Merge pull request #8491 from janpe2/jbig2Halftone-2
JBIG2 halftone regions and pattern dictionaries
This commit is contained in:
Jonas Jenwald
GitHub
commit
ca936ee0c7
@ -111,7 +111,7 @@ var Jbig2Image = (function Jbig2ImageClosure() {
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var SegmentTypes = [
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'SymbolDictionary', null, null, null, 'IntermediateTextRegion', null,
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'ImmediateTextRegion', 'ImmediateLosslessTextRegion', null, null, null,
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null, null, null, null, null, 'patternDictionary', null, null, null,
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null, null, null, null, null, 'PatternDictionary', null, null, null,
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'IntermediateHalftoneRegion', null, 'ImmediateHalftoneRegion',
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'ImmediateLosslessHalftoneRegion', null, null, null, null, null, null, null,
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null, null, null, null, null, 'IntermediateGenericRegion', null,
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@ -619,6 +619,148 @@ var Jbig2Image = (function Jbig2ImageClosure() {
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return bitmap;
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}
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function decodePatternDictionary(mmr, patternWidth, patternHeight,
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maxPatternIndex, template, decodingContext) {
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let at = [];
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at.push({
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x: -patternWidth,
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y: 0,
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});
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if (template === 0) {
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at.push({
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x: -3,
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y: -1,
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});
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at.push({
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x: 2,
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y: -2,
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});
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at.push({
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x: -2,
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y: -2,
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});
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}
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let collectiveWidth = (maxPatternIndex + 1) * patternWidth;
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let collectiveBitmap = decodeBitmap(mmr, collectiveWidth, patternHeight,
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template, false, null, at,
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decodingContext);
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// Divide collective bitmap into patterns.
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let patterns = [], i = 0, patternBitmap, xMin, xMax, y;
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while (i <= maxPatternIndex) {
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patternBitmap = [];
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xMin = patternWidth * i;
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xMax = xMin + patternWidth;
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for (y = 0; y < patternHeight; y++) {
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patternBitmap.push(collectiveBitmap[y].subarray(xMin, xMax));
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}
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patterns.push(patternBitmap);
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i++;
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}
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return patterns;
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}
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function decodeHalftoneRegion(mmr, patterns, template, regionWidth,
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regionHeight, defaultPixelValue, enableSkip,
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combinationOperator, gridWidth, gridHeight,
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gridOffsetX, gridOffsetY, gridVectorX,
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gridVectorY, decodingContext) {
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let skip = null;
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if (enableSkip) {
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throw new Jbig2Error('skip is not supported');
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}
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if (combinationOperator !== 0) {
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throw new Jbig2Error('operator ' + combinationOperator +
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' is not supported in halftone region');
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}
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// Prepare bitmap.
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let regionBitmap = [];
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let i, j, row;
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for (i = 0; i < regionHeight; i++) {
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row = new Uint8Array(regionWidth);
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if (defaultPixelValue) {
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for (j = 0; j < regionWidth; j++) {
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row[j] = defaultPixelValue;
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}
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}
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regionBitmap.push(row);
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}
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let numberOfPatterns = patterns.length;
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let pattern0 = patterns[0];
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let patternWidth = pattern0[0].length, patternHeight = pattern0.length;
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let bitsPerValue = log2(numberOfPatterns);
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let at = [];
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at.push({
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x: (template <= 1) ? 3 : 2,
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y: -1,
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});
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if (template === 0) {
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at.push({
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x: -3,
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y: -1,
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});
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at.push({
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x: 2,
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y: -2,
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});
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at.push({
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x: -2,
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y: -2,
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});
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}
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// Annex C. Gray-scale Image Decoding Procedure.
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let grayScaleBitPlanes = [];
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for (i = bitsPerValue - 1; i >= 0; i--) {
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grayScaleBitPlanes[i] = decodeBitmap(mmr, gridWidth, gridHeight,
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template, false, skip, at,
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decodingContext);
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}
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// 6.6.5.2 Rendering the patterns.
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let mg, ng, bit, patternIndex, patternBitmap, x, y, patternRow, regionRow;
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for (mg = 0; mg < gridHeight; mg++) {
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for (ng = 0; ng < gridWidth; ng++) {
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bit = 0;
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patternIndex = 0;
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for (j = bitsPerValue - 1; j >= 0; j--) {
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bit = grayScaleBitPlanes[j][mg][ng] ^ bit; // Gray decoding
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patternIndex |= bit << j;
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}
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patternBitmap = patterns[patternIndex];
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x = (gridOffsetX + mg * gridVectorY + ng * gridVectorX) >> 8;
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y = (gridOffsetY + mg * gridVectorX - ng * gridVectorY) >> 8;
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// Draw patternBitmap at (x, y).
