Added transparency, overprint mode & separation images

.github/workflows/dotnet-core.yml

@@ -15,7 +15,7 @@ env:
   # Project name to pack and publish
   PROJECT_NAME: Synercoding.FileFormats.Pdf
   # GitHub Packages Feed settings
-  GITHUB_FEED: https://nuget.pkg.github.com/synercoder/
+  GITHUB_FEED: https://nuget.pkg.github.com/synercoder/index.json 
   GITHUB_USER: synercoder
   GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
   # Official NuGet Feed settings
@@ -33,7 +33,7 @@ jobs:
       - name: Setup .NET Core
         uses: actions/setup-dotnet@v1
         with:
-          dotnet-version: 7.0.x
+          dotnet-version: 8.0.x
       - name: Restore
         run: dotnet restore
       - name: Build
@@ -45,7 +45,7 @@ jobs:
         run: dotnet pack -v normal -c Release --no-restore --include-symbols --include-source -p:SymbolPackageFormat=snupkg -p:PackageVersion=1.0.0-pre+$GITHUB_RUN_ID src/$PROJECT_NAME/$PROJECT_NAME.*proj
       - name: Upload Artifact
         if: matrix.os == 'ubuntu-latest'
-        uses: actions/upload-artifact@v2
+        uses: actions/upload-artifact@v4
         with:
           name: nupkg
           path: ./artifacts/pkg/Release/${{ env.PROJECT_NAME }}.*.nupkg
@@ -55,15 +55,16 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Download Artifact
-        uses: actions/download-artifact@v1
+        uses: actions/download-artifact@v4
         with:
           name: nupkg
-      - name: Push to GitHub Feed
-        run: |
-          for f in ./nupkg/*.nupkg
-          do
-            curl -vX PUT -u "$GITHUB_USER:$GITHUB_TOKEN" -F package=@$f $GITHUB_FEED
-          done
+          path: ./nupkg
+      - name: Setup .NET Core @ Latest
+        uses: actions/setup-dotnet@v1
+      - name: Publish Nuget to GitHub registry
+        run: dotnet nuget push ./nupkg/*.nupkg -k ${GITHUB_TOKEN} -s ${GITHUB_FEED} --skip-duplicate
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
   deploy:
     needs: build
     if: github.event_name == 'release'
@@ -73,7 +74,7 @@ jobs:
       - name: Setup .NET Core
         uses: actions/setup-dotnet@v1
         with:
-          dotnet-version: 7.0.x
+          dotnet-version: 8.0.x
       - name: Create Release NuGet package
         run: |
           arrTag=(${GITHUB_REF//\// })
@@ -82,12 +83,10 @@ jobs:
           VERSION="${VERSION//v}"
           echo Clean Version: $VERSION
           dotnet pack -v normal -c Release --include-symbols --include-source -p:SymbolPackageFormat=snupkg -p:PackageVersion=$VERSION -o nupkg src/$PROJECT_NAME/$PROJECT_NAME.*proj
-      - name: Push to GitHub Feed
-        run: |
-          for f in ./nupkg/*.nupkg
-          do
-            curl -vX PUT -u "$GITHUB_USER:$GITHUB_TOKEN" -F package=@$f $GITHUB_FEED
-          done
+      - name: Publish Nuget to GitHub registry
+        run: dotnet nuget push ./nupkg/*.nupkg -k ${GITHUB_TOKEN} -s ${GITHUB_FEED} --skip-duplicate
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
       - name: Push to NuGet Feed
         if: ${{ env.NUGET_FEED }} != ''
-        run: dotnet nuget push ./nupkg/*.nupkg --source $NUGET_FEED --skip-duplicate --api-key $NUGET_KEY
+        run: dotnet nuget push ./nupkg/*.nupkg --source $NUGET_FEED --skip-duplicate --api-key $NUGET_KEY

Directory.Build.props

@@ -41,7 +41,7 @@
   </PropertyGroup>
 
   <PropertyGroup>
-    <LangVersion>11.0</LangVersion>
+    <LangVersion>12.0</LangVersion>
     <Nullable>enable</Nullable>
     <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
     <Features>strict</Features>

Directory.Build.targets

@@ -7,7 +7,7 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Update="SixLabors.ImageSharp" Version="3.0.*" />
+    <PackageReference Update="SixLabors.ImageSharp" Version="3.1.*" />
   </ItemGroup>
 
   <!-- Disable auto imports/usings from ImageSharp -->

README.md

@@ -41,7 +41,10 @@ The PDF files created in this library are not fully PDF 1.7 compliant, because t
 This shortcoming shall be remedied when broader font support is implemented.
 
