit = new(16, 0, 0);
 
     /// <summary>
     /// The bits per sample for color images with 8 bits for each color channel.
     /// </summary>
-    public static readonly TiffBitsPerSample BitsPerSampleRgb8Bit = new TiffBitsPerSample(8, 8, 8);
+    public static readonly TiffBitsPerSample BitsPerSampleRgb8Bit = new(8, 8, 8);
 
     /// <summary>
-    /// The list of mimetypes that equate to a tiff.
+    /// The list of mime types that equate to a tiff.
     /// </summary>
-    public static readonly IEnumerable<string> MimeTypes = new[] { "image/tiff", "image/tiff-fx" };
+    public static readonly IEnumerable<string> MimeTypes = ["image/tiff", "image/tiff-fx"];
 
     /// <summary>
     /// The list of file extensions that equate to a tiff.
     /// </summary>
-    public static readonly IEnumerable<string> FileExtensions = new[] { "tiff", "tif" };
+    public static readonly IEnumerable<string> FileExtensions = ["tiff", "tif"];
 }

src/ImageSharp/Formats/Tiff/Ifd/EntryReader.cs

@@ -64,7 +64,7 @@ internal class HeaderReader : BaseExifReader
 
             ushort bytesize = this.ReadUInt16();
             ushort reserve = this.ReadUInt16();
-            if (bytesize == TiffConstants.BigTiffBytesize && reserve == 0)
+            if (bytesize == TiffConstants.BigTiffByteSize && reserve == 0)
             {
                 this.FirstIfdOffset = this.ReadUInt64();
                 return;

src/ImageSharp/Formats/Tiff/TiffBitsPerSample.cs

@@ -147,20 +147,20 @@ public readonly struct TiffBitsPerSample : IEquatable<TiffBitsPerSample>
     {
         if (this.Channel1 == 0)
         {
-            return new[] { this.Channel0 };
+            return [this.Channel0];
         }
 
         if (this.Channel2 == 0)
         {
-            return new[] { this.Channel0, this.Channel1 };
+            return [this.Channel0, this.Channel1];
         }
 
         if (this.Channel3 == 0)
         {
-            return new[] { this.Channel0, this.Channel1, this.Channel2 };
+            return [this.Channel0, this.Channel1, this.Channel2];
         }
 
-        return new[] { this.Channel0, this.Channel1, this.Channel2, this.Channel3 };
+        return [this.Channel0, this.Channel1, this.Channel2, this.Channel3];
     }
 
     /// <summary>

src/ImageSharp/Formats/Tiff/TiffDecoderOptionsParser.cs

@@ -63,7 +63,7 @@ internal static class TiffDecoderOptionsParser
         }
 
         TiffSampleFormat? sampleFormat = null;
-        if (exifProfile.TryGetValue(ExifTag.SampleFormat, out var formatValue))
+        if (exifProfile.TryGetValue(ExifTag.SampleFormat, out IExifValue<ushort[]> formatValue))
         {
             TiffSampleFormat[] sampleFormats = formatValue.Value.Select(a => (TiffSampleFormat)a).ToArray();
             sampleFormat = sampleFormats[0];
@@ -106,11 +106,11 @@ internal static class TiffDecoderOptionsParser
             options.PlanarConfiguration = DefaultPlanarConfiguration;
         }
 
-        options.Predictor = frameMetadata.Predictor ?? TiffPredictor.None;
-        options.PhotometricInterpretation = frameMetadata.PhotometricInterpretation ?? TiffPhotometricInterpretation.Rgb;
+        options.Predictor = frameMetadata.Predictor;
+        options.PhotometricInterpretation = frameMetadata.PhotometricInterpretation;
         options.SampleFormat = sampleFormat ?? TiffSampleFormat.UnsignedInteger;
-        options.BitsPerPixel = frameMetadata.BitsPerPixel != null ? (int)frameMetadata.BitsPerPixel.Value : (int)TiffBitsPerPixel.Bit24;
-        options.BitsPerSample = frameMetadata.BitsPerSample ?? new TiffBitsPerSample(0, 0, 0);
+        options.BitsPerPixel = (int)frameMetadata.BitsPerPixel;
+        options.BitsPerSample = frameMetadata.BitsPerSample;
 
         if (exifProfile.TryGetValue(ExifTag.ReferenceBlackWhite, out IExifValue<Rational[]> blackWhiteValue))
         {
@@ -142,9 +142,7 @@ internal static class TiffDecoderOptionsParser
         options.ParseCompression(frameMetadata.Compression, exifProfile);
         options.ParseColorType(exifProfile);
 
-        bool isTiled = VerifyRequiredFieldsArePresent(exifProfile, frameMetadata, options.PlanarConfiguration);
-
-        return isTiled;
+        return VerifyRequiredFieldsArePresent(exifProfile, frameMetadata, options.PlanarConfiguration);
     }
 
     /// <summary>
@@ -194,13 +192,6 @@ internal static class TiffDecoderOptionsParser
             }
         }
 
