mark a spot or pixel on the video preview window

   Hello,

I am using the image aquisition toolbox:

vidobj = videoinput('winvideo', 1,'YUY2_720x480' ); start(vidobj) preview(vidobj)

now I have a video window. BUT: how can I mark let's say pixel(200,300) on this preview, so that the mark also stays there, until I take it off? I need the user to place something at that spot, so making a snapshot is not a good solution: I need the continuous feed.

Thanks for suggestions!

[Istvan]

... and the other way around: can I click on a spot on the video window and get the pixel coordinates?