Signal processing for autonomous acquisition of objects in a cluttered background

摘要

A method and apparatus are disclosed for detecting moving objects silhouetted against background clutter. A correlation subsystem (12) is used to register the background of a current image frame (framestore 1) with an image frame taken two time periods earlier (framestore 3). A first difference image is generated by subtracting the registered images, with the first difference image being filtered by low pass filter (34) and thresholded by a three level segmenter (36). A second difference image is likewise generated between the current image frame and another image frame taken at a different subsequent time period. This second difference image is likewise filtered and thresholded. The two difference images are logically ANDed together by gate (39) whose output is connected to a formatter, sorter and feature extractor (40). Track files are generated in CPU (16) for comparing subsequently extracted image features with previously stored extracted features.