Change gifs to png

[Alfonso Martínez de Lizarrondo]

Not something about patents or anything, just the fact that in most cases png can give better compression than gifs, specially if they are processed with a specialized program. A list is available ​http://en.wikipedia.org/wiki/PNG#File_size_and_optimization_software

Pngcrush was good, but now it seems that it isn't the king. I've tested pngoutwin (trial) and it was able to shrink the fck_strip.gif from 4804 to 2870 bytes, and the toolbar.buttonbg.gif from 829 to 127 (well, and then the remaining gifs processed in the demo did get bigger, so we leave them just as they are)

Of course, the size of the images isn't really a very big deal, but every little detail can help to improve performance.

[Wojciech Olchawa]

We used the PNG format in the DOCS and it worked out great so I think that it is really a good idea.

[Frederico Caldeira Knabben]

Definitely something to be considered. Of course, we must well test its compatibility (specially with IE6).

It would also give us the possibility of having richer icons and even think about using transparencies.

[Alfonso Martínez de Lizarrondo]

My initial proposal is just to convert the gifs to png with the same color palette, no change except for the file format itself. All the browsers will handle it without any problem, it's about 5 minutes to do all the changes and it requires no special testing. Of course in the future it can be used for a richer iconset, but that's definitively another beast.

[Frederico Caldeira Knabben]

Ok... I've made an optimization effort in this sense while creating the current V3 skins. We should be ok in this sense now, having mostly optimized PNGs now, with GIFs just there were we can have benefit of it.