Compressed video is brighter/darker

I’ve used DVDShrink 3.2 on many DVDs and Rebuilder/CCE for a few DVDs and I just now notice the brightness/color of the resulting compressed video is slightly different than the original. Rebuilder/CCE produces slightly darker with more natural looking color – like using the “Levels adjustment” feature in Photoshop. DVDShrink produces sometimes slightly lighter and sometimes slightly darker results. I did this comparison by opening the VOB files in Media Player Classic and looking at them side by side. Has anyone noticed this difference and is there an explanation?

Anybody?

If anyone is still watching this thread, I found the answer in a filter called ColorMatrix.

What is ColorMatrix? And what’s the answer?

I only thought that I imagined the difference (the copies got slightly darker), but now it seems like maybe not…