remove EXIF information from PNG, JPEG and WebP images
jsr.io/@mary/exif-rm
typescript
jsr
feat: webp support
closes https://codeberg.org/mary-ext/pkg-exif-rm/issues/1
+88
+37
mod.ts
+37
mod.ts
···
10
10
const indices: [start: number, end: number][] = [];
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let start = 0;
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+
let webp = false;
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if (blen >= 2 && view.getUint16(0) === 0xffd8) {
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// JPEG
···
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pos = end;
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}
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+
} else if (
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blen >= 12 &&
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/* RIFF */ view.getUint32(0) === 0x52494646 &&
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/* WEBP */ view.getUint32(8) === 0x57454250
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) {
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// WebP
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let pos = 12;
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webp = true;
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+
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// RIFF format uses little-endian
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while (pos + 4 + 4 <= blen) {
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const marker = view.getUint32(pos, true);
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const chunkSize = view.getUint32(pos + 4, true);
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const end = pos + chunkSize + 4 + 4;
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if (/* EXIF */ marker === 0x46495845 || /* "XMP "" */ marker === 0x20504D58) {
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indices.push([start, pos]);
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start = end;
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}
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// Move to the next chunk, add padding byte if chunk size is odd
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pos = end;
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if (chunkSize & 1) {
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pos++;
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}
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}
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}
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if (start === 0) {
···
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return offset + (index[1] - index[0]);
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}, 0),
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);
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+
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if (webp) {
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// Alter the RIFF header to reflect the new size
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const view = new DataView(copy.buffer);
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const newSize = copy.byteLength - 8;
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view.setUint32(4, newSize, true);
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}
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return copy;
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};
samples/sample.webp
samples/sample.webp
This is a binary file and will not be displayed.
+51
test.ts
+51
test.ts
···
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assert(exifRemoved !== null);
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assertEquals(await identify(exifRemoved), {});
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});
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+
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Deno.test('removes EXIF from WebP files', async () => {
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const image = await Deno.readFile('./samples/sample.webp');
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// Verify the original image has EXIF data
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assertEquals(await identify(image), {
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'exif:ApertureValue': '45/8',
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'exif:ColorSpace': '1',
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'exif:ComponentsConfiguration': '...',
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'exif:CustomRendered': '0',
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'exif:DateTime': '2008:07:31 10:38:11',
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'exif:DateTimeDigitized': '2008:05:30 15:56:01',
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'exif:DateTimeOriginal': '2008:05:30 15:56:01',
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'exif:ExifOffset': '190',
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'exif:ExifVersion': '0221',
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'exif:ExposureBiasValue': '0/1',
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'exif:ExposureMode': '1',
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'exif:ExposureProgram': '1',
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'exif:ExposureTime': '1/160',
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'exif:FNumber': '71/10',
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'exif:Flash': '9',
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'exif:FlashPixVersion': '0100',
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'exif:FocalLength': '135/1',
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'exif:FocalPlaneResolutionUnit': '2',
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'exif:FocalPlaneXResolution': '324000/73',
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'exif:FocalPlaneYResolution': '2592000/583',
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'exif:Make': 'Canon',
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'exif:MeteringMode': '5',
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'exif:Model': 'Canon EOS 40D',
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'exif:Orientation': '1',
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'exif:PhotographicSensitivity': '100',
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'exif:PixelXDimension': '100',
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'exif:PixelYDimension': '68',
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'exif:ResolutionUnit': '2',
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'exif:SceneCaptureType': '0',
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'exif:ShutterSpeedValue': '59/8',
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'exif:Software': 'GIMP 2.4.5',
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'exif:SubSecTime': '00',
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'exif:SubSecTimeDigitized': '00',
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'exif:SubSecTimeOriginal': '00',
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'exif:WhiteBalance': '0',
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'exif:XResolution': '72/1',
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'exif:YResolution': '72/1',
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});
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const exifRemoved = remove(image);
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+
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// Verify the image has no EXIF data
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assert(exifRemoved !== null);
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assertEquals(await identify(exifRemoved), {});
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});