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JBIG2 - text region bitmap reading

This commit is contained in:
Jakub Melka 2019-11-01 18:20:49 +01:00
parent fc6985e35a
commit 0a8e66b16a
2 changed files with 149 additions and 8 deletions
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149
PdfForQtLib/sources/pdfjbig2decoder.cpp
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@ -35,6 +35,7 @@ struct PDFJBIG2TextRegionDecodingParameters
uint32_t SBW = 0;
uint32_t SBH = 0;
uint32_t SBNUMINSTANCES = 0;
uint8_t LOG2SBSTRIPS = 0;
uint8_t SBSTRIPS = 0;
uint32_t SBNUMSYMS = 0;
std::vector<const PDFJBIG2Bitmap*> SBSYMS;
@ -51,6 +52,7 @@ struct PDFJBIG2TextRegionDecodingParameters
uint8_t SBRTEMPLATE = 0;
PDFJBIG2ATPositions SBRAT = { };
PDFJBIG2ArithmeticDecoder* arithmeticDecoder = nullptr;
PDFBitReader* reader = nullptr;
};
/// Info structure for bitmap decoding parameters
@ -117,6 +119,8 @@ struct PDFJBIG2BitmapRefinementDecodingParameters
/// Positions of adaptative pixels
PDFJBIG2ATPositions GRAT = { };
PDFJBIG2ArithmeticDecoder* decoder = nullptr;
};
static constexpr PDFJBIG2HuffmanTableEntry PDFJBIG2StandardHuffmanTable_A[] =
@ -1344,7 +1348,8 @@ void PDFJBIG2Decoder::processTextRegion(const PDFJBIG2SegmentHeader& header)
const uint16_t flags = m_reader.readUnsignedWord();
const bool SBHUFF = flags & 0x0001;
const bool SBREFINE = flags & 0x0002;
const uint8_t SBSTRIPS = 1 << ((flags >> 2) & 0x03);
const uint8_t LOG2SBSTRIPS = ((flags >> 2) & 0x03);
const uint8_t SBSTRIPS = 1 << LOG2SBSTRIPS;
const uint8_t REFCORNER = (flags >> 4) & 0x03;
const bool TRANSPOSED = (flags >> 6) & 0x01;
const uint8_t SBCOMBOOP_value = (flags >> 7) & 0x03;
@ -1366,6 +1371,7 @@ void PDFJBIG2Decoder::processTextRegion(const PDFJBIG2SegmentHeader& header)
parameters.SBH = regionSegmentInfo.height;
parameters.SBRTEMPLATE = SBRTEMPLATE;
parameters.SBSTRIPS = SBSTRIPS;
parameters.LOG2SBSTRIPS = LOG2SBSTRIPS;
// Referenced segments data
PDFJBIG2ReferencedSegments references = getReferencedSegments(header);
@ -1645,6 +1651,8 @@ void PDFJBIG2Decoder::processTextRegion(const PDFJBIG2SegmentHeader& header)
resetArithmeticStatesGenericRefinement(parameters.SBRTEMPLATE, nullptr);
}
parameters.reader = &m_reader;
PDFJBIG2Bitmap bitmap = readTextBitmap(parameters);
if (bitmap.isValid())
{
@ -1834,6 +1842,10 @@ void PDFJBIG2Decoder::processGenericRefinementRegion(const PDFJBIG2SegmentHeader
parameters.GRREFERENCEX = 0;
parameters.GRREFERENCEY = 0;
PDFJBIG2ArithmeticDecoder decoder(&m_reader);
decoder.initialize();
parameters.decoder = &decoder;
PDFJBIG2Bitmap refinementBitmap = readRefinementBitmap(parameters);
if (refinementBitmap.isValid())
{
@ -2043,7 +2055,7 @@ PDFJBIG2Bitmap PDFJBIG2Decoder::getBitmap(const uint32_t segmentIndex, bool remo
return result;
}
PDFJBIG2Bitmap PDFJBIG2Decoder::readBitmap(const PDFJBIG2BitmapDecodingParameters& parameters)
PDFJBIG2Bitmap PDFJBIG2Decoder::readBitmap(PDFJBIG2BitmapDecodingParameters& parameters)
{
if (parameters.MMR)
{
@ -2240,7 +2252,7 @@ PDFJBIG2Bitmap PDFJBIG2Decoder::readBitmap(const PDFJBIG2BitmapDecodingParameter
return PDFJBIG2Bitmap();
}
