class Image { getPixel(x, y) { const index = x + y * this.width; const rntVal = { r: this.data[index * 4], g: this.data[index * 4 + 1], b: this.data[index * 4 + 2], a: this.data[index * 4 + 3] }; return rntVal; } setPixel(x, y, pix) { const index = x + y * this.width; this.data[index * 4] = pix.r; this.data[index * 4 + 1] = pix.g; this.data[index * 4 + 2] = pix.b; this.data[index * 4 + 3] = pix.a; } } const JpegImage = function jpegImage() { "use strict"; const dctZigZag = new Int32Array([ 0, 1, 8, 16, 9, 2, 3, 10, 17, 24, 32, 25, 18, 11, 4, 5, 12, 19, 26, 33, 40, 48, 41, 34, 27, 20, 13, 6, 7, 14, 21, 28, 35, 42, 49, 56, 57, 50, 43, 36, 29, 22, 15, 23, 30, 37, 44, 51, 58, 59, 52, 45, 38, 31, 39, 46, 53, 60, 61, 54, 47, 55, 62, 63 ]); const dctCos1 = 4017; const dctSin1 = 799; const dctCos3 = 3406; const dctSin3 = 2276; const dctCos6 = 1567; const dctSin6 = 3784; const dctSqrt2 = 5793; const dctSqrt1d2 = 2896; function constructor() {} function buildHuffmanTable(codeLengths, values) { let k = 0; const code = []; let i, j, length = 16; while(length > 0 && !codeLengths[length - 1]){ length--; } code.push({ children: [], index: 0 }); let p = code[0], q; for(i = 0; i < length; i++){ for(j = 0; j < codeLengths[i]; j++){ p = code.pop(); p.children[p.index] = values[k]; while(p.index > 0){ p = code.pop(); } p.index++; code.push(p); while(code.length <= i){ code.push(q = { children: [], index: 0 }); p.children[p.index] = q.children; p = q; } k++; } if (i + 1 < length) { code.push(q = { children: [], index: 0 }); p.children[p.index] = q.children; p = q; } } return code[0].children; } function decodeScan(data, offset, frame, components, resetInterval, spectralStart, spectralEnd, successivePrev, successive) { const mcusPerLine = frame.mcusPerLine; const progressive = frame.progressive; const startOffset = offset; let bitsData = 0, bitsCount = 0; function readBit() { if (bitsCount > 0) { bitsCount--; return bitsData >> bitsCount & 1; } bitsData = data[offset++]; if (bitsData === 0xFF) { const nextByte = data[offset++]; if (nextByte) { throw new Error("unexpected marker: " + (bitsData << 8 | nextByte).toString(16)); } } bitsCount = 7; return bitsData >>> 7; } function decodeHuffman(tree) { let node = tree, bit; while((bit = readBit()) !== null){ node = node[bit]; if (typeof node === "number") { return node; } if (typeof node !== "object") { throw new Error("invalid huffman sequence"); } } return null; } function receive(length) { let n = 0; while(length > 0){ const bit = readBit(); if (bit === null) { return; } n = n << 1 | bit; length--; } return n; } function receiveAndExtend(length) { const n = receive(length); if (n >= 1 << length - 1) { return n; } return n + (-1 << length) + 1; } function decodeBaseline(component, zz) { const t = decodeHuffman(component.huffmanTableDC); const diff = t === 0 ? 0 : receiveAndExtend(t); zz[0] = component.pred += diff; let k = 1; while(k < 64){ const rs = decodeHuffman(component.huffmanTableAC); const s = rs & 15, r = rs >> 4; if (s === 0) { if (r < 15) { break; } k += 16; continue; } k += r; const z = dctZigZag[k]; zz[z] = receiveAndExtend(s); k++; } } function decodeDCFirst(component, zz) { const t = decodeHuffman(component.huffmanTableDC); const diff = t === 0 ? 