non-photographic image that features high contrast sharp edges and smooth have gradient area on vardct mode
Hello, I using jpeg xl vardct mode compress a lot of non-photographic image, in vardct mode,
some image that features high contrast sharp edges and smooth have gradient area,
smooth area can't keep very well(keep smooth) and have some error(noise),
I using different jpeg xl flag, try to fix this issue.
cjxl --epf=3, enable this still can't fix smooth area,
cjxl --noise=0|1, --dots=0|1, --patches=0|1, --gaborish=0|1, enable or disable those flag can't get
too much benefit, some time thing will be worst.
cjxl reduce -s 7 to -s 3, -s 3 can let error(noise) better than -s 7, but still have error(noise),
cjxl --intensity_target=N, increase N can fix, but file size will increase too much,
cjxl reduce -d to 0.1 ~ 0.3, can fix, but file size will increase too much,
cjxl -m -Q(lossy modular), can fix, but i want using adaptive quantization and Butteraugli,
cjxl -m (lossless modular), can fix, lossless is good, but i want do some lossy compression.
I think probably some encoding method(loop filter?) will get some bad effect in non-photographic image?
like av1(avif) have CDEF, but some non-photographic encoding discuss,
suggest disable CDEF can get some benefit in non-photographic content.
Edit: disable some copyright image
command:
cjxl -d [0.5, 1.0, 1.45, 1.9] -s 7
cjxl -d [0.5, 1.0, 1.45, 1.9] -s 3
cjxl -m -Q [95, 90, 85, 80] -s 9 -g 2 -E 3 -I 1
cavif -Q [95, 90, 80] -s 1
Operating System: Windows 10
JPEG XL software version: jpeg-xl-v0.3.1-ef3f7a62
CPU / architecture / device: ryzen 1600, ram 16g