View Full Version : capture quality

June 17, 2005, 18:46:33
i work with ic2 with capture card having wdm video driver(coexant -bt878 chip) i have problem that when i run my applicatin with resulatin 320*240 i show good quality capture but when i run with 640*480 i found edge og picture look like flicking. my object work with 1000 rpm. so can`t get good result with 640*480 in image analysis.
so please send me where i missing.

Stefan Geissler
June 20, 2005, 08:25:32

What you see is the interlacing effect of your camera. It is not visible in the 240 lines resolution, because this video format displays only the half image (field). The 480 lines resolution displays the both fields. A field has a 640*240 resolution. There are two fields: One with the odd and one with the even lines of the image. In the 640*480 resolution the files are displayed combined. You can see the interlacing effects on fast moving objects because the fields are captured by the camera in sequence. They look like a comb.
The only way to avoid this would be a CCD DCam camera like the DFK 21F04.