Lower color bit-depth for anime? Good idea?

Just wondering if it's feasible and a good idea for improved compressibility of anime. Huge swaths of the same color all over the place, and yet they still require as much bitrate as movies to look good. Why is that? Do filters exist that would do this for me?

Excellent. Just what I was looking for.

I'd still like to see something like a "Motion GIF" codec, probably similar to MJPEG or Huffyuv. I guess with some palette tweaking this could give good results. Maybe it's also possible to improve such a codec for the use of delta frames. bb

@JohnMK: The reason why anime is harder to compress, in a nutshell, is that sharp edges are very hard to compress, and anime is nothing if not loaded with sharp edges. Smoothing areas of flat color and removing noise will take you a long ways in reducing bitrate, but for exceptionally small file sizes, you have to soften those edges. Thus, it becomes a compromise: small files vs. sharp edges. It's one of those decisions you don't like to make--like reducing resolution to achieve a certain bitrate. There are any number of softening or convolution filters which are easily found. I'm rather liking Convolution3d, at the moment. @ErMaC: MPNG rival HuffYUV for size efficiency? Probably, but I'd imagine that it'd be dirt-slow for encoding and decoding, both, as I don't think that it's a speed-optimized compression scheme. And isn't there already a "Motion GIF"? (e.g. GIF animations) :)

convolution3D gave me very good results with animeBQ preset. the guys in the avisynth forum r testing a new filter peachsmoother seems promising.

I checked out glzw and some other lossless codecs a long while ago. unfortunately i forgot what i exactly did, but here are the results (a text file i found on my hd): Code:

size looks good but the decoding was really slow and I noticed some weird colors around black edges (and in anime.. well, that's everything :/) so I wouldn't use it over huffyuv