0 : receiveAndExtend(t) << successive; zz[0] = component.pred += diff; } function decodeDCSuccessive(component, zz) { zz[0] |= readBit() << successive; } let eobrun = 0; function decodeACFirst(component, zz) { if (eobrun > 0) { eobrun--; return; } let k = spectralStart, e = spectralEnd; while(k <= e){ const rs = decodeHuffman(component.huffmanTableAC); const s = rs & 15, r = rs >> 4; if (s === 0) { if (r < 15) { eobrun = receive(r) + (1 << r) - 1; break; } k += 16; continue; } k += r; const z = dctZigZag[k]; zz[z] = receiveAndExtend(s) * (1 << successive); k++; } } let successiveACState = 0, successiveACNextValue; function decodeACSuccessive(component, zz) { let k = spectralStart, e = spectralEnd, r = 0; while(k <= e){ const z = dctZigZag[k]; const direction = zz[z] < 0 ? -1 : 1; switch(successiveACState){ case 0: const rs = decodeHuffman(component.huffmanTableAC); const s = rs & 15; r = rs >> 4; if (s === 0) { if (r < 15) { eobrun = receive(r) + (1 << r); successiveACState = 4; } else { r = 16; successiveACState = 1; } } else { if (s !== 1) { throw new Error("invalid ACn encoding"); } successiveACNextValue = receiveAndExtend(s); successiveACState = r ? 2 : 3; } continue; case 1: case 2: if (zz[z]) { zz[z] += (readBit() << successive) * direction; } else { r--; if (r === 0) { successiveACState = successiveACState == 2 ? 3 : 0; } } break; case 3: if (zz[z]) { zz[z] += (readBit() << successive) * direction; } else { zz[z] = successiveACNextValue << successive; successiveACState = 0; } break; case 4: if (zz[z]) { zz[z] += (readBit() << successive) * direction; } break; } k++; } if (successiveACState === 4) { eobrun--; if (eobrun === 0) { successiveACState = 0; } } } function decodeMcu(component, decode1, mcu, row, col) { const mcuRow = mcu / mcusPerLine | 0; const mcuCol = mcu % mcusPerLine; const blockRow = mcuRow * component.v + row; const blockCol = mcuCol * component.h + col; decode1(component, component.blocks[blockRow][blockCol]); } function decodeBlock(component, decode2, mcu) { const blockRow = mcu / component.blocksPerLine | 0; const blockCol = mcu % component.blocksPerLine; decode2(component, component.blocks[blockRow][blockCol]); } const componentsLength = components.length; let component1, i, j, k1, n1; let decodeFn; if (progressive) { if (spectralStart === 0) { decodeFn = successivePrev === 0 ? decodeDCFirst : decodeDCSuccessive; } else { decodeFn = successivePrev === 0 ? decodeACFirst : decodeACSuccessive; } } else { decodeFn = decodeBaseline; } let mcu1 = 0, marker; let mcuExpected; if (componentsLength == 1) { mcuExpected = components[0].blocksPerLine * components[0].blocksPerColumn; } else { mcuExpected = mcusPerLine * frame.mcusPerColumn; } if (!resetInterval) { resetInterval = mcuExpected; } let h, v; while(mcu1 < mcuExpected){ for(i = 0; i < componentsLength; i++){ components[i].pred = 0; } eobrun = 0; if (componentsLength == 1) { component1 = components[0]; for(n1 = 0; n1 < resetInterval; n1++){ decodeBlock(component1, decodeFn, mcu1); mcu1++; } } else { for(n1 = 0; n1 < resetInterval; n1++){ for(i = 0; i < componentsLength; i++){ component1 = components[i]; h = component1.h; v = component1.v; for(j = 0; j < v; j++){ for(k1 = 0; k1 < h; k1++){ decodeMcu(component1, decodeFn, mcu1, j, k1); } } } mcu1++; if (mcu1 === mcuExpected) { break; } } } bitsCount = 0; marker = data[offset] << 8 | data[offset + 1]; if (marker < 0xFF00) { throw new Error("marker was not found"); } if (marker >= 0xFFD0 && marker <= 0xFFD7) { offset += 2; } else { break; } } return offset - startOffset; } function buildComponentData(frame, component) { const lines = []; const blocksPerLine = component.blocksPerLine; const blocksPerColumn = component.blocksPerColumn; const samplesPerLine = blocksPerLine << 3; const R = new Int32Array(64), r = new Uint8Array(64); function quantizeAndInverse(zz, dataOut, dataIn) { const qt = component.quantizationTable; let v0, v1, v2, v3, v4, v5, v6, v7, t; const p = dataIn; let i; for(i = 0; i < 64; i++){ p[i] = zz[i] * qt[i]; } for(i = 0; i < 8; ++i){ const row = 8 * i; if (p[1 + row] == 0 && p[2 + row] == 0 && p[3 + row] == 0 && p[4 + row] == 0 && p[5 + row] == 0 && p[6 + row] == 0 && p[7 + row] == 0) { t = dctSqrt2 * p[0 + row] + 512 >> 10; p[0 + row] = t; p[1 + row] = t; p[2 + row] = t; p[3 + row] = t; p[4 + row] = t; p[5 + row] = t; p[6 + row] = t; p[7 + row] = t; continue; } v0 = dctSqrt2 * p[0 + row] + 128 >> 8; v1 = dctSqrt2 * p[4 + row] + 128 >> 8; v2 = p[2 + row]; v3 = p[6 + row]; v4 = dctSqrt1d2 * (p[1 + row] - p[7 + row]) + 128 >> 8; v7 = dctSqrt1d2 * (p[1 + row] + p[7 + row]) + 128 >> 8; v5 = p[3 + row] << 4; v6 = p[5 + row] << 4; t = v0 - v1 + 1 >> 1; v0 = v0 + v1 + 1 >> 1; v1 = t; t = v2 * dctSin6 + v3 * dctCos6 + 128 >> 8; v2 = v2 * dctCos6 - v3 * dctSin6 + 128 >> 8; v3 = t; t = v4 - v6 + 1 >> 1; v4 = v4 + v6 + 1 >> 1; v6 = t; t = v7 + v5 + 1 >> 1; v5 = v7 - v5 + 1 >> 1; v7 = t; t = v0 - v3 + 1 >> 1; v0 = v0 + v3 + 1 >> 1; v3 = t; t = v1 - v2 + 1 >> 1; v1 = v1 + v2 + 1 >> 1; v2 = t; t = v4 * dctSin3 + v7 * dctCos3 + 2048 >> 12; v4 = v4 * dctCos3 - v7 * dctSin3 + 2048 >> 12; v7 = t; t = v5 * dctSin1 + v6 * dctCos1 + 2048 >> 12; v5 = v5 * dctCos1 - v6 * dctSin1 + 2048 >> 12; v6 = t; p[0 + row] = v0 + v7; p[7 + row] = v0 - v7; p[1 + row] = v1 + v6; p[6 + row] = v1 - v6; p[2 + row] = v2 + v5; p[5 + row] = v2 - v5; p[3 + row] = v3 + v4; p[4 + row] = v3 - v4; } for(i = 0; i < 8; ++i){ const col = i; if (p[1 * 8 + col] == 0 && p[2 * 8 + col] == 0 && p[3 * 8 + col] == 0 && p[4 * 8 + col] == 0 && p[5 * 8 + col] == 0 && p[6 * 8 + col] == 0 && p[7 * 8 + col] == 0) { t = dctSqrt2 * dataIn[i + 0] + 8192 >> 14; p[0 * 8 + col] = t; p[1 * 8 + col] = t; p[2 * 8 + col] = t; p[3 * 8 + col] = t; p[4 * 8 + col] = t; p[5 * 8 + col] = t; p[6 * 8 + col] = t; p[7 * 8 + col] = t; continue; } v0 = dctSqrt2 * p[0 * 8 + col] + 2048 >> 12; v1 = dctSqrt2 * p[4 * 8 + col] + 2048 >> 12; v2 = p[2 * 8 + col]; v3 = p[6 * 8 + col]; v4 = dctSqrt1d2 * (p[1 * 8 + col] - p[7 * 8 + col]) + 2048 >> 12; v7 = dctSqrt1d2 * (p[1 * 8 + col] + p[7 * 8 + col]) + 2048 >> 12; v5 = p[3 * 8 + col]; v6 = p[5 * 8 + col]; t = v0 - v1 + 1 >> 1; v0 = v0 + v1 + 1 >> 1; v1 = t; t = v2 * dctSin6 + v3 * dctCos6 + 2048 >> 12; v2 = v2 * dctCos6 - v3 * dctSin6 + 2048 >> 12; v3 = t; t = v4 - v6 + 1 >> 1; v4 = v4 + v6 + 1 >> 1; v6 = t; t = v7 + v5 + 1 >> 1; v5 = v7 - v5 + 1 >> 1; v7 = t; t = v0 - v3 + 1 >> 1; v0 = v0 + v3 + 1 >> 1; v3 = t; t = v1 - v2 + 1 >> 1; v1 = v1 + v2 + 1 >> 1; v2 = t; t = v4 * dctSin3 + v7 * dctCos3 + 2048 >> 12; v4 = v4 * dctCos3 - v7 * dctSin3 + 2048 >> 12; v7 = t; t = v5 * dctSin1 + v6 * dctCos1 + 2048 >> 12; v5 = v5 * dctCos1 - v6 * dctSin1 + 2048 >> 12; v6 = t; p[0 * 8 + col] = v0 + v7; p[7 * 8 + col] = v0 - v7; p[1 * 8 + col] = v1 + v6; p[6 * 8 + col] = v1 - v6; p[2 * 8 + col] = v2 + v5; p[5 * 8 + col] = v2 - v5; p[3 * 8 + col] = v3 + v4; p[4 * 8 + col] = v3 - v4; } for(i = 0; i < 64; ++i){ const sample = 128 + (p[i] + 8 >> 4); dataOut[i] = sample < 0 ? 