-        // For BiColor compressed images, the BitsPerPixel value will be set explicitly to 1, so we don't throw in those cases.
-        // See: https://github.com/SixLabors/ImageSharp/issues/2587
-        if (frameMetadata.BitsPerPixel == null && !IsBiColorCompression(frameMetadata.Compression))
-        {
-            TiffThrowHelper.ThrowNotSupported("The TIFF BitsPerSample entry is missing which is required to decode the image!");
-        }
-
         return isTiled;
     }
 
@@ -224,7 +215,6 @@ internal static class TiffDecoderOptionsParser
                 switch (bitsPerChannel)
                 {
                     case 32:
-                    {
                         if (options.SampleFormat == TiffSampleFormat.Float)
                         {
                             options.ColorType = TiffColorType.WhiteIsZero32Float;
@@ -233,43 +223,30 @@ internal static class TiffDecoderOptionsParser
 
                         options.ColorType = TiffColorType.WhiteIsZero32;
                         break;
-                    }
 
                     case 24:
-                    {
                         options.ColorType = TiffColorType.WhiteIsZero24;
                         break;
-                    }
 
                     case 16:
-                    {
                         options.ColorType = TiffColorType.WhiteIsZero16;
                         break;
-                    }
 
                     case 8:
-                    {
                         options.ColorType = TiffColorType.WhiteIsZero8;
                         break;
-                    }
 
                     case 4:
-                    {
                         options.ColorType = TiffColorType.WhiteIsZero4;
                         break;
-                    }
 
                     case 1:
-                    {
                         options.ColorType = TiffColorType.WhiteIsZero1;
                         break;
-                    }
 
                     default:
-                    {
                         options.ColorType = TiffColorType.WhiteIsZero;
                         break;
-                    }
                 }
 
                 break;
@@ -291,7 +268,6 @@ internal static class TiffDecoderOptionsParser
                 switch (bitsPerChannel)
                 {
                     case 32:
-                    {
                         if (options.SampleFormat == TiffSampleFormat.Float)
                         {
                             options.ColorType = TiffColorType.BlackIsZero32Float;
@@ -300,43 +276,30 @@ internal static class TiffDecoderOptionsParser
 
                         options.ColorType = TiffColorType.BlackIsZero32;
                         break;
-                    }
 
                     case 24:
-                    {
                         options.ColorType = TiffColorType.BlackIsZero24;
                         break;
-                    }
 
                     case 16:
-                    {
                         options.ColorType = TiffColorType.BlackIsZero16;
                         break;
-                    }
 
                     case 8:
-                    {
                         options.ColorType = TiffColorType.BlackIsZero8;
                         break;
-                    }
 
                     case 4:
-                    {
                         options.ColorType = TiffColorType.BlackIsZero4;
                         break;
-                    }
 
                     case 1:
-                    {
                         options.ColorType = TiffColorType.BlackIsZero1;
                         break;
-                    }
 
                     default:
-                    {
                         options.ColorType = TiffColorType.BlackIsZero;
                         break;
-                    }
                 }
 
                 break;
@@ -535,29 +498,21 @@ internal static class TiffDecoderOptionsParser
         switch (compression ?? TiffCompression.None)
         {
             case TiffCompression.None:
-            {
                 options.CompressionType = TiffDecoderCompressionType.None;
                 break;
-            }
 
             case TiffCompression.PackBits:
-            {
                 options.CompressionType = TiffDecoderCompressionType.PackBits;
                 break;
-            }
 
             case TiffCompression.Deflate:
             case TiffCompression.OldDeflate:
-            {
                 options.CompressionType = TiffDecoderCompressionType.Deflate;
                 break;
-            }
 
             case TiffCompression.Lzw:
-            {
                 options.CompressionType = TiffDecoderCompressionType.Lzw;
                 break;
-            }
 
             case TiffCompression.CcittGroup3Fax:
             {
@@ -599,16 +554,13 @@ internal static class TiffDecoderOptionsParser
             }
 
             case TiffCompression.Ccitt1D:
-            {
                 options.CompressionType = TiffDecoderCompressionType.HuffmanRle;
                 options.BitsPerSample = new TiffBitsPerSample(1, 0, 0);
                 options.BitsPerPixel = 1;
 
                 break;
-            }
 
             case TiffCompression.OldJpeg:
-            {
                 if (!options.OldJpegCompressionStartOfImageMarker.HasValue)
                 {
                     TiffThrowHelper.ThrowNotSupported("Missing SOI marker offset for tiff with old jpeg compression");
@@ -629,10 +581,8 @@ internal static class TiffDecoderOptionsParser
                 }
 
                 break;
-            }
 
             case TiffCompression.Jpeg:
-            {
                 options.CompressionType = TiffDecoderCompressionType.Jpeg;
 
                 if (options.PhotometricInterpretation is TiffPhotometricInterpretation.YCbCr && options.JpegTables is null)
@@ -643,30 +593,14 @@ internal static class TiffDecoderOptionsParser
                 }
 
