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JPEG-image decoding, encoding & EXIF reading library for browser and node.js
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JavaScript
"use strict";
Object.defineProperty(exports, "__esModule", {
value: true
});
exports.JpegImage = void 0;
function _typeof(obj) { "@babel/helpers - typeof"; if (typeof Symbol === "function" && typeof Symbol.iterator === "symbol") { _typeof = function _typeof(obj) { return typeof obj; }; } else { _typeof = function _typeof(obj) { return obj && typeof Symbol === "function" && obj.constructor === Symbol && obj !== Symbol.prototype ? "symbol" : typeof obj; }; } return _typeof(obj); }
function _classCallCheck(instance, Constructor) { if (!(instance instanceof Constructor)) { throw new TypeError("Cannot call a class as a function"); } }
function _inherits(subClass, superClass) { if (typeof superClass !== "function" && superClass !== null) { throw new TypeError("Super expression must either be null or a function"); } subClass.prototype = Object.create(superClass && superClass.prototype, { constructor: { value: subClass, writable: true, configurable: true } }); if (superClass) _setPrototypeOf(subClass, superClass); }
function _setPrototypeOf(o, p) { _setPrototypeOf = Object.setPrototypeOf || function _setPrototypeOf(o, p) { o.__proto__ = p; return o; }; return _setPrototypeOf(o, p); }
function _createSuper(Derived) { var hasNativeReflectConstruct = _isNativeReflectConstruct(); return function _createSuperInternal() { var Super = _getPrototypeOf(Derived), result; if (hasNativeReflectConstruct) { var NewTarget = _getPrototypeOf(this).constructor; result = Reflect.construct(Super, arguments, NewTarget); } else { result = Super.apply(this, arguments); } return _possibleConstructorReturn(this, result); }; }
function _possibleConstructorReturn(self, call) { if (call && (_typeof(call) === "object" || typeof call === "function")) { return call; } return _assertThisInitialized(self); }
function _assertThisInitialized(self) { if (self === void 0) { throw new ReferenceError("this hasn't been initialised - super() hasn't been called"); } return self; }
function _isNativeReflectConstruct() { if (typeof Reflect === "undefined" || !Reflect.construct) return false; if (Reflect.construct.sham) return false; if (typeof Proxy === "function") return true; try { Date.prototype.toString.call(Reflect.construct(Date, [], function () {})); return true; } catch (e) { return false; } }
function _getPrototypeOf(o) { _getPrototypeOf = Object.setPrototypeOf ? Object.getPrototypeOf : function _getPrototypeOf(o) { return o.__proto__ || Object.getPrototypeOf(o); }; return _getPrototypeOf(o); }
/* Copyright 2014 Mozilla Foundation
*
* Licensed under the Apache License, Version 2.0 (the 'License');
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an 'AS IS' BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
var BaseException = function BaseExceptionClosure() {
// eslint-disable-next-line no-shadow
function BaseException(message) {
if (this.constructor === BaseException) {
unreachable("Cannot initialize BaseException.");
}
this.message = message;
this.name = this.constructor.name;
}
BaseException.prototype = new Error();
BaseException.constructor = BaseException;
return BaseException;
}();
var VerbosityLevel = {
ERRORS: 0,
WARNINGS: 1,
INFOS: 5
}; // Non-fatal warnings.
function warn(msg) {
if (verbosity >= VerbosityLevel.WARNINGS) {
console.log("Warning: ".concat(msg));
}
}
function unreachable(msg) {
throw new Error(msg);
}
function assert(cond, msg) {
if (!cond) {
unreachable(msg);
}
}
function readUint16(data, offset) {
return data[offset] << 8 | data[offset + 1];
}
var JpegError = /*#__PURE__*/function (_BaseException) {
_inherits(JpegError, _BaseException);
var _super = _createSuper(JpegError);
function JpegError(msg) {
_classCallCheck(this, JpegError);
return _super.call(this, "JPEG error: ".concat(msg));
}
return JpegError;
}(BaseException);
var DNLMarkerError = /*#__PURE__*/function (_BaseException2) {
_inherits(DNLMarkerError, _BaseException2);
var _super2 = _createSuper(DNLMarkerError);
function DNLMarkerError(message, scanLines) {
var _this;
_classCallCheck(this, DNLMarkerError);
_this = _super2.call(this, message);
_this.scanLines = scanLines;
return _this;
}
return DNLMarkerError;
}(BaseException);
var EOIMarkerError = /*#__PURE__*/function (_BaseException3) {
_inherits(EOIMarkerError, _BaseException3);
var _super3 = _createSuper(EOIMarkerError);
function EOIMarkerError() {
_classCallCheck(this, EOIMarkerError);
return _super3.apply(this, arguments);
}
return EOIMarkerError;
}(BaseException);
/**
* This code was forked from https://github.com/notmasteryet/jpgjs.
* The original version was created by GitHub user notmasteryet.
