Earth Mountain almost there, page-44

Most silicon chips are individually tested. For computer CPUs as an example, most CPUs start as the same complicated top-of-the-range CPU, but manufacturing defects mean that some parts of the chip will not work. Each individual CPU that comes off the production line is tested thoroughly for many days, to determine which parts survived the manufacturing process, and which parts did not. Then the CPU is packaged with the appropriate parts disabled, and given the corresponding part number and product name.

This is called 'binning'.

Presumably AKP would have a similar process where chips would be tested, and as BobF says, a lookup table can be created for each individual chip to identify bad pixels, and provide timing response data for each pixel. The information could probably be embedded in each individual chip at the time of packaging.