                 break;
-            }
 
             case TiffCompression.Webp:
-            {
                 options.CompressionType = TiffDecoderCompressionType.Webp;
                 break;
-            }
 
             default:
-            {
                 TiffThrowHelper.ThrowNotSupported($"The specified TIFF compression format '{compression}' is not supported");
                 break;
-            }
         }
     }
-
-    private static bool IsBiColorCompression(TiffCompression? compression)
-    {
-        if (compression is TiffCompression.Ccitt1D or TiffCompression.CcittGroup3Fax or
-            TiffCompression.CcittGroup4Fax)
-        {
-            return true;
-        }
-
-        return false;
-    }
 }

src/ImageSharp/Formats/Tiff/TiffEncoder.cs

@@ -47,7 +47,7 @@ public class TiffEncoder : QuantizingImageEncoder
     /// <inheritdoc/>
     protected override void Encode<TPixel>(Image<TPixel> image, Stream stream, CancellationToken cancellationToken)
     {
-        TiffEncoderCore encode = new(this, image.Configuration.MemoryAllocator);
+        TiffEncoderCore encode = new(this, image.Configuration);
         encode.Encode(image, stream, cancellationToken);
     }
 }

src/ImageSharp/Formats/Tiff/TiffEncoderCore.cs

@@ -1,8 +1,7 @@
 // Copyright (c) Six Labors.
 // Licensed under the Six Labors Split License.
-#nullable disable
 
-using SixLabors.ImageSharp.Advanced;
+using System.Diagnostics.CodeAnalysis;
 using SixLabors.ImageSharp.Compression.Zlib;
 using SixLabors.ImageSharp.Formats.Tiff.Compression;
 using SixLabors.ImageSharp.Formats.Tiff.Constants;
@@ -50,41 +49,22 @@ internal sealed class TiffEncoderCore : IImageEncoderInternals
     /// </summary>
     private readonly DeflateCompressionLevel compressionLevel;
 
-    /// <summary>
-    /// The default predictor is None.
-    /// </summary>
-    private const TiffPredictor DefaultPredictor = TiffPredictor.None;
-
-    /// <summary>
-    /// The default bits per pixel is Bit24.
-    /// </summary>
-    private const TiffBitsPerPixel DefaultBitsPerPixel = TiffBitsPerPixel.Bit24;
-
-    /// <summary>
-    /// The default compression is None.
-    /// </summary>
-    private const TiffCompression DefaultCompression = TiffCompression.None;
-
-    /// <summary>
-    /// The default photometric interpretation is Rgb.
-    /// </summary>
-    private const TiffPhotometricInterpretation DefaultPhotometricInterpretation = TiffPhotometricInterpretation.Rgb;
-
     /// <summary>
     /// Whether to skip metadata during encoding.
     /// </summary>
     private readonly bool skipMetadata;
 
-    private readonly List<(long, uint)> frameMarkers = new();
+    private readonly List<(long, uint)> frameMarkers = [];
 
     /// <summary>
     /// Initializes a new instance of the <see cref="TiffEncoderCore"/> class.
     /// </summary>
     /// <param name="options">The options for the encoder.</param>
-    /// <param name="memoryAllocator">The memory allocator.</param>
-    public TiffEncoderCore(TiffEncoder options, MemoryAllocator memoryAllocator)
+    /// <param name="configuration">The global configuration.</param>
+    public TiffEncoderCore(TiffEncoder options, Configuration configuration)
     {
-        this.memoryAllocator = memoryAllocator;
+        this.configuration = configuration;
+        this.memoryAllocator = configuration.MemoryAllocator;
         this.PhotometricInterpretation = options.PhotometricInterpretation;
         this.quantizer = options.Quantizer ?? KnownQuantizers.Octree;
         this.pixelSamplingStrategy = options.PixelSamplingStrategy;
@@ -135,35 +115,29 @@ internal sealed class TiffEncoderCore : IImageEncoderInternals
 
         // Determine the correct values to encode with.
         // EncoderOptions > Metadata > Default.
-        TiffBitsPerPixel? bitsPerPixel = this.BitsPerPixel ?? rootFrameTiffMetaData.BitsPerPixel;
+        TiffBitsPerPixel bitsPerPixel = this.BitsPerPixel ?? rootFrameTiffMetaData.BitsPerPixel;
 
-        TiffPhotometricInterpretation? photometricInterpretation = this.PhotometricInterpretation ?? rootFrameTiffMetaData.PhotometricInterpretation;
+        TiffPhotometricInterpretation photometricInterpretation = this.PhotometricInterpretation ?? rootFrameTiffMetaData.PhotometricInterpretation;
 
-        TiffPredictor predictor =
-            this.HorizontalPredictor
-            ?? rootFrameTiffMetaData.Predictor
-            ?? DefaultPredictor;
+        TiffPredictor predictor = this.HorizontalPredictor ?? rootFrameTiffMetaData.Predictor;
 
-        TiffCompression compression =
-            this.CompressionType
-            ?? rootFrameTiffMetaData.Compression
-            ?? DefaultCompression;
+        TiffCompression compression = this.CompressionType ?? rootFrameTiffMetaData.Compression;
 
