remove EXIF information from PNG, JPEG and WebP images
jsr.io/@mary/exif-rm
typescript
jsr
initial commit
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LICENSE
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LICENSE
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Permission is hereby granted, free of charge, to any person obtaining a copy
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of this software and associated documentation files (the "Software"), to deal
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in the Software without restriction, including without limitation the rights
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to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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copies of the Software, and to permit persons to whom the Software is
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furnished to do so, subject to the following conditions:
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The above copyright notice and this permission notice shall be included in all
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copies or substantial portions of the Software.
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THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
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SOFTWARE.
+8
README.md
+8
README.md
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deno.json
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deno.json
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{
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"name": "@mary/exif-rm",
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"version": "0.1.0",
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"exports": "./mod.ts",
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"fmt": {
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"useTabs": true,
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"indentWidth": 2,
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"lineWidth": 110,
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"semiColons": true,
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"singleQuote": true
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},
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"publish": {
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"exclude": [".vscode/", "samples/", "deno.lock", "test.ts"]
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}
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}
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deno.lock
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deno.lock
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{
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"version": "3",
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"packages": {
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"specifiers": {
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"jsr:@std/assert": "jsr:@std/assert@0.218.2",
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"jsr:@std/fmt@^0.218.2": "jsr:@std/fmt@0.218.2"
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},
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"jsr": {
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"@std/assert@0.218.2": {
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"integrity": "7f0a5a1a8cf86607cd6c2c030584096e1ffad27fc9271429a8cb48cfbdee5eaf",
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"dependencies": [
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"jsr:@std/fmt@^0.218.2"
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]
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},
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"@std/fmt@0.218.2": {
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"integrity": "99526449d2505aa758b6cbef81e7dd471d8b28ec0dcb1491d122b284c548788a"
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}
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}
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},
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"remote": {}
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}
+95
mod.ts
+95
mod.ts
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/**
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* Removes EXIF information from PNG and JPEG images
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* @returns A new image buffer with EXIF removed, will return `null` if
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* image is unsupported, or if there's nothing to remove.
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*/
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export const remove = (buf: ArrayBuffer): Uint8Array | null => {
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const view = new DataView(buf);
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const indices: [start: number, end: number][] = [];
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const blen = view.byteLength;
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let start = 0;
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if (blen >= 2 && view.getUint16(0) === 0xffd8) {
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// JPEG
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let pos = 2;
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while (pos + 4 + 5 <= blen) {
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const marker = view.getUint16(pos);
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if (/* Fill */ marker === 0xffff) {
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pos++;
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continue;
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} else if (
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/* App0..App15 */ (marker >= 0xffe0 && marker <= 0xffef) ||
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/* Comment */ marker === 0xfffe ||
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/* SOF0 */ marker === 0xffc0 ||
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/* SOF2 */ marker === 0xffc2 ||
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/* DHT */ marker === 0xffc4 ||
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/* DQT */ marker === 0xffdb ||
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/* DRI */ marker === 0xffdd ||
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/* SOS */ marker === 0xffda
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) {
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const flen = view.getUint16(pos + 2);
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const end = pos + 2 + flen;
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if (
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/* App1 */ marker === 0xffe1 &&
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/* Exif */ view.getUint32(pos + 4) === 0x45786966 &&
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/* null */ view.getUint16(pos + 8) === 0x0
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) {
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indices.push([start, pos]);
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start = end;
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}
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pos = end;
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continue;
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}
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break;
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}
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} else if (blen >= 8 && view.getUint32(0) === 0x89504e47 && view.getUint32(4) === 0x0d0a1a0a) {
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// PNG
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let pos = 8;
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while (pos + 4 + 4 <= blen) {
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const flen = view.getUint32(pos);
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const marker = view.getUint32(pos + 4);
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const end = pos + flen + 4 + 4 + 4;
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if (
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/* eXIf */ marker === 0x65584966 ||
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/* tIME */ marker === 0x74494d45 ||
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/* iTXt */ marker === 0x69545874 ||
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/* tEXt */ marker === 0x74455874 ||
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/* zTXT */ marker === 0x7a545874 ||
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/* dSIG */ marker === 0x64534947
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) {
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indices.push([start, pos]);
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start = end;
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}
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pos = end;
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}
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}
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if (start === 0) {
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return null;
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}
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const uint8 = new Uint8Array(buf);
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const copy = new Uint8Array(indices.reduce((accu, index) => accu + (index[1] - index[0]), blen - start));
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copy.set(
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uint8.subarray(start),
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indices.reduce((offset, index) => {
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copy.set(uint8.subarray(index[0], index[1]), offset);
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return offset + (index[1] - index[0]);
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}, 0),
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);
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return copy;
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};
samples/sample.jpg
samples/sample.jpg
This is a binary file and will not be displayed.
samples/sample.png
samples/sample.png
This is a binary file and will not be displayed.
+19
test.ts
+19
test.ts
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import { assert } from 'jsr:@std/assert';
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import { remove } from './mod.ts';
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Deno.test('removes EXIF from JPEG files', async () => {
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const image = await Deno.readFile('./samples/sample.jpg');
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const exifRemoved = remove(image.buffer);
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assert(exifRemoved != null);
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assert(exifRemoved.byteLength === 5480);
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});
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Deno.test('removes EXIF from PNG files', async () => {
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const image = await Deno.readFile('./samples/sample.png');
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const exifRemoved = remove(image.buffer);
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assert(exifRemoved != null);
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assert(exifRemoved.byteLength === 17638);
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});