@AntcuFaalb: thanks for the info! Actually, I prefer to use a derainbow filter that, even if is not that effective, at least leaves the chroma at its native resolution; even if I agree that we are less sensitive to chroma than luma, it's always true that laserdisc chroma is around 180 pixel (when captured at 720 pixel width) at best - probably could be reached using Happycube software and a good SuperNTSC disc; normal discs could be around 120-140 pixel, that will be reduced to 30-35 pixel with your method, too small for my tastes, and it will be really noticeable when upscaled to higher resolution, in particular 1920x1080.

@happycuber: I'm aware that consecutive frames have different phases, but that "trick" was the only one I was able to do to make an example; the picture could be found here: http://s22.postimg.org/vm22a3rn3/picture_5_X.png - hope you could see it following the link.

I wonder if it's possible somehow to reverse the chroma phase, even with some hardware; here in Italy, if the plug is reversed, the phase does not reverse...