Implement Lab and DeviceN color spaces and fix bug in SetNonStrokingColorspace() for Transparency Group XObjects

src/UglyToad.PdfPig.Tests/Integration/ColorSpaceTests.cs

@@ -1,12 +1,254 @@
 namespace UglyToad.PdfPig.Tests.Integration
 {
+    using System;
+    using System.IO;
     using System.Linq;
     using UglyToad.PdfPig.Content;
     using UglyToad.PdfPig.DocumentLayoutAnalysis.WordExtractor;
+    using UglyToad.PdfPig.Graphics.Colors;
     using Xunit;
 
     public class ColorSpaceTests
     {
+        private const string OutputFolder = "ColorSpaceTests";
+
+        public ColorSpaceTests()
+        {
+            Directory.CreateDirectory(OutputFolder);
+        }
+
+        [Fact]
+        public void IndexedDeviceNColorSpaceImages()
+        {
+            var path = IntegrationHelpers.GetDocumentPath("MOZILLA-3136-0.pdf");
+
+            using (var document = PdfDocument.Open(path))
+            {
+                // page 1
+                var page1 = document.GetPage(1);
+                var images1 = page1.GetImages().ToArray();
+
+                // image 12
+                var image12 = images1[12];
+                Assert.Equal(ColorSpace.Indexed, image12.ColorSpaceDetails.Type);
+                Assert.Equal(ColorSpace.DeviceN, image12.ColorSpaceDetails.BaseType);
+                Assert.True(image12.TryGetPng(out byte[] bytes1_12)); // Cyan square
+                File.WriteAllBytes(Path.Combine(OutputFolder, "MOZILLA-3136-0_1_12.png"), bytes1_12);
+
+                // image 13
+                var image13 = images1[13];
+                Assert.Equal(ColorSpace.Indexed, image13.ColorSpaceDetails.Type);
+                Assert.Equal(ColorSpace.DeviceN, image13.ColorSpaceDetails.BaseType);
+                Assert.True(image13.TryGetPng(out byte[] bytes1_13)); // Cyan square
+                File.WriteAllBytes(Path.Combine(OutputFolder, "MOZILLA-3136-0_1_13.png"), bytes1_13);
+            }
+        }
+
+        [Fact]
+        public void DeviceNColorSpaceImages()
+        {
+            var path = IntegrationHelpers.GetDocumentPath("DeviceN_CS_test.pdf");
+
+            using (var document = PdfDocument.Open(path))
+            {
+                // page 3
+                var page3 = document.GetPage(3);
+                var images3 = page3.GetImages().ToArray();
+
+                var image3_0 = images3[0];
+                var deviceNCs = image3_0.ColorSpaceDetails as DeviceNColorSpaceDetails;
+                Assert.NotNull(deviceNCs);
+                Assert.True(deviceNCs.AlternateColorSpaceDetails is ICCBasedColorSpaceDetails);
+                Assert.True(image3_0.TryGetPng(out byte[] bytes3_0));
+                File.WriteAllBytes(Path.Combine(OutputFolder, "DeviceN_CS_test_3_0.png"), bytes3_0);
+
+                var image3_2 = images3[2];
+                deviceNCs = image3_2.ColorSpaceDetails as DeviceNColorSpaceDetails;
+                Assert.NotNull(deviceNCs);
+                Assert.True(deviceNCs.AlternateColorSpaceDetails is ICCBasedColorSpaceDetails);
+                Assert.True(image3_2.TryGetPng(out byte[] bytes3_2));
+                File.WriteAllBytes(Path.Combine(OutputFolder, "DeviceN_CS_test_3_2.png"), bytes3_2);
+
+                // page 6
+                var page6 = document.GetPage(6);
+                var images6 = page6.GetImages().ToArray();
+
+                var image6_0 = images6[0];
+                deviceNCs = image6_0.ColorSpaceDetails as DeviceNColorSpaceDetails;
+                Assert.NotNull(deviceNCs);
+                Assert.True(deviceNCs.AlternateColorSpaceDetails is ICCBasedColorSpaceDetails);
+                Assert.True(image6_0.TryGetPng(out byte[] bytes6_0));
+                File.WriteAllBytes(Path.Combine(OutputFolder, "DeviceN_CS_test_6_0.png"), bytes6_0);
+
+                var image6_1 = images6[1];
+                deviceNCs = image6_0.ColorSpaceDetails as DeviceNColorSpaceDetails;
+                Assert.NotNull(deviceNCs);
+                Assert.True(deviceNCs.AlternateColorSpaceDetails is ICCBasedColorSpaceDetails);
+                Assert.True(image6_1.TryGetPng(out byte[] bytes6_1));
+                File.WriteAllBytes(Path.Combine(OutputFolder, "DeviceN_CS_test_6_1.png"), bytes6_1);
+
+                var image6_2 = images6[2];
+                deviceNCs = image6_2.ColorSpaceDetails as DeviceNColorSpaceDetails;
+                Assert.NotNull(deviceNCs);
+                Assert.True(deviceNCs.AlternateColorSpaceDetails is ICCBasedColorSpaceDetails);
+                Assert.True(image6_2.TryGetPng(out byte[] bytes6_2));
+                File.WriteAllBytes(Path.Combine(OutputFolder, "DeviceN_CS_test_6_2.png"), bytes6_2);
+            }
+        }
+
+        [Fact]
+        public void SeparationColorSpaceImages()
+        {
+            var path = IntegrationHelpers.GetDocumentPath("MOZILLA-7375-0.pdf");
+
+            using (var document = PdfDocument.Open(path))
+            {
+                var page1 = document.GetPage(1);
+                var images = page1.GetImages();
+                var image1page1 = images.ElementAt(0);
+                var separationCs = image1page1.ColorSpaceDetails as SeparationColorSpaceDetails;
+                Assert.NotNull(separationCs);
+                Assert.True(separationCs.AlternateColorSpaceDetails is DeviceCmykColorSpaceDetails);
+
+                foreach (var image in images)
+                {
+                    if (image.TryGetPng(out byte[] bytes))
+                    {
+                        // Can't check actual image processing yet because encoded not supported
+                    }
+                }
+            }
+        }
+
+        [Fact]
+        public void IndexedCalRgbColorSpaceImages()
+        {
+            var path = IntegrationHelpers.GetDocumentPath("MOZILLA-10084-0.pdf");
+
+            using (var document = PdfDocument.Open(path))
+            {
+                var page1 = document.GetPage(1);
+                var images1 = page1.GetImages().ToArray();
+
+                var image0 = images1[0];
+                Assert.Equal(ColorSpace.Indexed, image0.ColorSpaceDetails.Type);
+
+                var indexedCs = image0.ColorSpaceDetails as IndexedColorSpaceDetails;
+                Assert.NotNull(indexedCs);
+                Assert.Equal(ColorSpace.CalRGB, indexedCs.BaseColorSpaceDetails.Type);
+                Assert.True(image0.TryGetPng(out byte[] bytes0));
+                File.WriteAllBytes(Path.Combine(OutputFolder, "MOZILLA-10084-0_1_0.png"), bytes0);
+
+                var image1 = images1[1];
+                Assert.Equal(ColorSpace.Indexed, image1.ColorSpaceDetails.Type);
+                indexedCs = image1.ColorSpaceDetails as IndexedColorSpaceDetails;
+                Assert.NotNull(indexedCs);
+                Assert.Equal(ColorSpace.CalRGB, indexedCs.BaseColorSpaceDetails.Type);
+                Assert.True(image1.TryGetPng(out byte[] bytes1));
+                File.WriteAllBytes(Path.Combine(OutputFolder, "MOZILLA-10084-0_1_1.png"), bytes1);
+            }
+        }
+
+        [Fact]
+        public void StencilIndexedIccColorSpaceImages()
+        {
+            var path = IntegrationHelpers.GetDocumentPath("MOZILLA-10225-0.pdf");
+
+            using (var document = PdfDocument.Open(path))
+            {
+                // page 1
+                var page1 = document.GetPage(2);
+                var images1 = page1.GetImages().ToArray();
+
+                var image0 = images1[0];
+                Assert.Equal(ColorSpace.Indexed, image0.ColorSpaceDetails.Type); // Icc
+                Assert.True(image0.TryGetPng(out byte[] bytes0));
+                File.WriteAllBytes(Path.Combine(OutputFolder, "MOZILLA-10225-0_1_0.png"), bytes0);
+
+                var image1 = images1[1];
+                Assert.Equal(ColorSpace.Indexed, image1.ColorSpaceDetails.Type); // stencil
+                Assert.True(image1.TryGetPng(out byte[] bytes1));
+                File.WriteAllBytes(Path.Combine(OutputFolder, "MOZILLA-10225-0_1_1.png"), bytes1);
+
+                // page 23
+                var page23 = document.GetPage(23);
+                var images23 = page23.GetImages().ToArray();
+
+                var image23_0 = images23[0];
+                Assert.Equal(ColorSpace.Indexed, image23_0.ColorSpaceDetails.Type);
+                Assert.True(image23_0.TryGetPng(out byte[] bytes23_0));
+                File.WriteAllBytes(Path.Combine(OutputFolder, "MOZILLA-10225-0_23_0.png"), bytes23_0);
+
+                // page 332
+                var page332 = document.GetPage(332);
+                var images332 = page332.GetImages().ToArray();
+
+                var image332_0 = images332[0];
+                Assert.Equal(ColorSpace.ICCBased, image332_0.ColorSpaceDetails.Type);
+                Assert.True(image332_0.TryGetPng(out byte[] bytes332_0));
+                File.WriteAllBytes(Path.Combine(OutputFolder, "MOZILLA-10225-0_332_0.png"), bytes332_0);
+
+                // page 338
+                var page338 = document.GetPage(338);
+                var images338 = page338.GetImages().ToArray();
+
+                var image338_1 = images338[1];
+                Assert.Equal(ColorSpace.Indexed, image338_1.ColorSpaceDetails.Type);
+                Assert.True(image338_1.TryGetPng(out byte[] bytes338_1));
+                File.WriteAllBytes(Path.Combine(OutputFolder, "MOZILLA-10225-0_338_1.png"), bytes338_1);
+
+                // page 339
+                var page339 = document.GetPage(339);
+                var images339 = page339.GetImages().ToArray();
+
+                var image339_0 = images339[0];
+                Assert.Equal(ColorSpace.Indexed, image339_0.ColorSpaceDetails.Type);
+                Assert.True(image339_0.TryGetPng(out byte[] bytes339_0));
+                File.WriteAllBytes(Path.Combine(OutputFolder, "MOZILLA-10225-0_339_0.png"), bytes339_0);
+
+                var image339_1 = images339[1];
+                Assert.Equal(ColorSpace.Indexed, image339_1.ColorSpaceDetails.Type);
+                Assert.True(image339_1.TryGetPng(out byte[] bytes339_1));
+                File.WriteAllBytes(Path.Combine(OutputFolder, "MOZILLA-10225-0_339_1.png"), bytes339_1);
+
+                // page 341
+                var page341 = document.GetPage(341);
+                var images341 = page341.GetImages().ToArray();
+
+                var image341_0 = images341[0];
+                Assert.Equal(ColorSpace.Indexed, image341_0.ColorSpaceDetails.Type);
+                Assert.True(image341_0.TryGetPng(out byte[] bytes341_0));
+                File.WriteAllBytes(Path.Combine(OutputFolder, "MOZILLA-10225-0_341_0.png"), bytes341_0);
+            }
+        }
+
+        [Fact]
+        public void SeparationLabColorSpace()
+        {
+            // Test with TIKA_1552_0.pdf
+            // https://icolorpalette.com/color/pantone-289-c
+            // Pantone 289 C Color | #0C2340
+            // Rgb : rgb(12,35,64)
+            // CIE L*a*b* : 13.53, 2.89, -21.08
+
+            var path = IntegrationHelpers.GetDocumentPath("TIKA-1552-0.pdf");
+
+            using (var document = PdfDocument.Open(path))
+            {
+                var page1 = document.GetPage(1);
+
+                var background = page1.ExperimentalAccess.Paths[0];
+                Assert.True(background.IsFilled);
+
+                var (r, g, b) = background.FillColor.ToRGBValues();
+
+                // Colors picked from Acrobat reader: rgb(11, 34, 64)
+                Assert.Equal(10, ConvertToByte(r)); // Should be 11, but close enough
+                Assert.Equal(34, ConvertToByte(g));
+                Assert.Equal(64, ConvertToByte(b));
+            }
+        }
+
         [Fact]
         public void CanGetAllPagesImages()
         {
@@ -17,12 +259,11 @@
                 for (int p = 0; p < document.NumberOfPages; p++)
                 {
                     var page = document.GetPage(p + 1);
-                    var images = page.GetImages().ToArray();
-                    foreach (var image in images)
+                    foreach (var image in page.GetImages())
                     {
                         if (image.TryGetPng(out var png))
                         {
-
+                            // TODO
                         }
                     }
                 }
@@ -65,7 +306,7 @@
                 for (int r = 0; r < filledColors.Length; r++)
                 {
                     var color = filledColors[r];
-                    Assert.Equal(PdfPig.Graphics.Colors.ColorSpace.DeviceRGB, color.ColorSpace);
+                    Assert.Equal(ColorSpace.DeviceRGB, color.ColorSpace);
 