*
* - The JPEG specification can be found in the ITU CCITT Recommendation T.81
* (www.w3.org/Graphics/JPEG/itu-t81.pdf)
* - The JFIF specification can be found in the JPEG File Interchange Format
* (www.w3.org/Graphics/JPEG/jfif3.pdf)
* - The Adobe Application-Specific JPEG markers in the
* Supporting the DCT Filters in PostScript Level 2, Technical Note #5116
* (partners.adobe.com/public/developer/en/ps/sdk/5116.DCT_Filter.pdf)
*/
var JpegImage = function JpegImageClosure() {
// prettier-ignore
var dctZigZag = new Uint8Array([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]);
var dctCos1 = 4017; // cos(pi/16)
var dctSin1 = 799; // sin(pi/16)
var dctCos3 = 3406; // cos(3*pi/16)
var dctSin3 = 2276; // sin(3*pi/16)
var dctCos6 = 1567; // cos(6*pi/16)
var dctSin6 = 3784; // sin(6*pi/16)
var dctSqrt2 = 5793; // sqrt(2)
var dctSqrt1d2 = 2896; // sqrt(2) / 2
// eslint-disable-next-line no-shadow
function JpegImage() {
var _ref = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : {},
_ref$decodeTransform = _ref.decodeTransform,
decodeTransform = _ref$decodeTransform === void 0 ? null : _ref$decodeTransform,
_ref$colorTransform = _ref.colorTransform,
colorTransform = _ref$colorTransform === void 0 ? -1 : _ref$colorTransform;
this._decodeTransform = decodeTransform;
this._colorTransform = colorTransform;
}
function buildHuffmanTable(codeLengths, values) {
var k = 0,
code = [],
i,
j,
length = 16;
while (length > 0 && !codeLengths[length - 1]) {
length--;
}
code.push({
children: [],
index: 0
});
var 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) {
// p here points to last code
code.push(q = {
children: [],
index: 0
});
p.children[p.index] = q.children;
p = q;
}
}
return code[0].children;
}
function getBlockBufferOffset(component, row, col) {
return 64 * ((component.blocksPerLine + 1) * row + col);
}
function decodeScan(data, offset, frame, components, resetInterval, spectralStart, spectralEnd, successivePrev, successive) {
var parseDNLMarker = arguments.length > 9 && arguments[9] !== undefined ? arguments[9] : false;
var mcusPerLine = frame.mcusPerLine;
var progressive = frame.progressive;
var startOffset = offset;
var bitsData = 0,
bitsCount = 0;
function readBit() {
if (bitsCount > 0) {
bitsCount--;
return bitsData >> bitsCount & 1;
}
bitsData = data[offset++];
if (bitsData === 0xff) {
var nextByte = data[offset++];
if (nextByte) {
if (nextByte ===
/* DNL = */
0xdc && parseDNLMarker) {
offset += 2; // Skip marker length.
var scanLines = readUint16(data, offset);
offset += 2;
if (scanLines > 0 && scanLines !== frame.scanLines) {
throw new DNLMarkerError("Found DNL marker (0xFFDC) while parsing scan data", scanLines);
}
} else if (nextByte ===
/* EOI = */
0xd9) {
if (parseDNLMarker) {
// NOTE: only 8-bit JPEG images are supported in this decoder.
var maybeScanLines = blockRow * (frame.precision === 8 ? 8 : 0); // Heuristic to attempt to handle corrupt JPEG images with too
// large `scanLines` parameter, by falling back to the currently
// parsed number of scanLines when it's at least (approximately)
// one order of magnitude smaller than expected (fixes
// issue10880.pdf and issue10989.pdf).
if (maybeScanLines > 0 && Math.round(frame.scanLines / maybeScanLines) >= 10) {
throw new DNLMarkerError("Found EOI marker (0xFFD9) while parsing scan data, " + "possibly caused by incorrect `scanLines` parameter", maybeScanLines);
}
}
throw new EOIMarkerError("Found EOI marker (0xFFD9) while parsing scan data");
}
throw new JpegError("unexpected marker ".concat((bitsData << 8 | nextByte).toString(16)));
} // unstuff 0
}
bitsCount = 7;
return bitsData >>> 7;
}
function decodeHuffman(tree) {
var node = tree;
while (true) {
node = node[readBit()];
switch (_typeof(node)) {
case "number":
return node;
case "object":
continue;
}
throw new JpegError("invalid huffman sequence");
}
}
function receive(length) {
var n = 0;
while (length > 0) {
n = n << 1 | readBit();
length--;
}
return n;
}
function receiveAndExtend(length) {
if (length === 1) {
return readBit() === 1 ? 1 : -1;
}
var n = receive(length);
if (n >= 1 << length - 1) {
return n;
}
return n + (-1 << length) + 1;
}
function decodeBaseline(component, blockOffset) {
var t = decodeHuffman(component.huffmanTableDC);
var diff = t === 0 ? 0 : receiveAndExtend(t);
component.blockData[blockOffset] = component.pred += diff;
var k = 1;
while (k < 64) {
var rs = decodeHuffman(component.huffmanTableAC);
var s = rs & 15,
r = rs >> 4;
if (s === 0) {
if (r < 15) {
break;
}
k += 16;
continue;
}
k += r;
var z = dctZigZag[k];
component.blockData[blockOffset + z] = receiveAndExtend(s);
k++;
}
}
function decodeDCFirst(component, blockOffset) {
var t = decodeHuffman(component.huffmanTableDC);
var diff = t === 0 ? 0 : receiveAndExtend(t) << successive;
component.blockData[blockOffset] = component.pred += diff;
}
