Merge pull request #13338 from Snuffleupagus/images-class

Convert the `src/core/{jbig2, jpg, jpx}.js` files to use standard classes

src/core/jpg.js

@@ -12,7 +12,6 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-/* eslint-disable no-var */
 
 import { assert, BaseException, warn } from "../shared/util.js";
 import { readUint16 } from "./core_utils.js";
@@ -45,9 +44,8 @@ class EOIMarkerError extends BaseException {}
  *   (partners.adobe.com/public/developer/en/ps/sdk/5116.DCT_Filter.pdf)
  */
 
-var JpegImage = (function JpegImageClosure() {
+// prettier-ignore
-  // prettier-ignore
+const dctZigZag = new Uint8Array([
-  var dctZigZag = new Uint8Array([
      0,
      1,  8,
     16,  9,  2,
@@ -65,32 +63,25 @@ var JpegImage = (function JpegImageClosure() {
     63
   ]);
 
-  var dctCos1 = 4017; // cos(pi/16)
+const dctCos1 = 4017; // cos(pi/16)
-  var dctSin1 = 799; // sin(pi/16)
+const dctSin1 = 799; // sin(pi/16)
-  var dctCos3 = 3406; // cos(3*pi/16)
+const dctCos3 = 3406; // cos(3*pi/16)
-  var dctSin3 = 2276; // sin(3*pi/16)
+const dctSin3 = 2276; // sin(3*pi/16)
-  var dctCos6 = 1567; // cos(6*pi/16)
+const dctCos6 = 1567; // cos(6*pi/16)
-  var dctSin6 = 3784; // sin(6*pi/16)
+const dctSin6 = 3784; // sin(6*pi/16)
-  var dctSqrt2 = 5793; // sqrt(2)
+const dctSqrt2 = 5793; // sqrt(2)
-  var dctSqrt1d2 = 2896; // sqrt(2) / 2
+const dctSqrt1d2 = 2896; // sqrt(2) / 2
 
-  // eslint-disable-next-line no-shadow
+function buildHuffmanTable(codeLengths, values) {
-  function JpegImage({ decodeTransform = null, colorTransform = -1 } = {}) {
+  let k = 0,
-    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 });
+  const code = [{ children: [], index: 0 }];
-    var p = code[0],
+  let p = code[0],
     q;
   for (i = 0; i < length; i++) {
     for (j = 0; j < codeLengths[i]; j++) {
@@ -116,13 +107,13 @@ var JpegImage = (function JpegImageClosure() {
     }
   }
   return code[0].children;
-  }
+}
 
-  function getBlockBufferOffset(component, row, col) {
+function getBlockBufferOffset(component, row, col) {
   return 64 * ((component.blocksPerLine + 1) * row + col);
-  }
+}
 
-  function decodeScan(
+function decodeScan(
   data,
   offset,
   frame,
@@ -133,9 +124,9 @@ var JpegImage = (function JpegImageClosure() {
   successivePrev,
   successive,
   parseDNLMarker = false
-  ) {
+) {
-    var mcusPerLine = frame.mcusPerLine;
+  const mcusPerLine = frame.mcusPerLine;
-    var progressive = frame.progressive;
+  const progressive = frame.progressive;
 
   const startOffset = offset;
   let bitsData = 0,
@@ -148,7 +139,7 @@ var JpegImage = (function JpegImageClosure() {
     }
     bitsData = data[offset++];
     if (bitsData === 0xff) {
-        var nextByte = data[offset++];
+      const nextByte = data[offset++];
       if (nextByte) {
         if (nextByte === /* DNL = */ 0xdc && parseDNLMarker) {
           offset += 2; // Skip marker length.
@@ -196,7 +187,7 @@ var JpegImage = (function JpegImageClosure() {
   }
 
   function decodeHuffman(tree) {
-      var node = tree;
+    let node = tree;
     while (true) {
       node = node[readBit()];
       switch (typeof node) {
@@ -210,7 +201,7 @@ var JpegImage = (function JpegImageClosure() {
   }
 