-        // Make sure, the Encoder options makes sense in combination with each other.
-        this.SanitizeAndSetEncoderOptions(bitsPerPixel, image.PixelType.BitsPerPixel, photometricInterpretation, compression, predictor);
+        // Make sure the Encoder options makes sense in combination with each other.
+        this.SanitizeAndSetEncoderOptions(bitsPerPixel, photometricInterpretation, compression, predictor);
 
         using TiffStreamWriter writer = new(stream);
         Span<byte> buffer = stackalloc byte[4];
 
         long ifdMarker = WriteHeader(writer, buffer);
 
-        Image<TPixel> metadataImage = image;
+        Image<TPixel>? metadataImage = image;
 
         foreach (ImageFrame<TPixel> frame in image.Frames)
         {
             cancellationToken.ThrowIfCancellationRequested();
 
-            ifdMarker = this.WriteFrame(writer, frame, image.Metadata, metadataImage, ifdMarker);
+            ifdMarker = this.WriteFrame(writer, frame, image.Metadata, metadataImage, this.BitsPerPixel.Value, this.CompressionType.Value, ifdMarker);
             metadataImage = null;
         }
 
@@ -199,6 +173,8 @@ internal sealed class TiffEncoderCore : IImageEncoderInternals
     /// <param name="frame">The tiff frame.</param>
     /// <param name="imageMetadata">The image metadata (resolution values for each frame).</param>
     /// <param name="image">The image (common metadata for root frame).</param>
+    /// <param name="bitsPerPixel">The bits per pixel.</param>
+    /// <param name="compression">The compression type.</param>
     /// <param name="ifdOffset">The marker to write this IFD offset.</param>
     /// <returns>
     /// The next IFD offset value.
@@ -207,16 +183,18 @@ internal sealed class TiffEncoderCore : IImageEncoderInternals
         TiffStreamWriter writer,
         ImageFrame<TPixel> frame,
         ImageMetadata imageMetadata,
-        Image<TPixel> image,
+        Image<TPixel>? image,
+        TiffBitsPerPixel bitsPerPixel,
+        TiffCompression compression,
         long ifdOffset)
         where TPixel : unmanaged, IPixel<TPixel>
     {
         using TiffBaseCompressor compressor = TiffCompressorFactory.Create(
-            this.CompressionType ?? TiffCompression.None,
+            compression,
             writer.BaseStream,
             this.memoryAllocator,
             frame.Width,
-            (int)this.BitsPerPixel,
+            (int)bitsPerPixel,
             this.compressionLevel,
             this.HorizontalPredictor == TiffPredictor.Horizontal ? this.HorizontalPredictor.Value : TiffPredictor.None);
 
@@ -229,7 +207,7 @@ internal sealed class TiffEncoderCore : IImageEncoderInternals
             this.memoryAllocator,
             this.configuration,
             entriesCollector,
-            (int)this.BitsPerPixel);
+            (int)bitsPerPixel);
 
         int rowsPerStrip = CalcRowsPerStrip(frame.Height, colorWriter.BytesPerRow, this.CompressionType);
 
@@ -307,7 +285,7 @@ internal sealed class TiffEncoderCore : IImageEncoderInternals
         }
 
         uint dataOffset = (uint)writer.Position + (uint)(6 + (entries.Count * 12));
-        List<byte[]> largeDataBlocks = new();
+        List<byte[]> largeDataBlocks = [];
 
         entries.Sort((a, b) => (ushort)a.Tag - (ushort)b.Tag);
 
@@ -354,135 +332,80 @@ internal sealed class TiffEncoderCore : IImageEncoderInternals
         return nextIfdMarker;
     }
 
