CJXL(1)				        			       CJXL(1)

NAME
       cjxl - compress images to JPEG XL

SYNOPSIS
       cjxl [options...] input [output.jxl]

DESCRIPTION
       cjxl compresses an image or animation to the JPEG XL format. It is
       intended to spare users the trouble of determining a set of optimal
       parameters for each individual image. Instead, for a given target
       quality, it should provide consistent visual results across various
       kinds of images. The defaults have been chosen to be sensible, so that
       the following commands should give satisfactory results in most cases:

	   cjxl input.png output.jxl
	   cjxl input.jpg output.jxl
	   cjxl input.gif output.jxl

OPTIONS
       -h, --help
	   Displays the options that cjxl supports. On its own, it will only
	   show basic options. It can be combined with -v or -v -v to show
	   increasingly advanced options as well.

       -v, --verbose
	   Increases verbosity. Can be repeated to increase it further, and
	   also applies to --help.

       -d distance, --distance=distance
	   The preferred way to specify quality. It is specified in multiples
	   of a just-noticeable difference. That is, -d 0 is mathematically
	   lossless, -d 1 should be visually lossless, and higher distances
	   yield denser and denser files with lower and lower fidelity. Lossy
	   sources such as JPEG and GIF files are compressed losslessly by
	   default, and in the case of JPEG files specifically, the original
	   JPEG can then be reconstructed bit-for-bit. For lossless sources,
	   -d 1 is the default.

       -q quality, --quality=quality
	   Alternative way to indicate the desired quality. 100 is lossless
	   and lower values yield smaller files. There is no lower bound to
	   this quality parameter, but positive values should approximately
	   match the quality setting of libjpeg.

       -e effort, --effort=effort
	   Controls the amount of effort that goes into producing an “optimal”
	   file in terms of quality/size. That is to say, all other parameters
	   being equal, a higher effort should yield a file that is at least
	   as dense and possibly denser, and with at least as high and
	   possibly higher quality.

	   Recognized effort settings, from fastest to slowest, are:

	   •   1 or “lightning”

	   •   2 or “thunder”

	   •   3 or “falcon”

	   •   4 or “cheetah”

	   •   5 or “hare”

	   •   6 or “wombat”

	   •   7 or “squirrel” (default)

	   •   8 or “kitten”

	   •   9 or “tortoise”

EXAMPLES
	   # Compress a PNG file to a high-quality JPEG XL version.
	   $ cjxl input.png output.jxl

	   # Compress it at a slightly lower quality, appropriate for web use.
	   $ cjxl -d 2 input.png output.jxl

	   # Compress it losslessly. These are equivalent.
	   $ cjxl -d 0	 input.png lossless.jxl
	   $ cjxl -q 100 input.png lossless.jxl

	   # Compress a JPEG file losslessly.
	   $ cjxl input.jpeg lossless-jpeg.jxl

SEE ALSO
       djxl(1)

 				  07/03/2025			       CJXL(1)