djxl

Decode JPEG XL to PNG

$ djxl [image.jxl] [output.png]

$ djxl [image.jxl] [output.jpg]

$ djxl [image.jxl] [output.ppm]

$ djxl --info [image.jxl]

$ djxl --num_threads [4] [image.jxl] [output.png]

$ djxl --frame [5] [animation.jxl] [frame5.png]

djxl [options] input.jxl [output]

djxl is the reference JPEG XL decoder, converting JPEG XL images to other formats. It's part of the libjxl reference implementation and supports all JPEG XL features including animation, HDR, and lossless JPEG reconstruction.
JPEG XL files created by losslessly recompressing JPEG can be decoded back to the exact original JPEG bytes using the --jpeg flag. This allows JPEG XL to serve as a reversible compression layer.
The decoder supports various output formats with automatic format detection based on file extension, and can extract metadata and individual frames from animated images.

INPUT

JPEG XL file to decode.

Output file (format inferred from extension).

Show image information only.

Number of decoding threads.

Extract specific frame from animation.

Reconstruct exact JPEG if losslessly recompressed.

Output bit depth.

Display help information.

Output format support depends on build configuration. Some HDR features may require specific output formats. JPEG reconstruction requires original was losslessly compressed. Large images may use significant memory.

djxl is part of the libjxl reference implementation of JPEG XL, developed by the JPEG Committee with contributions from Google. JPEG XL was standardized in 2022 as a next-generation image format combining features from Google's PIK and Cloudinary's FUIF.

cjxl(1), djpeg(1), convert(1)