                     if (r % 2 == 0)
                     {
@@ -85,5 +326,11 @@
                 }
             }
         }
+
+        private static byte ConvertToByte(decimal componentValue)
+        {
+            var rounded = Math.Round(componentValue * 255, MidpointRounding.AwayFromZero);
+            return (byte)rounded;
+        }
     }
 }

src/UglyToad.PdfPig.Tests/PublicApiScannerTests.cs

@@ -122,8 +122,10 @@
                 "UglyToad.PdfPig.Graphics.Colors.DeviceGrayColorSpaceDetails",
                 "UglyToad.PdfPig.Graphics.Colors.DeviceRgbColorSpaceDetails",
                 "UglyToad.PdfPig.Graphics.Colors.DeviceCmykColorSpaceDetails",
+                "UglyToad.PdfPig.Graphics.Colors.DeviceNColorSpaceDetails",
                 "UglyToad.PdfPig.Graphics.Colors.ICCBasedColorSpaceDetails",
                 "UglyToad.PdfPig.Graphics.Colors.IndexedColorSpaceDetails",
+                "UglyToad.PdfPig.Graphics.Colors.LabColorSpaceDetails",
                 "UglyToad.PdfPig.Graphics.Colors.SeparationColorSpaceDetails",
                 "UglyToad.PdfPig.Graphics.Colors.UnsupportedColorSpaceDetails",
                 "UglyToad.PdfPig.Graphics.Core.LineCapStyle",

src/UglyToad.PdfPig.Tokens/NameToken.Constants.cs

@@ -349,6 +349,7 @@
         public static readonly NameToken Metadata = new NameToken("Metadata");
         public static readonly NameToken MissingWidth = new NameToken("MissingWidth");
         public static readonly NameToken Mix = new NameToken("Mix");
+        public static readonly NameToken MixingHints = new NameToken("MixingHints");
         public static readonly NameToken Mk = new NameToken("MK");
         public static readonly NameToken Ml = new NameToken("ML");
         public static readonly NameToken MmType1 = new NameToken("MMType1");

src/UglyToad.PdfPig/Graphics/Colors/CIEBasedColorSpaceTransformer.cs

@@ -5,10 +5,11 @@
 
     /// <summary>
     /// Transformer for CIEBased color spaces.
-    ///
+    /// <para>
     /// In addition to the PDF spec itself, the transformation implementation is based on the descriptions in:
     /// https://en.wikipedia.org/wiki/SRGB#The_forward_transformation_(CIE_XYZ_to_sRGB) and
     /// http://www.brucelindbloom.com/index.html?Eqn_XYZ_to_RGB.html
+    /// </para>
     /// </summary>
     internal class CIEBasedColorSpaceTransformer
     {
@@ -75,7 +76,7 @@
         /// Transforms the supplied ABC color to the RGB color of the <see cref="RGBWorkingSpace"/>
         /// that was supplied to this <see cref="CIEBasedColorSpaceTransformer"/> as the destination
         /// workspace.
-        /// A, B and C represent red, green and blue calibrated color values in the range 0 to 1. 
+        /// A, B and C represent red, green and blue calibrated color values in the range 0 to 1.
         /// </summary>
         public (double R, double G, double B) TransformToRGB((double A, double B, double C) color)
         {

src/UglyToad.PdfPig/Graphics/Colors/ColorSpaceDetails.cs

@@ -29,7 +29,12 @@
         /// The underlying type of ColorSpace, usually equal to <see cref="Type"/>
         /// unless <see cref="ColorSpace.Indexed"/>.
         /// </summary>
-        public ColorSpace BaseType { get; protected set; }
+        public ColorSpace BaseType { get; protected set; }
+
+        /// <summary>
+        /// The number of components for the underlying color space.
+        /// </summary>
+        public abstract int BaseNumberOfColorComponents { get; }
 
