I've been working on a transparency map for foot hair (don't ask), and came across something interesting: GIF works really well for transmaps. The map used in this image is about 1/2 million pixels. As a jpg it is 444K, as TIF it is 560K, while as GIF it is 276K. PNG is a similar size as GIF, but Photoshop is really slow to save PNG files so I've stuck with GIF. If you think about it, this makes a lot of sense. transmaps tend to be: 1. greyscale (GIF can do 8 bits of color without loss) 2. drawn by hand, with little high-frequency detail to be encoded (so JPG is not a win). 3. dominated by large regions of entirely black pixels, which a run-length encoded file format like GIF can handle very efficiently. I'd recommend that people try saving their transmaps as a GIF and see how big it is. For an exceedingly complex transmap (like for hair), it may not be a win, but for many other items you might save some memory and disk space. The Mac Poser can import GIF files directly in the Materials dialog, I assume Windows Poser can as well.

good tip thanks geek

heyas; i keep telling them that, but no one ever listens to me, of course. ("oh, shut up, bloodsong.") see what i mean? ;)

I think it is sort of strange that a GIF will be that much smaller than a JPEG, unless you are using the highest quality setting, which may mean no compression, I'm unsure. I am sure that GIF uses the same compression scheme as TIF (you did pick LZW compressed for that, didn't you?), so the file sizes are normally within a couple of bytes, it maybe smaller, as if I recall, grayscale TIFs don't include a color map, GIFs always have one.. The thing is, 276K for a foot is going to equal a 3 Mb or so map for the whole figure, which is rather on the large size for modem transfer, as a medium to high quality JPG it will be about 1 Mb, which is more like it, sure the quality isn't quite as good, but it will be much better than the quality of a GIF sized down to produce that small of a file. However, it is an excellent idea to do your stuff as GIFs or TIF (or just PhotoShop files, that is what I use) as long is it doesn't have to go over a modem. BTW, I was involved in writting the GIF89a spec years ago, GIF doesn't use Run Lenth Encoding. it uses LZW. BMP files can use RLE, little else does these days.