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JBIG2 - basic reading of segments

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Jakub Melka
2019-10-26 18:02:37 +02:00
parent ee4e21320e
commit abbe7a920a
5 changed files with 385 additions and 6 deletions
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95
PdfForQtLib/sources/pdfjbig2decoder.h
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@ -22,6 +22,7 @@
namespace pdf
{
class PDFRenderErrorReporter;
/// Arithmetic decoder state for JBIG2 data streams. It contains state for context,
/// state is stored as 8-bit value, where only 7 bits are used. 6 bits are used
@ -111,10 +112,102 @@ private:
PDFBitReader* m_reader;
};
enum class JBIG2SegmentType : uint32_t
{
Invalid,
SymbolDictionary, ///< See chapter 7.4.2 in specification
TextRegion, ///< See chapter 7.4.3 in specification
PatternDictionary, ///< See chapter 7.4.4 in specification
HalftoneRegion, ///< See chapter 7.4.5 in specification
GenericRegion, ///< See chapter 7.4.6 in specification
GenericRefinementRegion, ///< See chapter 7.4.7 in specification
PageInformation, ///< See chapter 7.4.8 in specification
EndOfPage, ///< See chapter 7.4.9 in specification
EndOfStripe, ///< See chapter 7.4.10 in specification
EndOfFile, ///< See chapter 7.4.11 in specification
Profiles, ///< See chapter 7.4.12 in specification
Tables, ///< See chapter 7.4.13 in specification
Extension ///< See chapter 7.4.14 in specification
};
class PDFJBIG2SegmentHeader
{
public:
explicit inline PDFJBIG2SegmentHeader() = default;
/// Returns segment type
inline JBIG2SegmentType getSegmentType() const { return m_segmentType; }
/// Returns segment number
inline uint32_t getSegmentNumber() const { return m_segmentNumber; }
/// Returns segment data length (or 0xFFFFFFFF, if length is not defined)
/// \sa isSegmentDataLengthDefined
inline uint32_t getSegmentDataLength() const { return m_segmentDataLength; }
/// Returns true, if segment is immediate (direct paint on page's bitmap)
inline bool isImmediate() const { return m_immediate; }
/// Returns true, if segment is lossless
inline bool isLossless() const { return m_lossless; }
/// Returns true, if segmend data length is defined
inline bool isSegmentDataLengthDefined() const { return m_segmentDataLength != 0xFFFFFFFF; }
/// Reads the segment header from the data stream. If error occurs, then
/// exception is thrown.
static PDFJBIG2SegmentHeader read(PDFBitReader* reader);
private:
uint32_t m_segmentNumber = 0;
uint32_t m_pageAssociation = 0;
uint32_t m_segmentDataLength = 0;
JBIG2SegmentType m_segmentType = JBIG2SegmentType::Invalid;
bool m_immediate = false;
bool m_lossless = false;
std::vector<uint32_t> m_referredSegments;
};
/// Decoder of JBIG2 data streams. Decodes the black/white monochrome image.
/// Handles also global segments. Decoder decodes data using the specification
/// ISO/IEC 14492:2001, T.88.
class PDFJBIG2Decoder
{
public:
PDFJBIG2Decoder();
explicit inline PDFJBIG2Decoder(QByteArray data, QByteArray globalData, PDFRenderErrorReporter* errorReporter) :
m_data(qMove(data)),
m_globalData(qMove(globalData)),
m_errorReporter(errorReporter),
m_reader(nullptr, 8)
{
}
void decode();
private:
/// Processes current data stream (reads all data from the stream, interprets
/// them as segments and processes the segments).
void processStream();
void processSymbolDictionary(const PDFJBIG2SegmentHeader& header);
void processTextRegion(const PDFJBIG2SegmentHeader& header);
void processPatternDictionary(const PDFJBIG2SegmentHeader& header);
void processHalftoneRegion(const PDFJBIG2SegmentHeader& header);
void processGenericRegion(const PDFJBIG2SegmentHeader& header);
void processGenericRefinementRegion(const PDFJBIG2SegmentHeader& header);
void processPageInformation(const PDFJBIG2SegmentHeader& header);
void processEndOfPage(const PDFJBIG2SegmentHeader& header);
void processEndOfStripe(const PDFJBIG2SegmentHeader& header);
void processEndOfFile(const PDFJBIG2SegmentHeader& header);
void processProfiles(const PDFJBIG2SegmentHeader& header);
void processCodeTables(const PDFJBIG2SegmentHeader& header);
void processExtension(const PDFJBIG2SegmentHeader& header);
QByteArray m_data;
QByteArray m_globalData;
PDFRenderErrorReporter* m_errorReporter;
PDFBitReader m_reader;
};
} // namespace pdf