Computer image analysis of kidney histopathological sections

Human renal histological sections have been photographed on a black and white transparency and digitized. The digitizing camera, an image dissector, converts a 2 cm2 picture into 400 x 400 numbers each representing the grey level value of sampled point. The grey levels are represented in the computer by number ranging between 0-255. In this scale 'O' stands for black and 255, for white. The program provides 2 grey level thresholds, which outline a window through which the picture is scanned. Only structures, whose grey level value lies in the window range, are taken into consideration. The thresholds are set during digitization from the console switches. Image analysis is performed on-line in real time.