Patent ID: 8160382

Claim:
A method for identifying targets by detecting and analyzing hotspots in 2-dimensional infrared (IR) images through the combined use of Sobel magnitude and Sobel direction images comprising: receiving as input an infra-red (IR) intensity image, a thresholded Sobel magnitude image, a thresholded Sobel direction image, and target size parameters; detecting potential targets by morphologically processing said Sobel magnitude image and combining it with said intensity image to create a masked image including detected hotspots; filtering out incorrectly detected hotspots by checking each hotspot for a minimum number of distinct directions in said Sobel direction image and removing potential distortions from horizon or littoral lines; and determining if the filtered hotspots are valid targets by evaluating the filtered hotspots against at least one of intensity, size, or width thresholds contained in said target size parameters, and discarding as non-targets the filtered hotspots that are not within a certain percentage of said thresholds.