星上时间延迟积分CCD拼接相机图像的实时处理

Abstract

A real-time image processing method based on a Field Programming Gate Array(FPGA) was proposed for Time Delay Integral(TDI)CCD space mosaic camera to improve its imaging quality and visual effect. Firstly, the TDICCD imaging system was corrected in a non-uniformity mode by a pixel level, by which the fixed-pattern noise and dark current noise were eliminated. Then, an adaptive median filter based on the inline max-min values was proposed to eliminate the random noise and pulse noise. Furthermore, an image after denoising was enhanced in the TDICCD image. By extracting the low-frequency part and the high frequency part of the image, the detail adjustment and contrast enhancement of the image were implemented. Finally, a linear stretching method based on image line data divided was proposed to improve the dynamic range of the real-time imaging system. Moreover, a real-time image processing method for the TDICCD space mosaic camera based on FPGA was designed, and the synthesized resources, algorithm errors and reliability in the FPGA were analyzed. The experimental results indicate that the average SNR of the imaging system has been improved from 48 db to 52 db, and the non-uniformity decreased from 3.41% to 1.73% within a TDICCD. The image contrast is enhanced greatly and the dynamic range is prompted by 6% in the self define criterion.