0 : sample > 0xFF ? 0xFF : sample; } } let i1, j; for(let blockRow = 0; blockRow < blocksPerColumn; blockRow++){ const scanLine = blockRow << 3; for(i1 = 0; i1 < 8; i1++){ lines.push(new Uint8Array(samplesPerLine)); } for(let blockCol = 0; blockCol < blocksPerLine; blockCol++){ quantizeAndInverse(component.blocks[blockRow][blockCol], r, R); let offset = 0, sample = blockCol << 3; for(j = 0; j < 8; j++){ const line = lines[scanLine + j]; for(i1 = 0; i1 < 8; i1++){ line[sample + i1] = r[offset++]; } } } } return lines; } function clampTo8bit(a) { return a < 0 ? 0 : a > 255 ? 255 : a; } constructor.prototype = { load: function load(path) {}, parse: function parse(data) { let offset = 0; function readUint16() { const value = data[offset] << 8 | data[offset + 1]; offset += 2; return value; } function readDataBlock() { const length = readUint16(); const array = data.subarray(offset, offset + length - 2); offset += array.length; return array; } function prepareComponents(frame) { let maxH = 0, maxV = 0; let component, componentId; for(componentId in frame.components){ if (frame.components.hasOwnProperty(componentId)) { component = frame.components[componentId]; if (maxH < component.h) { maxH = component.h; } if (maxV < component.v) { maxV = component.v; } } } const mcusPerLine = Math.ceil(frame.samplesPerLine / 8 / maxH); const mcusPerColumn = Math.ceil(frame.scanLines / 8 / maxV); for(componentId in frame.components){ if (frame.components.hasOwnProperty(componentId)) { component = frame.components[componentId]; const blocksPerLine = Math.ceil(Math.ceil(frame.samplesPerLine / 8) * component.h / maxH); const blocksPerColumn = Math.ceil(Math.ceil(frame.scanLines / 8) * component.v / maxV); const blocksPerLineForMcu = mcusPerLine * component.h; const blocksPerColumnForMcu = mcusPerColumn * component.v; const blocks = []; for(let i = 0; i < blocksPerColumnForMcu; i++){ const row = []; for(let j = 0; j < blocksPerLineForMcu; j++){ row.push(new Int32Array(64)); } blocks.push(row); } component.blocksPerLine = blocksPerLine; component.blocksPerColumn = blocksPerColumn; component.blocks = blocks; } } frame.maxH = maxH; frame.maxV = maxV; frame.mcusPerLine = mcusPerLine; frame.mcusPerColumn = mcusPerColumn; } let jfif = null; let adobe = null; let frame1, resetInterval; const quantizationTables = [], frames = []; const huffmanTablesAC = [], huffmanTablesDC = []; let fileMarker = readUint16(); if (fileMarker != 0xFFD8) { throw new Error("SOI not found"); } fileMarker = readUint16(); while(fileMarker != 0xFFD9){ let i, j; switch(fileMarker){ case 0xFF00: break; case 0xFFE0: case 0xFFE1: case 0xFFE2: case 0xFFE3: case 0xFFE4: case 0xFFE5: case 0xFFE6: case 0xFFE7: case 0xFFE8: case 0xFFE9: case 0xFFEA: case 0xFFEB: case 0xFFEC: case 0xFFED: case 0xFFEE: case 0xFFEF: case 0xFFFE: const appData = readDataBlock(); if (fileMarker === 