1. A die sorting apparatus for a wafer, comprising: a map file for storing records of testing information based upon testing performed on individual dice comprised in the wafer and their relative logical positions; an image capturing device for acquiring a image showing physical positions of the individual dice after the dice have been singulated; a processing device operative to associate the logical positions of each die from the map file with its physical position as illustrated by the image of the singulated dice to determine the actual physical position of the die; and a die pick-up device configured to selectively pick up dice that meet predetermined criteria according to the testing information from their actual physical positions as determined by the processing device.