Problem that PNG thumbnail size increases more than original

[madhyde]

When index color PNG is uploaded, WordPress generates full color PNG as a thumbnail.
But, in many cases, the thumbnail file size is larger than the original.
so, I wrote improvement patch. thumbnail color reconvert to same colors as the original(index color).

[madhyde]

improve index PNG's thumnail

[madhyde]

ScreenShot

[dd32]

Couldn't this also be applied to non-png's as well?

[madhyde]

Replying to dd32:
I think It's only index PNG's problem.

[Denis-de-Bernardy]

Replying to dd32:

Couldn't this also be applied to non-png's as well?

maybe to gif images. trouble with the patch is that the resampling might be better done in true colors, with the number of colors reduced in the aftermath.

[Denis-de-Bernardy]

oh, nevermind that, I misread the patch and it seems you did just that.

[dd32]

Gif was indeed what i was mainly thinking of.

[madhyde]

GIF is reduced automatically by the imagegif function.

[azaozz]

How much memory would that use for large image?

[madhyde]

Replying to azaozz:

How much memory would that use for large image?

Why do you warry about memory? This only applied the same flow as Gif to PNG. If a large image is even up-load, this doesn't use more work area than thumnail size.

[madhyde]

Did anyone test?
I tested all cases.
PNG(full-color and index-color), GIF(index-color), JPEG(full-color).
No problem.

[Denis-de-Bernardy]

haven't had time to test, sorry. but it definitely looks commit-worthy.

[Denis-de-Bernardy]

punting per IRC discussion

[Denis-de-Bernardy]

still applies clean

[azaozz]

(In [11737]) Generate same as original color depth thumbnails for PNG images, props madhyde, fixes #9887