Optical image processing by multiplex coding

Multiplex coding of optical images is discussed for photon-counting operation in both the signal- and dark-count-dominated domains. Both intensity measurement and signal detection are discussed. The advantage of multiplex operation in both situations is demonstrated and comparison made with alternative imaging techniques. The effects of code noise, detector area, response time, and dynamic range are discussed. It is shown that in dark-count-dominated operation, e.g., ir imaging applications, the limiting factor on multiplex gain is the light collection following image coding. Higher bandwidth detection is also required: for instance, a typical ir detector transmitting a 100 x 100 element image with individual element resolution of 2(5) will need a total dynamic range of 2(12) and an exponential response time a factor of 2.4 faster than for a single detector.