+    [MemberNotNull(nameof(BitsPerPixel), nameof(PhotometricInterpretation), nameof(CompressionType), nameof(HorizontalPredictor))]
     private void SanitizeAndSetEncoderOptions(
-        TiffBitsPerPixel? bitsPerPixel,
-        int inputBitsPerPixel,
-        TiffPhotometricInterpretation? photometricInterpretation,
+        TiffBitsPerPixel bitsPerPixel,
+        TiffPhotometricInterpretation photometricInterpretation,
         TiffCompression compression,
         TiffPredictor predictor)
     {
         // BitsPerPixel should be the primary source of truth for the encoder options.
-        if (bitsPerPixel.HasValue)
-        {
-            switch (bitsPerPixel)
-            {
-                case TiffBitsPerPixel.Bit1:
-                    if (IsOneBitCompression(compression))
-                    {
-                        // The “normal” PhotometricInterpretation for bilevel CCITT compressed data is WhiteIsZero.
-                        this.SetEncoderOptions(bitsPerPixel, TiffPhotometricInterpretation.WhiteIsZero, compression, TiffPredictor.None);
-                        break;
-                    }
-
-                    this.SetEncoderOptions(bitsPerPixel, TiffPhotometricInterpretation.BlackIsZero, compression, TiffPredictor.None);
-                    break;
-                case TiffBitsPerPixel.Bit4:
-                    this.SetEncoderOptions(bitsPerPixel, TiffPhotometricInterpretation.PaletteColor, compression, TiffPredictor.None);
-                    break;
-                case TiffBitsPerPixel.Bit8:
-                    this.SetEncoderOptions(bitsPerPixel, photometricInterpretation ?? TiffPhotometricInterpretation.BlackIsZero, compression, predictor);
-                    break;
-                case TiffBitsPerPixel.Bit16:
-                    // Assume desire to encode as L16 grayscale
-                    this.SetEncoderOptions(bitsPerPixel, TiffPhotometricInterpretation.BlackIsZero, compression, predictor);
-                    break;
-                case TiffBitsPerPixel.Bit6:
-                case TiffBitsPerPixel.Bit10:
-                case TiffBitsPerPixel.Bit12:
-                case TiffBitsPerPixel.Bit14:
-                case TiffBitsPerPixel.Bit30:
-                case TiffBitsPerPixel.Bit36:
-                case TiffBitsPerPixel.Bit42:
-                case TiffBitsPerPixel.Bit48:
-                    // Encoding not yet supported bits per pixel will default to 24 bits.
-                    this.SetEncoderOptions(TiffBitsPerPixel.Bit24, TiffPhotometricInterpretation.Rgb, compression, TiffPredictor.None);
-                    break;
-                case TiffBitsPerPixel.Bit64:
-                    // Encoding not yet supported bits per pixel will default to 32 bits.
-                    this.SetEncoderOptions(TiffBitsPerPixel.Bit32, TiffPhotometricInterpretation.Rgb, compression, TiffPredictor.None);
-                    break;
-                default:
-                    this.SetEncoderOptions(bitsPerPixel, TiffPhotometricInterpretation.Rgb, compression, predictor);
-                    break;
-            }
-
-            // Make sure 1 Bit compression is only used with 1 bit pixel type.
-            if (IsOneBitCompression(this.CompressionType) && this.BitsPerPixel != TiffBitsPerPixel.Bit1)
-            {
-                // Invalid compression / bits per pixel combination, fallback to no compression.
-                this.CompressionType = DefaultCompression;
-            }
-
-            return;
-        }
-
-        // If no photometric interpretation was chosen, the input image bit per pixel should be preserved.
-        if (!photometricInterpretation.HasValue)
+        switch (bitsPerPixel)
         {
-            if (IsOneBitCompression(this.CompressionType))
-            {
-                // We need to make sure bits per pixel is set to Bit1 now. WhiteIsZero is set because its the default for bilevel compressed data.
-                this.SetEncoderOptions(TiffBitsPerPixel.Bit1, TiffPhotometricInterpretation.WhiteIsZero, compression, TiffPredictor.None);
-                return;
-            }
-
-            // At the moment only 8, 16 and 32 bits per pixel can be preserved by the tiff encoder.
-            if (inputBitsPerPixel == 8)
-            {
-                this.SetEncoderOptions(TiffBitsPerPixel.Bit8, TiffPhotometricInterpretation.BlackIsZero, compression, predictor);
-                return;
-            }
-
-            if (inputBitsPerPixel == 16)
-            {
-                // Assume desire to encode as L16 grayscale
-                this.SetEncoderOptions(TiffBitsPerPixel.Bit16, TiffPhotometricInterpretation.BlackIsZero, compression, predictor);
-                return;
-            }
-
-            this.SetEncoderOptions(TiffBitsPerPixel.Bit24, TiffPhotometricInterpretation.Rgb, compression, predictor);
-            return;
-        }
-
-        switch (photometricInterpretation)
-        {
-            case TiffPhotometricInterpretation.BlackIsZero:
-            case TiffPhotometricInterpretation.WhiteIsZero:
-                if (IsOneBitCompression(this.CompressionType))
-                {
-                    this.SetEncoderOptions(TiffBitsPerPixel.Bit1, photometricInterpretation, compression, TiffPredictor.None);
-                    return;
-                }
-
-                if (inputBitsPerPixel == 16)
+            case TiffBitsPerPixel.Bit1:
+                if (IsOneBitCompression(compression))
                 {
-                    this.SetEncoderOptions(TiffBitsPerPixel.Bit16, photometricInterpretation, compression, predictor);
-                    return;
+                    // The “normal” PhotometricInterpretation for bilevel CCITT compressed data is WhiteIsZero.
+                    this.SetEncoderOptions(bitsPerPixel, TiffPhotometricInterpretation.WhiteIsZero, compression, TiffPredictor.None);
+                    break;
                 }
 