PDFJBIG2Bitmap PDFJBIG2Decoder::readRefinementBitmap(const PDFJBIG2BitmapRefinementDecodingParameters& parameters)
PDFJBIG2Bitmap PDFJBIG2Decoder::readRefinementBitmap(PDFJBIG2BitmapRefinementDecodingParameters& parameters)
{
// Use algorithm described in 6.3.5.6
PDFJBIG2Bitmap GRREG(parameters.GRW, parameters.GRH, 0x00);
@ -2251,9 +2263,7 @@ PDFJBIG2Bitmap PDFJBIG2Decoder::readRefinementBitmap(const PDFJBIG2BitmapRefinem
uint32_t LTP = 0;
const uint32_t LTPContext = !parameters.GRTEMPLATE ? 0b0000100000000 : 0b0010000000;
PDFBitReader reader(m_reader.getStream(), 1);
PDFJBIG2ArithmeticDecoder decoder(&reader);
decoder.initialize();
PDFJBIG2ArithmeticDecoder& decoder = *parameters.decoder;
auto createContext = [&](int x, int y) -> uint16_t
{
@ -2365,6 +2375,133 @@ PDFJBIG2Bitmap PDFJBIG2Decoder::readRefinementBitmap(const PDFJBIG2BitmapRefinem
return GRREG;
}
PDFJBIG2Bitmap PDFJBIG2Decoder::readTextBitmap(PDFJBIG2TextRegionDecodingParameters& parameters)
{
/* 6.4.5 step 1) */
PDFJBIG2Bitmap SBREG(parameters.SBW, parameters.SBH, parameters.SBDEFPIXEL);
Q_ASSERT(parameters.SBNUMSYMS == parameters.SBSYMS.size());
/* 6.4.5 step 2) */
int32_t STRIPT = checkInteger(parameters.SBHUFF ? parameters.SBHUFFDT.readSignedInteger() : parameters.arithmeticDecoder->getSignedInteger(parameters.IADT));
STRIPT *= -parameters.SBSTRIPS;
int32_t FIRSTS = 0;
uint32_t NINSTANCES = 0;
/* 6.4.5. step 3) */
while (NINSTANCES < parameters.SBNUMINSTANCES)
{
/* 6.4.5. step 3) b), using decoding procedure 6.4.6 */
int32_t DT = checkInteger(parameters.SBHUFF ? parameters.SBHUFFDT.readSignedInteger() : parameters.arithmeticDecoder->getSignedInteger(parameters.IADT));
STRIPT += DT * parameters.SBSTRIPS;
int32_t CURS = 0;
bool firstSymbolInstance = true;
while (NINSTANCES < parameters.SBNUMINSTANCES)
{
if (firstSymbolInstance)
{
/* 6.4.5. step 3) i), using decoding procedure 6.4.7 */
int32_t DFS = checkInteger(parameters.SBHUFF ? parameters.SBHUFFFS.readSignedInteger() : parameters.arithmeticDecoder->getSignedInteger(parameters.IAFS));
FIRSTS += DFS;
CURS = FIRSTS;
firstSymbolInstance = false;
}
else
{
/* 6.4.5. step 3) ii), using decoding procedure 6.4.8 */
std::optional<int32_t> DS = parameters.SBHUFF ? parameters.SBHUFFDS.readSignedInteger() : parameters.arithmeticDecoder->getSignedInteger(parameters.IADS);
if (DS.has_value())
{
const int32_t IDS = *DS;
CURS += IDS + parameters.SBDSOFFSET;
}
else
{
// End of strip, proceed to the next strip
break;
}
}
/* 6.4.5. step 3) iii), using decoding procedure 6.4.9 */
int32_t CURT = 0;
if (parameters.SBSTRIPS > 1)
{
CURT = parameters.SBHUFF ? parameters.reader->read(parameters.LOG2SBSTRIPS) : checkInteger(parameters.arithmeticDecoder->getSignedInteger(parameters.IAIT));
}
const int32_t TI = STRIPT + CURT;
/* 6.4.5. step 3) iv), using decoding procedure 6.4.10 */
uint32_t ID = parameters.SBHUFF ? checkInteger(parameters.SBSYMCODES.readSignedInteger()) : parameters.arithmeticDecoder->getIAID(parameters.SBSYMCODELEN, parameters.IAID);
/* 6.4.5. step 3) v), determine instance bitmap according to 6.4.11 */
if (ID >= parameters.SBNUMSYMS)
{
throw PDFException(PDFTranslationContext::tr("JBIG2 symbol index %1 not found in symbol table of length %2.").arg(ID).arg(parameters.SBNUMSYMS));
