Add CCITTFAX3 compression

PDFSharp.Extensions.csproj

@@ -31,8 +31,8 @@
     <WarningLevel>4</WarningLevel>
   </PropertyGroup>
   <ItemGroup>
-    <Reference Include="BitMiracle.LibTiff.NET, Version=2.3.642.0, Culture=neutral, processorArchitecture=MSIL">
-      <HintPath>packages\BitMiracle.LibTiff.NET.2.3.642.0\lib\net20\BitMiracle.LibTiff.NET.dll</HintPath>
+    <Reference Include="BitMiracle.LibTiff.NET40, Version=2.4.584.0, Culture=neutral, PublicKeyToken=53879b3e20e7a7d6, processorArchitecture=MSIL">
+      <HintPath>packages\BitMiracle.LibTiff.NET.2.4.584.1\lib\net40\BitMiracle.LibTiff.NET40.dll</HintPath>
     </Reference>
     <Reference Include="PdfSharp, Version=1.32.3057.0, Culture=neutral, PublicKeyToken=f94615aa0424f9eb, processorArchitecture=MSIL">
       <HintPath>packages\PDFsharp.1.32.3057.0\lib\net20\PdfSharp.dll</HintPath>

Pdf/PdfDictionaryExtensions.cs

@@ -133,7 +133,7 @@ private static byte[] GetTiffImageBufferFromCCITTFaxDecode(PdfDictionaryImageMet
         WriteTiffTag(buffer, TiffTag.IMAGEWIDTH, TiffType.LONG, 1, (uint)imageData.Width);
         WriteTiffTag(buffer, TiffTag.IMAGELENGTH, TiffType.LONG, 1, (uint)imageData.Height);
         WriteTiffTag(buffer, TiffTag.BITSPERSAMPLE, TiffType.SHORT, 1, (uint)imageData.BitsPerPixel);
-        WriteTiffTag(buffer, TiffTag.COMPRESSION, TiffType.SHORT, 1, (uint) Compression.CCITTFAX4); // CCITT Group 4 fax encoding.
+        WriteTiffTag(buffer, TiffTag.COMPRESSION, TiffType.SHORT, 1, (uint)imageData.Compression);
         WriteTiffTag(buffer, TiffTag.PHOTOMETRIC, TiffType.SHORT, 1, 0); // WhiteIsZero
         WriteTiffTag(buffer, TiffTag.STRIPOFFSETS, TiffType.LONG, 1, header_length);
         WriteTiffTag(buffer, TiffTag.SAMPLESPERPIXEL, TiffType.SHORT, 1, 1);
@@ -155,17 +155,31 @@ private static byte[] GetTiffImageBufferFromCCITTFaxDecode(PdfDictionaryImageMet
     /// <returns>The image retrieve from the dictionary. If not found or an invalid image, then null is returned.</returns>
     private static Image ImageFromCCITTFaxDecode(PdfDictionary dictionary)
     {
-      Image image = null;
       PdfDictionaryImageMetaData imageData = new PdfDictionaryImageMetaData(dictionary);
 
       PixelFormat format = GetPixelFormat(imageData.ColorSpace, imageData.BitsPerPixel, true);
       Bitmap bitmap = new Bitmap(imageData.Width, imageData.Height, format);
 
       // Determine if BLACK=1, create proper indexed color palette.
-      CCITTFaxDecodeParameters ccittFaxDecodeParameters = new CCITTFaxDecodeParameters(dictionary.Elements["/DecodeParms"].Get() as PdfDictionary);
+
+      PdfDictionary decodeParams;
+      var decodeParamsObject = dictionary.Elements["/DecodeParms"].Get();
+      if (decodeParamsObject is PdfArray)
+        decodeParams = (decodeParamsObject as PdfArray).First() as PdfDictionary;
+      else if (decodeParamsObject is PdfDictionary)
+        decodeParams = decodeParamsObject as PdfDictionary;
+      else
+        throw new NotSupportedException("Unknown format of CCITTFaxDecode params.");
+
+      CCITTFaxDecodeParameters ccittFaxDecodeParameters = new CCITTFaxDecodeParameters(decodeParams);
       if (ccittFaxDecodeParameters.BlackIs1) bitmap.Palette = PdfIndexedColorSpace.CreateColorPalette(Color.Black, Color.White);
       else bitmap.Palette = PdfIndexedColorSpace.CreateColorPalette(Color.White, Color.Black);
 
+      if (ccittFaxDecodeParameters.K == 0 || ccittFaxDecodeParameters.K > 0)
+        imageData.Compression = Compression.CCITTFAX3;
+      else if (ccittFaxDecodeParameters.K < 0)
+        imageData.Compression = Compression.CCITTFAX4;
+
       using (MemoryStream stream = new MemoryStream(GetTiffImageBufferFromCCITTFaxDecode(imageData, dictionary.Stream.Value))) {
         using (Tiff tiff = Tiff.ClientOpen("<INLINE>", "r", stream, new TiffStream())) {
           if (tiff == null) return (null);
@@ -641,7 +655,6 @@ public static PdfColorSpace Parse(PdfItem colorSpace)
           // Standard CMYK Colorspace
           { "/DeviceCMYK", (a) => {
             throw new NotImplementedException("CMYK encoded images are not supported.");
-            return (new PdfCMYKColorSpace());
           } },
         };
 
@@ -673,6 +686,9 @@ class PdfDictionaryImageMetaData
       /// <summary>The colorspace information for the image.</summary>
       public PdfColorSpace ColorSpace { get; set; }
 
+      /// <summary>The Compression for the image.</summary> 
+      public Compression Compression { get; set; }
+
       /// <param name="dictionary">The dictionary object o parse.</param>
       public PdfDictionaryImageMetaData(PdfDictionary dictionary)
       {
@@ -698,6 +714,8 @@ private void Initialize(PdfDictionary dictionary)
           ColorSpace = PdfDictionaryColorSpace.Parse(colorSpace);
         }
         else ColorSpace = new PdfRGBColorSpace(); // Default to RGB Color Space
+
+        Compression = Compression.CCITTFAX4;
       }
 
       /// <summary>

packages.config

@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
 <packages>
-  <package id="BitMiracle.LibTiff.NET" version="2.3.642.0" targetFramework="net40" />
+  <package id="BitMiracle.LibTiff.NET" version="2.4.584.1" targetFramework="net40" />
   <package id="PDFsharp" version="1.32.3057.0" targetFramework="net40" />
 </packages>