jpg.js 33 KB

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  1. /* Copyright 2017 Mozilla Foundation
  2. *
  3. * Licensed under the Apache License, Version 2.0 (the "License");
  4. * you may not use this file except in compliance with the License.
  5. * You may obtain a copy of the License at
  6. *
  7. * http://www.apache.org/licenses/LICENSE-2.0
  8. *
  9. * Unless required by applicable law or agreed to in writing, software
  10. * distributed under the License is distributed on an "AS IS" BASIS,
  11. * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  12. * See the License for the specific language governing permissions and
  13. * limitations under the License.
  14. */
  15. 'use strict';
  16. Object.defineProperty(exports, "__esModule", {
  17. value: true
  18. });
  19. exports.JpegImage = undefined;
  20. var _typeof = typeof Symbol === "function" && typeof Symbol.iterator === "symbol" ? function (obj) { return typeof obj; } : function (obj) { return obj && typeof Symbol === "function" && obj.constructor === Symbol && obj !== Symbol.prototype ? "symbol" : typeof obj; };
  21. var _util = require('../shared/util');
  22. var JpegImage = function JpegImageClosure() {
  23. 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]);
  24. var dctCos1 = 4017;
  25. var dctSin1 = 799;
  26. var dctCos3 = 3406;
  27. var dctSin3 = 2276;
  28. var dctCos6 = 1567;
  29. var dctSin6 = 3784;
  30. var dctSqrt2 = 5793;
  31. var dctSqrt1d2 = 2896;
  32. function JpegImage() {
  33. this.decodeTransform = null;
  34. this.colorTransform = -1;
  35. }
  36. function buildHuffmanTable(codeLengths, values) {
  37. var k = 0,
  38. code = [],
  39. i,
  40. j,
  41. length = 16;
  42. while (length > 0 && !codeLengths[length - 1]) {
  43. length--;
  44. }
  45. code.push({
  46. children: [],
  47. index: 0
  48. });
  49. var p = code[0],
  50. q;
  51. for (i = 0; i < length; i++) {
  52. for (j = 0; j < codeLengths[i]; j++) {
  53. p = code.pop();
  54. p.children[p.index] = values[k];
  55. while (p.index > 0) {
  56. p = code.pop();
  57. }
  58. p.index++;
  59. code.push(p);
  60. while (code.length <= i) {
  61. code.push(q = {
  62. children: [],
  63. index: 0
  64. });
  65. p.children[p.index] = q.children;
  66. p = q;
  67. }
  68. k++;
  69. }
  70. if (i + 1 < length) {
  71. code.push(q = {
  72. children: [],
  73. index: 0
  74. });
  75. p.children[p.index] = q.children;
  76. p = q;
  77. }
  78. }
  79. return code[0].children;
  80. }
  81. function getBlockBufferOffset(component, row, col) {
  82. return 64 * ((component.blocksPerLine + 1) * row + col);
  83. }
  84. function decodeScan(data, offset, frame, components, resetInterval, spectralStart, spectralEnd, successivePrev, successive) {
  85. var mcusPerLine = frame.mcusPerLine;
  86. var progressive = frame.progressive;
  87. var startOffset = offset,
  88. bitsData = 0,
  89. bitsCount = 0;
  90. function readBit() {
  91. if (bitsCount > 0) {
  92. bitsCount--;
  93. return bitsData >> bitsCount & 1;
  94. }
  95. bitsData = data[offset++];
  96. if (bitsData === 0xFF) {
  97. var nextByte = data[offset++];
  98. if (nextByte) {
  99. (0, _util.error)('JPEG error: unexpected marker ' + (bitsData << 8 | nextByte).toString(16));
  100. }
  101. }
  102. bitsCount = 7;
  103. return bitsData >>> 7;
  104. }
  105. function decodeHuffman(tree) {
  106. var node = tree;
  107. while (true) {
  108. node = node[readBit()];
  109. if (typeof node === 'number') {
  110. return node;
  111. }
  112. if ((typeof node === 'undefined' ? 'undefined' : _typeof(node)) !== 'object') {
  113. (0, _util.error)('JPEG error: invalid huffman sequence');
  114. }
  115. }
  116. }
  117. function receive(length) {
  118. var n = 0;
  119. while (length > 0) {
  120. n = n << 1 | readBit();
  121. length--;
  122. }
  123. return n;
  124. }
  125. function receiveAndExtend(length) {
  126. if (length === 1) {