   function receive(length) {
-      var n = 0;
+    let n = 0;
     while (length > 0) {
       n = (n << 1) | readBit();
       length--;
@@ -222,7 +213,7 @@ var JpegImage = (function JpegImageClosure() {
     if (length === 1) {
       return readBit() === 1 ? 1 : -1;
     }
-      var n = receive(length);
+    const n = receive(length);
     if (n >= 1 << (length - 1)) {
       return n;
     }
@@ -230,13 +221,13 @@ var JpegImage = (function JpegImageClosure() {
   }
 
   function decodeBaseline(component, blockOffset) {
-      var t = decodeHuffman(component.huffmanTableDC);
+    const t = decodeHuffman(component.huffmanTableDC);
-      var diff = t === 0 ? 0 : receiveAndExtend(t);
+    const diff = t === 0 ? 0 : receiveAndExtend(t);
     component.blockData[blockOffset] = component.pred += diff;
-      var k = 1;
+    let k = 1;
     while (k < 64) {
-        var rs = decodeHuffman(component.huffmanTableAC);
+      const rs = decodeHuffman(component.huffmanTableAC);
-        var s = rs & 15,
+      const s = rs & 15,
         r = rs >> 4;
       if (s === 0) {
         if (r < 15) {
@@ -246,15 +237,15 @@ var JpegImage = (function JpegImageClosure() {
         continue;
       }
       k += r;
-        var z = dctZigZag[k];
+      const z = dctZigZag[k];
       component.blockData[blockOffset + z] = receiveAndExtend(s);
       k++;
     }
   }
 
   function decodeDCFirst(component, blockOffset) {
-      var t = decodeHuffman(component.huffmanTableDC);
+    const t = decodeHuffman(component.huffmanTableDC);
-      var diff = t === 0 ? 0 : receiveAndExtend(t) << successive;
+    const diff = t === 0 ? 0 : receiveAndExtend(t) << successive;
     component.blockData[blockOffset] = component.pred += diff;
   }
 
@@ -262,17 +253,17 @@ var JpegImage = (function JpegImageClosure() {
     component.blockData[blockOffset] |= readBit() << successive;
   }
 
-    var eobrun = 0;
+  let eobrun = 0;
   function decodeACFirst(component, blockOffset) {
     if (eobrun > 0) {
       eobrun--;
       return;
     }
-      var k = spectralStart,
+    let k = spectralStart;
-        e = spectralEnd;
+    const e = spectralEnd;
     while (k <= e) {
-        var rs = decodeHuffman(component.huffmanTableAC);
+      const rs = decodeHuffman(component.huffmanTableAC);
-        var s = rs & 15,
+      const s = rs & 15,
         r = rs >> 4;
       if (s === 0) {
         if (r < 15) {
@@ -283,21 +274,21 @@ var JpegImage = (function JpegImageClosure() {
         continue;
       }
       k += r;
-        var z = dctZigZag[k];
+      const z = dctZigZag[k];
       component.blockData[blockOffset + z] =
         receiveAndExtend(s) * (1 << successive);
       k++;
     }
   }
 
-    var successiveACState = 0,
+  let successiveACState = 0,
     successiveACNextValue;
   function decodeACSuccessive(component, blockOffset) {
-      var k = spectralStart;
+    let k = spectralStart;
-      var e = spectralEnd;
+    const e = spectralEnd;
-      var r = 0;
+    let r = 0;
-      var s;
+    let s;
-      var rs;
+    let rs;
     while (k <= e) {
       const offsetZ = blockOffset + dctZigZag[k];
       const sign = component.blockData[offsetZ] < 0 ? -1 : 1;
@@ -337,8 +328,7 @@ var JpegImage = (function JpegImageClosure() {
           if (component.blockData[offsetZ]) {
             component.blockData[offsetZ] += sign * (readBit() << successive);
           } else {
-              component.blockData[offsetZ] =
+            component.blockData[offsetZ] = successiveACNextValue << successive;
-                successiveACNextValue << successive;
             successiveACState = 0;
           }
           break;
@@ -360,24 +350,24 @@ var JpegImage = (function JpegImageClosure() {
 
