New detection algorithm for dim IR point targets under complicated sea and sky background

In order to solve the detection problems of dim IR point targets under complicated sea and sky background, a detection algorithm integrating with multi-degree and multi-orientation gradient fusion is proposed. Based on the principle of IR radiation property of target, i.e., the gradient variations of pixel gray scale in horizontal and vertical directions, the algorithm handles the property of dim point target into analysis of image singularity and detects targets by means of multi-degree gradient step length. Then the detected results will be processed by voting fusion. Experimental results show that when IR threshold coefficient is 2.0-2.4, more than 95% of the detection probability and lower false-alarm probability for targets with signal-clutter-ratio of 1 can be obtained by the algorithm.