function decodeDCSuccessive(component, blockOffset) {
component.blockData[blockOffset] |= readBit() << successive;
}
var eobrun = 0;
function decodeACFirst(component, blockOffset) {
if (eobrun > 0) {
eobrun--;
return;
}
var k = spectralStart,
e = spectralEnd;
while (k <= e) {
var rs = decodeHuffman(component.huffmanTableAC);
var s = rs & 15,
r = rs >> 4;
if (s === 0) {
if (r < 15) {
eobrun = receive(r) + (1 << r) - 1;
break;
}
k += 16;
continue;
}
k += r;
var z = dctZigZag[k];
component.blockData[blockOffset + z] = receiveAndExtend(s) * (1 << successive);
k++;
}
}
var successiveACState = 0,
successiveACNextValue;
function decodeACSuccessive(component, blockOffset) {
var k = spectralStart;
var e = spectralEnd;
var r = 0;
var s;
var rs;
while (k <= e) {
var offsetZ = blockOffset + dctZigZag[k];
var sign = component.blockData[offsetZ] < 0 ? -1 : 1;
switch (successiveACState) {
case 0:
// initial state
rs = decodeHuffman(component.huffmanTableAC);
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 JpegError("invalid ACn encoding");
}
successiveACNextValue = receiveAndExtend(s);
successiveACState = r ? 2 : 3;
}
continue;
case 1: // skipping r zero items
case 2:
if (component.blockData[offsetZ]) {
component.blockData[offsetZ] += sign * (readBit() << successive);
} else {
r--;
if (r === 0) {
successiveACState = successiveACState === 2 ? 3 : 0;
}
}
break;
case 3:
// set value for a zero item
if (component.blockData[offsetZ]) {
component.blockData[offsetZ] += sign * (readBit() << successive);
} else {
component.blockData[offsetZ] = successiveACNextValue << successive;
successiveACState = 0;
}
break;
case 4:
// eob
if (component.blockData[offsetZ]) {
component.blockData[offsetZ] += sign * (readBit() << successive);
}
break;
}
k++;
}
if (successiveACState === 4) {
eobrun--;
if (eobrun === 0) {
successiveACState = 0;
}
}
}
var blockRow = 0;
function decodeMcu(component, decode, mcu, row, col) {
var mcuRow = mcu / mcusPerLine | 0;
var mcuCol = mcu % mcusPerLine;
blockRow = mcuRow * component.v + row;
var blockCol = mcuCol * component.h + col;
var blockOffset = getBlockBufferOffset(component, blockRow, blockCol);
decode(component, blockOffset);
}
function decodeBlock(component, decode, mcu) {
blockRow = mcu / component.blocksPerLine | 0;
var blockCol = mcu % component.blocksPerLine;
var blockOffset = getBlockBufferOffset(component, blockRow, blockCol);
decode(component, blockOffset);
}
var componentsLength = components.length;
var component, i, j, k, n;
var decodeFn;
if (progressive) {
if (spectralStart === 0) {
decodeFn = successivePrev === 0 ? decodeDCFirst : decodeDCSuccessive;
} else {
decodeFn = successivePrev === 0 ? decodeACFirst : decodeACSuccessive;
}
} else {
decodeFn = decodeBaseline;
}
var mcu = 0,
fileMarker;
var mcuExpected;
if (componentsLength === 1) {
mcuExpected = components[0].blocksPerLine * components[0].blocksPerColumn;
} else {
mcuExpected = mcusPerLine * frame.mcusPerColumn;
}
var h, v;
while (mcu <= mcuExpected) {
// reset interval stuff
var mcuToRead = resetInterval ? Math.min(mcuExpected - mcu, resetInterval) : mcuExpected; // The `mcuToRead === 0` case should only occur when all of the expected
// MCU data has been already parsed, i.e. when `mcu === mcuExpected`, but
// some corrupt JPEG images contain more data than intended and we thus
// want to skip over any extra RSTx markers below (fixes issue11794.pdf).
if (mcuToRead > 0) {
for (i = 0; i < componentsLength; i++) {
components[i].pred = 0;
}
eobrun = 0;
if (componentsLength === 1) {
component = components[0];
for (n = 0; n < mcuToRead; n++) {
decodeBlock(component, decodeFn, mcu);
mcu++;
}
} else {
for (n = 0; n < mcuToRead; n++) {
for (i = 0; i < componentsLength; i++) {
component = components[i];
h = component.h;
v = component.v;
for (j = 0; j < v; j++) {
for (k = 0; k < h; k++) {
decodeMcu(component, decodeFn, mcu, j, k);
}
}
}
mcu++;
}
}
} // find marker
bitsCount = 0;
fileMarker = findNextFileMarker(data, offset);
if (!fileMarker) {
break; // Reached the end of the image data without finding any marker.
}
if (fileMarker.invalid) {
// Some bad images seem to pad Scan blocks with e.g. zero bytes, skip
// past those to attempt to find a valid marker (fixes issue4090.pdf).
var partialMsg = mcuToRead > 0 ? "unexpected" : "excessive";
warn("decodeScan - ".concat(partialMsg, " MCU data, current marker is: ").concat(fileMarker.invalid));
offset = fileMarker.offset;
}
if (fileMarker.marker >= 0xffd0 && fileMarker.marker <= 0xffd7) {
// RSTx
offset += 2;
} else {
break;
}
}
return offset - startOffset;
} // A port of poppler's IDCT method which in turn is taken from:
// Christoph Loeffler, Adriaan Ligtenberg, George S. Moschytz,
// 'Practical Fast 1-D DCT Algorithms with 11 Multiplications',
// IEEE Intl. Conf. on Acoustics, Speech & Signal Processing, 1989,
// 988-991.