-                this.SetEncoderOptions(TiffBitsPerPixel.Bit8, photometricInterpretation, compression, predictor);
-                return;
-
-            case TiffPhotometricInterpretation.PaletteColor:
-                this.SetEncoderOptions(TiffBitsPerPixel.Bit8, photometricInterpretation, compression, predictor);
-                return;
-
-            case TiffPhotometricInterpretation.Rgb:
-                // Make sure 1 Bit compression is only used with 1 bit pixel type.
-                if (IsOneBitCompression(this.CompressionType))
+                this.SetEncoderOptions(bitsPerPixel, TiffPhotometricInterpretation.BlackIsZero, compression, TiffPredictor.None);
+                break;
+            case TiffBitsPerPixel.Bit4:
+                this.SetEncoderOptions(bitsPerPixel, TiffPhotometricInterpretation.PaletteColor, compression, TiffPredictor.None);
+                break;
+            case TiffBitsPerPixel.Bit8:
+
+                // Allow any combination of the below for 8 bit images.
+                if (photometricInterpretation is TiffPhotometricInterpretation.BlackIsZero
+                    or TiffPhotometricInterpretation.WhiteIsZero
+                    or TiffPhotometricInterpretation.PaletteColor)
                 {
-                    // Invalid compression / bits per pixel combination, fallback to no compression.
-                    compression = DefaultCompression;
+                    this.SetEncoderOptions(bitsPerPixel, photometricInterpretation, compression, predictor);
+                    break;
                 }
 
-                this.SetEncoderOptions(TiffBitsPerPixel.Bit24, photometricInterpretation, compression, predictor);
-                return;
+                this.SetEncoderOptions(bitsPerPixel, TiffPhotometricInterpretation.PaletteColor, compression, predictor);
+                break;
+            case TiffBitsPerPixel.Bit16:
+                // Assume desire to encode as L16 grayscale
+                this.SetEncoderOptions(bitsPerPixel, TiffPhotometricInterpretation.BlackIsZero, compression, predictor);
+                break;
+            case TiffBitsPerPixel.Bit6:
+            case TiffBitsPerPixel.Bit10:
+            case TiffBitsPerPixel.Bit12:
+            case TiffBitsPerPixel.Bit14:
+            case TiffBitsPerPixel.Bit30:
+            case TiffBitsPerPixel.Bit36:
+            case TiffBitsPerPixel.Bit42:
+            case TiffBitsPerPixel.Bit48:
+                // Encoding not yet supported bits per pixel will default to 24 bits.
+                this.SetEncoderOptions(TiffBitsPerPixel.Bit24, TiffPhotometricInterpretation.Rgb, compression, TiffPredictor.None);
+                break;
+            case TiffBitsPerPixel.Bit64:
+                // Encoding not yet supported bits per pixel will default to 32 bits.
+                this.SetEncoderOptions(TiffBitsPerPixel.Bit32, TiffPhotometricInterpretation.Rgb, compression, TiffPredictor.None);
+                break;
+            default:
+                this.SetEncoderOptions(bitsPerPixel, TiffPhotometricInterpretation.Rgb, compression, predictor);
+                break;
         }
 
-        this.SetEncoderOptions(DefaultBitsPerPixel, DefaultPhotometricInterpretation, compression, predictor);
+        // Make sure 1 Bit compression is only used with 1 bit pixel type.
+        if (IsOneBitCompression(this.CompressionType) && this.BitsPerPixel != TiffBitsPerPixel.Bit1)
+        {
+            // Invalid compression / bits per pixel combination, fallback to no compression.
+            this.CompressionType = TiffCompression.None;
+        }
     }
 
-    private void SetEncoderOptions(TiffBitsPerPixel? bitsPerPixel, TiffPhotometricInterpretation? photometricInterpretation, TiffCompression compression, TiffPredictor predictor)
+    [MemberNotNull(nameof(BitsPerPixel), nameof(PhotometricInterpretation), nameof(CompressionType), nameof(HorizontalPredictor))]
+    private void SetEncoderOptions(
+        TiffBitsPerPixel bitsPerPixel,
+        TiffPhotometricInterpretation photometricInterpretation,
+        TiffCompression compression,
+        TiffPredictor predictor)
     {
         this.BitsPerPixel = bitsPerPixel;
         this.PhotometricInterpretation = photometricInterpretation;

src/ImageSharp/Formats/Tiff/TiffFrameMetadata.cs

@@ -34,27 +34,27 @@ public class TiffFrameMetadata : IDeepCloneable
     /// <summary>
     /// Gets or sets the bits per pixel.
     /// </summary>
-    public TiffBitsPerPixel? BitsPerPixel { get; set; }
+    public TiffBitsPerPixel BitsPerPixel { get; set; } = TiffConstants.DefaultBitsPerPixel;
 
     /// <summary>
     /// Gets or sets number of bits per component.
     /// </summary>
-    public TiffBitsPerSample? BitsPerSample { get; set; }
+    public TiffBitsPerSample BitsPerSample { get; set; } = TiffConstants.DefaultBitsPerSample;
 
     /// <summary>
     /// Gets or sets the compression scheme used on the image data.
     /// </summary>
-    public TiffCompression? Compression { get; set; }
+    public TiffCompression Compression { get; set; } = TiffConstants.DefaultCompression;
 
     /// <summary>
     /// Gets or sets the color space of the image data.
     /// </summary>
-    public TiffPhotometricInterpretation? PhotometricInterpretation { get; set; }
+    public TiffPhotometricInterpretation PhotometricInterpretation { get; set; } = TiffConstants.DefaultPhotometricInterpretation;
 
