Compression Problem - DV Hates Red?

C

Clanche

New member
Ok I have been trying to tackle this for 2 days now but I am at a loss.. btw, first time post but long time reader, so hello everyone :smile:

I created this 6 second graphic in 3D studio max and rendered it as in uncompressed avi 720x480 (29.97fps, 0.9 aspect).

Here is the problem, when i bring it into Vegas and try to convert it to NTSF DV format, I'm loosing quality like crazy!
I also tried capturing to tape but same problem, and same thing happened with the basic DV export in movie maker.
I thought it was my file format at first, but messing around I realized that when the red was changed to something
else, the quality increased again and no longer had than super-pixelated affect. Same thing when exporting to MPG2..
red always ended up looking much worse than any other color... I thought that DV format was not (if not barely) a
compression and that my original render should seem almost identical

Screen captures:
CompressionProblem_UN1.jpg

1(uncompressed original render)

CompressionProblem_DV3.jpg
CompressionProblem_DV2.jpg
CompressionProblem_DV4.jpg

1(NTSC DV) 2(NTSC DV Black and White) 3(NTSC DV - Color Balanced Changed)

CompressionProblem_MPG3.jpg
CompressionProblem_MPG2.jpg
CompressionProblem_MPG4.jpg

1(NTSC MPEG2) 2(NTSC MPEG2 Black and White) 3(NTSC MPEG2 - Color Balanced Changed)


Any suggestions? I am doing something wrong? :embarasse
 
DV format is compressed approx. 5:1.
Compare full AVI and DV file sizes and you'll see.
This is well known DV codec problem, chroma resolution is less than luma resolution. Pure red against black makes things even worse.
Try chroma smoothing filter before you export to MPEG2, it helps.
 
This is exactly what I would expect. Color gets sampled at 1/4 the resolution of brightness, and when you're working with a pure-color object like red or blue, that's where it'll show the worst.

The same thing will happen when using a DV camera to film a primarily red or blue scene; shooting stage plays or musicals or dance recitals can be the worst when the lighting director puts up a "red wash" over the scene. Solid-color red or blue = lousy resolution with DV.
 
thanks for the help guys! ya it just seemed that DV doesn't like the red+black. atleast I know that its not my render. I re-created it with less red and moved the colors around and now it looks great.

thanks again! :)
 
You must log in or register to reply here.
Back
Top