  127. return readBit() === 1 ? 1 : -1;
  128. }
  129. var n = receive(length);
  130. if (n >= 1 << length - 1) {
  131. return n;
  132. }
  133. return n + (-1 << length) + 1;
  134. }
  135. function decodeBaseline(component, offset) {
  136. var t = decodeHuffman(component.huffmanTableDC);
  137. var diff = t === 0 ? 0 : receiveAndExtend(t);
  138. component.blockData[offset] = component.pred += diff;
  139. var k = 1;
  140. while (k < 64) {
  141. var rs = decodeHuffman(component.huffmanTableAC);
  142. var s = rs & 15,
  143. r = rs >> 4;
  144. if (s === 0) {
  145. if (r < 15) {
  146. break;
  147. }
  148. k += 16;
  149. continue;
  150. }
  151. k += r;
  152. var z = dctZigZag[k];
  153. component.blockData[offset + z] = receiveAndExtend(s);
  154. k++;
  155. }
  156. }
  157. function decodeDCFirst(component, offset) {
  158. var t = decodeHuffman(component.huffmanTableDC);
  159. var diff = t === 0 ? 0 : receiveAndExtend(t) << successive;
  160. component.blockData[offset] = component.pred += diff;
  161. }
  162. function decodeDCSuccessive(component, offset) {
  163. component.blockData[offset] |= readBit() << successive;
  164. }
  165. var eobrun = 0;
  166. function decodeACFirst(component, offset) {
  167. if (eobrun > 0) {
  168. eobrun--;
  169. return;
  170. }
  171. var k = spectralStart,
  172. e = spectralEnd;
  173. while (k <= e) {
  174. var rs = decodeHuffman(component.huffmanTableAC);
  175. var s = rs & 15,
  176. r = rs >> 4;
  177. if (s === 0) {
  178. if (r < 15) {
  179. eobrun = receive(r) + (1 << r) - 1;
  180. break;
  181. }
  182. k += 16;
  183. continue;
  184. }
  185. k += r;
  186. var z = dctZigZag[k];
  187. component.blockData[offset + z] = receiveAndExtend(s) * (1 << successive);
  188. k++;
  189. }
  190. }
  191. var successiveACState = 0,
  192. successiveACNextValue;
  193. function decodeACSuccessive(component, offset) {
  194. var k = spectralStart;
  195. var e = spectralEnd;
  196. var r = 0;
  197. var s;
  198. var rs;
  199. while (k <= e) {
  200. var z = dctZigZag[k];
  201. switch (successiveACState) {
  202. case 0:
  203. rs = decodeHuffman(component.huffmanTableAC);
  204. s = rs & 15;
  205. r = rs >> 4;
  206. if (s === 0) {
  207. if (r < 15) {
  208. eobrun = receive(r) + (1 << r);
  209. successiveACState = 4;
  210. } else {
  211. r = 16;
  212. successiveACState = 1;
  213. }
  214. } else {
  215. if (s !== 1) {
  216. (0, _util.error)('JPEG error: invalid ACn encoding');
  217. }
  218. successiveACNextValue = receiveAndExtend(s);
  219. successiveACState = r ? 2 : 3;
  220. }
  221. continue;
  222. case 1:
  223. case 2:
  224. if (component.blockData[offset + z]) {
  225. component.blockData[offset + z] += readBit() << successive;
  226. } else {
  227. r--;
  228. if (r === 0) {
  229. successiveACState = successiveACState === 2 ? 3 : 0;
  230. }
  231. }
  232. break;
  233. case 3:
  234. if (component.blockData[offset + z]) {
  235. component.blockData[offset + z] += readBit() << successive;
  236. } else {
  237. component.blockData[offset + z] = successiveACNextValue << successive;
  238. successiveACState = 0;
  239. }
  240. break;
  241. case 4:
  242. if (component.blockData[offset + z]) {
  243. component.blockData[offset + z] += readBit() << successive;
  244. }
  245. break;
  246. }
  247. k++;
  248. }
  249. if (successiveACState === 4) {
  250. eobrun--;
  251. if (eobrun === 0) {
  252. successiveACState = 0;
  253. }
  254. }
  255. }
  256. function decodeMcu(component, decode, mcu, row, col) {
  257. var mcuRow = mcu / mcusPerLine | 0;
  258. var mcuCol = mcu % mcusPerLine;
  259. var blockRow = mcuRow * component.v + row;
  260. var blockCol = mcuCol * component.h + col;
  261. var offset = getBlockBufferOffset(component, blockRow, blockCol);
  262. decode(component, offset);
  263. }
  264. function decodeBlock(component, decode, mcu) {
  265. var blockRow = mcu / component.blocksPerLine | 0;