         /// <summary>
         /// Create a new <see cref="ColorSpaceDetails"/>.
@@ -45,15 +50,25 @@
         /// </summary>
         public abstract IColor GetColor(params double[] values);
 
+        /// <summary>
+        /// Get the color, without check and caching.
+        /// </summary>
+        internal abstract double[] Process(params double[] values);
+
         /// <summary>
         /// Get the color that initialize the current stroking or nonstroking colour.
         /// </summary>
         public abstract IColor GetInitializeColor();
 
+        /// <summary>
+        /// Transform image bytes.
+        /// </summary>
+        internal abstract IReadOnlyList<byte> Transform(IReadOnlyList<byte> decoded);
+
         /// <summary>
         /// Convert to byte.
         /// </summary>
-        protected static byte ConvertToByte(decimal componentValue)
+        protected static byte ConvertToByte(double componentValue)
         {
             var rounded = Math.Round(componentValue * 255, MidpointRounding.AwayFromZero);
             return (byte)rounded;
@@ -73,10 +88,19 @@
 
         /// <inheritdoc/>
         public override int NumberOfColorComponents => 1;
+
+        /// <inheritdoc/>
+        public override int BaseNumberOfColorComponents => NumberOfColorComponents;
 
         private DeviceGrayColorSpaceDetails() : base(ColorSpace.DeviceGray)
         { }
 
+        /// <inheritdoc/>
+        internal override double[] Process(params double[] values)
+        {
+            return values;
+        }
+
         /// <inheritdoc/>
         public override IColor GetColor(params double[] values)
         {
@@ -105,6 +129,12 @@
         {
             return GrayColor.Black;
         }
+
+        /// <inheritdoc/>
+        internal override IReadOnlyList<byte> Transform(IReadOnlyList<byte> decoded)
+        {
+            return decoded;
+        }
     }
 
     /// <summary>
@@ -120,10 +150,19 @@
 
         /// <inheritdoc/>
         public override int NumberOfColorComponents => 3;
+
+        /// <inheritdoc/>
+        public override int BaseNumberOfColorComponents => NumberOfColorComponents;
 
         private DeviceRgbColorSpaceDetails() : base(ColorSpace.DeviceRGB)
         { }
 
+        /// <inheritdoc/>
+        internal override double[] Process(params double[] values)
+        {
+            return values;
+        }
+
         /// <inheritdoc/>
         public override IColor GetColor(params double[] values)
         {
@@ -151,6 +190,12 @@
         public override IColor GetInitializeColor()
         {
             return RGBColor.Black;
+        }
+
+        /// <inheritdoc/>
+        internal override IReadOnlyList<byte> Transform(IReadOnlyList<byte> decoded)
+        {
+            return decoded;
         }
     }
 
@@ -166,11 +211,20 @@
 
         /// <inheritdoc/>
         public override int NumberOfColorComponents => 4;
+
+        /// <inheritdoc/>
+        public override int BaseNumberOfColorComponents => NumberOfColorComponents;
 
         private DeviceCmykColorSpaceDetails() : base(ColorSpace.DeviceCMYK)
         {
         }
 
+        /// <inheritdoc/>
+        internal override double[] Process(params double[] values)
+        {
+            return values;
+        }
+
         /// <inheritdoc/>
         public override IColor GetColor(params double[] values)
         {
@@ -199,6 +253,12 @@
         public override IColor GetInitializeColor()
         {
             return CMYKColor.Black;
+        }
+
+        /// <inheritdoc/>
+        internal override IReadOnlyList<byte> Transform(IReadOnlyList<byte> decoded)
+        {
+            return decoded;
         }
     }
 
@@ -206,12 +266,12 @@
     /// An Indexed color space allows a PDF content stream to use small integers as indices into a color map or color table of arbitrary colors in some other space.
     /// A PDF consumer treats each sample value as an index into the color table and uses the color value it finds there.
     /// </summary>
-    public class IndexedColorSpaceDetails : ColorSpaceDetails
+    public sealed class IndexedColorSpaceDetails : ColorSpaceDetails
     {
         private readonly ConcurrentDictionary<double, IColor> cache = new ConcurrentDictionary<double, IColor>();
 
         /// <summary>
-        /// Creates a indexed color space useful for exracting stencil masks as black-and-white images,
+        /// Creates a indexed color space useful for extracting stencil masks as black-and-white images,
         /// i.e. with a color palette of two colors (black and white). If the decode parameter array is
         /// [0, 1] it indicates that black is at index 0 in the color palette, whereas [1, 0] indicates
         /// that the black color is at index 1.
@@ -224,6 +284,12 @@
 
         /// <inheritdoc/>
         public override int NumberOfColorComponents => 1;
+
+        /// <summary>
+        /// <inheritdoc/>
+        /// <para>In the case of <see cref="IndexedColorSpaceDetails"/>, gets the <see cref="IndexedColorSpaceDetails.BaseColorSpaceDetails"/>' <c>BaseNumberOfColorComponents</c>.</para>
+        /// </summary>
+        public override int BaseNumberOfColorComponents => BaseColorSpaceDetails.BaseNumberOfColorComponents;
 
         /// <summary>
         /// The base color space in which the values in the color table are to be interpreted.
@@ -254,6 +320,13 @@
             BaseType = baseColorSpaceDetails.BaseType;
         }
 
+        /// <inheritdoc/>
+        internal override double[] Process(params double[] values)
+        {
+            var csBytes = UnwrapIndexedColorSpaceBytes(new[] { (byte)values[0] });
+            return BaseColorSpaceDetails.Process(csBytes.Select(b => b / 255.0).ToArray());
+        }
+
         /// <inheritdoc/>
         public override IColor GetColor(params double[] values)
         {
@@ -274,9 +347,10 @@
             var multiplier = 1;
             Func<byte, IEnumerable<byte>> transformer = null;
             switch (BaseType)
-            {
+            {
                 case ColorSpace.DeviceRGB:
-                case ColorSpace.CalRGB:
+                case ColorSpace.CalRGB:
+                case ColorSpace.Lab:
                     transformer = x =>
                     {
                         var r = new byte[3];
@@ -288,7 +362,8 @@
                         return r;
                     };
                     multiplier = 3;
-                    break;
+                    break;
+
                 case ColorSpace.DeviceCMYK:
                     transformer = x =>
                     {
@@ -302,11 +377,28 @@
                     };
 
                     multiplier = 4;
-                    break;
+                    break;
+
                 case ColorSpace.DeviceGray:
-                case ColorSpace.CalGray:
+                case ColorSpace.CalGray:
+                case ColorSpace.Separation:
                     transformer = x => new[] { ColorTable[x] };
                     multiplier = 1;
+                    break;
+
+                case ColorSpace.DeviceN:
+                    transformer = x =>
+                    {
+                        var r = new byte[BaseColorSpaceDetails.NumberOfColorComponents];
+                        for (var i = 0; i < BaseColorSpaceDetails.NumberOfColorComponents; i++)
+                        {
+                            r[i] = ColorTable[x * BaseColorSpaceDetails.NumberOfColorComponents + i];
+                        }
+
+                        return r;
+                    };
+
+                    multiplier = BaseColorSpaceDetails.NumberOfColorComponents;
                     break;
             }
 