   let blockRow = 0;
   function decodeMcu(component, decode, mcu, row, col) {
-      var mcuRow = (mcu / mcusPerLine) | 0;
+    const mcuRow = (mcu / mcusPerLine) | 0;
-      var mcuCol = mcu % mcusPerLine;
+    const mcuCol = mcu % mcusPerLine;
     blockRow = mcuRow * component.v + row;
-      var blockCol = mcuCol * component.h + col;
+    const blockCol = mcuCol * component.h + col;
     const blockOffset = getBlockBufferOffset(component, blockRow, blockCol);
     decode(component, blockOffset);
   }
 
   function decodeBlock(component, decode, mcu) {
     blockRow = (mcu / component.blocksPerLine) | 0;
-      var blockCol = mcu % component.blocksPerLine;
+    const blockCol = mcu % component.blocksPerLine;
     const blockOffset = getBlockBufferOffset(component, blockRow, blockCol);
     decode(component, blockOffset);
   }
 
-    var componentsLength = components.length;
+  const componentsLength = components.length;
-    var component, i, j, k, n;
+  let component, i, j, k, n;
-    var decodeFn;
+  let decodeFn;
   if (progressive) {
     if (spectralStart === 0) {
       decodeFn = successivePrev === 0 ? decodeDCFirst : decodeDCSuccessive;
@@ -388,19 +378,19 @@ var JpegImage = (function JpegImageClosure() {
     decodeFn = decodeBaseline;
   }
 
-    var mcu = 0,
+  let mcu = 0,
     fileMarker;
-    var mcuExpected;
+  let mcuExpected;
   if (componentsLength === 1) {
     mcuExpected = components[0].blocksPerLine * components[0].blocksPerColumn;
   } else {
     mcuExpected = mcusPerLine * frame.mcusPerColumn;
   }
 
-    var h, v;
+  let h, v;
   while (mcu <= mcuExpected) {
     // reset interval stuff
-      var mcuToRead = resetInterval
+    const mcuToRead = resetInterval
       ? Math.min(mcuExpected - mcu, resetInterval)
       : mcuExpected;
 
@@ -461,26 +451,26 @@ var JpegImage = (function JpegImageClosure() {
   }
 
   return offset - startOffset;
-  }
+}
 
-  // A port of poppler's IDCT method which in turn is taken from:
+// A port of poppler's IDCT method which in turn is taken from:
-  //   Christoph Loeffler, Adriaan Ligtenberg, George S. Moschytz,
+//   Christoph Loeffler, Adriaan Ligtenberg, George S. Moschytz,
-  //   'Practical Fast 1-D DCT Algorithms with 11 Multiplications',
+//   'Practical Fast 1-D DCT Algorithms with 11 Multiplications',
-  //   IEEE Intl. Conf. on Acoustics, Speech & Signal Processing, 1989,
+//   IEEE Intl. Conf. on Acoustics, Speech & Signal Processing, 1989,
-  //   988-991.
+//   988-991.
-  function quantizeAndInverse(component, blockBufferOffset, p) {
+function quantizeAndInverse(component, blockBufferOffset, p) {
-    var qt = component.quantizationTable,
+  const qt = component.quantizationTable,
     blockData = component.blockData;
-    var v0, v1, v2, v3, v4, v5, v6, v7;
+  let v0, v1, v2, v3, v4, v5, v6, v7;
-    var p0, p1, p2, p3, p4, p5, p6, p7;
+  let p0, p1, p2, p3, p4, p5, p6, p7;
-    var t;
+  let t;
 
   if (!qt) {
     throw new JpegError("missing required Quantization Table.");
   }
 
   // inverse DCT on rows
-    for (var row = 0; row < 64; row += 8) {
+  for (let row = 0; row < 64; row += 8) {
     // gather block data
     p0 = blockData[blockBufferOffset + row];
     p1 = blockData[blockBufferOffset + row + 1];
@@ -561,7 +551,7 @@ var JpegImage = (function JpegImageClosure() {
   }
 