function quantizeAndInverse(component, blockBufferOffset, p) {
var qt = component.quantizationTable,
blockData = component.blockData;
var v0, v1, v2, v3, v4, v5, v6, v7;
var p0, p1, p2, p3, p4, p5, p6, p7;
var t;
if (!qt) {
throw new JpegError("missing required Quantization Table.");
} // inverse DCT on rows
for (var row = 0; row < 64; row += 8) {
// gather block data
p0 = blockData[blockBufferOffset + row];
p1 = blockData[blockBufferOffset + row + 1];
p2 = blockData[blockBufferOffset + row + 2];
p3 = blockData[blockBufferOffset + row + 3];
p4 = blockData[blockBufferOffset + row + 4];
p5 = blockData[blockBufferOffset + row + 5];
p6 = blockData[blockBufferOffset + row + 6];
p7 = blockData[blockBufferOffset + row + 7]; // dequant p0
p0 *= qt[row]; // check for all-zero AC coefficients
if ((p1 | p2 | p3 | p4 | p5 | p6 | p7) === 0) {
t = dctSqrt2 * p0 + 512 >> 10;
p[row] = t;
p[row + 1] = t;
p[row + 2] = t;
p[row + 3] = t;
p[row + 4] = t;
p[row + 5] = t;
p[row + 6] = t;
p[row + 7] = t;
continue;
} // dequant p1 ... p7
p1 *= qt[row + 1];
p2 *= qt[row + 2];
p3 *= qt[row + 3];
p4 *= qt[row + 4];
p5 *= qt[row + 5];
p6 *= qt[row + 6];
p7 *= qt[row + 7]; // stage 4
v0 = dctSqrt2 * p0 + 128 >> 8;
v1 = dctSqrt2 * p4 + 128 >> 8;
v2 = p2;
v3 = p6;
v4 = dctSqrt1d2 * (p1 - p7) + 128 >> 8;
v7 = dctSqrt1d2 * (p1 + p7) + 128 >> 8;
v5 = p3 << 4;
v6 = p5 << 4; // stage 3
v0 = v0 + v1 + 1 >> 1;
v1 = v0 - v1;
t = v2 * dctSin6 + v3 * dctCos6 + 128 >> 8;
v2 = v2 * dctCos6 - v3 * dctSin6 + 128 >> 8;
v3 = t;
v4 = v4 + v6 + 1 >> 1;
v6 = v4 - v6;
v7 = v7 + v5 + 1 >> 1;
v5 = v7 - v5; // stage 2
v0 = v0 + v3 + 1 >> 1;
v3 = v0 - v3;
v1 = v1 + v2 + 1 >> 1;
v2 = v1 - v2;
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; // stage 1
p[row] = v0 + v7;
p[row + 7] = v0 - v7;
p[row + 1] = v1 + v6;
p[row + 6] = v1 - v6;
p[row + 2] = v2 + v5;
p[row + 5] = v2 - v5;
p[row + 3] = v3 + v4;
p[row + 4] = v3 - v4;
} // inverse DCT on columns
for (var col = 0; col < 8; ++col) {
p0 = p[col];
p1 = p[col + 8];
p2 = p[col + 16];
p3 = p[col + 24];
p4 = p[col + 32];
p5 = p[col + 40];
p6 = p[col + 48];
p7 = p[col + 56]; // check for all-zero AC coefficients
if ((p1 | p2 | p3 | p4 | p5 | p6 | p7) === 0) {
t = dctSqrt2 * p0 + 8192 >> 14; // Convert to 8-bit.
if (t < -2040) {
t = 0;
} else if (t >= 2024) {
t = 255;
} else {
t = t + 2056 >> 4;
}
blockData[blockBufferOffset + col] = t;
blockData[blockBufferOffset + col + 8] = t;
blockData[blockBufferOffset + col + 16] = t;
blockData[blockBufferOffset + col + 24] = t;
blockData[blockBufferOffset + col + 32] = t;
blockData[blockBufferOffset + col + 40] = t;
blockData[blockBufferOffset + col + 48] = t;
blockData[blockBufferOffset + col + 56] = t;
continue;
} // stage 4
v0 = dctSqrt2 * p0 + 2048 >> 12;
v1 = dctSqrt2 * p4 + 2048 >> 12;
v2 = p2;
v3 = p6;
v4 = dctSqrt1d2 * (p1 - p7) + 2048 >> 12;
v7 = dctSqrt1d2 * (p1 + p7) + 2048 >> 12;
v5 = p3;
v6 = p5; // stage 3
// Shift v0 by 128.5 << 5 here, so we don't need to shift p0...p7 when
// converting to UInt8 range later.
v0 = (v0 + v1 + 1 >> 1) + 4112;
v1 = v0 - v1;
t = v2 * dctSin6 + v3 * dctCos6 + 2048 >> 12;
v2 = v2 * dctCos6 - v3 * dctSin6 + 2048 >> 12;
v3 = t;
v4 = v4 + v6 + 1 >> 1;
v6 = v4 - v6;
v7 = v7 + v5 + 1 >> 1;
v5 = v7 - v5; // stage 2
v0 = v0 + v3 + 1 >> 1;
v3 = v0 - v3;
v1 = v1 + v2 + 1 >> 1;
v2 = v1 - v2;
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; // stage 1
p0 = v0 + v7;
p7 = v0 - v7;
p1 = v1 + v6;
p6 = v1 - v6;
p2 = v2 + v5;
p5 = v2 - v5;
p3 = v3 + v4;
p4 = v3 - v4; // Convert to 8-bit integers.