 ### Sample program images
-The sample project called *Synercoding.FileFormats.Pdf.ConsoleTester* uses multiple images. Those images were taken from [Pexels.com](https://www.pexels.com/royalty-free-images/) and are licensed under the [Pexels License](https://www.pexels.com/photo-license/).
+The sample project called *Synercoding.FileFormats.Pdf.ConsoleTester* uses multiple images. 
+Those images were taken from:
+- [Pexels.com](https://www.pexels.com/royalty-free-images/) and are licensed under the [Pexels License](https://www.pexels.com/photo-license/)
+- [FreePngImg.com](https://freepngimg.com/png/59872-jaguar-panther-royalty-free-cougar-black-cheetah) and are licensed under [Creative Commons (CC BY-NC 4.0)](https://creativecommons.org/licenses/by-nc/4.0/)
 
 ## Sample usage
 

samples/Synercoding.FileFormats.Pdf.ConsoleTester/Program.cs

@@ -1,3 +1,4 @@
+using SixLabors.ImageSharp.PixelFormats;
 using Synercoding.FileFormats.Pdf.Extensions;
 using Synercoding.FileFormats.Pdf.LowLevel.Colors;
 using Synercoding.FileFormats.Pdf.LowLevel.Colors.ColorSpaces;
@@ -63,7 +64,7 @@ public static void Main(string[] args)
                         });
 
                         using (var forestStream = File.OpenRead("Pexels_com/android-wallpaper-art-backlit-1114897.jpg"))
-                        using (var forestImage = SixLabors.ImageSharp.Image.Load(forestStream))
+                        using (var forestImage = SixLabors.ImageSharp.Image.Load<Rgba32>(forestStream))
                         {
                             var scale = (double)forestImage.Width / forestImage.Height;
 
@@ -81,7 +82,7 @@ public static void Main(string[] args)
                     page.TrimBox = trimBox;
 
                     using (var barrenStream = File.OpenRead("Pexels_com/arid-barren-desert-1975514.jpg"))
-                    using (var barrenImage = SixLabors.ImageSharp.Image.Load(barrenStream))
+                    using (var barrenImage = SixLabors.ImageSharp.Image.Load<Rgba32>(barrenStream))
                     {
                         var scale = (double)barrenImage.Width / barrenImage.Height;
 
@@ -175,7 +176,7 @@ public static void Main(string[] args)
                     page.TrimBox = trimBox;
 
                     using (var forestStream = File.OpenRead("Pexels_com/android-wallpaper-art-backlit-1114897.jpg"))
-                    using (var forestImage = SixLabors.ImageSharp.Image.Load(forestStream))
+                    using (var forestImage = SixLabors.ImageSharp.Image.Load<Rgba32>(forestStream))
                     {
                         var scale = (double)forestImage.Width / forestImage.Height;
 
@@ -187,7 +188,7 @@ public static void Main(string[] args)
                 });
 
             using (var blurStream = File.OpenRead("Pexels_com/4k-wallpaper-blur-bokeh-1484253.jpg"))
-            using (var blurImage = SixLabors.ImageSharp.Image.Load(blurStream))
+            using (var blurImage = SixLabors.ImageSharp.Image.Load<Rgba32>(blurStream))
             {
                 var reusedImage = writer.AddImage(blurImage);
 
@@ -216,12 +217,43 @@ public static void Main(string[] args)
 
                     page.Content.AddShapes(trimBox, static (trim, context) =>
                     {
+                        context.SetExtendedGraphicsState(new ExtendedGraphicsState()
+                        {
+                            Overprint = true
+                        });
                         context.SetStroke(new SpotColor(new Separation(LowLevel.PdfName.Get("CutContour"), PredefinedColors.Magenta), 1));
                         context.Rectangle(trim);
                         context.Stroke();
                     });
                 });
             }
+
+            using (var pantherPngStream = File.OpenRead("FreePngImage_com/59872-jaguar-panther-royalty-free-cougar-black-cheetah.png"))
+            using (var pantherImage = SixLabors.ImageSharp.Image.Load<Rgba32>(pantherPngStream))
+            {
+                var pantherImg = writer.AddImage(pantherImage);
+                var transparentPanther = writer.AddSeparationImage(new Separation(LowLevel.PdfName.Get("White"), PredefinedColors.Yellow), pantherImage, GrayScaleMethod.AlphaChannel);
+
+                writer.AddPage(page =>
+                {
+                    page.MediaBox = mediaBox;
+                    page.TrimBox = trimBox;
+
+                    var scale = (double)transparentPanther.Width / transparentPanther.Height;
+                    var pantherSize = new Rectangle(0, 0, 216, 216 / scale, Unit.Millimeters);
+
+                    page.Content.AddImage(pantherImage, pantherSize);
+
+                    page.Content.WrapInState(pantherImage, (image, content) =>
+                    {
+                        content.SetExtendedGraphicsState(new ExtendedGraphicsState()
+                        {
+                            Overprint = true
+                        });
+                        content.AddImage(transparentPanther, pantherSize);
+                    });
+                });
+            }
         }
     }
 }

samples/Synercoding.FileFormats.Pdf.ConsoleTester/Synercoding.FileFormats.Pdf.ConsoleTester.csproj

