Research On Image Compression Of On-board Satellite CCD Remote Sensing Camera

With the increasing development of high spatial resolution and wide swath, an extensive amount of imaging data acquired from satellite remote sensing camera increases dramatically. As the bandwidth of satellite downlink channel is limited, remote sensing image must be compressed first. The remote sensing image compression is one of key technologies for spatial application. How to balance the complexity and performance of image compression is the hot issue. Research on image compression technology used for spatial remote sensing image is very important and valuable for theory and engineering application. Based on the project of image compression research for on-board satellite CCD remote sensing camera, the objective of this dissertation is to search the solution for remote sensing image compression.First, the dissertation analyses the characteristics of the CCD remote sensing camera, and also the image compression system used for engineering application. After research on JPEG2000 standard algorithm, the image compression system based on ADV212 is proposed. Taking into account the demand for lightness, the design with CCD imaging data collection and image compression integrated is proposed, and a single FPGA is their core control unit. The image compression system is implemented on hardware platform finally. The experiment results show that the proposed system meets the expected performance index, and satisfies to engineering application.Despite the excellent performance of JPEG2000 standard, it is too complicated. The JPEG2000 is not the best solution for satellite application with limited power demand. In addition, the use of ASIC is restricted. Therefore, secondly, the image compression algorithm proposed by CCSDS is described, with moderate complexity and excellent performance. To increase data processing speed of the discrete wavelet transform module, for push-broom type sensors imaging application, the pipeline structure for two-dimension discrete wavelet transform is proposed. Through the proposed pipeline structure, huge memory resource is saved. For the shortage of rate truncation, an improved rate control algorithm is proposed, and the quality of the reconstructed image is enhanced. The experimental results show that the PSNR can be increased at 0.67dB, compared to the original algorithm.However, wavelet transform is not optimal for representing directional characteristics for image. Finally, to solve the shortage of wavelet transform, the Bandelet transform used in remote sensing image compression is described. The scheme with Bandelet transform and arithmetic entropy is mainly analyzed. The result proves that the proposed scheme can preserve better subjective performance than compression measure based on wavelet transform.