   // inverse DCT on columns
-    for (var col = 0; col < 8; ++col) {
+  for (let col = 0; col < 8; ++col) {
     p0 = p[col];
     p1 = p[col + 8];
     p2 = p[col + 16];
@@ -706,30 +696,30 @@ var JpegImage = (function JpegImageClosure() {
     blockData[blockBufferOffset + col + 48] = p6;
     blockData[blockBufferOffset + col + 56] = p7;
   }
-  }
+}
 
-  function buildComponentData(frame, component) {
+function buildComponentData(frame, component) {
-    var blocksPerLine = component.blocksPerLine;
+  const blocksPerLine = component.blocksPerLine;
-    var blocksPerColumn = component.blocksPerColumn;
+  const blocksPerColumn = component.blocksPerColumn;
-    var computationBuffer = new Int16Array(64);
+  const computationBuffer = new Int16Array(64);
 
-    for (var blockRow = 0; blockRow < blocksPerColumn; blockRow++) {
+  for (let blockRow = 0; blockRow < blocksPerColumn; blockRow++) {
-      for (var blockCol = 0; blockCol < blocksPerLine; blockCol++) {
+    for (let blockCol = 0; blockCol < blocksPerLine; blockCol++) {
-        var offset = getBlockBufferOffset(component, blockRow, blockCol);
+      const offset = getBlockBufferOffset(component, blockRow, blockCol);
       quantizeAndInverse(component, offset, computationBuffer);
     }
   }
   return component.blockData;
-  }
+}
 
-  function findNextFileMarker(data, currentPos, startPos = currentPos) {
+function findNextFileMarker(data, currentPos, startPos = currentPos) {
   const maxPos = data.length - 1;
-    var newPos = startPos < currentPos ? startPos : currentPos;
+  let 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);
+  const currentMarker = readUint16(data, currentPos);
   if (currentMarker >= 0xffc0 && currentMarker <= 0xfffe) {
     return {
       invalid: null,
@@ -737,7 +727,7 @@ var JpegImage = (function JpegImageClosure() {
       offset: currentPos,
     };
   }
-    var newMarker = readUint16(data, newPos);
+  let 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.
@@ -749,16 +739,21 @@ var JpegImage = (function JpegImageClosure() {
     marker: newMarker,
     offset: newPos,
   };
+}
+
+class JpegImage {
+  constructor({ decodeTransform = null, colorTransform = -1 } = {}) {
+    this._decodeTransform = decodeTransform;
+    this._colorTransform = colorTransform;
   }
 
-  JpegImage.prototype = {
   parse(data, { dnlScanLines = null } = {}) {
     function readDataBlock() {
       const length = readUint16(data, offset);
       offset += 2;
       let endOffset = offset + length - 2;
 
-        var fileMarker = findNextFileMarker(data, endOffset, offset);
+      const fileMarker = findNextFileMarker(data, endOffset, offset);
       if (fileMarker && fileMarker.invalid) {
         warn(
           "readDataBlock - incorrect length, current marker is: " +
@@ -767,26 +762,26 @@ var JpegImage = (function JpegImageClosure() {
         endOffset = fileMarker.offset;
       }
 
-        var array = data.subarray(offset, endOffset);
+      const array = data.subarray(offset, endOffset);
       offset += array.length;
       return array;
     }
 
     function prepareComponents(frame) {
-        var mcusPerLine = Math.ceil(frame.samplesPerLine / 8 / frame.maxH);
+      const mcusPerLine = Math.ceil(frame.samplesPerLine / 8 / frame.maxH);
-        var mcusPerColumn = Math.ceil(frame.scanLines / 8 / frame.maxV);
+      const mcusPerColumn = Math.ceil(frame.scanLines / 8 / frame.maxV);
-        for (var i = 0; i < frame.components.length; i++) {
+      for (let i = 0, ii = frame.components.length; i < ii; i++) {
-          component = frame.components[i];
+        const component = frame.components[i];
-          var blocksPerLine = Math.ceil(
+        const blocksPerLine = Math.ceil(
           (Math.ceil(frame.samplesPerLine / 8) * component.h) / frame.maxH
         );
-          var blocksPerColumn = Math.ceil(
+        const blocksPerColumn = Math.ceil(
           (Math.ceil(frame.scanLines / 8) * component.v) / frame.maxV
         );
-          var blocksPerLineForMcu = mcusPerLine * component.h;
+        const blocksPerLineForMcu = mcusPerLine * component.h;
-          var blocksPerColumnForMcu = mcusPerColumn * component.v;
+        const blocksPerColumnForMcu = mcusPerColumn * component.v;
 