if (p0 < 16) {
p0 = 0;
} else if (p0 >= 4080) {
p0 = 255;
} else {
p0 >>= 4;
}
if (p1 < 16) {
p1 = 0;
} else if (p1 >= 4080) {
p1 = 255;
} else {
p1 >>= 4;
}
if (p2 < 16) {
p2 = 0;
} else if (p2 >= 4080) {
p2 = 255;
} else {
p2 >>= 4;
}
if (p3 < 16) {
p3 = 0;
} else if (p3 >= 4080) {
p3 = 255;
} else {
p3 >>= 4;
}
if (p4 < 16) {
p4 = 0;
} else if (p4 >= 4080) {
p4 = 255;
} else {
p4 >>= 4;
}
if (p5 < 16) {
p5 = 0;
} else if (p5 >= 4080) {
p5 = 255;
} else {
p5 >>= 4;
}
if (p6 < 16) {
p6 = 0;
} else if (p6 >= 4080) {
p6 = 255;
} else {
p6 >>= 4;
}
if (p7 < 16) {
p7 = 0;
} else if (p7 >= 4080) {
p7 = 255;
} else {
p7 >>= 4;
} // store block data
blockData[blockBufferOffset + col] = p0;
blockData[blockBufferOffset + col + 8] = p1;
blockData[blockBufferOffset + col + 16] = p2;
blockData[blockBufferOffset + col + 24] = p3;
blockData[blockBufferOffset + col + 32] = p4;
blockData[blockBufferOffset + col + 40] = p5;
blockData[blockBufferOffset + col + 48] = p6;
blockData[blockBufferOffset + col + 56] = p7;
}
}
function buildComponentData(frame, component) {
var blocksPerLine = component.blocksPerLine;
var blocksPerColumn = component.blocksPerColumn;
var computationBuffer = new Int16Array(64);
for (var blockRow = 0; blockRow < blocksPerColumn; blockRow++) {
for (var blockCol = 0; blockCol < blocksPerLine; blockCol++) {
var offset = getBlockBufferOffset(component, blockRow, blockCol);
quantizeAndInverse(component, offset, computationBuffer);
}
}
return component.blockData;
}
function findNextFileMarker(data, currentPos) {
var startPos = arguments.length > 2 && arguments[2] !== undefined ? arguments[2] : currentPos;
var maxPos = data.length - 1;
var newPos = startPos < currentPos ? startPos : currentPos;
if (currentPos >= maxPos) {
return null; // Don't attempt to read non-existent data and just return.
}
var currentMarker = readUint16(data, currentPos);
if (currentMarker >= 0xffc0 && currentMarker <= 0xfffe) {
return {
invalid: null,
marker: currentMarker,
offset: currentPos
};
}
var newMarker = readUint16(data, newPos);
while (!(newMarker >= 0xffc0 && newMarker <= 0xfffe)) {
if (++newPos >= maxPos) {
return null; // Don't attempt to read non-existent data and just return.
}
newMarker = readUint16(data, newPos);
}
return {
invalid: currentMarker.toString(16),
marker: newMarker,
offset: newPos
};
}
JpegImage.prototype = {
parse: function parse(data) {
var _ref2 = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : {},
_ref2$dnlScanLines = _ref2.dnlScanLines,
dnlScanLines = _ref2$dnlScanLines === void 0 ? null : _ref2$dnlScanLines;
function readDataBlock() {
var length = readUint16(data, offset);
offset += 2;
var endOffset = offset + length - 2;
var fileMarker = findNextFileMarker(data, endOffset, offset);
if (fileMarker && fileMarker.invalid) {
warn("readDataBlock - incorrect length, current marker is: " + fileMarker.invalid);
endOffset = fileMarker.offset;
}
var array = data.subarray(offset, endOffset);
offset += array.length;
return array;
}
function prepareComponents(frame) {
var mcusPerLine = Math.ceil(frame.samplesPerLine / 8 / frame.maxH);
var mcusPerColumn = Math.ceil(frame.scanLines / 8 / frame.maxV);
for (var i = 0; i < frame.components.length; i++) {
component = frame.components[i];
var blocksPerLine = Math.ceil(Math.ceil(frame.samplesPerLine / 8) * component.h / frame.maxH);
var blocksPerColumn = Math.ceil(Math.ceil(frame.scanLines / 8) * component.v / frame.maxV);
var blocksPerLineForMcu = mcusPerLine * component.h;
var blocksPerColumnForMcu = mcusPerColumn * component.v;
var blocksBufferSize = 64 * blocksPerColumnForMcu * (blocksPerLineForMcu + 1);
component.blockData = new Int16Array(blocksBufferSize);
component.blocksPerLine = blocksPerLine;
component.blocksPerColumn = blocksPerColumn;
}
frame.mcusPerLine = mcusPerLine;
frame.mcusPerColumn = mcusPerColumn;
}
var offset = 0;
var jfif = null;
var adobe = null;
var frame, resetInterval;
var numSOSMarkers = 0;
var quantizationTables = [];
var huffmanTablesAC = [],
huffmanTablesDC = [];
var fileMarker = readUint16(data, offset);
offset += 2;
if (fileMarker !==
/* SOI (Start of Image) = */
0xffd8) {
throw new JpegError("SOI not found");
}
fileMarker = readUint16(data, offset);
offset += 2;
markerLoop: while (fileMarker !==
/* EOI (End of Image) = */
0xffd9) {
var i, j, l;
switch (fileMarker) {
case 0xffe0: // APP0 (Application Specific)
case 0xffe1: // APP1
case 0xffe2: // APP2
case 0xffe3: // APP3
case 0xffe4: // APP4
case 0xffe5: // APP5
case 0xffe6: // APP6
case 0xffe7: // APP7
case 0xffe8: // APP8
case 0xffe9: // APP9
case 0xffea: // APP10
case 0xffeb: // APP11
case 0xffec: // APP12
case 0xffed: // APP13
case 0xffee: // APP14
case 0xffef: // APP15
case 0xfffe:
// COM (Comment)
var appData = readDataBlock();
if (fileMarker === 0xffe0) {
// 'JFIF\x00'
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])
};
}
} // TODO APP1 - Exif
if (fileMarker === 0xffee) {
// 'Adobe'
if (appData[0] === 0x41 && appData[1] === 0x64 && appData[2] === 0x6f && appData[3] === 0x62 && appData[4] === 0x65) {
adobe = {
version: appData[5] << 8 | appData[6],
flags0: appData[7] << 8 | appData[8],
flags1: appData[9] << 8 | appData[10],
transformCode: appData[11]
};
}
}
break;
case 0xffdb:
// DQT (Define Quantization Tables)
var quantizationTablesLength = readUint16(data, offset);
offset += 2;
var quantizationTablesEnd = quantizationTablesLength + offset - 2;
var z;
while (offset < quantizationTablesEnd) {
var quantizationTableSpec = data[offset++];
var tableData = new Uint16Array(64);
if (quantizationTableSpec >> 4 === 0) {
// 8 bit values
for (j = 0; j < 64; j++) {
z = dctZigZag[j];
tableData[z] = data[offset++];
}
} else if (quantizationTableSpec >> 4 === 1) {
// 16 bit values
for (j = 0; j < 64; j++) {
z = dctZigZag[j];
tableData[z] = readUint16(data, offset);
offset += 2;
}
} else {
throw new JpegError("DQT - invalid table spec");
}
quantizationTables[quantizationTableSpec & 15] = tableData;
}
break;
case 0xffc0: // SOF0 (Start of Frame, Baseline DCT)
case 0xffc1: // SOF1 (Start of Frame, Extended DCT)
case 0xffc2:
// SOF2 (Start of Frame, Progressive DCT)
if (frame) {
throw new JpegError("Only single frame JPEGs supported");
}
offset += 2; // Skip marker length.
