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JBIG2 halftoning

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This commit is contained in:
Jakub Melka
2019-11-05 17:34:07 +01:00
parent 23d61dc8bc
commit 06e0036cda
3 changed files with 199 additions and 3 deletions
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2
PdfForQtLib/sources/pdfccittfaxdecoder.h
View File

@@ -81,6 +81,8 @@ public:
PDFImageData decode();
const PDFBitReader* getReader() const { return &m_reader; }
private:
/// Skip zero bits at the start
void skipFill();

197
PdfForQtLib/sources/pdfjbig2decoder.cpp
View File

@@ -322,6 +322,9 @@ struct PDFJBIG2BitmapDecodingParameters
/// Data with encoded image
QByteArray data;
/// End position in the data after reading MMR
int dataEndPosition = 0;
/// State of arithmetic decoder
PDFJBIG2ArithmeticDecoderState* arithmeticDecoderState = nullptr;
@@ -2235,6 +2238,7 @@ void PDFJBIG2Decoder::processPatternDictionary(const PDFJBIG2SegmentHeader& head
void PDFJBIG2Decoder::processHalftoneRegion(const PDFJBIG2SegmentHeader& header)
{
const int segmentStartPosition = m_reader.getPosition();
PDFJBIG2RegionSegmentInformationField field = readRegionSegmentInformationField();
const uint8_t flags = m_reader.readUnsignedByte();
const bool HMMR = flags & 0x01;
@@ -2248,6 +2252,35 @@ void PDFJBIG2Decoder::processHalftoneRegion(const PDFJBIG2SegmentHeader& header)
const uint32_t HGY = m_reader.readSignedInt();
const uint16_t HRX = m_reader.readUnsignedWord();
const uint16_t HRY = m_reader.readUnsignedWord();
const int HBW = field.width;
const int HBH = field.height;
PDFJBIG2BitOperation HCOMBOOPValue = PDFJBIG2BitOperation::Invalid;
switch (HCOMBOOP)
{
case 0:
HCOMBOOPValue = PDFJBIG2BitOperation::Or;
break;
case 1:
HCOMBOOPValue = PDFJBIG2BitOperation::And;
break;
case 2:
HCOMBOOPValue = PDFJBIG2BitOperation::Xor;
break;
case 3:
HCOMBOOPValue = PDFJBIG2BitOperation::NotXor;
break;
case 4:
HCOMBOOPValue = PDFJBIG2BitOperation::Replace;
break;
default:
throw PDFException(PDFTranslationContext::tr("JBIG2 region segment information - invalid bit operation mode."));
}
PDFJBIG2ReferencedSegments references = getReferencedSegments(header);
if (references.patternDictionaries.size() != 1)
@@ -2267,9 +2300,168 @@ void PDFJBIG2Decoder::processHalftoneRegion(const PDFJBIG2SegmentHeader& header)
const int HPW = firstBitmap->getWidth();
const int HPH = firstBitmap->getHeight();
/* 6.6 step 1) */
PDFJBIG2Bitmap HTREG(HBW, HBH, HDEFPIXEL ? 0xFF : 0x00);
// TODO: JBIG2 - processHalftoneRegion
throw PDFException(PDFTranslationContext::tr("JBIG2 NOT IMPLEMENTED."));
/* 6.6 step 2) compute HSKIP bitmap */
PDFJBIG2Bitmap HSKIP;
if (HENABLESKIP)
{
/* 6.6.5.1 */
HSKIP = PDFJBIG2Bitmap(HGW, HGH, 0x00);
for (int MG = 0; MG < static_cast<int>(HGH); ++MG)
{
for (int NG = 0; NG < static_cast<int>(HGW); ++NG)
{
/* 6.6.5.1 1) a) i) */
const int x = (static_cast<int>(HGX) + MG * static_cast<int>(HRY) + NG * static_cast<int>(HRX)) / 256;
const int y = (static_cast<int>(HGY) + MG * static_cast<int>(HRX) - NG * static_cast<int>(HRY)) / 256;
/* 6.6.5.1 1) a) ii) */
if ((x + static_cast<int>(HPW) <= 0) || (x >= HBW) || (y + static_cast<int>(HPH) <= 0) || (y >= HBH))
{
HSKIP.setPixel(NG, MG, 0xFF);
}
}
}
}
/* 6.6 step 3) */
const uint8_t HBPP = log2ceil(HNUMPATS);
Q_ASSERT(HBPP > 0);
if (HBPP > 8)
{
throw PDFException(PDFTranslationContext::tr("JBIG2 halftoning with more than 8 grayscale bit planes not supported (current bitplanes: %1).").arg(HBPP));
}
/* 6.6 step 4) */
QByteArray mmrData;
PDFJBIG2ArithmeticDecoder arithmeticDecoder(&m_reader);
PDFJBIG2ArithmeticDecoderState genericState;
if (!HMMR)
{
arithmeticDecoder.initialize();
PDFJBIG2ArithmeticDecoderStates::resetArithmeticStatesGeneric(&genericState, HTEMPLATE, nullptr);
}
else
{
// Determine segment data length
const int segmentDataStartPosition = m_reader.getPosition();
const int segmentHeaderBytes = segmentDataStartPosition - segmentStartPosition;
