Background Suppression for Dim and Small Targets Based on Pyramidal Dual-tree Directional Filter Bank.

The complex background suppression is difficult for infrared warning system detecting long distance target. A background suppression method based on pyramidal dual-tree directional filter bank was proposed for some dim and small targets and retina theory was introduced to improve its ability. Firstly, the filter bank was adopted to decompose the input infrared image into multiple scales and directions and extract the image's features. Then,, according to the difference between target and background clutter signal, the decomposed sub-band's coefficients were adjusted by using improved retina theory equations to suppress the background details and enhance target information. Several groups of experiment results demonstrate that the proposed method can detect the target with SCR > 1. 6 effectively, compared with several classical background suppression method, such as two-dimensional least means square (TDLMS) and max median (MMed) filters. [ABSTRACT FROM AUTHOR]