Color spaces and images - bugfixing, compliance to PDF 2.0 specification

PdfForQtLib/sources/pdfcolorspaces.cpp

@@ -1401,7 +1401,7 @@ PDFSeparationColorSpace::PDFSeparationColorSpace(QByteArray&& colorName, PDFColo
 
 QColor PDFSeparationColorSpace::getDefaultColor(const PDFCMS* cms, RenderingIntent intent, PDFRenderErrorReporter* reporter) const
 {
-    return getColor(PDFColor(0.0f), cms, intent, reporter);
+    return getColor(PDFColor(1.0f), cms, intent, reporter);
 }
 
 QColor PDFSeparationColorSpace::getColor(const PDFColor& color, const PDFCMS* cms, RenderingIntent intent, PDFRenderErrorReporter* reporter) const
@@ -1528,9 +1528,10 @@ PDFDeviceNColorSpace::PDFDeviceNColorSpace(PDFDeviceNColorSpace::Type type,
     m_processColorSpace(qMove(processColorSpace)),
     m_tintTransform(qMove(tintTransform)),
     m_colorantsPrintingOrder(qMove(colorantsPrintingOrder)),
-    m_processColorSpaceComponents(qMove(processColorSpaceComponents))
+    m_processColorSpaceComponents(qMove(processColorSpaceComponents)),
+    m_isNone(false)
 {
-
+    m_isNone = std::all_of(m_colorants.cbegin(), m_colorants.cend(), [](const auto& colorant) { return colorant.name == "None"; });
 }
 
 QColor PDFDeviceNColorSpace::getDefaultColor(const PDFCMS* cms, RenderingIntent intent, PDFRenderErrorReporter* reporter) const
@@ -1550,6 +1551,13 @@ QColor PDFDeviceNColorSpace::getDefaultColor(const PDFCMS* cms, RenderingIntent
 
 QColor PDFDeviceNColorSpace::getColor(const PDFColor& color, const PDFCMS* cms, RenderingIntent intent, PDFRenderErrorReporter* reporter) const
 {
+    // According to the PDF 2.0 specification, DeviceN color space, with all colorant name "None"
+    // should not produce any visible output.
+    if (m_isNone)
+    {
+        return Qt::transparent;
+    }
+
     // Input values
     std::vector<double> inputColor(color.size(), 0.0);
     for (size_t i = 0, count = inputColor.size(); i < count; ++i)

PdfForQtLib/sources/pdfcolorspaces.h

@@ -678,6 +678,14 @@ public:
     /// Returns type of DeviceN color space
     Type getType() const { return m_type; }
 
+    const Colorants& getColorants() const { return m_colorants; }
+    const PDFColorSpacePointer& getAlternateColorSpace() const { return m_alternateColorSpace; }
+    const PDFColorSpacePointer& getProcessColorSpace() const { return m_processColorSpace; }
+    const PDFFunctionPtr& getTintTransform() const { return m_tintTransform; }
+    const std::vector<QByteArray>& getPrintingOrder() const { return m_colorantsPrintingOrder; }
+    const std::vector<QByteArray>& getProcessColorSpaceComponents() const { return m_processColorSpaceComponents; }
+    bool isNone() const { return m_isNone; }
+
     /// Creates DeviceN color space from provided values.
     /// \param colorSpaceDictionary Color space dictionary
     /// \param document Document
@@ -698,6 +706,7 @@ private:
     PDFFunctionPtr m_tintTransform;
     std::vector<QByteArray> m_colorantsPrintingOrder;
     std::vector<QByteArray> m_processColorSpaceComponents;
+    bool m_isNone;
 };
 
 class PDFPatternColorSpace : public PDFAbstractColorSpace

PdfForQtLib/sources/pdfimage.cpp

@@ -73,6 +73,17 @@ PDFImage PDFImage::createImage(const PDFDocument* document,
     bool imageMask = loader.readBooleanFromDictionary(dictionary, "ImageMask", false);
     std::vector<PDFReal> matte = loader.readNumberArrayFromDictionary(dictionary, "Matte");
     PDFInteger sMaskInData = loader.readIntegerFromDictionary(dictionary, "SMaskInData", 0);
+    image.m_interpolate = loader.readBooleanFromDictionary(dictionary, "Interpolate", false);
+    image.m_alternates = loader.readObjectList<PDFAlternateImage>(dictionary->get("Alternates"));
+    image.m_name = loader.readNameFromDictionary(dictionary, "Name");
+    image.m_structuralParent = loader.readIntegerFromDictionary(dictionary, "StructParent", 0);
+    image.m_webCaptureContentSetId = loader.readStringFromDictionary(dictionary, "ID");
+    image.m_OPI = dictionary->get("OPI");
+    image.m_OC = dictionary->get("OC");
+    image.m_metadata = dictionary->get("Metadata");
+    image.m_associatedFiles = dictionary->get("AF");
+    image.m_measure = dictionary->get("Measure");
+    image.m_pointData = dictionary->get("PtData");
 
     if (isSoftMask && (imageMask || dictionary->hasKey("Mask") || dictionary->hasKey("SMask")))
     {
@@ -706,9 +717,9 @@ PDFImage PDFImage::createImage(const PDFDocument* document,
     }
     else if (imageMask)
     {
-        // We intentionally have 8 bits in the following code, because if ImageMask is set to true, then "BitsPerComponent"
+        // If ImageMask is set to true, then "BitsPerComponent" should have always value of 1.
-        // should have always value of 1.
+        // If this entry is not specified, then the value should be implicitly 1.
-        const unsigned int bitsPerComponent = static_cast<unsigned int>(loader.readIntegerFromDictionary(dictionary, "BitsPerComponent", 8));
+        const unsigned int bitsPerComponent = static_cast<unsigned int>(loader.readIntegerFromDictionary(dictionary, "BitsPerComponent", 1));
 
         if (bitsPerComponent != 1)
         {
@@ -840,6 +851,19 @@ OPJ_OFF_T PDFJPEG2000ImageData::skip(OPJ_OFF_T p_nb_bytes, void* p_user_data)
     return length;
 }
 
