METHOD AND APPARATUS FOR THE DETECTION OF ACCUMULATIONS OF PARTICLES SUCH AS METAPHASE PLATES

For the detection of accumulations of particles, for instance metaphase plates, in an image converted by a raster process into electrical signals, there is first effected an electronic dilation in several directions, the parameters of the dilation being so selected that images of the chromosomes of the metaphase plates agglomerate to form unitary structures. Thereupon, an electronic erosion of images is effected in several directions, the parameters of the erosion being so selected that images of cells and impurities disappear but the agglomerated metaphase-plate images are retained. A circuit is described which consists essentially of length discriminators, decision-logic devices, delay-storage devices with provision for establishing input digital preset values, in which circuit the entire evaluation process takes place with the speed of the scanning process.