[daros]

It's important to use less memory during rendering.
Bump maps or opacity maps are ok in 8 bit depth.

David Rossmann

[tom]

i'm not sure the bitmap depth is a critera in this algorithm.
i think channel depth of every pixel is taken into account.
thus, 256 color bitmap has the same weight pixels as in 24 bit in terms of channel depth [it's 8].
i mean R,G and B is still in the range of 0-255
however, i may be wrong

[daros]

It's possible tom.