> imageoptim clocking in at around half the total filesize of optimage
Only that ImageOptim ruined most of JPEG images while PNG images are ~7.5% bigger.
> imageoptim is dramatically smaller on all of them
There are myriad ways to make them much smaller at the cost of visual quality: blurring, posterization, rescaling, etc. The question is where to stop. With visually lossless, you can apply these techniques in advance and have predictable results. For example, Optimage does choose chroma sampling when it is not destructive to original.
> the 'broken gradient' (I can't see it)
It can be seen on a calibrated display, sorry.
> the orange sneakers (imageoptim's looks better and not overblown colors)
Original colors are "overblown" [1].
> or the rotated beach scene
It is rotated.
[1] https://webkit.org/blog-files/color-gamut/
Only that ImageOptim ruined most of JPEG images while PNG images are ~7.5% bigger.
> imageoptim is dramatically smaller on all of them
There are myriad ways to make them much smaller at the cost of visual quality: blurring, posterization, rescaling, etc. The question is where to stop. With visually lossless, you can apply these techniques in advance and have predictable results. For example, Optimage does choose chroma sampling when it is not destructive to original.
> the 'broken gradient' (I can't see it)
It can be seen on a calibrated display, sorry.
> the orange sneakers (imageoptim's looks better and not overblown colors)
Original colors are "overblown" [1].
> or the rotated beach scene
It is rotated.
[1] https://webkit.org/blog-files/color-gamut/