CR2 to JXL Converter

Encoding: the CR2 uses lossless JPEG-compressed sensor data, cut into vertical slices; JXL uses lossy VarDCT or lossless modular coding; existing JPEGs can be repacked without loss, and the download is a JPEG XL encoded with libjxl compiled to WebAssembly, lossy at the quality you choose or lossless.

Bit depth: 12 or 14 bits per channel in the CR2; JXL allows 8 to 16 bits per channel, or floating point, and the JXL written here has 8 bits per channel. The sensor's 14 bits are not used: the 8-bit camera preview is converted.

Colour: camera RGB from a Bayer mosaic, with the Picture Style recorded in the maker notes in the CR2; JXL supports sRGB, Display P3, linear and other spaces described in the codestream, written here as 8-bit sRGB.

Metadata: the CR2 can carry EXIF, Canon maker notes (Picture Style, lens, focus points) and the embedded previews; JXL can carry EXIF and XMP boxes in the container form, often stripped by encoders, but nothing is copied across.

CR2 is the raw format of Canon EOS cameras from 2004 until CR3 replaced it in 2018. It holds the sensor's 12 or 14-bit readings, losslessly compressed, plus a large JPEG preview rendered with the camera's Picture Style.

CR2 is TIFF-based: the TIFF header is followed by the letters 'CR' and version 2.0, then four image directories: a large JPEG preview with the EXIF block, a 160×120 thumbnail, a small uncompressed RGB image, and the sensor data as lossless JPEG cut into vertical slices.

CR2 files usually come from Canon EOS DSLRs made from 2004 to 2018, such as the 5D Mark II and III, 6D, 7D and the Rebel series.

JPEG XL is a next-generation format designed to replace JPEG. It compresses better than JPEG and WebP, supports lossless, HDR and progressive decoding, and can losslessly repack existing JPEGs.

A JPEG XL file is either a bare codestream starting with FF 0A or an ISO base media container whose 'jxlc' box holds the codestream. A recompressed JPEG keeps a 'jbrd' box that lets the original JPEG bytes be rebuilt exactly.

JXL is the better choice for archiving and future-proof high quality storage, while CR2 suits editing Canon photos in a raw developer.

JXL strengths: Excellent lossy and lossless compression; Progressive decoding and HDR; Huge image sizes. Drawbacks to weigh: Browser support is limited (Safari only by default); Few apps can open it yet.