@@ -335,7 +427,186 @@
             // initialize the corresponding current colour to 0.
             return GetColor(0);
         }
-    }
+
+        /// <summary>
+        /// <inheritdoc/>
+        /// <para>
+        /// Unwrap then transform using base color space details.
+        /// </para>
+        /// </summary>
+        internal override IReadOnlyList<byte> Transform(IReadOnlyList<byte> decoded)
+        {
+            var unwraped = UnwrapIndexedColorSpaceBytes(decoded);
+            return BaseColorSpaceDetails.Transform(unwraped);
+        }
+    }
+
+    /// <summary>
+    /// DeviceN colour spaces may contain an arbitrary number of colour components. They provide greater flexibility than
+    /// is possible with standard device colour spaces such as DeviceCMYK or with individual Separation colour spaces.
+    /// </summary>
+    public sealed class DeviceNColorSpaceDetails : ColorSpaceDetails
+    {
+        /// <summary>
+        /// <inheritdoc/>
+        /// <para>The 'N' in DeviceN.</para>
+        /// </summary>
+        public override int NumberOfColorComponents { get; }
+
+        /// <inheritdoc/>
+        public override int BaseNumberOfColorComponents => AlternateColorSpaceDetails.NumberOfColorComponents;
+
+        /// <summary>
+        /// Specifies name objects specifying the individual colour components. The length of the array shall
+        /// determine the number of components in the DeviceN colour space.
+        /// </summary>
+        /// <remarks>
+        /// The component names shall all be different from one another, except for the name None, which may be repeated.
+        /// <para>
+        /// The special name All, used by Separation colour spaces, shall not be used.
+        /// </para>
+        /// </remarks>
+        public IReadOnlyList<NameToken> Names { get; }
+
+        /// <summary>
+        /// If the colorant name associated with a DeviceN color space does not correspond to a colorant available on the device,
+        /// the application arranges for subsequent painting operations to be performed in an alternate color space.
+        /// The intended colors can be approximated by colors in a device or CIE-based color space
+        /// which are then rendered with the usual primary or process colorants.
+        /// </summary>
+        public ColorSpaceDetails AlternateColorSpaceDetails { get; }
+
+        /// <summary>
+        /// The optional attributes parameter shall be a dictionary containing additional information about the components of
+        /// colour space that conforming readers may use. Conforming readers need not use the alternateSpace and tintTransform
+        /// parameters, and may instead use custom blending algorithms, along with other information provided in the attributes
+        /// dictionary if present.
+        /// </summary>
+        public DeviceNColorSpaceAttributes? Attributes { get; }
+
+        /// <summary>
+        /// During subsequent painting operations, an application calls this function to transform a tint value into
+        /// color component values in the alternate color space.
+        /// The function is called with the tint value and must return the corresponding color component values.
+        /// That is, the number of components and the interpretation of their values depend on the <see cref="AlternateColorSpaceDetails"/>.
+        /// </summary>
+        public PdfFunction TintFunction { get; }
+
+        /// <summary>
+        /// Create a new <see cref="DeviceNColorSpaceDetails"/>.
+        /// </summary>
+        public DeviceNColorSpaceDetails(IReadOnlyList<NameToken> names, ColorSpaceDetails alternateColorSpaceDetails,
+            PdfFunction tintFunction, DeviceNColorSpaceAttributes? attributes = null)
+            : base(ColorSpace.DeviceN)
+        {
+            Names = names;
+            NumberOfColorComponents = Names.Count;
+            AlternateColorSpaceDetails = alternateColorSpaceDetails;
+            Attributes = attributes;
+            TintFunction = tintFunction;
+        }
+
+        /// <inheritdoc/>
+        internal override double[] Process(params double[] values)
+        {
+            var evaled = TintFunction.Eval(values[0]);
+            return AlternateColorSpaceDetails.Process(evaled);
+        }
+
+        /// <inheritdoc/>
+        public override IColor GetColor(params double[] values)
+        {
+            if (values == null || values.Length != NumberOfColorComponents)
+            {
+                throw new ArgumentException($"Invalid number of imputs, expecting {NumberOfColorComponents} but got {values.Length}", nameof(values));
+            }
+
+            // TODO - use attributes
+
+            // TODO - caching
+            var evaled = TintFunction.Eval(values);
+            return AlternateColorSpaceDetails.GetColor(evaled);
+        }
+
+        /// <inheritdoc/>
+        internal override IReadOnlyList<byte> Transform(IReadOnlyList<byte> decoded)
+        {
+            var transformed = new List<byte>();
+            for (var i = 0; i < decoded.Count; i += NumberOfColorComponents)
+            {
+                double[] comps = new double[NumberOfColorComponents];
+                for (int n = 0; n < NumberOfColorComponents; n++)
+                {
+                    comps[n] = decoded[i + n] / 255.0;
+                }
+
+                var colors = Process(comps);
+                for (int c = 0; c < colors.Length; c++)
+                {
+                    transformed.Add(ConvertToByte(colors[c]));
+                }
+            }
+
+            return transformed;
+        }
+
+        /// <inheritdoc/>
+        public override IColor GetInitializeColor()
+        {
+            // When this space is set to the current colour space (using the CS or cs operators), each component
+            // shall be given an initial value of 1.0. The SCN and scn operators respectively shall set the current
+            // stroking and nonstroking colour.
+            return GetColor(Enumerable.Repeat(1.0, NumberOfColorComponents).ToArray());
+        }
+
+        /// <summary>
+        /// DeviceN Color Space Attributes.
+        /// </summary>
+        public struct DeviceNColorSpaceAttributes
+        {
+            /// <summary>
+            /// A name specifying the preferred treatment for the colour space. Values shall be <c>DeviceN</c> or <c>NChannel</c>. Default value: <c>DeviceN</c>.
+            /// </summary>
+            public NameToken Subtype { get; }
+
+            /// <summary>
+            /// Colorants - dictionary - Required if Subtype is NChannel and the colour space includes spot colorants; otherwise optional.
+            /// </summary>
+            public DictionaryToken Colorants { get; }
+
+            /// <summary>
+            /// Process - dictionary - Required if Subtype is NChannel and the colour space includes components of a process colour space, otherwise optional.
+            /// </summary>
+            public DictionaryToken Process { get; }
+
+            /// <summary>
+            /// MixingHints - dictionary - Optional
+            /// </summary>
+            public DictionaryToken MixingHints { get; }
+
+            /// <summary>
+            /// TODO
+            /// </summary>
+            public DeviceNColorSpaceAttributes()
+            {
+                Subtype = NameToken.Devicen;
+                Colorants = null;
+                Process = null;
+                MixingHints = null;
+            }
+
+            /// <summary>
+            /// TODO
+            /// </summary>
+            public DeviceNColorSpaceAttributes(NameToken subtype, DictionaryToken colorants, DictionaryToken process, DictionaryToken mixingHints)
+            {
+                Subtype = subtype;
+                Colorants = colorants;
+                Process = process;
+                MixingHints = mixingHints;
+            }
+        }
+    }
 
     /// <summary>
     /// A Separation color space provides a means for specifying the use of additional colorants or
@@ -343,12 +614,15 @@
     /// When such a space is the current color space, the current color is a single-component value, called a tint,
     /// that controls the application of the given colorant or color components only.
     /// </summary>
-    public class SeparationColorSpaceDetails : ColorSpaceDetails
+    public sealed class SeparationColorSpaceDetails : ColorSpaceDetails
     {
         private readonly ConcurrentDictionary<double, IColor> cache = new ConcurrentDictionary<double, IColor>();
 
         /// <inheritdoc/>
         public override int NumberOfColorComponents => 1;
+
+        /// <inheritdoc/>
+        public override int BaseNumberOfColorComponents => AlternateColorSpaceDetails.NumberOfColorComponents;
 
         /// <summary>
         /// Specifies the name of the colorant that this Separation color space is intended to represent.
@@ -394,6 +668,13 @@
             TintFunction = tintFunction;
         }
 
+        /// <inheritdoc/>
+        internal override double[] Process(params double[] values)
+        {
+            var evaled = TintFunction.Eval(values[0]);
+            return AlternateColorSpaceDetails.Process(evaled);
+        }
+
         /// <inheritdoc/>
         public override IColor GetColor(params double[] values)
         {
@@ -411,15 +692,17 @@
             });
         }
 
-        internal IReadOnlyList<byte> TransformToRGB(IReadOnlyList<byte> values)
+        /// <inheritdoc/>
+        internal override IReadOnlyList<byte> Transform(IReadOnlyList<byte> values)
         {
             var transformed = new List<byte>();
             for (var i = 0; i < values.Count; i += 3)
             {
-                var (r, g, b) = GetColor(values[i++] / 255.0).ToRGBValues();
-                transformed.Add(ConvertToByte(r));
-                transformed.Add(ConvertToByte(g));
-                transformed.Add(ConvertToByte(b));
+                var colors = Process(values[i++] / 255.0);
+                for (int c = 0; c < colors.Length; c++)
+                {
+                    transformed.Add(ConvertToByte(colors[c]));
+                }
             }
 
             return transformed;
@@ -439,11 +722,14 @@
     /// CalGray - A CIE A color space with a single transformation.
     /// A represents the gray component of a calibrated gray space. The component must be in the range 0.0 to 1.0.
     /// </summary>
-    public class CalGrayColorSpaceDetails : ColorSpaceDetails
+    public sealed class CalGrayColorSpaceDetails : ColorSpaceDetails
     {
         /// <inheritdoc/>
         public override int NumberOfColorComponents => 1;
 