  266. var blockCol = mcu % component.blocksPerLine;
  267. var offset = getBlockBufferOffset(component, blockRow, blockCol);
  268. decode(component, offset);
  269. }
  270. var componentsLength = components.length;
  271. var component, i, j, k, n;
  272. var decodeFn;
  273. if (progressive) {
  274. if (spectralStart === 0) {
  275. decodeFn = successivePrev === 0 ? decodeDCFirst : decodeDCSuccessive;
  276. } else {
  277. decodeFn = successivePrev === 0 ? decodeACFirst : decodeACSuccessive;
  278. }
  279. } else {
  280. decodeFn = decodeBaseline;
  281. }
  282. var mcu = 0,
  283. fileMarker;
  284. var mcuExpected;
  285. if (componentsLength === 1) {
  286. mcuExpected = components[0].blocksPerLine * components[0].blocksPerColumn;
  287. } else {
  288. mcuExpected = mcusPerLine * frame.mcusPerColumn;
  289. }
  290. var h, v;
  291. while (mcu < mcuExpected) {
  292. var mcuToRead = resetInterval ? Math.min(mcuExpected - mcu, resetInterval) : mcuExpected;
  293. for (i = 0; i < componentsLength; i++) {
  294. components[i].pred = 0;
  295. }
  296. eobrun = 0;
  297. if (componentsLength === 1) {
  298. component = components[0];
  299. for (n = 0; n < mcuToRead; n++) {
  300. decodeBlock(component, decodeFn, mcu);
  301. mcu++;
  302. }
  303. } else {
  304. for (n = 0; n < mcuToRead; n++) {
  305. for (i = 0; i < componentsLength; i++) {
  306. component = components[i];
  307. h = component.h;
  308. v = component.v;
  309. for (j = 0; j < v; j++) {
  310. for (k = 0; k < h; k++) {
  311. decodeMcu(component, decodeFn, mcu, j, k);
  312. }
  313. }
  314. }
  315. mcu++;
  316. }
  317. }
  318. bitsCount = 0;
  319. fileMarker = findNextFileMarker(data, offset);
  320. if (fileMarker && fileMarker.invalid) {
  321. (0, _util.warn)('decodeScan - unexpected MCU data, next marker is: ' + fileMarker.invalid);
  322. offset = fileMarker.offset;
  323. }
  324. var marker = fileMarker && fileMarker.marker;
  325. if (!marker || marker <= 0xFF00) {
  326. (0, _util.error)('JPEG error: marker was not found');
  327. }
  328. if (marker >= 0xFFD0 && marker <= 0xFFD7) {
  329. offset += 2;
  330. } else {
  331. break;
  332. }
  333. }
  334. fileMarker = findNextFileMarker(data, offset);
  335. if (fileMarker && fileMarker.invalid) {
  336. (0, _util.warn)('decodeScan - unexpected Scan data, next marker is: ' + fileMarker.invalid);
  337. offset = fileMarker.offset;
  338. }
  339. return offset - startOffset;
  340. }
  341. function quantizeAndInverse(component, blockBufferOffset, p) {
  342. var qt = component.quantizationTable,
  343. blockData = component.blockData;
  344. var v0, v1, v2, v3, v4, v5, v6, v7;
  345. var p0, p1, p2, p3, p4, p5, p6, p7;
  346. var t;
  347. if (!qt) {
  348. (0, _util.error)('JPEG error: missing required Quantization Table.');
  349. }
  350. for (var row = 0; row < 64; row += 8) {
  351. p0 = blockData[blockBufferOffset + row];
  352. p1 = blockData[blockBufferOffset + row + 1];
  353. p2 = blockData[blockBufferOffset + row + 2];
  354. p3 = blockData[blockBufferOffset + row + 3];
  355. p4 = blockData[blockBufferOffset + row + 4];
  356. p5 = blockData[blockBufferOffset + row + 5];
  357. p6 = blockData[blockBufferOffset + row + 6];
  358. p7 = blockData[blockBufferOffset + row + 7];
  359. p0 *= qt[row];
  360. if ((p1 | p2 | p3 | p4 | p5 | p6 | p7) === 0) {
  361. t = dctSqrt2 * p0 + 512 >> 10;
  362. p[row] = t;
  363. p[row + 1] = t;
  364. p[row + 2] = t;
  365. p[row + 3] = t;
  366. p[row + 4] = t;
  367. p[row + 5] = t;
  368. p[row + 6] = t;
  369. p[row + 7] = t;
  370. continue;
  371. }
  372. p1 *= qt[row + 1];
  373. p2 *= qt[row + 2];
  374. p3 *= qt[row + 3];
  375. p4 *= qt[row + 4];
  376. p5 *= qt[row + 5];
  377. p6 *= qt[row + 6];
  378. p7 *= qt[row + 7];
  379. v0 = dctSqrt2 * p0 + 128 >> 8;
  380. v1 = dctSqrt2 * p4 + 128 >> 8;
  381. v2 = p2;
  382. v3 = p6;
  383. v4 = dctSqrt1d2 * (p1 - p7) + 128 >> 8;
  384. v7 = dctSqrt1d2 * (p1 + p7) + 128 >> 8;