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if (x >= 0 && x + patternWidth <= regionWidth && y >= 0 &&
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y + patternHeight <= regionHeight) {
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for (i = 0; i < patternHeight; i++) {
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regionRow = regionBitmap[y + i];
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patternRow = patternBitmap[i];
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for (j = 0; j < patternWidth; j++) {
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regionRow[x + j] |= patternRow[j];
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}
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}
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} else {
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let regionX, regionY;
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for (i = 0; i < patternHeight; i++) {
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regionY = y + i;
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if (regionY < 0 || regionY >= regionHeight) {
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continue;
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}
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regionRow = regionBitmap[regionY];
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patternRow = patternBitmap[i];
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for (j = 0; j < patternWidth; j++) {
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regionX = x + j;
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if (regionX >= 0 && regionX < regionWidth) {
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regionRow[regionX] |= patternRow[j];
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}
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}
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}
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}
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}
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}
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return regionBitmap;
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}
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function readSegmentHeader(data, start) {
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var segmentHeader = {};
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segmentHeader.number = readUint32(data, start);
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@ -850,6 +992,44 @@ var Jbig2Image = (function Jbig2ImageClosure() {
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}
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args = [textRegion, header.referredTo, data, position, end];
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break;
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case 16: // PatternDictionary
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// 7.4.4. Pattern dictionary segment syntax
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let patternDictionary = {};
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let patternDictionaryFlags = data[position++];
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patternDictionary.mmr = !!(patternDictionaryFlags & 1);
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patternDictionary.template = (patternDictionaryFlags >> 1) & 3;
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patternDictionary.patternWidth = data[position++];
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patternDictionary.patternHeight = data[position++];
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patternDictionary.maxPatternIndex = readUint32(data, position);
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position += 4;
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args = [patternDictionary, header.number, data, position, end];
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break;
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case 22: // ImmediateHalftoneRegion
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case 23: // ImmediateLosslessHalftoneRegion
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// 7.4.5 Halftone region segment syntax
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let halftoneRegion = {};
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halftoneRegion.info = readRegionSegmentInformation(data, position);
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position += RegionSegmentInformationFieldLength;
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let halftoneRegionFlags = data[position++];
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halftoneRegion.mmr = !!(halftoneRegionFlags & 1);
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halftoneRegion.template = (halftoneRegionFlags >> 1) & 3;
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halftoneRegion.enableSkip = !!(halftoneRegionFlags & 8);
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halftoneRegion.combinationOperator = (halftoneRegionFlags >> 4) & 7;
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halftoneRegion.defaultPixelValue = (halftoneRegionFlags >> 7) & 1;
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halftoneRegion.gridWidth = readUint32(data, position);
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position += 4;
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halftoneRegion.gridHeight = readUint32(data, position);
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position += 4;
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halftoneRegion.gridOffsetX = readUint32(data, position) & 0xFFFFFFFF;
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position += 4;
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halftoneRegion.gridOffsetY = readUint32(data, position) & 0xFFFFFFFF;
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position += 4;
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halftoneRegion.gridVectorX = readUint16(data, position);
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position += 2;
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halftoneRegion.gridVectorY = readUint16(data, position);
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position += 2;
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args = [halftoneRegion, header.referredTo, data, position, end];
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break;
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case 38: // ImmediateGenericRegion
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case 39: // ImmediateLosslessGenericRegion
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var genericRegion = {};
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@ -1086,6 +1266,32 @@ var Jbig2Image = (function Jbig2ImageClosure() {
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function SimpleSegmentVisitor_onImmediateLosslessTextRegion() {
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this.onImmediateTextRegion.apply(this, arguments);
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},
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onPatternDictionary(dictionary, currentSegment, data, start, end) {
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let patterns = this.patterns;
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if (!patterns) {
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this.patterns = patterns = {};
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}
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let decodingContext = new DecodingContext(data, start, end);
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patterns[currentSegment] = decodePatternDictionary(dictionary.mmr,
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dictionary.patternWidth, dictionary.patternHeight,
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dictionary.maxPatternIndex, dictionary.template, decodingContext);
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},
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onImmediateHalftoneRegion(region, referredSegments, data, start, end) {
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// HalftoneRegion refers to exactly one PatternDictionary.
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let patterns = this.patterns[referredSegments[0]];
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let regionInfo = region.info;
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let decodingContext = new DecodingContext(data, start, end);
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let bitmap = decodeHalftoneRegion(region.mmr, patterns,
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region.template, regionInfo.width, regionInfo.height,
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region.defaultPixelValue, region.enableSkip, region.combinationOperator,
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region.gridWidth, region.gridHeight, region.gridOffsetX,
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region.gridOffsetY, region.gridVectorX, region.gridVectorY,
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decodingContext);
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this.drawBitmap(regionInfo, bitmap);
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},
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onImmediateLosslessHalftoneRegion() {
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this.onImmediateHalftoneRegion.apply(this, arguments);
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},
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};
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function Jbig2Image() {}
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1
test/pdfs/pr8491.pdf.link
Normal file
1
test/pdfs/pr8491.pdf.link
Normal file
@ -0,0 +1 @@
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https://github.com/mozilla/pdf.js/files/1055278/castle_halftone.pdf
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@ -3618,5 +3618,12 @@
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"md5": "ced0e2d88cfd5b4d3a55d937ea288af1",
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"rounds": 1,
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"type": "eq"
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},
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{ "id": "pr8491",
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"file": "pdfs/pr8491.pdf",
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"md5": "36ea2e28cd77e9e70731f574ab27cbe0",
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"rounds": 1,
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"link": true,
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"type": "eq"
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}
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]
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