JXL to RAF Converter

Encoding: the JXL uses lossy VarDCT or lossless modular coding; existing JPEGs can be repacked without loss; RAF uses uncompressed or lossless compressed sensor data in Fujifilm's own container, and the download is a Linear DNG: demosaiced 8-bit RGB with the colour matrices raw editors need.

Bit depth: 8 to 16 bits per channel, or floating point in the JXL; RAF allows 12 to 16 bits per channel depending on the camera, and the DNG written here has 8 bits per channel, linearised. High-bit-depth JPEG XL files are reduced to 8 bits per channel.

Colour: sRGB, Display P3, linear and other spaces described in the codestream in the JXL; RAF supports camera RGB from an X-Trans 6×6 or Bayer 2×2 mosaic, written here as 8-bit sRGB.

Transparency: the JXL stores it as an extra channel in the codestream; the DNG has none, so transparent areas are filled with the colour you choose.

Animation: frames inside a single codestream; the DNG holds one image, so only the first frame is converted.

Metadata: the JXL can carry EXIF and XMP boxes in the container form, often stripped by encoders; RAF can carry EXIF and Fujifilm maker notes, including the Film Simulation, but nothing is copied across.

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 files usually come from image editors, archival pipelines and lossless JPEG recompression.

RAF is the raw format of Fujifilm cameras, from the X series to the medium-format GFX. Most X-series bodies use an X-Trans sensor with a 6×6 colour filter pattern instead of the usual Bayer 2×2.

RAF is not TIFF at the top level: it opens with the text 'FUJIFILMCCD-RAW', then a header with the camera model and offsets to three blocks: a JPEG preview near the start of the file, a header describing the sensor layout, and the sensor data.

RAF files come from Fujifilm X-T, X-H, X-S, X-E, X100 and GFX cameras.

Forms and workflows that ask for RAF usually feed a raw editor, and each of those opens DNG as well, so the DNG can take the RAF's place. Keep the JXL if you only need to view or share the picture.

What RAF offers when it comes straight from the camera: Film Simulation baked into the embedded JPEG; Lossless compressed option on recent bodies; Large medium-format files from GFX cameras. Its drawbacks: Fujifilm's own container rather than TIFF; X-Trans demosaicing differs between raw editors; Film Simulations need camera-matching profiles in third-party editors.