JPEG 2000 is a container of boxes, and it is built to carry other formats whole. A single .jp2 can hold a complete EXIF block, an XMP packet, an IPTC record, a Photoshop image-resource block and a GeoTIFF ground position, each sealed inside a uuid box where no image viewer looks. This scan walks those boxes in your browser and decodes what is inside them.
Scan a JPEG 2000 fileThe structure itself is the smallest part of the story: image size, component count, bit depth, colour space and the wavelet settings the encoder chose. JPEG 2000 supports depths far beyond 8-bit, which is why medical imaging and national archives use it, and the codestream also carries a comment marker where encoders sign their work. A 16x16 test image in our own corpus names its encoder as Kakadu 3.2 in exactly that marker, and no box-level tool sees it because the marker lives inside the compressed codestream rather than in any box.
The identity travels in the uuid boxes. A GeoJP2 file carries a full GeoTIFF block, so the image is pinned to a place on Earth: the same corpus file gives up a ground position of 334159.280 east, 4429865.180 north in NAD83 UTM zone 18N. Those are metres rather than degrees, so this scan reports them as what they are instead of passing them off as latitude and longitude, and names the coordinate system beside them. A carried EXIF box can hold the photographer, the camera body serial, the capture time and GPS, exactly as it would in a JPEG.
JPEG 2000 also allows free-form XML boxes with no schema at all, so applications write whatever they kept. The scan pulls the named values out rather than reporting a byte count: in the corpus file that is a caption, a description, a creation time and a full postal address, 70 Lighthouse St, Charlotte, New York, 14612, US. None of it is visible in an image viewer, and none of it is removed by re-saving the picture.
This is a selection. The full field manual documents the fields read from each format.
A JPEG 2000 holds its own structural data (size, components, bit depth, colour space, tiling and compression settings) plus whole metadata formats carried inside uuid boxes: EXIF, XMP, IPTC, Photoshop image resources and GeoTIFF geolocation. It can also carry free-form XML with no schema. The codestream itself holds a comment marker that usually names the encoder.
It can, in two separate ways. A GeoJP2 file carries a GeoTIFF block giving the ground position of the raster, often in a projected system such as UTM rather than in degrees. A carried EXIF block can also hold ordinary GPS tags. This scan reads both and reports projected coordinates as eastings and northings rather than pretending they are latitude and longitude.
Not yet. JPEG 2000 is read but not modified. The boxes that carry EXIF, XMP and geolocation could be removed cleanly, but writing a stripper is separate work from writing a reader, and nothing is claimed here that the tool does not do.
Because the format was designed as a container rather than a single image stream. Where a JPEG appends metadata in application segments, a JPEG 2000 nests whole documents in typed boxes, so a single file can carry an EXIF IFD, an XMP packet and a GeoTIFF block side by side without any of them conflicting.
File X-Ray reads JPEG 2000 files entirely in your browser - the file never leaves your device. This format is inspected, not modified. Scan a file now.