0xFFE0) { if (appData[0] === 0x4A && appData[1] === 0x46 && appData[2] === 0x49 && appData[3] === 0x46 && appData[4] === 0) { jfif = { version: { major: appData[5], minor: appData[6] }, densityUnits: appData[7], xDensity: appData[8] << 8 | appData[9], yDensity: appData[10] << 8 | appData[11], thumbWidth: appData[12], thumbHeight: appData[13], thumbData: appData.subarray(14, 14 + 3 * appData[12] * appData[13]) }; } } if (fileMarker === 0xFFEE) { if (appData[0] === 0x41 && appData[1] === 0x64 && appData[2] === 0x6F && appData[3] === 0x62 && appData[4] === 0x65 && appData[5] === 0) { adobe = { version: appData[6], flags0: appData[7] << 8 | appData[8], flags1: appData[9] << 8 | appData[10], transformCode: appData[11] }; } } break; case 0xFFDB: const quantizationTablesLength = readUint16(); const quantizationTablesEnd = quantizationTablesLength + offset - 2; while(offset < quantizationTablesEnd){ const quantizationTableSpec = data[offset++]; const tableData = new Int32Array(64); if (quantizationTableSpec >> 4 === 0) { for(j = 0; j < 64; j++){ const z = dctZigZag[j]; tableData[z] = data[offset++]; } } else if (quantizationTableSpec >> 4 === 1) { for(j = 0; j < 64; j++){ const z = dctZigZag[j]; tableData[z] = readUint16(); } } else { throw new Error("DQT: invalid table spec"); } quantizationTables[quantizationTableSpec & 15] = tableData; } break; case 0xFFC0: case 0xFFC1: case 0xFFC2: readUint16(); frame1 = {}; frame1.extended = fileMarker === 0xFFC1; frame1.progressive = fileMarker === 0xFFC2; frame1.precision = data[offset++]; frame1.scanLines = readUint16(); frame1.samplesPerLine = readUint16(); frame1.components = {}; frame1.componentsOrder = []; let componentsCount = data[offset++], componentId; for(i = 0; i < componentsCount; i++){ componentId = data[offset]; const h = data[offset + 1] >> 4; const v = data[offset + 1] & 15; const qId = data[offset + 2]; frame1.componentsOrder.push(componentId); frame1.components[componentId] = { h: h, v: v, quantizationIdx: qId }; offset += 3; } prepareComponents(frame1); frames.push(frame1); break; case 0xFFC4: const huffmanLength = readUint16(); for(i = 2; i < huffmanLength;){ const huffmanTableSpec = data[offset++]; const codeLengths = new Uint8Array(16); let codeLengthSum = 0; for(j = 0; j < 16; j++, offset++){ codeLengthSum += codeLengths[j] = data[offset]; } const huffmanValues = new Uint8Array(codeLengthSum); for(j = 0; j < codeLengthSum; j++, offset++){ huffmanValues[j] = data[offset]; } i += 17 + codeLengthSum; (huffmanTableSpec >> 4 === 0 ? huffmanTablesDC : huffmanTablesAC)[huffmanTableSpec & 15] = buildHuffmanTable(codeLengths, huffmanValues); } break; case 0xFFDD: readUint16(); resetInterval = readUint16(); break; case 0xFFDA: readUint16(); const selectorsCount = data[offset++]; let components = [], component; for(i = 0; i < selectorsCount; i++){ component = frame1.components[data[offset++]]; const tableSpec = data[offset++]; component.huffmanTableDC = huffmanTablesDC[tableSpec >> 4]; component.huffmanTableAC = huffmanTablesAC[tableSpec & 15]; components.push(component); } const spectralStart = data[offset++]; const spectralEnd = data[offset++]; const successiveApproximation = data[offset++]; const processed = decodeScan(data, offset, frame1, components, resetInterval, spectralStart, spectralEnd, successiveApproximation >> 4, successiveApproximation & 15); offset += processed; break; case 0xFFFF: if (data[offset] !