  385. v5 = p3 << 4;
  386. v6 = p5 << 4;
  387. v0 = v0 + v1 + 1 >> 1;
  388. v1 = v0 - v1;
  389. t = v2 * dctSin6 + v3 * dctCos6 + 128 >> 8;
  390. v2 = v2 * dctCos6 - v3 * dctSin6 + 128 >> 8;
  391. v3 = t;
  392. v4 = v4 + v6 + 1 >> 1;
  393. v6 = v4 - v6;
  394. v7 = v7 + v5 + 1 >> 1;
  395. v5 = v7 - v5;
  396. v0 = v0 + v3 + 1 >> 1;
  397. v3 = v0 - v3;
  398. v1 = v1 + v2 + 1 >> 1;
  399. v2 = v1 - v2;
  400. t = v4 * dctSin3 + v7 * dctCos3 + 2048 >> 12;
  401. v4 = v4 * dctCos3 - v7 * dctSin3 + 2048 >> 12;
  402. v7 = t;
  403. t = v5 * dctSin1 + v6 * dctCos1 + 2048 >> 12;
  404. v5 = v5 * dctCos1 - v6 * dctSin1 + 2048 >> 12;
  405. v6 = t;
  406. p[row] = v0 + v7;
  407. p[row + 7] = v0 - v7;
  408. p[row + 1] = v1 + v6;
  409. p[row + 6] = v1 - v6;
  410. p[row + 2] = v2 + v5;
  411. p[row + 5] = v2 - v5;
  412. p[row + 3] = v3 + v4;
  413. p[row + 4] = v3 - v4;
  414. }
  415. for (var col = 0; col < 8; ++col) {
  416. p0 = p[col];
  417. p1 = p[col + 8];
  418. p2 = p[col + 16];
  419. p3 = p[col + 24];
  420. p4 = p[col + 32];
  421. p5 = p[col + 40];
  422. p6 = p[col + 48];
  423. p7 = p[col + 56];
  424. if ((p1 | p2 | p3 | p4 | p5 | p6 | p7) === 0) {
  425. t = dctSqrt2 * p0 + 8192 >> 14;
  426. t = t < -2040 ? 0 : t >= 2024 ? 255 : t + 2056 >> 4;
  427. blockData[blockBufferOffset + col] = t;
  428. blockData[blockBufferOffset + col + 8] = t;
  429. blockData[blockBufferOffset + col + 16] = t;
  430. blockData[blockBufferOffset + col + 24] = t;
  431. blockData[blockBufferOffset + col + 32] = t;
  432. blockData[blockBufferOffset + col + 40] = t;
  433. blockData[blockBufferOffset + col + 48] = t;
  434. blockData[blockBufferOffset + col + 56] = t;
  435. continue;
  436. }
  437. v0 = dctSqrt2 * p0 + 2048 >> 12;
  438. v1 = dctSqrt2 * p4 + 2048 >> 12;
  439. v2 = p2;
  440. v3 = p6;
  441. v4 = dctSqrt1d2 * (p1 - p7) + 2048 >> 12;
  442. v7 = dctSqrt1d2 * (p1 + p7) + 2048 >> 12;
  443. v5 = p3;
  444. v6 = p5;
  445. v0 = (v0 + v1 + 1 >> 1) + 4112;
  446. v1 = v0 - v1;
  447. t = v2 * dctSin6 + v3 * dctCos6 + 2048 >> 12;
  448. v2 = v2 * dctCos6 - v3 * dctSin6 + 2048 >> 12;
  449. v3 = t;
  450. v4 = v4 + v6 + 1 >> 1;
  451. v6 = v4 - v6;
  452. v7 = v7 + v5 + 1 >> 1;
  453. v5 = v7 - v5;
  454. v0 = v0 + v3 + 1 >> 1;
  455. v3 = v0 - v3;
  456. v1 = v1 + v2 + 1 >> 1;
  457. v2 = v1 - v2;
  458. t = v4 * dctSin3 + v7 * dctCos3 + 2048 >> 12;
  459. v4 = v4 * dctCos3 - v7 * dctSin3 + 2048 >> 12;
  460. v7 = t;
  461. t = v5 * dctSin1 + v6 * dctCos1 + 2048 >> 12;
  462. v5 = v5 * dctCos1 - v6 * dctSin1 + 2048 >> 12;
  463. v6 = t;
  464. p0 = v0 + v7;
  465. p7 = v0 - v7;
  466. p1 = v1 + v6;
  467. p6 = v1 - v6;
  468. p2 = v2 + v5;
  469. p5 = v2 - v5;
  470. p3 = v3 + v4;
  471. p4 = v3 - v4;
  472. p0 = p0 < 16 ? 0 : p0 >= 4080 ? 255 : p0 >> 4;
  473. p1 = p1 < 16 ? 0 : p1 >= 4080 ? 255 : p1 >> 4;
  474. p2 = p2 < 16 ? 0 : p2 >= 4080 ? 255 : p2 >> 4;
  475. p3 = p3 < 16 ? 0 : p3 >= 4080 ? 255 : p3 >> 4;
  476. p4 = p4 < 16 ? 0 : p4 >= 4080 ? 255 : p4 >> 4;
  477. p5 = p5 < 16 ? 0 : p5 >= 4080 ? 255 : p5 >> 4;
  478. p6 = p6 < 16 ? 0 : p6 >= 4080 ? 255 : p6 >> 4;
  479. p7 = p7 < 16 ? 0 : p7 >= 4080 ? 255 : p7 >> 4;
  480. blockData[blockBufferOffset + col] = p0;
  481. blockData[blockBufferOffset + col + 8] = p1;
  482. blockData[blockBufferOffset + col + 16] = p2;
  483. blockData[blockBufferOffset + col + 24] = p3;
  484. blockData[blockBufferOffset + col + 32] = p4;
  485. blockData[blockBufferOffset + col + 40] = p5;
  486. blockData[blockBufferOffset + col + 48] = p6;
  487. blockData[blockBufferOffset + col + 56] = p7;
  488. }
  489. }
  490. function buildComponentData(frame, component) {
  491. var blocksPerLine = component.blocksPerLine;
  492. var blocksPerColumn = component.blocksPerColumn;
  493. var computationBuffer = new Int16Array(64);
  494. for (var blockRow = 0; blockRow < blocksPerColumn; blockRow++) {
  495. for (var blockCol = 0; blockCol < blocksPerLine; blockCol++) {
