It would be helpful to have the expected result near the browser output.
anyway, I think the "correct" scaling is at the very least objectionable. from a numeric point of view, it whould mix in gray, but from a visual poin of view we do preceive the outer box as darker because non linearity in dislpay and perception.
> anyway, I think the "correct" scaling is at the very least objectionable. from a numeric point of view, it whould mix in gray, but from a visual poin of view we do preceive the outer box as darker because non linearity in dislpay and perception.
I can barely perceive a brightness difference between the two areas. Meanwhile, scaling the gamma-encoded image results in a severely wrong result where the outside is far darker than the inside.
I noticed some extreme weirdness with the "correct scaling" example.
For me (Firefox on Linux using LCD displays) , it looks different depending on which monitor I'm using - on one, the outer part of the gray square looks like there are yellow dots, while on the other monitor, it flickers, but only while the image is over a particular place on the physical monitor (this happens with other images where adjacent pixels frequently have a large difference in color).
Also, the apparent color changes depending on the zoom level - at anything other than 100% zoom, the effects described above disappear and the outer square appears darker than the inner one (although not uniformly). This may be linked to the bug that causes the browser to scale the image incorrectly.
> on one, the outer part of the gray square looks like there are yellow dots, while on the other monitor, it flickers, but only while the image is over a particular place on the physical monitor (this happens with other images where adjacent pixels frequently have a large difference in color).
Your monitor likely has a 6-bit panel and uses FRC to emulate an 8-bit display. This tends to cause content-dependent flickering and other temporal artifacts.
anyway, I think the "correct" scaling is at the very least objectionable. from a numeric point of view, it whould mix in gray, but from a visual poin of view we do preceive the outer box as darker because non linearity in dislpay and perception.