Does anything like that exist?:
A4 or bigger sized plate which would with ca. 1 mm precision detect regions of the plate which were covered. So if you place your hand on the plate you will obtain a binary image of the hand with
0 = no light = hand
1 = light = no hand.
I would be a very simple binary scanner of plate or strip dimensions.
Which technology would you recommend to do the task? Preferably, it should be possible to buy the strip or plate and it should be connectable to PC.