  496. var offset = getBlockBufferOffset(component, blockRow, blockCol);
  497. quantizeAndInverse(component, offset, computationBuffer);
  498. }
  499. }
  500. return component.blockData;
  501. }
  502. function clamp0to255(a) {
  503. return a <= 0 ? 0 : a >= 255 ? 255 : a;
  504. }
  505. function findNextFileMarker(data, currentPos, startPos) {
  506. function peekUint16(pos) {
  507. return data[pos] << 8 | data[pos + 1];
  508. }
  509. var maxPos = data.length - 1;
  510. var newPos = startPos < currentPos ? startPos : currentPos;
  511. if (currentPos >= maxPos) {
  512. return null;
  513. }
  514. var currentMarker = peekUint16(currentPos);
  515. if (currentMarker >= 0xFFC0 && currentMarker <= 0xFFFE) {
  516. return {
  517. invalid: null,
  518. marker: currentMarker,
  519. offset: currentPos
  520. };
  521. }
  522. var newMarker = peekUint16(newPos);
  523. while (!(newMarker >= 0xFFC0 && newMarker <= 0xFFFE)) {
  524. if (++newPos >= maxPos) {
  525. return null;
  526. }
  527. newMarker = peekUint16(newPos);
  528. }
  529. return {
  530. invalid: currentMarker.toString(16),
  531. marker: newMarker,
  532. offset: newPos
  533. };
  534. }
  535. JpegImage.prototype = {
  536. parse: function parse(data) {
  537. function readUint16() {
  538. var value = data[offset] << 8 | data[offset + 1];
  539. offset += 2;
  540. return value;
  541. }
  542. function readDataBlock() {
  543. var length = readUint16();
  544. var endOffset = offset + length - 2;
  545. var fileMarker = findNextFileMarker(data, endOffset, offset);
  546. if (fileMarker && fileMarker.invalid) {
  547. (0, _util.warn)('readDataBlock - incorrect length, next marker is: ' + fileMarker.invalid);
  548. endOffset = fileMarker.offset;
  549. }
  550. var array = data.subarray(offset, endOffset);
  551. offset += array.length;
  552. return array;
  553. }
  554. function prepareComponents(frame) {
  555. var mcusPerLine = Math.ceil(frame.samplesPerLine / 8 / frame.maxH);
  556. var mcusPerColumn = Math.ceil(frame.scanLines / 8 / frame.maxV);
  557. for (var i = 0; i < frame.components.length; i++) {
  558. component = frame.components[i];
  559. var blocksPerLine = Math.ceil(Math.ceil(frame.samplesPerLine / 8) * component.h / frame.maxH);
  560. var blocksPerColumn = Math.ceil(Math.ceil(frame.scanLines / 8) * component.v / frame.maxV);
  561. var blocksPerLineForMcu = mcusPerLine * component.h;
  562. var blocksPerColumnForMcu = mcusPerColumn * component.v;
  563. var blocksBufferSize = 64 * blocksPerColumnForMcu * (blocksPerLineForMcu + 1);
  564. component.blockData = new Int16Array(blocksBufferSize);
  565. component.blocksPerLine = blocksPerLine;
  566. component.blocksPerColumn = blocksPerColumn;
  567. }
  568. frame.mcusPerLine = mcusPerLine;
  569. frame.mcusPerColumn = mcusPerColumn;
  570. }
  571. var offset = 0;
  572. var jfif = null;
  573. var adobe = null;
  574. var frame, resetInterval;
  575. var quantizationTables = [];
  576. var huffmanTablesAC = [],
  577. huffmanTablesDC = [];
  578. var fileMarker = readUint16();
  579. if (fileMarker !== 0xFFD8) {
  580. (0, _util.error)('JPEG error: SOI not found');
  581. }
  582. fileMarker = readUint16();
  583. while (fileMarker !== 0xFFD9) {
  584. var i, j, l;
  585. switch (fileMarker) {
  586. case 0xFFE0:
  587. case 0xFFE1:
  588. case 0xFFE2:
  589. case 0xFFE3:
  590. case 0xFFE4:
  591. case 0xFFE5:
  592. case 0xFFE6:
  593. case 0xFFE7:
  594. case 0xFFE8:
  595. case 0xFFE9:
  596. case 0xFFEA:
  597. case 0xFFEB:
  598. case 0xFFEC:
  599. case 0xFFED:
  600. case 0xFFEE:
  601. case 0xFFEF:
  602. case 0xFFFE:
  603. var appData = readDataBlock();
  604. if (fileMarker === 0xFFE0) {
  605. if (appData[0] === 0x4A && appData[1] === 0x46 && appData[2] === 0x49 && appData[3] === 0x46 && appData[4] === 0) {
  606. jfif = {
  607. version: {
  608. major: appData[5],
  609. minor: appData[6]
  610. },
