many thanks for your reply.
Indeed I already use the "frame grab" feature to extract frames from the original video.
My question deals with a different aspect. Let me explain.
I create a video viewer whose frame "window" is different from that of the original frames (smaller or bigger, doesn't matter).
I play the movie and, during playback, I make brightness-contrast-hue ... adjustements (it works perfectly).
So far, everything is fine.
I pause streaming. At this point I would like to "export" the image I actually see on the screen (and not the corresponding original frame), but I don't know how to do it. The Picturebox containing the video-frame seems to be empty and also a brutal "screen capture" is not able to grab the screen area corresponding to the video-display: it's transparent ... where are the coloured pixels?
Again, many thanks for your advices.