[PD] image flashing

[amalia.dg at tiscali.it]

Dear all,
I have some problems with my video tracking patch: the image that I can
capture with my webcam have some periodic flash that maybe are depending
from the frame rate. When the image flash there are obviously some
problems with the data collected by the tracking patch.

Do you know what can I do in order to solve this problem?

thanks in advance,
amalia