  611. densityUnits: appData[7],
  612. xDensity: appData[8] << 8 | appData[9],
  613. yDensity: appData[10] << 8 | appData[11],
  614. thumbWidth: appData[12],
  615. thumbHeight: appData[13],
  616. thumbData: appData.subarray(14, 14 + 3 * appData[12] * appData[13])
  617. };
  618. }
  619. }
  620. if (fileMarker === 0xFFEE) {
  621. if (appData[0] === 0x41 && appData[1] === 0x64 && appData[2] === 0x6F && appData[3] === 0x62 && appData[4] === 0x65) {
  622. adobe = {
  623. version: appData[5] << 8 | appData[6],
  624. flags0: appData[7] << 8 | appData[8],
  625. flags1: appData[9] << 8 | appData[10],
  626. transformCode: appData[11]
  627. };
  628. }
  629. }
  630. break;
  631. case 0xFFDB:
  632. var quantizationTablesLength = readUint16();
  633. var quantizationTablesEnd = quantizationTablesLength + offset - 2;
  634. var z;
  635. while (offset < quantizationTablesEnd) {
  636. var quantizationTableSpec = data[offset++];
  637. var tableData = new Uint16Array(64);
  638. if (quantizationTableSpec >> 4 === 0) {
  639. for (j = 0; j < 64; j++) {
  640. z = dctZigZag[j];
  641. tableData[z] = data[offset++];
  642. }
  643. } else if (quantizationTableSpec >> 4 === 1) {
  644. for (j = 0; j < 64; j++) {
  645. z = dctZigZag[j];
  646. tableData[z] = readUint16();
  647. }
  648. } else {
  649. (0, _util.error)('JPEG error: DQT - invalid table spec');
  650. }
  651. quantizationTables[quantizationTableSpec & 15] = tableData;
  652. }
  653. break;
  654. case 0xFFC0:
  655. case 0xFFC1:
  656. case 0xFFC2:
  657. if (frame) {
  658. (0, _util.error)('JPEG error: Only single frame JPEGs supported');
  659. }
  660. readUint16();
  661. frame = {};
  662. frame.extended = fileMarker === 0xFFC1;
  663. frame.progressive = fileMarker === 0xFFC2;
  664. frame.precision = data[offset++];
  665. frame.scanLines = readUint16();
  666. frame.samplesPerLine = readUint16();
  667. frame.components = [];
  668. frame.componentIds = {};
  669. var componentsCount = data[offset++],
  670. componentId;
  671. var maxH = 0,
  672. maxV = 0;
  673. for (i = 0; i < componentsCount; i++) {
  674. componentId = data[offset];
  675. var h = data[offset + 1] >> 4;
  676. var v = data[offset + 1] & 15;
  677. if (maxH < h) {
  678. maxH = h;
  679. }
  680. if (maxV < v) {
  681. maxV = v;
  682. }
  683. var qId = data[offset + 2];
  684. l = frame.components.push({
  685. h: h,
  686. v: v,
  687. quantizationId: qId,
  688. quantizationTable: null
  689. });
  690. frame.componentIds[componentId] = l - 1;
  691. offset += 3;
  692. }
  693. frame.maxH = maxH;
  694. frame.maxV = maxV;
  695. prepareComponents(frame);
  696. break;
  697. case 0xFFC4:
  698. var huffmanLength = readUint16();
  699. for (i = 2; i < huffmanLength;) {
  700. var huffmanTableSpec = data[offset++];
  701. var codeLengths = new Uint8Array(16);
  702. var codeLengthSum = 0;
  703. for (j = 0; j < 16; j++, offset++) {
  704. codeLengthSum += codeLengths[j] = data[offset];
  705. }
  706. var huffmanValues = new Uint8Array(codeLengthSum);
  707. for (j = 0; j < codeLengthSum; j++, offset++) {
  708. huffmanValues[j] = data[offset];
  709. }
  710. i += 17 + codeLengthSum;
  711. (huffmanTableSpec >> 4 === 0 ? huffmanTablesDC : huffmanTablesAC)[huffmanTableSpec & 15] = buildHuffmanTable(codeLengths, huffmanValues);
  712. }
  713. break;
  714. case 0xFFDD:
  715. readUint16();
  716. resetInterval = readUint16();
  717. break;
  718. case 0xFFDA:
  719. readUint16();
  720. var selectorsCount = data[offset++];
  721. var components = [],
  722. component;
  723. for (i = 0; i < selectorsCount; i++) {
  724. var componentIndex = frame.componentIds[data[offset++]];
  725. component = frame.components[componentIndex];
  726. var tableSpec = data[offset++];
  727. component.huffmanTableDC = huffmanTablesDC[tableSpec >> 4];
  728. component.huffmanTableAC = huffmanTablesAC[tableSpec & 15];
  729. components.push(component);
  730. }