@@ -2,7 +2,7 @@
 
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFramework>net6.0</TargetFramework>
+    <TargetFramework>net8.0</TargetFramework>
   </PropertyGroup>
 
   <ItemGroup>
@@ -15,4 +15,10 @@
     </None>
   </ItemGroup>
 
+  <ItemGroup>
+    <None Update="FreePngImage_com\*.png">
+      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
+    </None>
+  </ItemGroup>
+
 </Project>

src/Directory.Build.props

@@ -2,7 +2,7 @@
 <Project>
 
   <PropertyGroup>
-    <TargetFrameworks>net7.0;net6.0</TargetFrameworks>
+    <TargetFrameworks>net8.0</TargetFrameworks>
     <MSBuildAllProjects>$(MSBuildAllProjects);$(MSBuildThisFileDirectory)..\Directory.Build.props</MSBuildAllProjects>
     <SynercodingProjectCategory>src</SynercodingProjectCategory>
   </PropertyGroup>

src/Synercoding.FileFormats.Pdf/ExtendedGraphicsState.cs

@@ -0,0 +1,23 @@
+namespace Synercoding.FileFormats.Pdf;
+
+/// <summary>
+/// Class representing an ExtGState dictionary.
+/// </summary>
+public sealed record class ExtendedGraphicsState
+{
+    /// <summary>
+    /// A flag specifying whether to apply overprint.
+    /// There are two separate overprint parameters: one for stroking and one for all other painting operations.
+    /// Specifying an <see cref="Overprint"/> entry sets both parameters
+    /// unless there is also an <see cref="OverprintNonStroking"/> entry in the same graphics state parameter dictionary,
+    /// in which case the <see cref="Overprint"/> entry sets only the overprint parameter for stroking.
+    /// </summary>
+    public bool? Overprint { get; set; }
+
+    /// <summary>
+    /// A flag specifying whether to apply overprint for painting operations other than stroking.
+    /// If this entry is absent, the <see cref="Overprint"/> entry, if any, sets this parameter.
+    /// </summary>
+    public bool? OverprintNonStroking { get; set; }
+}
+

src/Synercoding.FileFormats.Pdf/Extensions/IPageContentContextExtensions.cs

@@ -1,3 +1,4 @@
+using SixLabors.ImageSharp.PixelFormats;
 using Synercoding.FileFormats.Pdf.Internals;
 using Synercoding.FileFormats.Pdf.LowLevel.Colors.ColorSpaces;
 using Synercoding.FileFormats.Pdf.LowLevel.Text;
@@ -61,7 +62,7 @@ public static IPageContentContext AddImage(this IPageContentContext context, Sys
     /// <returns>The same <paramref name="context"/> to enable chaining operations.</returns>
     public static IPageContentContext AddImage(this IPageContentContext context, System.IO.Stream stream)
     {
-        using var image = SixLabors.ImageSharp.Image.Load(stream);
+        using var image = SixLabors.ImageSharp.Image.Load<Rgba32>(stream);
 
         return context.AddImage(image);
     }
@@ -73,7 +74,7 @@ public static IPageContentContext AddImage(this IPageContentContext context, Sys
     /// <param name="image">The image to place</param>
     /// <param name="matrix">The placement matrix to use</param>
     /// <returns>The same <paramref name="context"/> to enable chaining operations.</returns>
-    public static IPageContentContext AddImage(this IPageContentContext context, SixLabors.ImageSharp.Image image, Matrix matrix)
+    public static IPageContentContext AddImage(this IPageContentContext context, SixLabors.ImageSharp.Image<Rgba32> image, Matrix matrix)
     {
         return context.WrapInState((image, matrix), static (tuple, context) =>
         {
@@ -89,7 +90,7 @@ public static IPageContentContext AddImage(this IPageContentContext context, Six
     /// <param name="image">The image to place</param>
     /// <param name="rectangle">The rectangle of where to place the image.</param>
     /// <returns>The same <paramref name="context"/> to enable chaining operations.</returns>
-    public static IPageContentContext AddImage(this IPageContentContext context, SixLabors.ImageSharp.Image image, Rectangle rectangle)
+    public static IPageContentContext AddImage(this IPageContentContext context, SixLabors.ImageSharp.Image<Rgba32> image, Rectangle rectangle)
         => context.AddImage(image, rectangle.AsPlacementMatrix());
 
