We're using the standard zlib code to do the compression.
We are using compression settings similar to pngcrush, however -- since customers yelled quite loudly that they wanted more compression for PNG.
The only way around that is to offer a UI when you save, asking if you want speed and little compression, or to take a while and get better compression.
Chris Cox wrote:
That would be great, maybe a kind of slider like the jpg one?
Another way could be an "options" button in the save dialog, somewhere next to save and cancel.
It could be set once and stay that way instead of having a second dialog popup each time you save.
Really, we'd have to ask each time you save, otherwise there would be no good way to ever change the choice.
Yes, it would be much like saving JPEG.
You have specific file options button that sets persistent configurations so it doesn't ask each time.
But to think of it, maybe that would clash or override settings that are pre-existent in a file...