We have a POS app in which the cashiers can press a key to take a snapshot of the customer. This is accomplished by having the program run a script., WHen the script exits, the POS program proceeds.

This script is simple and stupid right now - it runs streamer to take a single 640x480 jpeg, then runs zgv to display the pic, then asks the cashier if it's okay; if it is, it's saved as <custid>.jpg else loop to the top of the script and take another picture.

This works fine, but it takes streamer about 2.5 seconds to snap the pic, and the person may have moved or turned his head...

What I'd like is either
(1) a snapshot NOW, or

(2) (better) a streaming picture displayed until the cashier likes that he sees and presses a key to "freeze" the picture (i.e. save the current frame as the jpg).

Any ideas?