Research Of Satellite Image Compression System And Earth System

An efficient compression method is proposed for satellite images in this thesis based on inter-frame DCT transform and mixed bitrate truncation. And a corresponding universal ground-testing system is also designed. The proposed satellite image compression system could achieve flexible compression rates, and the ground-testing system provides the testing image sources.The inter-frame DCT transform and adaptive bitrate truncation is introduced in our satellite image compression system based on wavelet transform and fast SPIHT algorithm. The proposed system solves the problem existing in the traditional algorithms that the images with complicated texture always have poor reconstruction quality because of the even bitrate allocation. An FPGA hardware system has been designed according to the above compression scheme, which could meet the technical requirements in terms of reconstruction quality, resource occupation and reliability, etc.The testing system consists of a mother board of a simulated camera and two PCI high-speed data collection cards. The ground-testing system is configured at the personal computer by the users, and the testing images in the local hard disk is sent to the mother board of the simulated camera via the PCI high-speed data collection card. The testing image is buffered on the mother board. After buffering, the image data are read out from the buffer and transmitted to the compression system according to the designed interface timing. Owing to the configuration of the ground-testing system, it is compatible to other compression systems through some simple modification on interface. The highest parallel rate could achieve as high as 100MB/s, and the highest serial rate could achieve 128Mbps.