Use the built-in jpg.js decoder for JPEG images with non-default EX…

…IF orientation (bug 1942064) The new EXIF parsing, during `JpegImage.canUseImageDecoder`, takes *well below* `1 ms` in my testing which should be fast enough to not be an issue. The EXIF parsing is done using https://github.com/exif-js/exif-js/, which is released under the MIT License. Note that while it's available on NPM we're however not using that since: - The package is not fully up-to-date, given the latest changes in the Git repository. - We only need a *subset* of the functionality, and this way we're able to simplify and shorten the code. - Given the age of that project the code isn't directly compatible with JavaScript modules.
mozilla · Jan 19, 2025 · 9bd4b4c · 9bd4b4c
1 parent 50b7922
commit 9bd4b4c
Show file tree

Hide file tree

Showing 7 changed files with 302 additions and 0 deletions.
diff --git a/external/exif-js/LICENSE.md b/external/exif-js/LICENSE.md
@@ -0,0 +1,21 @@
+The MIT License (MIT)
+
+Copyright (c) 2008 Jacob Seidelin
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.
diff --git a/external/exif-js/exif.js b/external/exif-js/exif.js
@@ -0,0 +1,235 @@
+/* The MIT License (MIT)
+ *
+ * Copyright (c) 2008 Jacob Seidelin
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+/**
+ * This implementation is based on
+ *   https://github.com/exif-js/exif-js/blob/51a8f7d2f3aa71cb03463c84088067c9a4ebe8cb/exif.js
+ *
+ * with the following modifications:
+ *  - Removal of, for the PDF.js use-case, unneeded and unused methods.
+ *  - Skip `ExifIFDPointer` tags, `GPSInfoIFDPointer` tags and
+ *    thumbnail image extraction.
+ *  - Removal of debug logging.
+ *  - Make it pass PDF.js linting, and general modernization of the code.
+ */
+
+const TiffTags = {
+  0x0100: "ImageWidth",
+  0x0101: "ImageHeight",
+  0x8769: "ExifIFDPointer",
+  0x8825: "GPSInfoIFDPointer",
+  0xa005: "InteroperabilityIFDPointer",
+  0x0102: "BitsPerSample",
+  0x0103: "Compression",
+  0x0106: "PhotometricInterpretation",
+  0x0112: "Orientation",
+  0x0115: "SamplesPerPixel",
+  0x011c: "PlanarConfiguration",
+  0x0212: "YCbCrSubSampling",
+  0x0213: "YCbCrPositioning",
+  0x011a: "XResolution",
+  0x011b: "YResolution",
+  0x0128: "ResolutionUnit",
+  0x0111: "StripOffsets",
+  0x0116: "RowsPerStrip",
+  0x0117: "StripByteCounts",
+  0x0201: "JPEGInterchangeFormat",
+  0x0202: "JPEGInterchangeFormatLength",
+  0x012d: "TransferFunction",
+  0x013e: "WhitePoint",
+  0x013f: "PrimaryChromaticities",
+  0x0211: "YCbCrCoefficients",
+  0x0214: "ReferenceBlackWhite",
+  0x0132: "DateTime",
+  0x010e: "ImageDescription",
+  0x010f: "Make",
+  0x0110: "Model",
+  0x0131: "Software",
+  0x013b: "Artist",
+  0x8298: "Copyright",
+};
+
+function readTags(file, tiffStart, dirStart, strings, bigEnd) {
+  const entries = file.getUint16(dirStart, !bigEnd),
+    tags = Object.create(null);
+
+  for (let i = 0; i < entries; i++) {
+    const entryOffset = dirStart + i * 12 + 2;
+    const tag = strings[file.getUint16(entryOffset, !bigEnd)];
+    tags[tag] = readTagValue(file, entryOffset, tiffStart, dirStart, bigEnd);
+  }
+  return tags;
+}
+
+function readTagValue(file, entryOffset, tiffStart, dirStart, bigEnd) {
+  const type = file.getUint16(entryOffset + 2, !bigEnd),
+    numValues = file.getUint32(entryOffset + 4, !bigEnd),
+    valueOffset = file.getUint32(entryOffset + 8, !bigEnd) + tiffStart;
+  let offset, vals, val, n, numerator, denominator;
+
+  switch (type) {
+    case 1: // byte, 8-bit unsigned int
+    case 7: // undefined, 8-bit byte, value depending on field
+      if (numValues === 1) {
+        return file.getUint8(entryOffset + 8, !bigEnd);
+      }
+      offset = numValues > 4 ? valueOffset : entryOffset + 8;
+      vals = [];
+      for (n = 0; n < numValues; n++) {
+        vals[n] = file.getUint8(offset + n);
+      }
+      return vals;
+
+    case 2: // ascii, 8-bit byte
+      offset = numValues > 4 ? valueOffset : entryOffset + 8;
