Animated PNG: Simple Animation with an Alpha Channel
Why Is This a Good Thing?
You can do a lot with GIF animation, but the web has long been missing a simple animation format with full 24-bit color and 8-bit transparency (Alpha channel) to take animation to the next level. Say good-bye to loss of color resolution and lack of transparency control.
For example, take a look at the animations below:
Both show the same GIF animation. Against white it looks great (it was hand-tuned to work with white), but it's not so nice against any other background.
That's where Animated PNG comes in. A single animation will work against any background (solid, patterned, whatever) and still look great, shadows and all. To view the following example properly, you will need a browser that supports APNG such as FireFox or Opera :
If all you see is two static images, your browser does not yet support APNG. Too bad. With the right browser, you would be seeing an animation that looks good (well, for a cheesy animation) against any background.
APNG stands for "Animated PNG" and is a new extension
to the PNG file format that promises to allow the simple
creation of gorgeous frame-based animations with 24-bit color and
full Alpha-channel support. The big limitation of the GIF format
has always been a lack of bits. Each frame is limited to only 256
colors, and even worse, transparency is limited to only
1 bit (opaque or transparent and nothing in between).
APNG promises to fix this limitation. You can learn
a lot more about the development of this PNG extension
APNG spec homepage.
Big Important Note
The PNG Committee rejected the APNG proposal, making this implementaiton not "official". Two browsers currently have support for APNG 0.10, FireFox 3 (or newer) and Opera 9.5 (or newer), so you can start experimenting with APNG on a web page today. Whether or not this support will continue is uncertain.
What Works and What's Not Quite Done
Version 4.2+ of GIF Movie Gear supports just about the full APNG 0.10 functionality: frames with 24-bit color and full 8-bit transparency (Alpha channel), option to skip the first frame (Animation>Properties), control of disposal methods (much like in GIF), and control of image blending (APNG-only feature seting in Frame>Properties). Delays are still limited to GIF's 1/100th second granularity (vs. APNG's numerator/denominator capabilities).
A Quick and Dirty Example
Remember the not-so-professional animation at the top
of the page? It
by a non-artist
with only a passing knowledge of Photoshop. When opened
in GMG, you can see what the individual frames look like:
Tell Us About It
Well? What do you think? Tell us about it. Email us at firstname.lastname@example.org to rant, rave, whatever. We'd also love to see any cool PNG animations you've built!