-// Implement image rendering intent
+PDFAlternateImage PDFAlternateImage::parse(const PDFObjectStorage* storage, PDFObject object)
+{
+    PDFAlternateImage result;
+
+    if (const PDFDictionary* dictionary = storage->getDictionaryFromObject(object))
+    {
+        PDFDocumentDataLoaderDecorator loader(storage);
+        result.m_image = loader.readReferenceFromDictionary(dictionary, "Image");
+        result.m_oc = loader.readReferenceFromDictionary(dictionary, "OC");
+        result.m_defaultForPrinting = loader.readBooleanFromDictionary(dictionary, "DefaultForPrinting", false);
+    }
+
+    return result;
+}
 
 }   // namespace pdf

PdfForQtLib/sources/pdfimage.h

@@ -18,6 +18,7 @@
 #ifndef PDFIMAGE_H
 #define PDFIMAGE_H
 
+#include "pdfobject.h"
 #include "pdfcolorspaces.h"
 
 #include <QByteArray>
@@ -28,8 +29,31 @@ namespace pdf
 {
 class PDFStream;
 class PDFDocument;
+class PDFObjectStorage;
 class PDFRenderErrorReporter;
 
+/// Alternate image object. Defines alternate image, which
+/// can be shown in some circumstances instead of main image.
+class PDFAlternateImage
+{
+public:
+    explicit inline PDFAlternateImage() = default;
+
+    /// Parses alternate image dictionary object.
+    /// \param storage Object storage
+    /// \param object Alternate image object
+    static PDFAlternateImage parse(const PDFObjectStorage* storage, PDFObject object);
+
+    PDFObjectReference getImage() const { return m_image; }
+    PDFObjectReference getOc() const { return m_oc; }
+    bool isDefaultForPrinting() const { return m_defaultForPrinting; }
+
+private:
+    PDFObjectReference m_image;
+    PDFObjectReference m_oc;
+    bool m_defaultForPrinting = false;
+};
+
 class PDFImage
 {
 public:
@@ -54,6 +78,33 @@ public:
     /// Returns rendering intent of the image
     RenderingIntent getRenderingIntent() const { return m_renderingIntent; }
 
+    /// Color space of image samples
+    const PDFColorSpacePointer& getColorSpace() const { return m_colorSpace; }
+
+    /// Should PDF processor perform interpolation on this image?
+    bool isInterpolated() const { return m_interpolate; }
+
+    /// Array of alternate images
+    const std::vector<PDFAlternateImage>& getAlternates() const { return m_alternates; }
+
+    /// Returns name of image, under which is referenced in resources dictionary.
+    /// It was mandatory in PDF 1.0, otherwise it is optional and now it is deprecated
+    /// in PDF 2.0 specification.
+    const QByteArray& getName() const { return m_name; }
+
+    /// Returns idenfitier to structural parent in structure tree
+    PDFInteger getStructuralParent() const { return m_structuralParent; }
+
+    /// Web capture content set identifier
+    const QByteArray& getWebCaptureContentSetID() const { return m_webCaptureContentSetId; }
+
+    const PDFObject& getOPI() const { return m_OPI; }
+    const PDFObject& getOC() const { return m_OC; }
+    const PDFObject& getMetadata() const { return m_metadata; }
+    const PDFObject& getAssociatedFiles() const { return m_associatedFiles; }
+    const PDFObject& getMeasure() const { return m_measure; }
+    const PDFObject& getPointData() const { return m_pointData; }
+
 private:
     PDFImage() = default;
 
@@ -61,6 +112,17 @@ private:
     PDFImageData m_softMask;
     PDFColorSpacePointer m_colorSpace;
     RenderingIntent m_renderingIntent = RenderingIntent::Perceptual;
+    bool m_interpolate = false;
+    std::vector<PDFAlternateImage> m_alternates;
+    QByteArray m_name;
+    QByteArray m_webCaptureContentSetId;
+    PDFInteger m_structuralParent = 0;
+    PDFObject m_OPI;
+    PDFObject m_OC;
+    PDFObject m_metadata;
+    PDFObject m_associatedFiles;
+    PDFObject m_measure;
+    PDFObject m_pointData;
 };
 
 }   // namespace pdf

PdfForQtLib/sources/pdfpagecontentprocessor.cpp

@@ -500,7 +500,11 @@ void PDFPageContentProcessor::processContent(const QByteArray& content)
                             { "H", "Height" },
                             { "IM", "ImageMask" },
                             { "I", "Interpolate" },
-                            { "W", "Width" }
+                            { "W", "Width" },
+                            { "L", "Length" },
+                            { "G", "DeviceGray" },
+                            { "RGB", "DeviceRGB" },
+                            { "CMYK", "DeviceCMYK" }
                         };
 
                         std::shared_ptr<PDFDictionary> dictionarySharedPointer = std::make_shared<PDFDictionary>();