XMP
Extensible Metadata Platform
An Adobe-created XML metadata standard for embedding editing history, keywords, and rights information in files.
Chi tiết kỹ thuật
XMP data is stored in a structured binary format within JPEG and TIFF files, defined by the JEIDA/JEITA standard (now Exif 3.0). It captures dozens of fields: aperture (f-stop), shutter speed, ISO sensitivity, focal length, flash status, white balance, and GPS coordinates with altitude. Privacy-sensitive users should strip EXIF before sharing photos online, as GPS data can reveal precise location. Most social platforms strip EXIF on upload, but direct file sharing preserves it.
Ví dụ
```javascript
// Read EXIF data from image file
const buffer = await file.arrayBuffer();
const view = new DataView(buffer);
// Check JPEG SOI marker
if (view.getUint16(0) === 0xFFD8) {
// EXIF starts at APP1 marker (0xFFE1)
// Fields: camera model, aperture, ISO, GPS coords
}
// Strip EXIF: re-draw on canvas → export (removes metadata)
```