     /// <summary>
     /// Gets or sets a mathematical operator that is applied to the image data before an encoding scheme is applied.
     /// </summary>
-    public TiffPredictor? Predictor { get; set; }
+    public TiffPredictor Predictor { get; set; } = TiffConstants.DefaultPredictor;
 
     /// <summary>
     /// Gets or sets the set of inks used in a separated (<see cref="TiffPhotometricInterpretation.Separated"/>) image.
@@ -89,7 +89,7 @@ public class TiffFrameMetadata : IDeepCloneable
                 meta.BitsPerSample = bitsPerSample;
             }
 
-            meta.BitsPerPixel = meta.BitsPerSample?.BitsPerPixel();
+            meta.BitsPerPixel = meta.BitsPerSample.BitsPerPixel();
 
             if (profile.TryGetValue(ExifTag.Compression, out IExifValue<ushort>? compressionValue))
             {
@@ -111,6 +111,7 @@ public class TiffFrameMetadata : IDeepCloneable
                 meta.InkSet = (TiffInkSet)inkSetValue.Value;
             }
 
+            // TODO: Why do we remove this? Encoding should overwrite.
             profile.RemoveValue(ExifTag.BitsPerSample);
             profile.RemoveValue(ExifTag.Compression);
             profile.RemoveValue(ExifTag.PhotometricInterpretation);

src/ImageSharp/Formats/Tiff/TiffMetadata.cs

@@ -1,12 +1,14 @@
 // Copyright (c) Six Labors.
 // Licensed under the Six Labors Split License.
 
+using SixLabors.ImageSharp.PixelFormats;
+
 namespace SixLabors.ImageSharp.Formats.Tiff;
 
 /// <summary>
 /// Provides Tiff specific metadata information for the image.
 /// </summary>
-public class TiffMetadata : IDeepCloneable
+public class TiffMetadata : IFormatMetadata<TiffMetadata>
 {
     /// <summary>
     /// Initializes a new instance of the <see cref="TiffMetadata"/> class.
@@ -36,5 +38,17 @@ public class TiffMetadata : IDeepCloneable
     public TiffFormatType FormatType { get; set; }
 
     /// <inheritdoc/>
-    public IDeepCloneable DeepClone() => new TiffMetadata(this);
+    public static TiffMetadata FromFormatConnectingMetadata(FormatConnectingMetadata metadata) => throw new NotImplementedException();
+
+    /// <inheritdoc/>
+    public PixelTypeInfo GetPixelTypeInfo() => throw new NotImplementedException();
+
+    /// <inheritdoc/>
+    public FormatConnectingMetadata ToFormatConnectingMetadata() => throw new NotImplementedException();
+
+    /// <inheritdoc/>
+    IDeepCloneable IDeepCloneable.DeepClone() => this.DeepClone();
+
+    /// <inheritdoc/>
+    public TiffMetadata DeepClone() => new(this);
 }

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

@@ -30,7 +30,7 @@ public abstract class TiffEncoderBaseTester
         using Image<TPixel> input = provider.GetImage();
         using var memStream = new MemoryStream();
         TiffFrameMetadata inputMeta = input.Frames.RootFrame.Metadata.GetTiffMetadata();
-        TiffCompression inputCompression = inputMeta.Compression ?? TiffCompression.None;
+        TiffCompression inputCompression = inputMeta.Compression;
 
         // act
         input.Save(memStream, tiffEncoder);

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

@@ -15,7 +15,7 @@ public class TiffEncoderHeaderTests
     public void WriteHeader_WritesValidHeader()
     {
         using MemoryStream stream = new();
-        TiffEncoderCore encoder = new(Encoder, Configuration.Default.MemoryAllocator);
+        TiffEncoderCore encoder = new(Encoder, Configuration.Default);
 
         using (TiffStreamWriter writer = new(stream))
         {
@@ -29,7 +29,7 @@ public class TiffEncoderHeaderTests
     public void WriteHeader_ReturnsFirstIfdMarker()
     {
         using MemoryStream stream = new();
-        TiffEncoderCore encoder = new(Encoder, Configuration.Default.MemoryAllocator);
+        TiffEncoderCore encoder = new(Encoder, Configuration.Default);
 
         using TiffStreamWriter writer = new(stream);
         long firstIfdMarker = TiffEncoderCore.WriteHeader(writer, stackalloc byte[4]);

