The research about high-dynamic and low-gray target image differential capture technology based on laser active detection

The extraction and capture of the target by the medium-long wave infrared optical system is mainly achieved based on the gray difference between the target image and the background image. Under complex background conditions, such as air-to-ground alarms or target detection and capture will be strongly disturbed by the background environment. Especially under dynamic conditions, the background and the target are in a rapid change, how to detect real-time ground-to-air missile seeker and other weak targets is very difficult. It is one of the technical difficulties in the current image processing field to quickly locate and extract from high-dynamic low-contrast grayscale images. In this paper, a fast differential capture method for cat eye echo images using a highly active and low-gray optical target such as a seeker using laser active illumination detection is proposed to achieve efficient capture and extraction of the target. Using a 3.5-um band, 1 W average power laser to illuminate medium-wave infrared-waveband seeker with a 100 mm aperture, to achieve echo imaging of 2–4 orders of magnitude higher than traditional diffuse reflection, using 500 Hz large frame rate medium-wave imaging to achieve quick alignment and fast differential imaging of the target background. From the simulation and experimental results, this image processing method can effectively improve the optical system’s detection capabilities and capture speed and effectively solve the problems of low-gray level dynamic target detection and high-precision positioning in complex background.