+        /// <inheritdoc/>
+        public override int BaseNumberOfColorComponents => NumberOfColorComponents;
+
         private readonly CIEBasedColorSpaceTransformer colorSpaceTransformer;
 
         /// <summary>
@@ -506,24 +792,32 @@
         /// </summary>
         private RGBColor TransformToRGB(double colorA)
         {
-            var colorRgb = colorSpaceTransformer.TransformToRGB((colorA, colorA, colorA));
-            return new RGBColor((decimal)colorRgb.R, (decimal)colorRgb.G, (decimal)colorRgb.B);
+            var (R, G, B) = colorSpaceTransformer.TransformToRGB((colorA, colorA, colorA));
+            return new RGBColor((decimal)R, (decimal)G, (decimal)B);
         }
 
-        internal IReadOnlyList<byte> TransformToRGB(IReadOnlyList<byte> decoded)
+        /// <inheritdoc/>
+        internal override IReadOnlyList<byte> Transform(IReadOnlyList<byte> decoded)
         {
             var transformed = new List<byte>();
             for (var i = 0; i < decoded.Count; i++)
             {
                 var component = decoded[i] / 255.0;
-                var rgbPixel = TransformToRGB(component);
+                var rgbPixel = Process(component);
                 // We only need one component here 
-                transformed.Add(ConvertToByte(rgbPixel.R));
+                transformed.Add(ConvertToByte(rgbPixel[0]));
             }
 
             return transformed;
         }
 
+        /// <inheritdoc/>
+        internal override double[] Process(params double[] values)
+        {
+            var (R, _, _) = colorSpaceTransformer.TransformToRGB((values[0], values[0], values[0]));
+            return new double[] { R };
+        }
+
         /// <inheritdoc/>
         public override IColor GetColor(params double[] values)
         {
@@ -552,11 +846,14 @@
     /// CalRGB - A CIE ABC color space with a single transformation.
     /// A, B and C represent red, green and blue color values in the range 0.0 to 1.0.
     /// </summary>
-    public class CalRGBColorSpaceDetails : ColorSpaceDetails
+    public sealed class CalRGBColorSpaceDetails : ColorSpaceDetails
     {
         /// <inheritdoc/>
         public override int NumberOfColorComponents => 3;
 
+        /// <inheritdoc/>
+        public override int BaseNumberOfColorComponents => NumberOfColorComponents;
+
         private readonly CIEBasedColorSpaceTransformer colorSpaceTransformer;
 
         /// <summary>
@@ -636,24 +933,31 @@
         /// </summary>
         private RGBColor TransformToRGB((double A, double B, double C) colorAbc)
         {
-            var colorRgb = colorSpaceTransformer.TransformToRGB((colorAbc.A, colorAbc.B, colorAbc.C));
-            return new RGBColor((decimal)colorRgb.R, (decimal)colorRgb.G, (decimal)colorRgb.B);
+            var (R, G, B) = colorSpaceTransformer.TransformToRGB((colorAbc.A, colorAbc.B, colorAbc.C));
+            return new RGBColor((decimal)R, (decimal)G, (decimal)B);
         }
 
-        internal IReadOnlyList<byte> TransformToRGB(IReadOnlyList<byte> decoded)
+        /// <inheritdoc/>
+        internal override IReadOnlyList<byte> Transform(IReadOnlyList<byte> decoded)
         {
             var transformed = new List<byte>();
             for (var i = 0; i < decoded.Count; i += 3)
             {
-                var rgbPixel = TransformToRGB((decoded[i] / 255.0, decoded[i + 1] / 255.0, decoded[i + 2] / 255.0));
-                transformed.Add(ConvertToByte(rgbPixel.R));
-                transformed.Add(ConvertToByte(rgbPixel.G));
-                transformed.Add(ConvertToByte(rgbPixel.B));
+                var rgbPixel = Process(decoded[i] / 255.0, decoded[i + 1] / 255.0, decoded[i + 2] / 255.0);
+                transformed.Add(ConvertToByte(rgbPixel[0]));
+                transformed.Add(ConvertToByte(rgbPixel[1]));
+                transformed.Add(ConvertToByte(rgbPixel[2]));
             }
 
             return transformed;
-        }
+        }
 
+        /// <inheritdoc/>
+        internal override double[] Process(params double[] values)
+        {
+            var (R, G, B) = colorSpaceTransformer.TransformToRGB((values[0], values[1], values[2]));
+            return new double[] { R, G, B };
+        }
 
         /// <inheritdoc/>
         public override IColor GetColor(params double[] values)
@@ -675,6 +979,149 @@
             // be substituted.)
             return TransformToRGB((0, 0, 0));
         }
+    }
+
+    /// <summary>
+    /// CIE (Commission Internationale de l'Éclairage) colorspace.
+    /// Specifies color related to human visual perception with the aim of producing consistent color on different output devices.
+    /// CalRGB - A CIE ABC color space with a single transformation.
+    /// A, B and C represent red, green and blue color values in the range 0.0 to 1.0.
+    /// </summary>
+    public sealed class LabColorSpaceDetails : ColorSpaceDetails
+    {
+        private readonly CIEBasedColorSpaceTransformer colorSpaceTransformer;
+
+        /// <inheritdoc/>
+        public override int NumberOfColorComponents => 3;
+
+        /// <inheritdoc/>
+        public override int BaseNumberOfColorComponents => NumberOfColorComponents;
+
+        /// <summary>
+        /// An array of three numbers [XW  YW  ZW] specifying the tristimulus value, in the CIE 1931 XYZ space of the
+        /// diffuse white point. The numbers XW and ZW shall be positive, and YW shall be equal to 1.0.
+        /// </summary>
+        public IReadOnlyList<double> WhitePoint { get; }
+
+        /// <summary>
+        /// An array of three numbers [XB  YB  ZB] specifying the tristimulus value, in the CIE 1931 XYZ space of the
+        /// diffuse black point. All three numbers must be non-negative. Default value: [0.0  0.0  0.0].
+        /// </summary>
+        public IReadOnlyList<double> BlackPoint { get; }
+
+        /// <summary>
+        /// An array of four numbers [a_min a_max b_min b_max] that shall specify the range of valid values for the a* and b* (B and C)
+        /// components of the colour space — that is, a_min ≤ a* ≤ a_max and b_min ≤ b* ≤ b_max
+        /// <para>Component values falling outside the specified range shall be adjusted to the nearest valid value without error indication.</para>
+        /// Default value: [−100 100 −100 100].
+        /// </summary>
+        public IReadOnlyList<double> Matrix { get; }
+
+        /// <summary>
+        /// Create a new <see cref="LabColorSpaceDetails"/>.
+        /// </summary>
+        public LabColorSpaceDetails([NotNull] IReadOnlyList<decimal> whitePoint, [CanBeNull] IReadOnlyList<decimal> blackPoint, [CanBeNull] IReadOnlyList<decimal> matrix)
+            : base(ColorSpace.Lab)
+        {
+            WhitePoint = whitePoint?.Select(v => (double)v).ToArray() ?? throw new ArgumentNullException(nameof(whitePoint));
+            if (WhitePoint.Count != 3)
+            {
+                throw new ArgumentOutOfRangeException(nameof(whitePoint), whitePoint, $"Must consist of exactly three numbers, but was passed {whitePoint.Count}.");
+            }
+
+            BlackPoint = blackPoint?.Select(v => (double)v).ToArray() ?? new[] { 0.0, 0.0, 0.0 };
+            if (BlackPoint.Count != 3)
+            {
+                throw new ArgumentOutOfRangeException(nameof(blackPoint), blackPoint, $"Must consist of exactly three numbers, but was passed {blackPoint.Count}.");
+            }
+
+            Matrix = matrix?.Select(v => (double)v).ToArray() ?? new[] { -100.0, 100.0, -100.0, 100.0 };
+            if (Matrix.Count != 4)
+            {
+                throw new ArgumentOutOfRangeException(nameof(matrix), matrix, $"Must consist of exactly four numbers, but was passed {matrix.Count}.");
+            }
+
+            colorSpaceTransformer = new CIEBasedColorSpaceTransformer((WhitePoint[0], WhitePoint[1], WhitePoint[2]), RGBWorkingSpace.sRGB);
+        }
+
+        /// <summary>
+        /// Transforms the supplied ABC color to RGB (sRGB) using the properties of this <see cref="LabColorSpaceDetails"/>
+        /// in the transformation process.
+        /// A, B and C represent the L*, a*, and b* components of a CIE 1976 L*a*b* space. The range of the first (L*)
+        /// component shall be 0 to 100; the ranges of the second and third (a* and b*) components shall be defined by
+        /// the Range entry in the colour space dictionary
+        /// </summary>
+        private RGBColor TransformToRGB((double A, double B, double C) colorAbc)
+        {
+            var rgb = Process(colorAbc.A, colorAbc.B, colorAbc.C);
+            return new RGBColor((decimal)rgb[0], (decimal)rgb[1], (decimal)rgb[2]);
+        }
+
+        /// <inheritdoc/>
+        internal override IReadOnlyList<byte> Transform(IReadOnlyList<byte> decoded)
+        {
+            var transformed = new List<byte>();
+            for (var i = 0; i < decoded.Count; i += 3)
+            {
+                var rgbPixel = Process(decoded[i] / 255.0, decoded[i + 1] / 255.0, decoded[i + 2] / 255.0);
+                transformed.Add(ConvertToByte(rgbPixel[0]));
+                transformed.Add(ConvertToByte(rgbPixel[1]));
+                transformed.Add(ConvertToByte(rgbPixel[2]));
+            }
+
+            return transformed;
+        }
+
+        private static double g(double x)
+        {
+            if (x > 6.0 / 29.0)
+            {
+                return x * x * x;
+            }
+            return 108.0 / 841.0 * (x - 4.0 / 29.0);
+        }
+
+        /// <inheritdoc/>
+        internal override double[] Process(params double[] values)
+        {
+            // Component Ranges: L*: [0 100]; a* and b*: [−128 127]
+            double b = PdfFunction.ClipToRange(values[1], Matrix[0], Matrix[1]);
+            double c = PdfFunction.ClipToRange(values[2], Matrix[2], Matrix[3]);
+
+            double M = (values[0] + 16.0) / 116.0;
+            double L = M + (b / 500.0);
+            double N = M - (c / 200.0);
+
+            double X = WhitePoint[0] * g(L);
+            double Y = WhitePoint[1] * g(M);
+            double Z = WhitePoint[2] * g(N);
+
+            var (R, G, B) = colorSpaceTransformer.TransformToRGB((X, Y, Z));
+            return new double[] { R, G, B };
+        }
+
+        /// <inheritdoc/>
+        public override IColor GetColor(params double[] values)
+        {
+            if (values == null || values.Length != NumberOfColorComponents)
+            {
+                throw new ArgumentException($"Invalid number of imputs, expecting {NumberOfColorComponents} but got {values.Length}", nameof(values));
+            }
+
+            return TransformToRGB((values[0], values[1], values[2]));
+        }
+
+        /// <inheritdoc/>
+        public override IColor GetInitializeColor()
+        {
+            // Setting the current stroking or nonstroking colour space to any CIE-based colour space shall
+            // initialize all components of the corresponding current colour to 0.0 (unless the range of valid
+            // values for a given component does not include 0.0, in which case the nearest valid value shall
+            // be substituted.)
+            double b = PdfFunction.ClipToRange(0, Matrix[0], Matrix[1]);
+            double c = PdfFunction.ClipToRange(0, Matrix[2], Matrix[3]);
+            return TransformToRGB((0, b, c));
+        }
     }
 