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

@@ -31,7 +31,7 @@ public class TiffEncoderTests : TiffEncoderBaseTester
     public void EncoderOptions_SetPhotometricInterpretation_Works(TiffPhotometricInterpretation? photometricInterpretation, TiffBitsPerPixel expectedBitsPerPixel)
     {
         // arrange
-        TiffEncoder tiffEncoder = new() { PhotometricInterpretation = photometricInterpretation };
+        TiffEncoder tiffEncoder = new() { BitsPerPixel = expectedBitsPerPixel, PhotometricInterpretation = photometricInterpretation };
         using Image input = expectedBitsPerPixel is TiffBitsPerPixel.Bit16
             ? new Image<L16>(10, 10)
             : new Image<Rgb24>(10, 10);
@@ -57,8 +57,7 @@ public class TiffEncoderTests : TiffEncoderBaseTester
     public void EncoderOptions_SetBitPerPixel_Works(TiffBitsPerPixel bitsPerPixel)
     {
         // arrange
-        TiffEncoder tiffEncoder = new()
-        { BitsPerPixel = bitsPerPixel };
+        TiffEncoder tiffEncoder = new() { BitsPerPixel = bitsPerPixel };
         using Image input = new Image<Rgb24>(10, 10);
         using MemoryStream memStream = new();
 
@@ -156,7 +155,11 @@ public class TiffEncoderTests : TiffEncoderBaseTester
     {
         // arrange
         TiffEncoder tiffEncoder = new()
-        { PhotometricInterpretation = photometricInterpretation, Compression = compression };
+        {
+            BitsPerPixel = expectedBitsPerPixel,
+            PhotometricInterpretation = photometricInterpretation,
+            Compression = compression
+        };
         using Image input = expectedBitsPerPixel is TiffBitsPerPixel.Bit16
             ? new Image<L16>(10, 10)
             : new Image<Rgb24>(10, 10);
@@ -199,25 +202,6 @@ public class TiffEncoderTests : TiffEncoderBaseTester
         Assert.Equal(expectedBitsPerPixel, frameMetaData.BitsPerPixel);
     }
 
-    [Fact]
-    public void TiffEncoder_PreservesBitsPerPixel_WhenInputIsL8()
-    {
-        // arrange
-        TiffEncoder tiffEncoder = new();
-        using Image input = new Image<L8>(10, 10);
-        using MemoryStream memStream = new();
-        const TiffBitsPerPixel expectedBitsPerPixel = TiffBitsPerPixel.Bit8;
-
-        // act
-        input.Save(memStream, tiffEncoder);
-
-        // assert
-        memStream.Position = 0;
-        using Image<Rgba32> output = Image.Load<Rgba32>(memStream);
-        TiffFrameMetadata frameMetaData = output.Frames.RootFrame.Metadata.GetTiffMetadata();
-        Assert.Equal(expectedBitsPerPixel, frameMetaData.BitsPerPixel);
-    }
-
     [Theory]
     [WithFile(RgbUncompressed, PixelTypes.Rgba32, TiffCompression.None)]
     [WithFile(RgbLzwNoPredictor, PixelTypes.Rgba32, TiffCompression.Lzw)]
@@ -241,11 +225,11 @@ public class TiffEncoderTests : TiffEncoderBaseTester
     }
 
     [Theory]
-    [WithFile(RgbLzwNoPredictor, PixelTypes.Rgba32, null)]
+    [WithFile(RgbLzwNoPredictor, PixelTypes.Rgba32, TiffPredictor.None)]
     [WithFile(RgbLzwPredictor, PixelTypes.Rgba32, TiffPredictor.Horizontal)]
-    [WithFile(RgbDeflate, PixelTypes.Rgba32, null)]
+    [WithFile(RgbDeflate, PixelTypes.Rgba32, TiffPredictor.None)]
     [WithFile(RgbDeflatePredictor, PixelTypes.Rgba32, TiffPredictor.Horizontal)]
-    public void TiffEncoder_PreservesPredictor<TPixel>(TestImageProvider<TPixel> provider, TiffPredictor? expectedPredictor)
+    public void TiffEncoder_PreservesPredictor<TPixel>(TestImageProvider<TPixel> provider, TiffPredictor expectedPredictor)
         where TPixel : unmanaged, IPixel<TPixel>
     {
         // arrange

tests/ImageSharp.Tests/TestUtilities/TestImageExtensions.cs

@@ -697,23 +697,6 @@ public static class TestImageExtensions
         return new AllocatorBufferCapacityConfigurator(allocator, Unsafe.SizeOf<TPixel>());
     }
 
-    internal static Image<Rgba32> ToGrayscaleImage(this Buffer2D<float> buffer, float scale)
-    {
-        Image<Rgba32> image = new(buffer.Width, buffer.Height);
-
-        Assert.True(image.Frames.RootFrame.DangerousTryGetSinglePixelMemory(out Memory<Rgba32> pixelMem));
-        Span<Rgba32> pixels = pixelMem.Span;
-        Span<float> bufferSpan = buffer.DangerousGetSingleSpan();
-
-        for (int i = 0; i < bufferSpan.Length; i++)
-        {
-            float value = bufferSpan[i] * scale;
-            pixels[i] = Rgba32.FromVector4(new Vector4(value, value, value, 1f));
-        }
-
-        return image;
-    }
-
     private class MakeOpaqueProcessor : IImageProcessor
     {
         public IImageProcessor<TPixel> CreatePixelSpecificProcessor<TPixel>(Configuration configuration, Image<TPixel> source, Rectangle sourceRectangle)