a few basic question about colorspaces/curves

[zee944]

1. When I open an .M2V file taken from a DVD in VirtualDub, I can't see what colorspace it is in. If I open it through a .D2V file, VirtualDub says it's YV12. Does that mean all DVD's native format is YV12?

2. Does Blu-Ray still use 8 bit per color channels like DVD?

3. It is possible to adjust the colors in an RGB image through curves. I do that regularely with GiCoCu() with .AMP files. If I have a curve in an .AMP file or in an array, is this possible somehow in YUV colorspace too?

4. How many (lossy) conversions between colorspaces leads to noticeable loss? I know this question is a bit generic, then for instance, does a YV12 -> RGB32 -> YV12 -> RGB32 (so 4 conversions all in all) cause noticeable harm on a video? Or the loss remains theoretical what no human eye could detect? (I only mean what comes from the rounding error, not from the clipping!)

Thanks for any answers

[Dogway]

3. Not that I know, but Im interested as well. Theres a good filter that someone pointed me out before "EXP-Labo" but works on RGB too. Im also interested in how do you get .AMP files, Photoshop only exports .ACV curve files...

4. In clear gradients (Skies for example) you can easily get noticeable posterization in 2 conversions.

EDIT: whoa, what a tool. Thank you

[zee944]

Originally Posted by Dogway

3. Not that I know, but Im interested as well. Theres a good filter that someone pointed me out before "EXP-Labo" but works on RGB too. Im also interested in how do you get .AMP files, Photoshop only exports .ACV curve files...

I forgot to answer you in another thread. Look for "gradation curves" filter by BugsBunny. You can draw your curve in VirtualDub with that and use the saved .AMP or .ACV file in GiCoCu.