== 0xFF) { offset--; } break; default: if (data[offset - 3] == 0xFF && data[offset - 2] >= 0xC0 && data[offset - 2] <= 0xFE) { offset -= 3; break; } throw new Error("unknown JPEG marker " + fileMarker.toString(16)); } fileMarker = readUint16(); } if (frames.length != 1) { throw new Error("only single frame JPEGs supported"); } for(let i3 = 0; i3 < frames.length; i3++){ const cp = frames[i3].components; for(const j in cp){ cp[j].quantizationTable = quantizationTables[cp[j].quantizationIdx]; delete cp[j].quantizationIdx; } } this.width = frame1.samplesPerLine; this.height = frame1.scanLines; this.jfif = jfif; this.adobe = adobe; this.components = []; for(let i2 = 0; i2 < frame1.componentsOrder.length; i2++){ const component = frame1.components[frame1.componentsOrder[i2]]; this.components.push({ lines: buildComponentData(frame1, component), scaleX: component.h / frame1.maxH, scaleY: component.v / frame1.maxV }); } }, getData: function getData(width, height) { const scaleX = this.width / width, scaleY = this.height / height; let component1, component2, component3, component4; let component1Line, component2Line, component3Line, component4Line; let x, y; let offset = 0; let Y, Cb, Cr, K, C, M, Ye, R, G, B; let colorTransform; const dataLength = width * height * this.components.length; const data = new Uint8Array(dataLength); switch(this.components.length){ case 1: component1 = this.components[0]; for(y = 0; y < height; y++){ component1Line = component1.lines[0 | y * component1.scaleY * scaleY]; for(x = 0; x < width; x++){ Y = component1Line[0 | x * component1.scaleX * scaleX]; data[offset++] = Y; } } break; case 2: component1 = this.components[0]; component2 = this.components[1]; for(y = 0; y < height; y++){ component1Line = component1.lines[0 | y * component1.scaleY * scaleY]; component2Line = component2.lines[0 | y * component2.scaleY * scaleY]; for(x = 0; x < width; x++){ Y = component1Line[0 | x * component1.scaleX * scaleX]; data[offset++] = Y; Y = component2Line[0 | x * component2.scaleX * scaleX]; data[offset++] = Y; } } break; case 3: colorTransform = true; if (this.adobe && this.adobe.transformCode) { colorTransform = true; } else if (typeof this.colorTransform !== "undefined") { colorTransform = !!this.colorTransform; } component1 = this.components[0]; component2 = this.components[1]; component3 = this.components[2]; for(y = 0; y < height; y++){ component1Line = component1.lines[0 | y * component1.scaleY * scaleY]; component2Line = component2.lines[0 | y * component2.scaleY * scaleY]; component3Line = component3.lines[0 | y * component3.scaleY * scaleY]; for(x = 0; x < width; x++){ if (!colorTransform) { R = component1Line[0 | x * component1.scaleX * scaleX]; G = component2Line[0 | x * component2.scaleX * scaleX]; B = component3Line[0 | x * component3.scaleX * scaleX]; } else { Y = component1Line[0 | x * component1.scaleX * scaleX]; Cb = component2Line[0 | x * component2.scaleX * scaleX]; Cr = component3Line[0 | x * component3.scaleX * scaleX]; R = clampTo8bit(Y + 1.402 * (Cr - 128)); G = clampTo8bit(Y - 0.3441363 * (Cb - 128) - 0.71413636 * (Cr - 128)); B = clampTo8bit(Y + 1.772 * (Cb - 128)); } data[offset++] = R; data[offset++] = G; data[offset++] = B; } } break; case 4: if (!this.adobe) { throw new Error("Unsupported color mode (4 components)"); } colorTransform = false; if (this.adobe && this.adobe.transformCode) { colorTransform = true; } else if (typeof this.colorTransform !