frame = {};
frame.extended = fileMarker === 0xffc1;
frame.progressive = fileMarker === 0xffc2;
frame.precision = data[offset++];
var sofScanLines = readUint16(data, offset);
offset += 2;
frame.scanLines = dnlScanLines || sofScanLines;
frame.samplesPerLine = readUint16(data, offset);
offset += 2;
frame.components = [];
frame.componentIds = {};
var componentsCount = data[offset++],
componentId;
var maxH = 0,
maxV = 0;
for (i = 0; i < componentsCount; i++) {
componentId = data[offset];
var h = data[offset + 1] >> 4;
var v = data[offset + 1] & 15;
if (maxH < h) {
maxH = h;
}
if (maxV < v) {
maxV = v;
}
var qId = data[offset + 2];
l = frame.components.push({
h: h,
v: v,
quantizationId: qId,
quantizationTable: null // See comment below.
});
frame.componentIds[componentId] = l - 1;
offset += 3;
}
frame.maxH = maxH;
frame.maxV = maxV;
prepareComponents(frame);
break;
case 0xffc4:
// DHT (Define Huffman Tables)
var huffmanLength = readUint16(data, offset);
offset += 2;
for (i = 2; i < huffmanLength;) {
var huffmanTableSpec = data[offset++];
var codeLengths = new Uint8Array(16);
var codeLengthSum = 0;
for (j = 0; j < 16; j++, offset++) {
codeLengthSum += codeLengths[j] = data[offset];
}
var 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:
// DRI (Define Restart Interval)
offset += 2; // Skip marker length.
resetInterval = readUint16(data, offset);
offset += 2;
break;
case 0xffda:
// SOS (Start of Scan)
// A DNL marker (0xFFDC), if it exists, is only allowed at the end
// of the first scan segment and may only occur once in an image.
// Furthermore, to prevent an infinite loop, do *not* attempt to
// parse DNL markers during re-parsing of the JPEG scan data.
var parseDNLMarker = ++numSOSMarkers === 1 && !dnlScanLines;
offset += 2; // Skip marker length.
var selectorsCount = data[offset++];
var components = [],
component;
for (i = 0; i < selectorsCount; i++) {
var index = data[offset++];
var componentIndex = frame.componentIds[index];
component = frame.components[componentIndex];
component.index = index;
var tableSpec = data[offset++];
component.huffmanTableDC = huffmanTablesDC[tableSpec >> 4];
component.huffmanTableAC = huffmanTablesAC[tableSpec & 15];
components.push(component);
}
var spectralStart = data[offset++];
var spectralEnd = data[offset++];
var successiveApproximation = data[offset++];
try {
var processed = decodeScan(data, offset, frame, components, resetInterval, spectralStart, spectralEnd, successiveApproximation >> 4, successiveApproximation & 15, parseDNLMarker);
offset += processed;
} catch (ex) {
if (ex instanceof DNLMarkerError) {
warn("".concat(ex.message, " -- attempting to re-parse the JPEG image."));
return this.parse(data, {
dnlScanLines: ex.scanLines
});
} else if (ex instanceof EOIMarkerError) {
warn("".concat(ex.message, " -- ignoring the rest of the image data."));
break markerLoop;
}
throw ex;
}
break;
case 0xffdc:
// DNL (Define Number of Lines)
// Ignore the marker, since it's being handled in `decodeScan`.
offset += 4;
break;
case 0xffff:
// Fill bytes
if (data[offset] !== 0xff) {
// Avoid skipping a valid marker.
offset--;
}
break;
default:
// Could be incorrect encoding -- the last 0xFF byte of the previous
// block could have been eaten by the encoder, hence we fallback to
// `startPos = offset - 3` when looking for the next valid marker.
