A Double-Neighborhood Gradient Method for Infrared Small Target Detection

Effective and efficient infrared (IR) small target detection is essential for IR search and tracking (IRST) systems. The current methods have some limitations in background suppression or detection of targets close to each other. In this letter, a double-neighborhood gradient method (DNGM) is proposed. First, a new technology of the tri-layer sliding window is designed to measure the double-neighborhood gradient. Then, the DNGM is obtained by multiplying the double-neighborhood gradient. In this way, even the sizes of the targets may vary, ranging from 2 ×1 to 9 ×9 pixels, the target can be better highlighted under a fixed scale, and background interference can be suppressed. Finally, the target is segmented from the DNGM salience map by an adaptive threshold. Experiments illustrate that the proposed method can avoid the “expansion effect” of the traditional multiscale human vision system (HVS) method and can accurately detect multiple targets close to each other. Besides, the proposed method is more robust and real-time than the existing methods.