}
bool RI = 0;
if (parameters.SBREFINE)
{
RI = parameters.SBHUFF ? parameters.reader->read(1) : parameters.arithmeticDecoder->getSignedInteger(parameters.IARI);
}
PDFJBIG2Bitmap IB;
if (RI == 0)
{
IB = *parameters.SBSYMS[ID];
}
else
{
/* 6.4.11 1), 2), 3), 4) */
int32_t RDW = checkInteger(parameters.SBHUFF ? parameters.SBHUFFRDW.readSignedInteger() : parameters.arithmeticDecoder->getSignedInteger(parameters.IARDW));
int32_t RDH = checkInteger(parameters.SBHUFF ? parameters.SBHUFFRDH.readSignedInteger() : parameters.arithmeticDecoder->getSignedInteger(parameters.IARDH));
int32_t RDX = checkInteger(parameters.SBHUFF ? parameters.SBHUFFRDX.readSignedInteger() : parameters.arithmeticDecoder->getSignedInteger(parameters.IARDX));
int32_t RDY = checkInteger(parameters.SBHUFF ? parameters.SBHUFFRDY.readSignedInteger() : parameters.arithmeticDecoder->getSignedInteger(parameters.IARDY));
/* 6.4.11 5) */
int32_t bmsize = parameters.SBHUFF ? checkInteger(parameters.SBHUFFRSIZE.readSignedInteger()) : 0;
if (parameters.SBHUFF)
{
parameters.reader->alignToBytes();
}
/* 6.4.11 6) */
const PDFJBIG2Bitmap* IBO = parameters.SBSYMS[ID];
const int WOI = IBO->getWidth();
const int HOI = IBO->getHeight();
// Apply the refinement procedure acc. to Table 12
PDFJBIG2BitmapRefinementDecodingParameters refinementParameters;
refinementParameters.decoder = parameters.arithmeticDecoder;
refinementParameters.arithmeticDecoderState = parameters.refinementDecoderState;
refinementParameters.GRW = WOI + RDW;
refinementParameters.GRH = HOI + RDH;
refinementParameters.GRTEMPLATE = parameters.SBRTEMPLATE;
refinementParameters.GRREFERENCE = IBO;
refinementParameters.GRREFERENCEX = (RDW / 2) + RDX;
refinementParameters.GRREFERENCEY = (RDH / 2) + RDY;
refinementParameters.TPGRON = false;
refinementParameters.GRAT = parameters.SBRAT;
IB = readRefinementBitmap(refinementParameters);
/* 6.4.11 7 */
if (parameters.SBHUFF)
{
parameters.reader->alignToBytes();
}
}
pokracovat zde
}
}
return SBREG;
}
PDFJBIG2RegionSegmentInformationField PDFJBIG2Decoder::readRegionSegmentInformationField()
{
PDFJBIG2RegionSegmentInformationField result;

8
PdfForQtLib/sources/pdfjbig2decoder.h
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@ -593,11 +593,15 @@ private:
/// Reads bitmap using decoding parameters
/// \param parameters Decoding parameters
PDFJBIG2Bitmap readBitmap(const PDFJBIG2BitmapDecodingParameters& parameters);
PDFJBIG2Bitmap readBitmap(PDFJBIG2BitmapDecodingParameters& parameters);
/// Reads refined bitmap using decoding parameters
/// \param parameters Decoding parameters
PDFJBIG2Bitmap readRefinementBitmap(const PDFJBIG2BitmapRefinementDecodingParameters& parameters);
PDFJBIG2Bitmap readRefinementBitmap(PDFJBIG2BitmapRefinementDecodingParameters& parameters);
/// Reads text bitmap using decoding parameters
/// \param parameters Decoding parameters
PDFJBIG2Bitmap readTextBitmap(PDFJBIG2TextRegionDecodingParameters& parameters);
/// Reads the region segment information field (see chapter 7.4.1)
PDFJBIG2RegionSegmentInformationField readRegionSegmentInformationField();