var nextFileMarker = findNextFileMarker(data,
/* currentPos = */
offset - 2,
/* startPos = */
offset - 3);
if (nextFileMarker && nextFileMarker.invalid) {
warn("JpegImage.parse - unexpected data, current marker is: " + nextFileMarker.invalid);
offset = nextFileMarker.offset;
break;
}
if (offset >= data.length - 1) {
warn("JpegImage.parse - reached the end of the image data " + "without finding an EOI marker (0xFFD9).");
break markerLoop;
}
throw new JpegError("JpegImage.parse - unknown marker: " + fileMarker.toString(16));
}
fileMarker = readUint16(data, offset);
offset += 2;
}
this.width = frame.samplesPerLine;
this.height = frame.scanLines;
this.jfif = jfif;
this.adobe = adobe;
this.components = [];
for (i = 0; i < frame.components.length; i++) {
component = frame.components[i]; // Prevent errors when DQT markers are placed after SOF{n} markers,
// by assigning the `quantizationTable` entry after the entire image
// has been parsed (fixes issue7406.pdf).
var quantizationTable = quantizationTables[component.quantizationId];
if (quantizationTable) {
component.quantizationTable = quantizationTable;
}
this.components.push({
index: component.index,
output: buildComponentData(frame, component),
scaleX: component.h / frame.maxH,
scaleY: component.v / frame.maxV,
blocksPerLine: component.blocksPerLine,
blocksPerColumn: component.blocksPerColumn
});
}
this.numComponents = this.components.length;
return undefined;
},
_getLinearizedBlockData: function _getLinearizedBlockData(width, height) {
var isSourcePDF = arguments.length > 2 && arguments[2] !== undefined ? arguments[2] : false;
var scaleX = this.width / width,
scaleY = this.height / height;
var component, componentScaleX, componentScaleY, blocksPerScanline;
var x, y, i, j, k;
var index;
var offset = 0;
var output;
var numComponents = this.components.length;
var dataLength = width * height * numComponents;
var data = new Uint8ClampedArray(dataLength);
var xScaleBlockOffset = new Uint32Array(width);
var mask3LSB = 0xfffffff8; // used to clear the 3 LSBs
var lastComponentScaleX;
for (i = 0; i < numComponents; i++) {
component = this.components[i];
componentScaleX = component.scaleX * scaleX;
componentScaleY = component.scaleY * scaleY;
offset = i;
output = component.output;
blocksPerScanline = component.blocksPerLine + 1 << 3; // Precalculate the `xScaleBlockOffset`. Since it doesn't depend on the
// component data, that's only necessary when `componentScaleX` changes.
if (componentScaleX !== lastComponentScaleX) {
for (x = 0; x < width; x++) {
j = 0 | x * componentScaleX;
xScaleBlockOffset[x] = (j & mask3LSB) << 3 | j & 7;
}
lastComponentScaleX = componentScaleX;
} // linearize the blocks of the component
for (y = 0; y < height; y++) {
j = 0 | y * componentScaleY;
index = blocksPerScanline * (j & mask3LSB) | (j & 7) << 3;
for (x = 0; x < width; x++) {
data[offset] = output[index + xScaleBlockOffset[x]];
offset += numComponents;
}
}
} // decodeTransform contains pairs of multiplier (-256..256) and additive
var transform = this._decodeTransform; // In PDF files, JPEG images with CMYK colour spaces are usually inverted
// (this can be observed by extracting the raw image data).
// Since the conversion algorithms (see below) were written primarily for
// the PDF use-cases, attempting to use `JpegImage` to parse standalone
// JPEG (CMYK) images may thus result in inverted images (see issue 9513).
//
// Unfortunately it's not (always) possible to tell, from the image data
// alone, if it needs to be inverted. Thus in an attempt to provide better
// out-of-box behaviour when `JpegImage` is used standalone, default to
// inverting JPEG (CMYK) images if and only if the image data does *not*
// come from a PDF file and no `decodeTransform` was passed by the user.
if (!isSourcePDF && numComponents === 4 && !transform) {
// prettier-ignore
transform = new Int32Array([-256, 255, -256, 255, -256, 255, -256, 255]);
}
if (transform) {
for (i = 0; i < dataLength;) {
for (j = 0, k = 0; j < numComponents; j++, i++, k += 2) {
data[i] = (data[i] * transform[k] >> 8) + transform[k + 1];
}
}
}
return data;
},
get _isColorConversionNeeded() {
if (this.adobe) {
// The adobe transform marker overrides any previous setting.
return !!this.adobe.transformCode;
}
if (this.numComponents === 3) {
if (this._colorTransform === 0) {
// If the Adobe transform marker is not present and the image
// dictionary has a 'ColorTransform' entry, explicitly set to `0`,
// then the colours should *not* be transformed.
return false;
} else if (this.components[0].index ===
/* "R" = */
0x52 && this.components[1].index ===
/* "G" = */
0x47 && this.components[2].index ===
/* "B" = */
0x42) {
// If the three components are indexed as RGB in ASCII
// then the colours should *not* be transformed.
return false;
}
return true;
} // `this.numComponents !== 3`
if (this._colorTransform === 1) {
// If the Adobe transform marker is not present and the image
// dictionary has a 'ColorTransform' entry, explicitly set to `1`,
// then the colours should be transformed.