+      return getStringFromDB(file, offset, numValues - 1);
+
+    case 3: // short, 16 bit int
+      if (numValues === 1) {
+        return file.getUint16(entryOffset + 8, !bigEnd);
+      }
+      offset = numValues > 2 ? valueOffset : entryOffset + 8;
+      vals = [];
+      for (n = 0; n < numValues; n++) {
+        vals[n] = file.getUint16(offset + 2 * n, !bigEnd);
+      }
+      return vals;
+
+    case 4: // long, 32 bit int
+      if (numValues === 1) {
+        return file.getUint32(entryOffset + 8, !bigEnd);
+      }
+      vals = [];
+      for (n = 0; n < numValues; n++) {
+        vals[n] = file.getUint32(valueOffset + 4 * n, !bigEnd);
+      }
+      return vals;
+
+    case 5: // rational = two long values, first is numerator, second is denominator
+      if (numValues === 1) {
+        numerator = file.getUint32(valueOffset, !bigEnd);
+        denominator = file.getUint32(valueOffset + 4, !bigEnd);
+        val = numerator / denominator;
+        return val;
+      }
+      vals = [];
+      for (n = 0; n < numValues; n++) {
+        numerator = file.getUint32(valueOffset + 8 * n, !bigEnd);
+        denominator = file.getUint32(valueOffset + 4 + 8 * n, !bigEnd);
+        vals[n] = numerator / denominator;
+      }
+      return vals;
+
+    case 9: // slong, 32 bit signed int
+      if (numValues === 1) {
+        return file.getInt32(entryOffset + 8, !bigEnd);
+      }
+      vals = [];
+      for (n = 0; n < numValues; n++) {
+        vals[n] = file.getInt32(valueOffset + 4 * n, !bigEnd);
+      }
+      return vals;
+
+    case 10: // signed rational, two slongs, first is numerator, second is denominator
+      if (numValues === 1) {
+        return (
+          file.getInt32(valueOffset, !bigEnd) /
+          file.getInt32(valueOffset + 4, !bigEnd)
+        );
+      }
+      vals = [];
+      for (n = 0; n < numValues; n++) {
+        vals[n] =
+          file.getInt32(valueOffset + 8 * n, !bigEnd) /
+          file.getInt32(valueOffset + 4 + 8 * n, !bigEnd);
+      }
+      return vals;
+  }
+  throw new Error(`readTagValue - unsupported type: "${type}".`);
+}
+
+function getStringFromDB(buffer, start, length) {
+  let outstr = "";
+  for (let n = start; n < start + length; n++) {
+    outstr += String.fromCharCode(buffer.getUint8(n));
+  }
+  return outstr;
+}
+
+/**
+ * @param [DataView] file
+ * @param [number] start
+ * @return {Object | null}
+ */
+function readEXIFData(file, start) {
+  if (getStringFromDB(file, start, 4) !== "Exif") {
+    // console.log("Not valid EXIF data! " + getStringFromDB(file, start, 4));
+    return null;
+  }
+
+  const tiffOffset = start + 6;
+  let bigEnd;
+
+  // test for TIFF validity and endianness
+  if (file.getUint16(tiffOffset) === 0x4949) {
+    bigEnd = false;
+  } else if (file.getUint16(tiffOffset) === 0x4d4d) {
+    bigEnd = true;
+  } else {
+    // console.log("Not valid TIFF data! (no 0x4949 or 0x4D4D)");
+    return null;
+  }
+
+  if (file.getUint16(tiffOffset + 2, !bigEnd) !== 0x002a) {
+    // console.log("Not valid TIFF data! (no 0x002A)");
+    return null;
+  }
+
+  const firstIFDOffset = file.getUint32(tiffOffset + 4, !bigEnd);
+
+  if (firstIFDOffset < 0x00000008) {
+    // console.log(
+    //   "Not valid TIFF data! (First offset less than 8)",
+    //   file.getUint32(tiffOffset + 4, !bigEnd)
+    // );
+    return null;
+  }
+
+  const tags = readTags(
+    file,
+    tiffOffset,
+    tiffOffset + firstIFDOffset,
+    TiffTags,
+    bigEnd
+  );
+
+  // Skip `ExifIFDPointer` tags.
+  //
+  // Skip `GPSInfoIFDPointer` tags.
+  //
+  // Skip thumbnail image extraction.
+
+  return tags;
+}
+
+export { readEXIFData };
diff --git a/gulpfile.mjs b/gulpfile.mjs
@@ -1646,6 +1646,7 @@ function buildLib(defines, dir) {
       encoding: false,
     }),
     gulp.src("test/unit/*.js", { base: ".", encoding: false }),
+    gulp.src("external/exif-js/*.js", { base: "exif-js/", encoding: false }),
     gulp.src("external/openjpeg/*.js", { base: "openjpeg/", encoding: false }),
   ]);
 

