Research On The Image Collection And Image Processing System Based On TDI CCD Camera

Aerospace camera is the most important space remote sensor, it is used widely. In the civil, they can be used for mining, urban planning, Land utilization, resource management, agricultural research, environmental monitoring, news reports and geographic information service and so on many domains, In the military, they can be used for information gathering, defense monitoring, change detection, precise surveying and target guidance and so on. Therefore, many countries of the world were actively developing aerospace camera, remote sensing work. CCD image sensor compared to CMOS image sensors, relies on its color saturation, image more sharper and simple sense more realer, especially the excellent performance at low illumination environment, make its advantages in aerospace, medicine, chemical, industry and military and so many fields. So the research on the image Collection and Image Processing based on the aerospace camera system still has important scientific significance. In this paper, we took the CCD 8091 of Fairchild which is a 9216 pixels per line of the TDI (Time, Delay and Integration) CCD as the object of study, and in-depth study of the hardware driver circuit of the imaging system, high-speed image data signal processing, the non-uniformity correction of the CCD and eliminate noise in the camera image. With combination of internal structure and working principle of TDI CCD and we had the detailed analyses the driving timing diagram, designed the driver circuit. According to the overall design requirements, the use of separate programmable control power module, realized the high reliability, and the small discusses, low interference of EMI, and improved the performance of the camera. In order to guarantee the quality and high-speed of imaging system, it adopts 12-bit AD, for the stability of output, using the popular Camera Link output interface, and the results show that, the design of the imaging system work at 20MHZ clock and the maximum data rate 120MHZ with the six-channel works simultaneously. We conducted calibration experiments to correct the non-uniformity of the six tapsThere are the stripe noises in the image of the CCD camera, and we analysis the reasons of the strip noise. First, the structure of the TDI CCD device produced the vertical stripes. For the limited of the manufacturing materials and technology, the inhomogeneity of structure and material in the photographic window glass of the TDI CCD can cause vertical stripes. Besides the inconsistencies of the focal plane environment of the camera and driver timing of the circuit system also can produce irregular vertical stripes. These stripe noises caused by the camera system can seriously affect image quality, which bring great interference about the following image processing, combined with fourier transform and wavelet transform theories, this paper proposes take three methods to eliminate noise strip, the quality of image was significantly improved and the image was evaluated objectively.