I was trying to create some moving images using IMAQ functions, displaying them in a Display Window (I've got a dual-monitor setup, and was using Monitor 2 as my "Screen"). I created a "black" screen-size Image as a background, then made my "movie" (updating the images at around 250 Hz) which filled a rectangular area inside the screen (so it had a black border).
What I didn't notice, at first, was that under some conditions, my image had a thin (1 pixel?) blue line at the edges, best seen when the image itself had black along the border. The reason I missed it at first was that this "blue border" disappeared when I clicked the mouse (to activate a control for the movie). At first, I thought it was my background Screen color (I use a plain blue background), but changing the screen background didn't change the color of the "blue border".
This seems very curious to me. When I originally coded this, my "movie" took up the entire Monitor screen, and the "blue border" was not noticed. In fact, I just ran the full-screen movie again, and if I squint, I can see the blue border on the right edge, which also disappeared on a mouse click.
Can anyone suggest why this is happening? It's not a big deal, but is totally unexpected, and may suggest "something not quite right" in IMAQ Image creation.
Bob Schor
