WebP + Alpha Channel via PNG

JPEG: 35KB. WebP: 13KB. Alpha Mask: 7KB. PNG: 12KB.
WebP + Alpha: 20KB
JPEG + Alpha: 42KB
PNG-24: 127KB

Demo Code

How does it work?



What Browsers?

Chrome 7.0 and Firefox 4.0 were both tested. Opera doesn't work for reasons that I'm not sure about. I would appreciate it if someone fixes it and submits a patch :)


I'm @antimatter15 (please help me get my followed/following ratio over 1.0!). I know practically nothing about video, VP8, Matroska, EBML, WebP, WebM, codecs, binary, compression though all of them fascinate me, and I loved "A Digital Media Primer for Geeks". At time of writing I'm fifteen, though I don't find that much of an accomplishment. My site is at antimatter15.com and hopefully you'll find some other cool stuff there too.