Re: Fast way of splitting an image into bit planes ?

In alt.lang.asm Skybuck Flying <BloodyShame@[EMAIL PROTECTED]
> wrote in part:
> Only question remaining is which way of walking through
> memory will be more efficient ?

The generally preferred technique when there is lots of work
_and_ lots of memory is cache blocking -- breaking the problem
down into chunks that will fit inside cache.

I do not know why you want to deswizzle all 24 bits,
usually separating R G & B is all that is needed.

> Walking 24 times through the same memory doesn't seem
> to smart...

No, it is not

> But then again walking once through the input memory and
> then doing massive random access for the output doesn't
> seem smart as well.

No it is not.  Most likely block the input to fill up whole
output words, 24*32 = 768 values if I understand you.

> Hmmm since this is graphics related, maybe graphics cards
> have a special ability to do this ?????

They do have specialize hardware.  But I don't think bitwise.

-- Robert