diff --git a/src/core/jpg.js b/src/core/jpg.js
@@ -15,6 +15,7 @@
 
 import { assert, BaseException, warn } from "../shared/util.js";
 import { grayToRGBA } from "../shared/image_utils.js";
+import { readEXIFData } from "../../external/exif-js/exif.js";
 import { readUint16 } from "./core_utils.js";
 
 class JpegError extends BaseException {
@@ -804,6 +805,16 @@ class JpegImage {
     this._colorTransform = colorTransform;
   }
 
+  static #getEXIF(data) {
+    try {
+      const dv = new DataView(data.buffer, data.byteOffset, data.byteLength);
+      return readEXIFData(dv, 0);
+    } catch (ex) {
+      warn(`#getEXIF - EXIF parsing failed: "${ex}".`);
+    }
+    return null;
+  }
+
   static canUseImageDecoder(data, colorTransform = -1) {
     let offset = 0;
     let numComponents = null;
@@ -817,6 +828,32 @@ class JpegImage {
 
     markerLoop: while (fileMarker !== /* EOI (End of Image) = */ 0xffd9) {
       switch (fileMarker) {
+        case 0xffe1: // APP1 - Exif
+          const { appData, newOffset } = readDataBlock(data, offset);
+          offset = newOffset;
+
+          // 'Exif\x00\x00'
+          if (
+            appData[0] === 0x45 &&
+            appData[1] === 0x78 &&
+            appData[2] === 0x69 &&
+            appData[3] === 0x66 &&
+            appData[4] === 0 &&
+            appData[5] === 0
+          ) {
+            const exif = this.#getEXIF(appData);
+
+            if (exif) {
+              // Skip images with non-default orientation
+              // (fixes bug1942064.pdf).
+              if (exif.Orientation !== undefined && exif.Orientation !== 1) {
+                return false;
+              }
+            }
+          }
+          fileMarker = readUint16(data, offset);
+          offset += 2;
+          continue;
         case 0xffc0: // SOF0 (Start of Frame, Baseline DCT)
         case 0xffc1: // SOF1 (Start of Frame, Extended DCT)
         case 0xffc2: // SOF2 (Start of Frame, Progressive DCT)

diff --git a/test/pdfs/.gitignore b/test/pdfs/.gitignore
@@ -503,6 +503,7 @@
 !annotation-line-without-appearance.pdf
 !bug1669099.pdf
 !annotation-square-circle.pdf
+!bug1942064.pdf
 !annotation-square-circle-without-appearance.pdf
 !annotation-stamp.pdf
 !issue14048.pdf

diff --git a/test/pdfs/bug1942064.pdf b/test/pdfs/bug1942064.pdf
diff --git a/test/test_manifest.json b/test/test_manifest.json
@@ -8997,6 +8997,13 @@
     "link": true,
     "type": "other"
   },
+  {
+    "id": "bug1942064",
+    "file": "pdfs/bug1942064.pdf",
+    "md5": "d50b5ebb8cab1211609d16faa54ec47d",
+    "rounds": 1,
+    "type": "eq"
+  },
   {
     "id": "issue16221-text",
     "file": "pdfs/issue16221.pdf",