  731. var spectralStart = data[offset++];
  732. var spectralEnd = data[offset++];
  733. var successiveApproximation = data[offset++];
  734. var processed = decodeScan(data, offset, frame, components, resetInterval, spectralStart, spectralEnd, successiveApproximation >> 4, successiveApproximation & 15);
  735. offset += processed;
  736. break;
  737. case 0xFFFF:
  738. if (data[offset] !== 0xFF) {
  739. offset--;
  740. }
  741. break;
  742. default:
  743. if (data[offset - 3] === 0xFF && data[offset - 2] >= 0xC0 && data[offset - 2] <= 0xFE) {
  744. offset -= 3;
  745. break;
  746. }
  747. (0, _util.error)('JPEG error: unknown marker ' + fileMarker.toString(16));
  748. }
  749. fileMarker = readUint16();
  750. }
  751. this.width = frame.samplesPerLine;
  752. this.height = frame.scanLines;
  753. this.jfif = jfif;
  754. this.adobe = adobe;
  755. this.components = [];
  756. for (i = 0; i < frame.components.length; i++) {
  757. component = frame.components[i];
  758. var quantizationTable = quantizationTables[component.quantizationId];
  759. if (quantizationTable) {
  760. component.quantizationTable = quantizationTable;
  761. }
  762. this.components.push({
  763. output: buildComponentData(frame, component),
  764. scaleX: component.h / frame.maxH,
  765. scaleY: component.v / frame.maxV,
  766. blocksPerLine: component.blocksPerLine,
  767. blocksPerColumn: component.blocksPerColumn
  768. });
  769. }
  770. this.numComponents = this.components.length;
  771. },
  772. _getLinearizedBlockData: function getLinearizedBlockData(width, height) {
  773. var scaleX = this.width / width,
  774. scaleY = this.height / height;
  775. var component, componentScaleX, componentScaleY, blocksPerScanline;
  776. var x, y, i, j, k;
  777. var index;
  778. var offset = 0;
  779. var output;
  780. var numComponents = this.components.length;
  781. var dataLength = width * height * numComponents;
  782. var data = new Uint8Array(dataLength);
  783. var xScaleBlockOffset = new Uint32Array(width);
  784. var mask3LSB = 0xfffffff8;
  785. for (i = 0; i < numComponents; i++) {
  786. component = this.components[i];
  787. componentScaleX = component.scaleX * scaleX;
  788. componentScaleY = component.scaleY * scaleY;
  789. offset = i;
  790. output = component.output;
  791. blocksPerScanline = component.blocksPerLine + 1 << 3;
  792. for (x = 0; x < width; x++) {
  793. j = 0 | x * componentScaleX;
  794. xScaleBlockOffset[x] = (j & mask3LSB) << 3 | j & 7;
  795. }
  796. for (y = 0; y < height; y++) {
  797. j = 0 | y * componentScaleY;
  798. index = blocksPerScanline * (j & mask3LSB) | (j & 7) << 3;
  799. for (x = 0; x < width; x++) {
  800. data[offset] = output[index + xScaleBlockOffset[x]];
  801. offset += numComponents;
  802. }
  803. }
  804. }
  805. var transform = this.decodeTransform;
  806. if (transform) {
  807. for (i = 0; i < dataLength;) {
  808. for (j = 0, k = 0; j < numComponents; j++, i++, k += 2) {
  809. data[i] = (data[i] * transform[k] >> 8) + transform[k + 1];
  810. }
  811. }
  812. }
  813. return data;
  814. },
  815. _isColorConversionNeeded: function isColorConversionNeeded() {
  816. if (this.adobe && this.adobe.transformCode) {
  817. return true;
  818. } else if (this.numComponents === 3) {
  819. if (!this.adobe && this.colorTransform === 0) {
  820. return false;
  821. }
  822. return true;
  823. }
  824. if (!this.adobe && this.colorTransform === 1) {
  825. return true;
  826. }
  827. return false;
  828. },
  829. _convertYccToRgb: function convertYccToRgb(data) {
  830. var Y, Cb, Cr;
  831. for (var i = 0, length = data.length; i < length; i += 3) {
  832. Y = data[i];
  833. Cb = data[i + 1];
  834. Cr = data[i + 2];
  835. data[i] = clamp0to255(Y - 179.456 + 1.402 * Cr);
  836. data[i + 1] = clamp0to255(Y + 135.459 - 0.344 * Cb - 0.714 * Cr);
  837. data[i + 2] = clamp0to255(Y - 226.816 + 1.772 * Cb);
  838. }
  839. return data;
  840. },
