Color problems

Soulhealer wrote on 9/21/2001, 4:40 PM
I'm quite new at this so there's a chance I'm doing something wrong. When I render the movie even in AVI format uncompresse I get a kind of halo effect on large color surfaces like walls. It's like when light reflect on a surface the changing of gradien of the colors is not smoothly done and also given a blocky effect.
I capture from a s-vhs video camera, an s-video cable to a All-In-Wonder RADEON capture card.
My system as 128meg ram, a dedicated disc for capture of 40 gig, Pentium III650, Win98 SE

The problem is annoying because it degrades the quality of the video.

Thank's for any help

Comments

wvg wrote on 9/21/2001, 11:26 PM
Sounds like the colors are over saturated. You can correct by applying the HSL filter making SMALL adjustments to the saturation and maybe the lumaniace levels.
SonyEPM wrote on 9/24/2001, 8:52 AM
Are these MPEG files you are capturing? If so, expect artifacts when re-rendering.
Chienworks wrote on 9/24/2001, 9:30 AM
Another problem could be insufficient bit-depth. Normally video uses
24 bits (8 for each of the three primary colors, red, green, & blue) which
allows for 16,777,216 colors, or virtually unlimited smooth shading.
Some capture programs will use fewer bits to save disk space. If you
use too few, there won't be enough colors to allow for smooth shading.
Usually 15 bits is about the minimum you can get away with, but even
this will result in the "banding" you're seeing in large smooth surfaces.

Check the capture program you're using for video format setup. Try
setting it to 24 bit RGB and this should get rid of the problem. If the
resulting .AVI files are too huge, try 15 bits and see if that is
acceptable. I've also had really good results with YUV9, which i'm
assuming is 9 bits but uses a dynamic palatte (anyone out there know
if my guess is correct?) to pick the right set of colors needed for each
frame.
Soulhealer wrote on 9/24/2001, 3:55 PM
Thank's for all your answers. I tried several things but it did not work.

1- It doesn't seem to be a saturation problem because I tried the HSL filters and it did not work.

2- I am not rendering in MPEG format when I have these problems. In fact, when I capture in MPEG 640x480 the image is great. But the format is not that good for video editing.

3- I capture using the software the came with my Radeon. I capture in AVI format 320x240 29.47 UYVY (native).

I can't seem to find a way to change the color depth.

Any suggestion would help.

Soulhealer

SonyEPM wrote on 9/24/2001, 4:13 PM
Have you tried rendering back to the exact same settings as the file(s) you captured?
Soulhealer wrote on 9/24/2001, 5:36 PM
Yes and it does the same thing.

soulhealer
hcronco wrote on 4/20/2002, 2:35 AM
I got the same problem. When I capture it, it's fine, but the first time I render it, the gradient is terrible. It didnt use to do this, either, I dont know what it is, thinking of reinstalling.