A JPEG XL source, a bare codestream or one in its container, is
fetched, detected and decoded, and orig of one is JPEG XL. The format
jxl works in plain and encrypted URLs and on the generator page,
served as image/jxl, and auto chooses it first when Accept names
image/jxl.
govips sends libvips a JPEG XL distance with every save, and libvips
then ignores the quality, so q is turned into a distance with libvips'
formula, keeping 100 lossy. govips cannot have libvips strip metadata
from JPEG XL, so it is removed from the image before saving; libvips
8.16 and later still add an EXIF block of their own, with nothing from
the source. The conversion to sRGB moved ahead of the format switch.
Model: opus-5-5
auto is a format in the /v1/image/ path, an encrypted URL's token and
the generator page. Once the signature or token is checked, pixa
chooses AVIF when Accept names image/avif, else WebP when it names
image/webp, else JPEG when the most specific of image/jpeg, image/* and
*/* allows it or Accept is absent. q=0 refuses a format; a header
allowing none of the three answers 406, one that does not parse 400.
The signature and token cover auto itself; the cache key and ETag use
the chosen format. Answers from then on carry Vary: Accept.
Model: opus-5-5