     /// <summary>
@@ -682,11 +1129,12 @@
     /// enable a page description to specify color values in a way that is related to human visual perception.
     /// The goal is for the same color specification to produce consistent results on different output devices,
     /// within the limitations of each device.
-    ///
+    /// <para>
     /// Currently support for this color space is limited in PdfPig. Calculations will only be based on
     /// the color space of <see cref="AlternateColorSpaceDetails"/>.
+    /// </para>
     /// </summary>
-    public class ICCBasedColorSpaceDetails : ColorSpaceDetails
+    public sealed class ICCBasedColorSpaceDetails : ColorSpaceDetails
     {
         /// <summary>
         /// The number of color components in the color space described by the ICC profile data.
@@ -695,6 +1143,9 @@
         /// </summary>
         public override int NumberOfColorComponents { get; }
 
+        /// <inheritdoc/>
+        public override int BaseNumberOfColorComponents => NumberOfColorComponents;
+
         /// <summary>
         /// An alternate color space that can be used in case the one specified in the stream data is not
         /// supported. Non-conforming readers may use this color space. The alternate color space may be any
@@ -753,6 +1204,14 @@
             Metadata = metadata;
         }
 
+        /// <inheritdoc/>
+        internal override double[] Process(params double[] values)
+        {
+            // TODO - use ICC profile
+
+            return AlternateColorSpaceDetails.Process(values);
+        }
+
         /// <inheritdoc/>
         public override IColor GetColor(params double[] values)
         {
@@ -776,13 +1235,21 @@
             double v = PdfFunction.ClipToRange(0.0, (double)Range[0], (double)Range[1]);
             double[] init = Enumerable.Repeat(v, NumberOfColorComponents).ToArray();
             return GetColor(init);
+        }
+
+        /// <inheritdoc/>
+        internal override IReadOnlyList<byte> Transform(IReadOnlyList<byte> decoded)
+        {
+            // TODO - use ICC profile
+
+            return AlternateColorSpaceDetails.Transform(decoded);
         }
     }
 
     /// <summary>
     /// A ColorSpace which the PdfPig library does not currently support. Please raise a PR if you need support for this ColorSpace.
     /// </summary>
-    public class UnsupportedColorSpaceDetails : ColorSpaceDetails
+    public sealed class UnsupportedColorSpaceDetails : ColorSpaceDetails
     {
         /// <summary>
         /// The single instance of the <see cref="UnsupportedColorSpaceDetails"/>.
@@ -797,23 +1264,39 @@
         /// </summary>
         public override int NumberOfColorComponents => throw new InvalidOperationException("UnsupportedColorSpaceDetails");
 
-        //private readonly IColor debugColor = new RGBColor(255m / 255m, 20m / 255m, 147m / 255m);
+        /// <summary>
+        /// <inheritdoc/>
+        /// <para>
+        /// Cannot be called for <see cref="UnsupportedColorSpaceDetails"/>, will throw a <see cref="InvalidOperationException"/>.
+        /// </para>
+        /// </summary>
+        public override int BaseNumberOfColorComponents => NumberOfColorComponents;
 
         private UnsupportedColorSpaceDetails() : base(ColorSpace.DeviceGray)
         {
         }
 
+        /// <inheritdoc/>
+        internal override double[] Process(params double[] values)
+        {
+            throw new InvalidOperationException("UnsupportedColorSpaceDetails");
+        }
+
         /// <inheritdoc/>
         public override IColor GetColor(params double[] values)
         {
-            //return debugColor;
             throw new InvalidOperationException("UnsupportedColorSpaceDetails");
         }
 
         /// <inheritdoc/>
         public override IColor GetInitializeColor()
         {
-            //return debugColor;
+            throw new InvalidOperationException("UnsupportedColorSpaceDetails");
+        }
+
+        /// <inheritdoc/>
+        internal override IReadOnlyList<byte> Transform(IReadOnlyList<byte> decoded)
+        {
             throw new InvalidOperationException("UnsupportedColorSpaceDetails");
         }
     }

src/UglyToad.PdfPig/Graphics/ContentStreamProcessor.cs

@@ -513,7 +513,7 @@
                 {
                     if (csArrayToken.Data[0] is NameToken firstColorSpaceName)
                     {
-                        startState.ColorSpaceContext.SetNonStrokingColorspace(csNameToken, formGroupToken);
+                        startState.ColorSpaceContext.SetNonStrokingColorspace(firstColorSpaceName, formGroupToken);
                     }
                     else
                     {

src/UglyToad.PdfPig/Images/ColorSpaceDetailsByteConverter.cs

@@ -42,32 +42,9 @@
             if (strideWidth != imageWidth)
             {
                 decoded = RemoveStridePadding(decoded.ToArray(), strideWidth, imageWidth, imageHeight, bytesPerPixel);
-            }
-
-            if (details is SeparationColorSpaceDetails separation)
-            {
-                decoded = separation.TransformToRGB(decoded);
             }
-            else
-            {
-                // In case of indexed color space images, unwrap indices to actual pixel component values
-                if (details is IndexedColorSpaceDetails indexed)
-                {
-                    decoded = indexed.UnwrapIndexedColorSpaceBytes(decoded);
 