-          var blocksBufferSize =
+        const blocksBufferSize =
           64 * blocksPerColumnForMcu * (blocksPerLineForMcu + 1);
         component.blockData = new Int16Array(blocksBufferSize);
         component.blocksPerLine = blocksPerLine;
@@ -796,13 +791,13 @@ var JpegImage = (function JpegImageClosure() {
       frame.mcusPerColumn = mcusPerColumn;
     }
 
-      var offset = 0;
+    let offset = 0;
-      var jfif = null;
+    let jfif = null;
-      var adobe = null;
+    let adobe = null;
-      var frame, resetInterval;
+    let frame, resetInterval;
     let numSOSMarkers = 0;
-      var quantizationTables = [];
+    const quantizationTables = [];
-      var huffmanTablesAC = [],
+    const huffmanTablesAC = [],
       huffmanTablesDC = [];
 
     let fileMarker = readUint16(data, offset);
@@ -814,7 +809,7 @@ var JpegImage = (function JpegImageClosure() {
     offset += 2;
 
     markerLoop: while (fileMarker !== /* EOI (End of Image) = */ 0xffd9) {
-        var i, j, l;
+      let i, j, l;
       switch (fileMarker) {
         case 0xffe0: // APP0 (Application Specific)
         case 0xffe1: // APP1
@@ -833,7 +828,7 @@ var JpegImage = (function JpegImageClosure() {
         case 0xffee: // APP14
         case 0xffef: // APP15
         case 0xfffe: // COM (Comment)
-            var appData = readDataBlock();
+          const appData = readDataBlock();
 
           if (fileMarker === 0xffe0) {
             // 'JFIF\x00'
@@ -881,11 +876,11 @@ var JpegImage = (function JpegImageClosure() {
         case 0xffdb: // DQT (Define Quantization Tables)
           const quantizationTablesLength = readUint16(data, offset);
           offset += 2;
-            var quantizationTablesEnd = quantizationTablesLength + offset - 2;
+          const quantizationTablesEnd = quantizationTablesLength + offset - 2;
-            var z;
+          let z;
           while (offset < quantizationTablesEnd) {
-              var quantizationTableSpec = data[offset++];
+            const quantizationTableSpec = data[offset++];
-              var tableData = new Uint16Array(64);
+            const tableData = new Uint16Array(64);
             if (quantizationTableSpec >> 4 === 0) {
               // 8 bit values
               for (j = 0; j < 64; j++) {
@@ -925,21 +920,20 @@ var JpegImage = (function JpegImageClosure() {
           offset += 2;
           frame.components = [];
           frame.componentIds = {};
-            var componentsCount = data[offset++],
+          const componentsCount = data[offset++];
-              componentId;
+          let maxH = 0,
-            var maxH = 0,
             maxV = 0;
           for (i = 0; i < componentsCount; i++) {
-              componentId = data[offset];
+            const componentId = data[offset];
-              var h = data[offset + 1] >> 4;
+            const h = data[offset + 1] >> 4;
-              var v = data[offset + 1] & 15;
+            const v = data[offset + 1] & 15;
             if (maxH < h) {
               maxH = h;
             }
             if (maxV < v) {
               maxV = v;
             }
-              var qId = data[offset + 2];
+            const qId = data[offset + 2];
             l = frame.components.push({
               h,
               v,
@@ -958,13 +952,13 @@ var JpegImage = (function JpegImageClosure() {
           const huffmanLength = readUint16(data, offset);
           offset += 2;
           for (i = 2; i < huffmanLength; ) {
-              var huffmanTableSpec = data[offset++];
+            const huffmanTableSpec = data[offset++];
-              var codeLengths = new Uint8Array(16);
+            const codeLengths = new Uint8Array(16);
-              var codeLengthSum = 0;
+            let codeLengthSum = 0;
             for (j = 0; j < 16; j++, offset++) {
               codeLengthSum += codeLengths[j] = data[offset];
             }
-              var huffmanValues = new Uint8Array(codeLengthSum);
+            const huffmanValues = new Uint8Array(codeLengthSum);
             for (j = 0; j < codeLengthSum; j++, offset++) {
               huffmanValues[j] = data[offset];
             }
@@ -992,24 +986,23 @@ var JpegImage = (function JpegImageClosure() {
 
