Depends on image type...
Graphics? I'll 2nd birdman: a big table, unless it's repetitive and/or symmetrical. Mine is built into a ceiling fan and spells messages. It took a solid month for me to get the code right, partly due to lower case descenders in the upper vs lower arc. The "static" pix (see attachments) are time lapsed, the .avi is from a camcorder.
Funniest part of these things: people over ~35 have a Really Difficult time reading it, under 30 get it instantly. I think it's the younger can let the motion "paint" the image, yet older can't resist following the motion. One older (~50s) man INSISTED there was something wrong with the device; after 3 patient explanations of "how" to read it, I gave up.
A genuine trick is how to download new data while running. I'm on my 4th approach. Good Hunting, it's a Great toy once working... <<<)))