If you printed bar codes on tracing paper/acetate etc. and then positioned several in front of one another, could you extract the individual codes from the aggregate overlaid image? I feel intuitively like there would be a limit on this, as given enough bar codes, the aggregate image would be plain black. It would be good to understand if this is possible in any circumstances and if so, what are the mathematical limits.
It looks as though I wouldn't be able to tell the difference between black on white and white on black. However, if all the items are at slightly different positions, unlike the picture, i.e. different x,y positions and different angles, then can I distinguish each one, from a single "Scan"?