-                    // Use the base color space in potential further decoding
-                    details = indexed.BaseColorSpaceDetails;
-                }
-
-                if (details is CalRGBColorSpaceDetails calRgb)
-                {
-                    decoded = calRgb.TransformToRGB(decoded);
-                }
-                else if (details is CalGrayColorSpaceDetails calGray)
-                {
-                    decoded = calGray.TransformToRGB(decoded);
-                }
-            }
+            decoded = details.Transform(decoded);
 
             return decoded.ToArray();
         }

src/UglyToad.PdfPig/Images/Png/PngFromPdfImageFactory.cs

@@ -10,15 +10,9 @@
         {
             bytes = null;
 
-            var hasValidDetails = image.ColorSpaceDetails != null &&
-                                  !(image.ColorSpaceDetails is UnsupportedColorSpaceDetails);
-
-            var actualColorSpace = image.ColorSpaceDetails.BaseType;
+            var hasValidDetails = image.ColorSpaceDetails != null && !(image.ColorSpaceDetails is UnsupportedColorSpaceDetails);
 
-            var isColorSpaceSupported = hasValidDetails &&
-                (actualColorSpace == ColorSpace.DeviceGray || actualColorSpace == ColorSpace.DeviceRGB
-                || actualColorSpace == ColorSpace.DeviceCMYK || actualColorSpace == ColorSpace.CalGray
-                || actualColorSpace == ColorSpace.CalRGB);
+            var isColorSpaceSupported = hasValidDetails && image.ColorSpaceDetails.BaseType != ColorSpace.Pattern;
 
             if (!isColorSpaceSupported || !image.TryGetBytes(out var bytesPure))
             {
@@ -30,10 +24,7 @@
                 bytesPure = ColorSpaceDetailsByteConverter.Convert(image.ColorSpaceDetails, bytesPure,
                     image.BitsPerComponent, image.WidthInSamples, image.HeightInSamples);
 
-                var numberOfComponents =
-                    actualColorSpace == ColorSpace.DeviceCMYK ? 4 :
-                    actualColorSpace == ColorSpace.DeviceRGB ? 3 :
-                    actualColorSpace == ColorSpace.CalRGB ? 3 : 1;
+                var numberOfComponents = image.ColorSpaceDetails.BaseNumberOfColorComponents;
 
                 var is3Byte = numberOfComponents == 3;
 
@@ -55,42 +46,56 @@
                 if (!isCorrectlySized)
                 {
                     return false;
-                }
-
-                var i = 0;
-                for (var col = 0; col < image.HeightInSamples; col++)
-                {
-                    for (var row = 0; row < image.WidthInSamples; row++)
-                    {
-                        if (actualColorSpace == ColorSpace.DeviceCMYK)
-                        {
-                            /*
-                             * Where CMYK in 0..1
-                             * R = 255 × (1-C) × (1-K)
-                             * G = 255 × (1-M) × (1-K)
-                             * B = 255 × (1-Y) × (1-K)
-                             */
-
-                            var c = (bytesPure[i++]/255d);
-                            var m = (bytesPure[i++]/255d);
-                            var y = (bytesPure[i++]/255d);
-                            var k = (bytesPure[i++]/255d);
-                            var r = (byte)(255 * (1 - c) * (1 - k));
-                            var g = (byte)(255 * (1 - m) * (1 - k));
-                            var b = (byte)(255 * (1 - y) * (1 - k));
-
-                            builder.SetPixel(r, g, b, row, col);
-                        }
-                        else if (is3Byte)
-                        {
-                            builder.SetPixel(bytesPure[i++], bytesPure[i++], bytesPure[i++], row, col);
-                        }
-                        else
-                        {
-                            var pixel = bytesPure[i++];
-                            builder.SetPixel(pixel, pixel, pixel, row, col);
-                        }
-                    }
+                }
+
+                if (image.ColorSpaceDetails.BaseType == ColorSpace.DeviceCMYK || numberOfComponents == 4)
+                {
+                    int i = 0;
+                    for (int col = 0; col < image.HeightInSamples; col++)
+                    {
+                        for (int row = 0; row < image.WidthInSamples; row++)
+                        {
+                            /*
+                             * Where CMYK in 0..1
+                             * R = 255 × (1-C) × (1-K)
+                             * G = 255 × (1-M) × (1-K)
+                             * B = 255 × (1-Y) × (1-K)
+                             */
+
+                            double c = (bytesPure[i++] / 255d);
+                            double m = (bytesPure[i++] / 255d);
+                            double y = (bytesPure[i++] / 255d);
+                            double k = (bytesPure[i++] / 255d);
+                            var r = (byte)(255 * (1 - c) * (1 - k));
+                            var g = (byte)(255 * (1 - m) * (1 - k));
+                            var b = (byte)(255 * (1 - y) * (1 - k));
+
+                            builder.SetPixel(r, g, b, row, col);
+                        }
+                    }
+                }
+                else if (is3Byte)
+                {
+                    int i = 0;
+                    for (int col = 0; col < image.HeightInSamples; col++)
+                    {
+                        for (int row = 0; row < image.WidthInSamples; row++)
+                        {
+                            builder.SetPixel(bytesPure[i++], bytesPure[i++], bytesPure[i++], row, col);
+                        }
+                    }
+                }
+                else
+                {
+                    int i = 0;
+                    for (int col = 0; col < image.HeightInSamples; col++)
+                    {
+                        for (int row = 0; row < image.WidthInSamples; row++)
+                        {
+                            byte pixel = bytesPure[i++];
+                            builder.SetPixel(pixel, pixel, pixel, row, col);
+                        }
+                    }
                 }
 
                 bytes = builder.Save();

src/UglyToad.PdfPig/Util/ColorSpaceDetailsParser.cs

@@ -48,7 +48,8 @@
             {
                 if (cannotRecurse)
                 {
-                    return UnsupportedColorSpaceDetails.Instance;
+                    // Not sure if always Gray, it's just a single color.
+                    return DeviceGrayColorSpaceDetails.Instance;
                 }
 
                 var colorSpaceDetails = GetColorSpaceDetails(colorSpace, imageDictionary.Without(NameToken.Filter).Without(NameToken.F), scanner, resourceStore, filterProvider, true);
@@ -166,8 +167,49 @@
 
                         return new CalRGBColorSpaceDetails(whitePoint, blackPoint, gamma, matrix);
                     }
-                case ColorSpace.Lab:
-                    return UnsupportedColorSpaceDetails.Instance;
+                case ColorSpace.Lab:
+                    {
+                        if (!TryGetColorSpaceArray(imageDictionary, resourceStore, scanner, out var colorSpaceArray)
+                             || colorSpaceArray.Length != 2)
+                        {
+                            return UnsupportedColorSpaceDetails.Instance;
+                        }
+
+                        var first = colorSpaceArray[0] as NameToken;
+
+                        if (first == null || !ColorSpaceMapper.TryMap(first, resourceStore, out var innerColorSpace)
+                            || innerColorSpace != ColorSpace.Lab)
+                        {
+                            return UnsupportedColorSpaceDetails.Instance;
+                        }
+
+                        var second = colorSpaceArray[1];
+
+                        // WhitePoint is required
+                        if (!DirectObjectFinder.TryGet(second, scanner, out DictionaryToken dictionaryToken) ||
+                            !dictionaryToken.TryGet(NameToken.WhitePoint, scanner, out ArrayToken whitePointToken))
+                        {
+                            return UnsupportedColorSpaceDetails.Instance;
+                        }
+
+                        var whitePoint = whitePointToken.Data.OfType<NumericToken>().Select(x => x.Data).ToList();
+
+                        // BlackPoint is optional
+                        IReadOnlyList<decimal> blackPoint = null;
+                        if (dictionaryToken.TryGet(NameToken.BlackPoint, scanner, out ArrayToken blackPointToken))
+                        {
+                            blackPoint = blackPointToken.Data.OfType<NumericToken>().Select(x => x.Data).ToList();
+                        }
+
+                        // Matrix is optional
+                        IReadOnlyList<decimal> matrix = null;
+                        if (dictionaryToken.TryGet(NameToken.Matrix, scanner, out ArrayToken matrixToken))
+                        {
+                            matrix = matrixToken.Data.OfType<NumericToken>().Select(x => x.Data).ToList();
+                        }
+
+                        return new LabColorSpaceDetails(whitePoint, blackPoint, matrix);
+                    }
                 case ColorSpace.ICCBased:
                     {
                         if (!TryGetColorSpaceArray(imageDictionary, resourceStore, scanner, out var colorSpaceArray)
@@ -255,14 +297,14 @@
                                 filterProvider,
                                 true);
                         }
-                        else if (DirectObjectFinder.TryGet(second, scanner, out ArrayToken baseColorSpaceArrayToken)
-                        && baseColorSpaceArrayToken.Length > 0 && baseColorSpaceArrayToken[0] is NameToken baseColorSpaceArrayNameToken
-                        && ColorSpaceMapper.TryMap(baseColorSpaceArrayNameToken, resourceStore, out var baseColorSpaceArrayColorSpace))
+                        else if (DirectObjectFinder.TryGet(second, scanner, out ArrayToken baseColorSpaceArrayToken)
+                            && baseColorSpaceArrayToken.Length > 0 && baseColorSpaceArrayToken[0] is NameToken baseColorSpaceArrayNameToken
+                            && ColorSpaceMapper.TryMap(baseColorSpaceArrayNameToken, resourceStore, out var baseColorSpaceArrayColorSpace))
                         {
                             var pseudoImageDictionary = new DictionaryToken(
                                 new Dictionary<NameToken, IToken>
-                                {
-                                    {NameToken.ColorSpace, baseColorSpaceArrayToken}
+                                {
+                                    { NameToken.ColorSpace, baseColorSpaceArrayToken }
                                 });
 
