"Lenny" wrote in message
...
The ATI Halo picture has 17000 more colors than the NVidia one (which
is
running Detonator 50). I used Paint Shop Pro 7 to analyze the pictures.

When you do this color counting stuff, just make sure you're not using
jpeg
images as your base comparison, because that would skew the results. Maybe
not to the extent of adding or removing as much as 17.000 shades, but jpeg
IS a very heavy-handed compression scheme.

Just FYI...

Yes, but they are both JPG. That would only be valid if one were an
uncompressed bitmap and the other a jpeg. I would assume JPEG compression
removes an even amount of all colors, right? You can look at both images
and tell that one of them is alot darker than the other, with more washed
out colors.

I also did a comparison of 3 different Aquamark jpg images that were
greyscaled, one was ATI, one was GeForce at full precision (32-bit), another
one was at 16 bit. And the GeForce-32-bit actually had the most shades of
grey (about 4500), more than the ATI, but the 16-bit was the worst. There
were several hundred more shades in the NVidia-32-bit image than the ATI
image, and about 1000 more in the 32-bit vs. the 16-bit.

Working with uncompressed images would be the best, but if JPEG's all you
have, that's all you have.

Here's another case... two uncompressed bitmaps I took from Aquamark 3:

Det 45 frame 609 has 39134 colors
Det 51 frame 609 has 36926 colors

That's a difference of 2208 colors. Det 51 is displaying about 5 percent
fewer colors. If you do a subtraction function of the two images, you find
most of the color loss is concentrated on the submarine hull, almost
exclusively (terrain lighting is mostly unaffected). Rather than being a
bright greenish-yellow, it's more a dark, muddy green.