2 ms·
Is this your test, just in case? https://ache.one/articles/web-image-formats https://ache.one/articles/web-image-formats I'm not very sure how you have compare
by lifthrasiir 3y ago
Is this your test, just in case? https://ache.one/articles/web-image-formats https://ache.one/articles/web-image-formats
I'm not very sure how you have compared the speed. `cjxl -e 9` for example is known to be very slow because it is AFAIK basically `-e 8` with a brute-force parameter search (and I think this level should be hidden in some way for this exact reason, it is very misleading). Also I assume that you have done an end-to-end command line test with relatively small inputs, which might be a major pitfall (because it doesn't only measure the PNG encoder/decoder but also all program invocation time and finalization time, which can be specficially optimized [1]).
Also only relying on a single objective metric might be misleading, and Jon Sneyers (one of JPEG XL devs) has a very good plot that illustrates this [2] and pointed out that actual images have to be also manually reviewed to reduce mistakes. Many comparisons are made against images with similar SSIM scores, but it is unclear if they indeed had similar qualities. And an ideal perceptual metric is not enough, specifics on "taking the AVIF format points as a basis and comparing them with the similarity and similar ratio points" would be necessary to evaluate the test.
[1] For example you can skip `free` on complicated structures because they will be reclaimed by the kernel anyway. Of course this is totally unacceptable for libraries.
[2] https://twitter.com/jonsneyers/status/1560924579719258113 https://twitter.com/jonsneyers/status/1560924579719258113 (The ideal metric should strongly correlate to the human score and should not distort the relative score difference. Most metrics---except for SSIMULACRA 2 which specifically being developed with this dataset---are bad at both.)