                             baseDetails = GetColorSpaceDetails(
@@ -349,15 +391,15 @@
                                 filterProvider,
                                 true);
                         }
-                        else if (DirectObjectFinder.TryGet(colorSpaceArray[2], scanner, out ArrayToken alternateArrayToken)
-                        && alternateArrayToken.Length > 0
-                        && alternateArrayToken[0] is NameToken alternateColorSpaceNameToken
-                        && ColorSpaceMapper.TryMap(alternateColorSpaceNameToken, resourceStore, out var alternateArrayColorSpace))
+                        else if (DirectObjectFinder.TryGet(colorSpaceArray[2], scanner, out ArrayToken alternateArrayToken)
+                            && alternateArrayToken.Length > 0
+                            && alternateArrayToken[0] is NameToken alternateColorSpaceNameToken
+                            && ColorSpaceMapper.TryMap(alternateColorSpaceNameToken, resourceStore, out var alternateArrayColorSpace))
                         {
                             var pseudoImageDictionary = new DictionaryToken(
                                 new Dictionary<NameToken, IToken>
-                                {
-                                {NameToken.ColorSpace, alternateArrayToken}
+                                {
+                                    { NameToken.ColorSpace, alternateArrayToken }
                                 });
 
                             alternateColorSpaceDetails = GetColorSpaceDetails(
@@ -391,8 +433,104 @@
 
                         return new SeparationColorSpaceDetails(separationNameToken, alternateColorSpaceDetails, function);
                     }
-                case ColorSpace.DeviceN:
-                    return UnsupportedColorSpaceDetails.Instance;
+                case ColorSpace.DeviceN:
+                    {
+                        if (!TryGetColorSpaceArray(imageDictionary, resourceStore, scanner, out var colorSpaceArray)
+                             || (colorSpaceArray.Length != 4 && colorSpaceArray.Length != 5))
+                        {
+                            // Error instead?
+                            return UnsupportedColorSpaceDetails.Instance;
+                        }
+
+                        if (!DirectObjectFinder.TryGet(colorSpaceArray[0], scanner, out NameToken deviceNColorSpaceNameToken)
+                            || !deviceNColorSpaceNameToken.Equals(NameToken.Devicen))
+                        {
+                            return UnsupportedColorSpaceDetails.Instance;
+                        }
+
+                        if (!DirectObjectFinder.TryGet(colorSpaceArray[1], scanner, out ArrayToken deviceNNamesToken))
+                        {
+                            return UnsupportedColorSpaceDetails.Instance;
+                        }
+
+                        ColorSpaceDetails alternateColorSpaceDetails;
+                        if (DirectObjectFinder.TryGet(colorSpaceArray[2], scanner, out NameToken alternateNameToken)
+                            && ColorSpaceMapper.TryMap(alternateNameToken, resourceStore, out var baseColorSpaceName))
+                        {
+                            alternateColorSpaceDetails = GetColorSpaceDetails(
+                                baseColorSpaceName,
+                                imageDictionary,
+                                scanner,
+                                resourceStore,
+                                filterProvider,
+                                true);
+                        }
+                        else if (DirectObjectFinder.TryGet(colorSpaceArray[2], scanner, out ArrayToken alternateArrayToken)
+                            && alternateArrayToken.Length > 0
+                            && alternateArrayToken[0] is NameToken alternateColorSpaceNameToken
+                            && ColorSpaceMapper.TryMap(alternateColorSpaceNameToken, resourceStore, out var alternateArrayColorSpace))
+                        {
+                            var pseudoImageDictionary = new DictionaryToken(
+                                new Dictionary<NameToken, IToken>
+                                {
+                                    { NameToken.ColorSpace, alternateArrayToken }
+                                });
+
+                            alternateColorSpaceDetails = GetColorSpaceDetails(
+                                alternateArrayColorSpace,
+                                pseudoImageDictionary,
+                                scanner,
+                                resourceStore,
+                                filterProvider,
+                                true);
+                        }
+                        else
+                        {
+                            return UnsupportedColorSpaceDetails.Instance;
+                        }
+
+                        var func = colorSpaceArray[3];
+                        PdfFunction tintFunc = PdfFunctionParser.Create(func, scanner, filterProvider);
+
+                        if (colorSpaceArray.Length > 4 && DirectObjectFinder.TryGet(colorSpaceArray[4], scanner, out DictionaryToken deviceNAttributesToken))
+                        {
+                            // Optionnal
+
+                            // Subtype - NameToken - Optional - Default value: DeviceN.
+                            NameToken subtype = NameToken.Devicen;
+                            if (deviceNAttributesToken.ContainsKey(NameToken.Subtype))
+                            {
+                                subtype = deviceNAttributesToken.Get<NameToken>(NameToken.Subtype, scanner);
+                            }
+
+                            // Colorants - dictionary - Required if Subtype is NChannel and the colour space includes spot colorants; otherwise optional
+                            DictionaryToken colorants = null;
+                            if (deviceNAttributesToken.ContainsKey(NameToken.Colorants))
+                            {
+                                colorants = deviceNAttributesToken.Get<DictionaryToken>(NameToken.Colorants, scanner);
+                            }
+
+                            // Process - dictionary - Required if Subtype is NChannel and the colour space includes components of a process colour space, otherwise optional; PDF 1.6
+                            DictionaryToken process = null;
+                            if (deviceNAttributesToken.ContainsKey(NameToken.Process))
+                            {
+                                process = deviceNAttributesToken.Get<DictionaryToken>(NameToken.Process, scanner);
+                            }
+
+                            // MixingHints - dictionary - Optional
+                            DictionaryToken mixingHints = null;
+                            if (deviceNAttributesToken.ContainsKey(NameToken.MixingHints))
+                            {
+                                mixingHints = deviceNAttributesToken.Get<DictionaryToken>(NameToken.MixingHints, scanner);
+                            }
+
+                            var attributes = new DeviceNColorSpaceDetails.DeviceNColorSpaceAttributes(subtype, colorants, process, mixingHints);
+
+                            return new DeviceNColorSpaceDetails(deviceNNamesToken.Data.OfType<NameToken>().ToArray(), alternateColorSpaceDetails, tintFunc, attributes);
+                        }
+
+                        return new DeviceNColorSpaceDetails(deviceNNamesToken.Data.OfType<NameToken>().ToArray(), alternateColorSpaceDetails, tintFunc);
+                    }
                 default:
                     return UnsupportedColorSpaceDetails.Instance;
             }

src/UglyToad.PdfPig/Util/PdfFunctionParser.cs

@@ -16,12 +16,12 @@
             DictionaryToken functionDictionary;
             StreamToken functionStream = null;
 
-            if (function is StreamToken fs)
+            if (DirectObjectFinder.TryGet(function, scanner, out StreamToken fs))
             {
                 functionDictionary = fs.StreamDictionary;
                 functionStream = new StreamToken(fs.StreamDictionary, fs.Decode(filterProvider, scanner));
             }
-            else if (function is DictionaryToken fd)
+            else if (DirectObjectFinder.TryGet(function, scanner, out DictionaryToken fd))
             {
                 functionDictionary = fd;
             }