return true;
}
return false;
},
_convertYccToRgb: function convertYccToRgb(data) {
var Y, Cb, Cr;
for (var i = 0, length = data.length; i < length; i += 3) {
Y = data[i];
Cb = data[i + 1];
Cr = data[i + 2];
data[i] = Y - 179.456 + 1.402 * Cr;
data[i + 1] = Y + 135.459 - 0.344 * Cb - 0.714 * Cr;
data[i + 2] = Y - 226.816 + 1.772 * Cb;
}
return data;
},
_convertYcckToRgb: function convertYcckToRgb(data) {
var Y, Cb, Cr, k;
var offset = 0;
for (var i = 0, length = data.length; i < length; i += 4) {
Y = data[i];
Cb = data[i + 1];
Cr = data[i + 2];
k = data[i + 3];
data[offset++] = -122.67195406894 + Cb * (-6.60635669420364e-5 * Cb + 0.000437130475926232 * Cr - 5.4080610064599e-5 * Y + 0.00048449797120281 * k - 0.154362151871126) + Cr * (-0.000957964378445773 * Cr + 0.000817076911346625 * Y - 0.00477271405408747 * k + 1.53380253221734) + Y * (0.000961250184130688 * Y - 0.00266257332283933 * k + 0.48357088451265) + k * (-0.000336197177618394 * k + 0.484791561490776);
data[offset++] = 107.268039397724 + Cb * (2.19927104525741e-5 * Cb - 0.000640992018297945 * Cr + 0.000659397001245577 * Y + 0.000426105652938837 * k - 0.176491792462875) + Cr * (-0.000778269941513683 * Cr + 0.00130872261408275 * Y + 0.000770482631801132 * k - 0.151051492775562) + Y * (0.00126935368114843 * Y - 0.00265090189010898 * k + 0.25802910206845) + k * (-0.000318913117588328 * k - 0.213742400323665);
data[offset++] = -20.810012546947 + Cb * (-0.000570115196973677 * Cb - 2.63409051004589e-5 * Cr + 0.0020741088115012 * Y - 0.00288260236853442 * k + 0.814272968359295) + Cr * (-1.53496057440975e-5 * Cr - 0.000132689043961446 * Y + 0.000560833691242812 * k - 0.195152027534049) + Y * (0.00174418132927582 * Y - 0.00255243321439347 * k + 0.116935020465145) + k * (-0.000343531996510555 * k + 0.24165260232407);
} // Ensure that only the converted RGB data is returned.
return data.subarray(0, offset);
},
_convertYcckToCmyk: function convertYcckToCmyk(data) {
var Y, Cb, Cr;
for (var i = 0, length = data.length; i < length; i += 4) {
Y = data[i];
Cb = data[i + 1];
Cr = data[i + 2];
data[i] = 434.456 - Y - 1.402 * Cr;
data[i + 1] = 119.541 - Y + 0.344 * Cb + 0.714 * Cr;
data[i + 2] = 481.816 - Y - 1.772 * Cb; // K in data[i + 3] is unchanged
}
return data;
},
_convertCmykToRgb: function convertCmykToRgb(data) {
var c, m, y, k;
var offset = 0;
for (var i = 0, length = data.length; i < length; i += 4) {
c = data[i];
m = data[i + 1];
y = data[i + 2];
k = data[i + 3];
data[offset++] = 255 + c * (-0.00006747147073602441 * c + 0.0008379262121013727 * m + 0.0002894718188643294 * y + 0.003264231057537806 * k - 1.1185611867203937) + m * (0.000026374107616089405 * m - 0.00008626949158638572 * y - 0.0002748769067499491 * k - 0.02155688794978967) + y * (-0.00003878099212869363 * y - 0.0003267808279485286 * k + 0.0686742238595345) - k * (0.0003361971776183937 * k + 0.7430659151342254);
data[offset++] = 255 + c * (0.00013596372813588848 * c + 0.000924537132573585 * m + 0.00010567359618683593 * y + 0.0004791864687436512 * k - 0.3109689587515875) + m * (-0.00023545346108370344 * m + 0.0002702845253534714 * y + 0.0020200308977307156 * k - 0.7488052167015494) + y * (0.00006834815998235662 * y + 0.00015168452363460973 * k - 0.09751927774728933) - k * (0.00031891311758832814 * k + 0.7364883807733168);
data[offset++] = 255 + c * (0.000013598650411385307 * c + 0.00012423956175490851 * m + 0.0004751985097583589 * y - 0.0000036729317476630422 * k - 0.05562186980264034) + m * (0.00016141380598724676 * m + 0.0009692239130725186 * y + 0.0007782692450036253 * k - 0.44015232367526463) + y * (5.068882914068769e-7 * y + 0.0017778369011375071 * k - 0.7591454649749609) - k * (0.0003435319965105553 * k + 0.7063770186160144);
} // Ensure that only the converted RGB data is returned.
return data.subarray(0, offset);
},
getData: function getData(_ref3) {
var width = _ref3.width,
height = _ref3.height,
_ref3$forceRGB = _ref3.forceRGB,
forceRGB = _ref3$forceRGB === void 0 ? false : _ref3$forceRGB,
_ref3$isSourcePDF = _ref3.isSourcePDF,
isSourcePDF = _ref3$isSourcePDF === void 0 ? false : _ref3$isSourcePDF;
if (this.numComponents > 4) {
throw new JpegError("Unsupported color mode");
} // Type of data: Uint8ClampedArray(width * height * numComponents)
var data = this._getLinearizedBlockData(width, height, isSourcePDF);
if (this.numComponents === 1 && forceRGB) {
var dataLength = data.length;
var rgbData = new Uint8ClampedArray(dataLength * 3);
var offset = 0;
for (var i = 0; i < dataLength; i++) {
var grayColor = data[i];
rgbData[offset++] = grayColor;
rgbData[offset++] = grayColor;
rgbData[offset++] = grayColor;
}
return rgbData;
} else if (this.numComponents === 3 && this._isColorConversionNeeded) {
return this._convertYccToRgb(data);
} else if (this.numComponents === 4) {
if (this._isColorConversionNeeded) {
if (forceRGB) {
return this._convertYcckToRgb(data);
}
return this._convertYcckToCmyk(data);
} else if (forceRGB) {
return this._convertCmykToRgb(data);
}
}
return data;
}
};
return JpegImage;
}();
exports.JpegImage = JpegImage;