Unable to receive the same picture quality as the tv card software

Hi,
I am trying to develop a software that includes watching tv (no tv capture just plain watching tv or any other feed that comes from the tv card). I am developing the software in asp.net and it is going to run on a pc with win xp. The problem is that the picture I am receiving is very poor in comparison to the picture I receive with the software that comes with the tv card but I cant integrate the tv cards software I need to use my own. I have tried using several libraries for video display, including OpenCV, Viscom Video Capture ActiveX and a .NET library. But the picture quality is till poor. I need HELP!!!! Does anybody have a suggestion? What am I doing wrong?
Thanks in advance…
Michel "Not4sale"