Abstract: Level data on an output line (24) carrying the digitized output of a video camera and analog-to-digital converter (12) is processed by a combination circuit (10) to store in an acquisition memory (16) the results of a feature-identification or histogram operation. In a histogram operation, the memory locations of the acquistion memory (16) represent the bins into which the levels represented by the level data are sorted, and the contents of those locations indicate the number of picture elements whose levels fall in those bins. In feature identification, the contents of successive memory locations in the acquistion memory (16) contain the positions of those picture elements whose levels have a selected feature. Common circuitry performs both the histogram and feature-identification functions.