Abstract
An improved method for automatic chromosome analysis consists of a preprocessing procedure and a boundary algorithm. The starting point is a transparency, converted by a flying spot scanner into an array of about 6*105 points, with a six-bit grey scale. Preprocessing applies to each grey level a Laplacian operator extended to a suitable region, corresponding to a high pass filter. This makes the threshold selection less critical and partially restores the degradation of the imaging process. The boundary algorithm isolates connected regions of the array by following isodensity contours and codes the boundary using three successive chains. From these chains the arm tips and centromeres are localized. A symmetry index is defined to check the reliability of the localizations.