== "undefined") { colorTransform = !!this.colorTransform; } component1 = this.components[0]; component2 = this.components[1]; component3 = this.components[2]; component4 = this.components[3]; for(y = 0; y < height; y++){ component1Line = component1.lines[0 | y * component1.scaleY * scaleY]; component2Line = component2.lines[0 | y * component2.scaleY * scaleY]; component3Line = component3.lines[0 | y * component3.scaleY * scaleY]; component4Line = component4.lines[0 | y * component4.scaleY * scaleY]; for(x = 0; x < width; x++){ if (!colorTransform) { C = component1Line[0 | x * component1.scaleX * scaleX]; M = component2Line[0 | x * component2.scaleX * scaleX]; Ye = component3Line[0 | x * component3.scaleX * scaleX]; K = component4Line[0 | x * component4.scaleX * scaleX]; } else { Y = component1Line[0 | x * component1.scaleX * scaleX]; Cb = component2Line[0 | x * component2.scaleX * scaleX]; Cr = component3Line[0 | x * component3.scaleX * scaleX]; K = component4Line[0 | x * component4.scaleX * scaleX]; C = 255 - clampTo8bit(Y + 1.402 * (Cr - 128)); M = 255 - clampTo8bit(Y - 0.3441363 * (Cb - 128) - 0.71413636 * (Cr - 128)); Ye = 255 - clampTo8bit(Y + 1.772 * (Cb - 128)); } data[offset++] = 255 - C; data[offset++] = 255 - M; data[offset++] = 255 - Ye; data[offset++] = 255 - K; } } break; default: throw new Error("Unsupported color mode"); } return data; }, copyToImageData: function copyToImageData(imageData) { const width = imageData.width, height = imageData.height; const imageDataArray = imageData.data; const data = this.getData(width, height); let i = 0, j = 0, x, y; let Y, K, C, M, R, G, B; switch(this.components.length){ case 1: for(y = 0; y < height; y++){ for(x = 0; x < width; x++){ Y = data[i++]; imageDataArray[j++] = Y; imageDataArray[j++] = Y; imageDataArray[j++] = Y; imageDataArray[j++] = 255; } } break; case 3: for(y = 0; y < height; y++){ for(x = 0; x < width; x++){ R = data[i++]; G = data[i++]; B = data[i++]; imageDataArray[j++] = R; imageDataArray[j++] = G; imageDataArray[j++] = B; imageDataArray[j++] = 255; } } break; case 4: for(y = 0; y < height; y++){ for(x = 0; x < width; x++){ C = data[i++]; M = data[i++]; Y = data[i++]; K = data[i++]; R = 255 - clampTo8bit(C * (1 - K / 255) + K); G = 255 - clampTo8bit(M * (1 - K / 255) + K); B = 255 - clampTo8bit(Y * (1 - K / 255) + K); imageDataArray[j++] = R; imageDataArray[j++] = G; imageDataArray[j++] = B; imageDataArray[j++] = 255; } } break; default: throw new Error("Unsupported color mode"); } } }; return constructor; }(); const decode = function(jpegData, colorTransform = true) { const arr = new Uint8Array(jpegData); const decoder = new JpegImage(); decoder.parse(arr); decoder.colorTransform = colorTransform; const image = new Image(); image.height = decoder.height; image.width = decoder.width; image.data = new Uint8Array(decoder.width * decoder.height * 4); decoder.copyToImageData(image); return image; }; export { decode as decode };