     /// <summary>
@@ -98,7 +99,7 @@ public static IPageContentContext AddImage(this IPageContentContext context, Six
     /// <param name="context">The context to add the image to.</param>
     /// <param name="image">The image to place</param>
     /// <returns>The same <paramref name="context"/> to enable chaining operations.</returns>
-    public static IPageContentContext AddImage(this IPageContentContext context, SixLabors.ImageSharp.Image image)
+    public static IPageContentContext AddImage(this IPageContentContext context, SixLabors.ImageSharp.Image<Rgba32> image)
     {
         var name = context.RawContentStream.Resources.AddImage(image);
 

src/Synercoding.FileFormats.Pdf/GraphicState.cs → src/Synercoding.FileFormats.Pdf/GraphicsState.cs

@@ -7,9 +7,9 @@ namespace Synercoding.FileFormats.Pdf;
 /// <summary>
 /// Class representing the grahpic state of a PDF at a certain moment in time.
 /// </summary>
-public sealed class GraphicState
+public sealed class GraphicsState
 {
-    internal GraphicState()
+    internal GraphicsState()
     {
         CTM = Matrix.Identity;
         Fill = PredefinedColors.Black;
@@ -111,9 +111,9 @@ internal GraphicState()
     /// </summary>
     public double TextRise { get; internal set; }
 
-    internal GraphicState Clone()
+    internal GraphicsState Clone()
     {
-        return new GraphicState()
+        return new GraphicsState()
         {
             CTM = CTM,
             Fill = Fill,

src/Synercoding.FileFormats.Pdf/GrayScaleMethod.cs

@@ -0,0 +1,28 @@
+namespace Synercoding.FileFormats.Pdf;
+
+/// <summary>
+/// What method is used to generate a 1 component grayscale pixel byte array
+/// </summary>
+public enum GrayScaleMethod
+{
+    /// <summary>
+    /// Use the red channel
+    /// </summary>
+    RedChannel,
+    /// <summary>
+    /// Use the green channel
+    /// </summary>
+    GreenChannel,
+    /// <summary>
+    /// Use the blue channel
+    /// </summary>
+    BlueChannel,
+    /// <summary>
+    /// Use the alpha channel
+    /// </summary>
+    AlphaChannel,
+    /// <summary>
+    /// Use the average of the Red, Green and Blue channels.
+    /// </summary>
+    AverageOfRGBChannels
+}

src/Synercoding.FileFormats.Pdf/IContentContext.cs

@@ -19,7 +19,7 @@ public interface IContentContext<TSelf>
     /// <summary>
     /// Represents the current graphic state
     /// </summary>
-    GraphicState GraphicState { get; }
+    GraphicsState GraphicState { get; }
 
     /// <summary>
     /// Wrap the <paramref name="contentOperations"/> in save and restore state operators
@@ -40,7 +40,7 @@ public interface IContentContext<TSelf>
     Task<TSelf> WrapInStateAsync<T>(T data, Func<T, TSelf, Task> contentOperations);
 
     /// <summary>
-    /// Concatenate a matrix to <see cref="GraphicState.CTM"/>
+    /// Concatenate a matrix to <see cref="GraphicsState.CTM"/>
     /// </summary>
     /// <param name="matrix">The matrix to concat</param>
     /// <returns>This <see cref="IContentContext{TSelf}"/> to enable chaining operations</returns>
@@ -94,5 +94,12 @@ public interface IContentContext<TSelf>
     /// <param name="dashPattern">The dash pattern to set</param>
     /// <returns>This <see cref="IContentContext{TSelf}"/> to enable chaining operations</returns>
     TSelf SetDashPattern(Dash dashPattern);
+
+    /// <summary>
+    /// Set an extended graphics state (ExtGState) dictionary.
+    /// </summary>
+    /// <param name="extendedGraphicsState">The state to apply.</param>
+    /// <returns>This <see cref="IContentContext{TSelf}"/> to enable chaining operations</returns>
+    TSelf SetExtendedGraphicsState(ExtendedGraphicsState extendedGraphicsState);
 }
 

src/Synercoding.FileFormats.Pdf/ITextContentContext.cs

@@ -101,7 +101,7 @@ public interface ITextContentContext : IContentContext<ITextContentContext>
     ITextContentContext ShowTextOnNextLine(string text);
 
     /// <summary>
-    /// Operation to show text on the next line and setting the <see cref="GraphicState.WordSpacing"/> and <see cref="GraphicState.CharacterSpacing"/>
+    /// Operation to show text on the next line and setting the <see cref="GraphicsState.WordSpacing"/> and <see cref="GraphicsState.CharacterSpacing"/>
     /// </summary>
     /// <param name="text">The text to show</param>
     /// <param name="wordSpacing">The word spacing to set</param>