           offset += 2; // Skip marker length.
 
-            var selectorsCount = data[offset++];
+          const selectorsCount = data[offset++],
-            var components = [],
+            components = [];
-              component;
           for (i = 0; i < selectorsCount; i++) {
             const index = data[offset++];
-              var componentIndex = frame.componentIds[index];
+            const componentIndex = frame.componentIds[index];
-              component = frame.components[componentIndex];
+            const component = frame.components[componentIndex];
             component.index = index;
-              var tableSpec = data[offset++];
+            const tableSpec = data[offset++];
             component.huffmanTableDC = huffmanTablesDC[tableSpec >> 4];
             component.huffmanTableAC = huffmanTablesAC[tableSpec & 15];
             components.push(component);
           }
-            var spectralStart = data[offset++];
+          const spectralStart = data[offset++],
-            var spectralEnd = data[offset++];
+            spectralEnd = data[offset++],
-            var successiveApproximation = data[offset++];
+            successiveApproximation = data[offset++];
           try {
-              var processed = decodeScan(
+            const processed = decodeScan(
               data,
               offset,
               frame,
@@ -1083,13 +1076,13 @@ var JpegImage = (function JpegImageClosure() {
     this.jfif = jfif;
     this.adobe = adobe;
     this.components = [];
-      for (i = 0; i < frame.components.length; i++) {
+    for (let i = 0, ii = frame.components.length; i < ii; i++) {
-        component = frame.components[i];
+      const 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];
+      const quantizationTable = quantizationTables[component.quantizationId];
       if (quantizationTable) {
         component.quantizationTable = quantizationTable;
       }
@@ -1105,22 +1098,22 @@ var JpegImage = (function JpegImageClosure() {
     }
     this.numComponents = this.components.length;
     return undefined;
-    },
+  }
 
   _getLinearizedBlockData(width, height, isSourcePDF = false) {
-      var scaleX = this.width / width,
+    const scaleX = this.width / width,
       scaleY = this.height / height;
 
-      var component, componentScaleX, componentScaleY, blocksPerScanline;
+    let component, componentScaleX, componentScaleY, blocksPerScanline;
-      var x, y, i, j, k;
+    let x, y, i, j, k;
-      var index;
+    let index;
-      var offset = 0;
+    let offset = 0;
-      var output;
+    let output;
-      var numComponents = this.components.length;
+    const numComponents = this.components.length;
-      var dataLength = width * height * numComponents;
+    const dataLength = width * height * numComponents;
-      var data = new Uint8ClampedArray(dataLength);
+    const data = new Uint8ClampedArray(dataLength);
-      var xScaleBlockOffset = new Uint32Array(width);
+    const xScaleBlockOffset = new Uint32Array(width);
-      var mask3LSB = 0xfffffff8; // used to clear the 3 LSBs
+    const mask3LSB = 0xfffffff8; // used to clear the 3 LSBs
     let lastComponentScaleX;
 
     for (i = 0; i < numComponents; i++) {
@@ -1178,7 +1171,7 @@ var JpegImage = (function JpegImageClosure() {
       }
     }
     return data;
-    },
+  }
 
   get _isColorConversionNeeded() {
     if (this.adobe) {
@@ -1210,11 +1203,11 @@ var JpegImage = (function JpegImageClosure() {
       return true;
     }
     return false;
-    },
+  }
 