if (header.isSegmentDataLengthDefined())
{
int segmentDataBytes = header.getSegmentDataLength() - segmentHeaderBytes;
mmrData = m_reader.readSubstream(segmentDataBytes);
}
else
{
throw PDFException(PDFTranslationContext::tr("JBIG2 unknown data length for halftone dictionary."));
}
}
/* Annex C5 decoding procedure */
PDFJBIG2BitmapDecodingParameters parameters;
parameters.MMR = HMMR;
parameters.GBW = HGW;
parameters.GBH = HGH;
parameters.GBTEMPLATE = HTEMPLATE;
parameters.SKIP = HENABLESKIP ? &HSKIP : nullptr;
parameters.TPGDON = false;
parameters.GBAT[0] = { ((HTEMPLATE <= 1) ? 3 : 2), -1 };
parameters.GBAT[1] = { -3, -1 };
parameters.GBAT[2] = { 2, -2 };
parameters.GBAT[3] = { -2, -2 };
parameters.arithmeticDecoder = &arithmeticDecoder;
parameters.arithmeticDecoderState = &genericState;
parameters.data = qMove(mmrData);
PDFJBIG2Bitmap GI(HGW, HGH, 0x00);
for (int J = HBPP - 1; J >= 0; --J)
{
PDFJBIG2Bitmap PLANE = readBitmap(parameters);
if (HMMR)
{
// We must find EOFB symbol in the data. We hope, that EOFB symbol
// lies in the compressed data, otherwise we can't do anything...
PDFBitReader reader(&parameters.data, 1);
while (!reader.isAtEnd())
{
if (reader.look(24) == 0x1001)
{
reader.read(24);
reader.alignToBytes();
parameters.data = parameters.data.mid(reader.getPosition());
break;
}
else
{
reader.read(1);
}
}
}
if (PLANE.getWidth() != HGW || PLANE.getHeight() != HGH)
{
throw PDFException(PDFTranslationContext::tr("JBIG2 invalid halftone grayscale bit plane image."));
}
for (int x = 0; x < static_cast<int>(HGW); ++x)
{
for (int y = 0; y < static_cast<int>(HGH); ++y)
{
// Old bit is in the first position of grayscale image
const uint8_t oldPixel = GI.getPixel(x, y);
const uint8_t bit = (oldPixel ^ PLANE.getPixel(x, y)) & 0x01;
GI.setPixel(x, y, (oldPixel << 1) | bit);
}
}
}
/* 6.6 step 5) - 6.6.5.2 render the grid */
for (int MG = 0; MG < static_cast<int>(HGH); ++MG)
{
for (int NG = 0; NG < static_cast<int>(HGW); ++NG)
{
/* 6.6.5.2 1) a) i) */
const int x = (static_cast<int>(HGX) + MG * static_cast<int>(HRY) + NG * static_cast<int>(HRX)) / 256;
const int y = (static_cast<int>(HGY) + MG * static_cast<int>(HRX) - NG * static_cast<int>(HRY)) / 256;
/* 6.6.5.1 1) a) ii) */
const uint8_t index = GI.getPixel(NG, MG);
if (Q_UNLIKELY(index >= HNUMPATS))
{
throw PDFException(PDFTranslationContext::tr("JBIG2 halftoning pattern index %1 out of bounds [0, %2]").arg(index).arg(HNUMPATS));
}
HTREG.paint(*HPATS[index], x, y, HCOMBOOPValue, false, 0x00);
}
}
if (HTREG.isValid())
{
if (header.isImmediate())
{
m_pageBitmap.paint(HTREG, field.offsetX, field.offsetY, field.operation, m_pageSizeUndefined, m_pageDefaultPixelValue);
}
else
{
m_segments[header.getSegmentNumber()] = std::make_unique<PDFJBIG2Bitmap>(qMove(HTREG));
}
}
else
{
throw PDFException(PDFTranslationContext::tr("JBIG2 - invalid bitmap for halftone region."));
}
if (!HMMR)
{
arithmeticDecoder.finalize();
}
}
void PDFJBIG2Decoder::processGenericRegion(const PDFJBIG2SegmentHeader& header)
@@ -2664,6 +2856,7 @@ PDFJBIG2Bitmap PDFJBIG2Decoder::readBitmap(PDFJBIG2BitmapDecodingParameters& par
PDFCCITTFaxDecoder decoder(&parameters.data, ccittParameters);
PDFImageData data = decoder.decode();
parameters.dataEndPosition = decoder.getReader()->getPosition();
PDFJBIG2Bitmap bitmap(data.getWidth(), data.getHeight(), m_pageDefaultPixelValue);

3
PdfForQtLib/sources/pdfutils.h
View File

@@ -325,6 +325,7 @@ unsigned char* convertByteArrayToUcharPtr(QByteArray& data)
/// License for this function is public domain.
inline constexpr uint8_t log2ceil(uint32_t value)
{
const uint32_t originalValue = value;
constexpr uint8_t MULTIPLY_DE_BRUIJN_BIT_POSITION[32] =
{
0, 9, 1, 10, 13, 21, 2, 29, 11, 14, 16, 18, 22, 25, 3, 30,
@@ -340,7 +341,7 @@ inline constexpr uint8_t log2ceil(uint32_t value)
uint8_t logarithm = MULTIPLY_DE_BRUIJN_BIT_POSITION[static_cast<uint32_t>((value * 0x07C4ACDDU) >> 27)];
// Ceil
if ((1U << logarithm) < value)
if ((1U << logarithm) < originalValue)
{
++logarithm;
}