An image processing system for morphological investigation of liver cell nuclei in biopsy specimens is demonstrated. The present study deals with the age dependence of normal hepatic nuclear areas. The results were compared with those of conventional methods. METHODS The image processing system consists of a microscope, an image dissector and a computer (central processing unit, display, teletype, magnetic tape devices and line printer). 74 liver biopsies were investigated. They sshowed no signs of acute or chronic diseases. Paraffin sections of 4 micron in thickness were prepared and stained by Feulgen method. 8-10 biopsies were available for each decade from 1-8. 18,000 liver cell nuclei from all specimens were isolated and measured automatically. Using the image processing system and adequate computer programs 20 parameters of all isolated nuclei were gained (parameters of shape, size and structure of the nuclei). For sampling and processing of the information the following programs are developed: PROBE Program for investigation of optimal parameters of scanning and processing. SAMPL Program for scanning, object isolation, feature extraction and storage of data records. KORRL Program for investigation of correlations between the features of objects. LISTE Program for listing of data records. ULTRA Program for search of objects with extremal features. CODER Program for correction od data records. ADAPT Program for training of classificators. SCHAU Program for demonstration and checking of the classificator. MORPH Program for output of feature distributions and statistical parameters. Following object features were calculated and investigated: features of size: KOFL area within the object contour; KKFL minimal covex area of the object; ZKFL object area without holes; KONL length of the object contour.