-    _convertYccToRgb: function convertYccToRgb(data) {
+  _convertYccToRgb(data) {
-      var Y, Cb, Cr;
+    let Y, Cb, Cr;
-      for (var i = 0, length = data.length; i < length; i += 3) {
+    for (let i = 0, length = data.length; i < length; i += 3) {
       Y = data[i];
       Cb = data[i + 1];
       Cr = data[i + 2];
@@ -1223,12 +1216,12 @@ var JpegImage = (function JpegImageClosure() {
       data[i + 2] = Y - 226.816 + 1.772 * Cb;
     }
     return data;
-    },
+  }
 
-    _convertYcckToRgb: function convertYcckToRgb(data) {
+  _convertYcckToRgb(data) {
-      var Y, Cb, Cr, k;
+    let Y, Cb, Cr, k;
-      var offset = 0;
+    let offset = 0;
-      for (var i = 0, length = data.length; i < length; i += 4) {
+    for (let i = 0, length = data.length; i < length; i += 4) {
       Y = data[i];
       Cb = data[i + 1];
       Cr = data[i + 2];
@@ -1293,11 +1286,11 @@ var JpegImage = (function JpegImageClosure() {
     }
     // Ensure that only the converted RGB data is returned.
     return data.subarray(0, offset);
-    },
+  }
 
-    _convertYcckToCmyk: function convertYcckToCmyk(data) {
+  _convertYcckToCmyk(data) {
-      var Y, Cb, Cr;
+    let Y, Cb, Cr;
-      for (var i = 0, length = data.length; i < length; i += 4) {
+    for (let i = 0, length = data.length; i < length; i += 4) {
       Y = data[i];
       Cb = data[i + 1];
       Cr = data[i + 2];
@@ -1307,12 +1300,12 @@ var JpegImage = (function JpegImageClosure() {
       // K in data[i + 3] is unchanged
     }
     return data;
-    },
+  }
 
-    _convertCmykToRgb: function convertCmykToRgb(data) {
+  _convertCmykToRgb(data) {
-      var c, m, y, k;
+    let c, m, y, k;
-      var offset = 0;
+    let offset = 0;
-      for (var i = 0, length = data.length; i < length; i += 4) {
+    for (let i = 0, length = data.length; i < length; i += 4) {
       c = data[i];
       m = data[i + 1];
       y = data[i + 2];
@@ -1377,7 +1370,7 @@ var JpegImage = (function JpegImageClosure() {
     }
     // Ensure that only the converted RGB data is returned.
     return data.subarray(0, offset);
-    },
+  }
 
   getData({ width, height, forceRGB = false, isSourcePDF = false }) {
     if (
@@ -1393,14 +1386,14 @@ var JpegImage = (function JpegImageClosure() {
       throw new JpegError("Unsupported color mode");
     }
     // Type of data: Uint8ClampedArray(width * height * numComponents)
-      var data = this._getLinearizedBlockData(width, height, isSourcePDF);
+    const data = this._getLinearizedBlockData(width, height, isSourcePDF);
 
     if (this.numComponents === 1 && forceRGB) {
-        var dataLength = data.length;
+      const dataLength = data.length;
-        var rgbData = new Uint8ClampedArray(dataLength * 3);
+      const rgbData = new Uint8ClampedArray(dataLength * 3);
-        var offset = 0;
+      let offset = 0;
-        for (var i = 0; i < dataLength; i++) {
+      for (let i = 0; i < dataLength; i++) {
-          var grayColor = data[i];
+        const grayColor = data[i];
         rgbData[offset++] = grayColor;
         rgbData[offset++] = grayColor;
         rgbData[offset++] = grayColor;
@@ -1419,10 +1412,7 @@ var JpegImage = (function JpegImageClosure() {
       }
     }
     return data;
-    },
+  }
-  };
+}
-
-  return JpegImage;
-})();
 
 export { JpegImage };