Research And Realization Of Hyper-spectral Image Compression Based On DSP

In the military and civil domain, hyper-spectral image,having been applied in target classification, target identification, target tracking etc, has important research value and great application significance. With the rapid development of the remote technology and the enhancement of remote sensor resolution,the hyper-spectral image , as one of the main remote sensing data, which increased a lot, brings in serious problems about transmission and storage of hyper-spectral image data. So far, one kind of mature or standard hyper-spectral image compression technology has been not farmed. Therefore, the research on remote hyper-spectral image compression coding has great application value.Because hyper-spectral image has abundance detail and great data quantity, there always has some limits in some degree to compress the image adopting traditional compression methods,And it is much harder to achieve lossless compression about the hyper-spectral image. At present, much attention has been paid to the nearly lossless compression research. In this paper, taking the moving-scanned hyper-spectral image as the study object, Combined with the image's unique feature caused by the special shooting method, a simple DPCM predication model is build. And choose the LeGall5/3 wavelet base to realize the integral wavelet transformation on the difference image from the model, base on integral lifting scheme The algorithm above only refer to some add and subtract and shift operations, and it can rebuild the wavelet transform coefficients perfectly. And it is easy to present on the hardware. The related program which includes image-data reading module, image-pretreatment module, spectral-prediction module, IWT module, and Embedded Zero-tree Wavelets module have been completed by using the standard C, and the very algorithm compiled for the design have passed the test by using the CCS integrated development environment and the TDS320DM642EVM development board. Finally, gathered the CCS integrated development environment and the TDS320DM642EVM development board, the algorithm has been optimized by using the compiler optimization, software assembly line technology, data-packing technology, DMA, improved disposition and storage space, etc, which have raised the utilization rate of hardware source and the usability of the system much.The experiments shows that the average compression ratio of compress a 512×512×8bit hyper-spectral image lossless is about 1.878, by using the system to compress a 512×512×8bit hyper-spectral image. The effect is better than the JPEG-LS alogorithm and the k-l transform compression algorithm to the 2-D images. The peak signal-to-noise ratio(PSNR) of reconstruction images is infinite and satisfies the image quality requirements. Using the system algorithm to deal with a 512×512×8bit hyper-spectral images, under the condition of TMS320DM642, cost about 13.274s. When optimized, the average time is about 7.563s. The processing speed is improved by 43.44%, which the optimizing effect is obvious.