Abstract: A laser-based target discriminator system for discriminating desired objects from other objects and clutter in an image scene is disclosed. The system is operative to scan a pulsed laser beam a plurality of times across an image area, the scans covering different juxtaposed strip portions of the image area. Range differential signals are derived from the sensed information of successive laser pulsed echoes of each scan corresponding to the image elements thereof. From the range differential signalling, a binary image map of the image area is generated and converted into a second topological image map having index codes which are derived from predetermined groupings of the binary values of the first image map. Clusters of contiguous image elements are identified from the second image map based on the derived codes of the indices thereof. Desired clusters may be discriminated from the identified clusters based on measured predefined parameters thereof.