I thought it's possible to hack into the data files and extract the images straight. Short of that... maybe get a graphic card with TV/in (do they have this anyways) and hook it up to the PC.
Yeah, I am using PC to play PS2(no TV XD), and running with PowerVCR II, however, I cant get better quality screenshot then this since 640x480 is max resolution I can get, was wondering if there is a better program for that.