add TiffInkSet property

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

@@ -0,0 +1,26 @@
+// Copyright (c) Six Labors.
+// Licensed under the Six Labors Split License.
+
+using SixLabors.ImageSharp.Metadata.Profiles.Exif;
+
+namespace SixLabors.ImageSharp.Formats.Tiff.Constants;
+
+/// <summary>
+/// Enumeration representing the set of inks used in a separated (<see cref="TiffPhotometricInterpretation.Separated"/>) image.
+/// </summary>
+public enum TiffInkSet : ushort
+{
+    /// <summary>
+    /// CMYK.
+    /// The order of the components is cyan, magenta, yellow, black.
+    /// Usually, a value of 0 represents 0% ink coverage and a value of 255 represents 100% ink coverage for that component, but see DotRange.
+    /// The <see cref="ExifTagValue.InkNames"/> field should not exist when InkSet=1.
+    /// </summary>
+    Cmyk = 1,
+
+    /// <summary>
+    /// Not CMYK.
+    /// See the <see cref="ExifTagValue.InkNames"/> field for a description of the inks to be used.
+    /// </summary>
+    NotCmyk = 2
+}

src/ImageSharp/Formats/Tiff/TiffFrameMetadata.cs

@@ -55,6 +55,11 @@ public class TiffFrameMetadata : IDeepCloneable
     /// </summary>
     public TiffPredictor? Predictor { get; set; }
 
+    /// <summary>
+    /// Gets or sets the set of inks used in a separated (<see cref="TiffPhotometricInterpretation.Separated"/>) image.
+    /// </summary>
+    public TiffInkSet? InkSet { get; set; }
+
     /// <summary>
     /// Returns a new <see cref="TiffFrameMetadata"/> instance parsed from the given Exif profile.
     /// </summary>
@@ -102,6 +107,11 @@ public class TiffFrameMetadata : IDeepCloneable
                 meta.Predictor = (TiffPredictor)predictorValue.Value;
             }
 
+            if (profile.TryGetValue(ExifTag.InkSet, out IExifValue<ushort>? inkSetValue))
+            {
+                meta.InkSet = (TiffInkSet)inkSetValue.Value;
+            }
+
             profile.RemoveValue(ExifTag.BitsPerSample);
             profile.RemoveValue(ExifTag.Compression);
             profile.RemoveValue(ExifTag.PhotometricInterpretation);