  841. _convertYcckToRgb: function convertYcckToRgb(data) {
  842. var Y, Cb, Cr, k;
  843. var offset = 0;
  844. for (var i = 0, length = data.length; i < length; i += 4) {
  845. Y = data[i];
  846. Cb = data[i + 1];
  847. Cr = data[i + 2];
  848. k = data[i + 3];
  849. var r = -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);
  850. var g = 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);
  851. var b = -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);
  852. data[offset++] = clamp0to255(r);
  853. data[offset++] = clamp0to255(g);
  854. data[offset++] = clamp0to255(b);
  855. }
  856. return data;
  857. },
  858. _convertYcckToCmyk: function convertYcckToCmyk(data) {
  859. var Y, Cb, Cr;
  860. for (var i = 0, length = data.length; i < length; i += 4) {
  861. Y = data[i];
  862. Cb = data[i + 1];
  863. Cr = data[i + 2];
  864. data[i] = clamp0to255(434.456 - Y - 1.402 * Cr);
  865. data[i + 1] = clamp0to255(119.541 - Y + 0.344 * Cb + 0.714 * Cr);
  866. data[i + 2] = clamp0to255(481.816 - Y - 1.772 * Cb);
  867. }
  868. return data;
  869. },
  870. _convertCmykToRgb: function convertCmykToRgb(data) {
  871. var c, m, y, k;
  872. var offset = 0;
  873. var min = -255 * 255 * 255;
  874. var scale = 1 / 255 / 255;
  875. for (var i = 0, length = data.length; i < length; i += 4) {
  876. c = data[i];
  877. m = data[i + 1];
  878. y = data[i + 2];
  879. k = data[i + 3];
  880. var r = c * (-4.387332384609988 * c + 54.48615194189176 * m + 18.82290502165302 * y + 212.25662451639585 * k - 72734.4411664936) + m * (1.7149763477362134 * m - 5.6096736904047315 * y - 17.873870861415444 * k - 1401.7366389350734) + y * (-2.5217340131683033 * y - 21.248923337353073 * k + 4465.541406466231) - k * (21.86122147463605 * k + 48317.86113160301);
  881. var g = c * (8.841041422036149 * c + 60.118027045597366 * m + 6.871425592049007 * y + 31.159100130055922 * k - 20220.756542821975) + m * (-15.310361306967817 * m + 17.575251261109482 * y + 131.35250912493976 * k - 48691.05921601825) + y * (4.444339102852739 * y + 9.8632861493405 * k - 6341.191035517494) - k * (20.737325471181034 * k + 47890.15695978492);
  882. var b = c * (0.8842522430003296 * c + 8.078677503112928 * m + 30.89978309703729 * y - 0.23883238689178934 * k - 3616.812083916688) + m * (10.49593273432072 * m + 63.02378494754052 * y + 50.606957656360734 * k - 28620.90484698408) + y * (0.03296041114873217 * y + 115.60384449646641 * k - 49363.43385999684) - k * (22.33816807309886 * k + 45932.16563550634);
  883. data[offset++] = r >= 0 ? 255 : r <= min ? 0 : 255 + r * scale | 0;
  884. data[offset++] = g >= 0 ? 255 : g <= min ? 0 : 255 + g * scale | 0;
  885. data[offset++] = b >= 0 ? 255 : b <= min ? 0 : 255 + b * scale | 0;
  886. }
  887. return data;
  888. },
  889. getData: function getData(width, height, forceRGBoutput) {
  890. if (this.numComponents > 4) {
  891. (0, _util.error)('JPEG error: Unsupported color mode');
  892. }
  893. var data = this._getLinearizedBlockData(width, height);
  894. if (this.numComponents === 1 && forceRGBoutput) {
  895. var dataLength = data.length;
  896. var rgbData = new Uint8Array(dataLength * 3);
  897. var offset = 0;
  898. for (var i = 0; i < dataLength; i++) {
  899. var grayColor = data[i];
  900. rgbData[offset++] = grayColor;
  901. rgbData[offset++] = grayColor;
  902. rgbData[offset++] = grayColor;
  903. }
  904. return rgbData;
  905. } else if (this.numComponents === 3 && this._isColorConversionNeeded()) {
  906. return this._convertYccToRgb(data);
  907. } else if (this.numComponents === 4) {
  908. if (this._isColorConversionNeeded()) {
  909. if (forceRGBoutput) {
  910. return this._convertYcckToRgb(data);
  911. }
  912. return this._convertYcckToCmyk(data);
  913. } else if (forceRGBoutput) {
  914. return this._convertCmykToRgb(data);
  915. }
  916. }
  917. return data;
  918. }
  919. };
  920. return JpegImage;
  921. }();
  922. exports.JpegImage = JpegImage;