"Stephen Bell" <ste### [at] yahoocom> wrote in message
news:3ac68c86$1@news.povray.org...
> I hadn't thought about that.  How does an animated GIF compress?

    It doesn't. It uses every bit of information in the original image. It
simply layers the image so that the different frames display sequentially.

> If more of
> the image in different frames is changed, does it really affect the
> compression?

    Yes. Well, not the compression (see above) but the file size. Every
pixel you remove saves space, and if you remove it over the rather large
number of frames you have, it multiplies. BTW, how many frames -do- you have
and do you need them all? It seems -very- smooth and that is good, but could
you remove 10% and still have smoothness?

> I'm using Microsoft GIF animator.  Is there a better program
> out there?

    I have never used it, but many programs will remove unchanged pixels for
you leaving a rectangle that contains all changing pixels. This requires
that -all- pixels that do not need to change -really- don't change. No
shadows, no radiosity, and often, no AA.

> Mostly I just need to reduce the color depth from 256 colors
> down to a more reasonable level.  I think that would help a lot.

    It would. Drastically. But you can reduce it to a reasonable level, IOW,
you don't have to go down to 16 colors, you could find the required number
for your image. Also, a small decrease in height and width will return a
large bonus in reduced file size.

Post a reply to this message