随着星载遥感技术的不断发展,产生的遥感数据也变得日渐庞大,目前有限的通信带宽远不能满足遥感图像数据传输的需求。因此研究面向星载应用的图像压缩技术对空间应用技术的发展有着十分重要的意义。采用传统单核数字信号处理器(DSP)难以满足性能需求,而采用现场可编程门阵列(FPGA)则难以满足功耗需求,近年来随着硬件技术发展,多核DSP技术已经成熟,且在弹载场景已有比较成熟的多核DSP图像压缩解决方案,可供星载应用参考。基于多核DSP,即TI公司的C6678多核浮点DSP平台,构建一个并行图像压缩系统,并充分利用多核DSP的硬件资源。考虑星载遥感图像压缩对压缩质量、压缩速度等多方面指标都有着较高的要求,系统采用JPEG2000标准进行图像压缩,并且采用了主核负责外部通信与内部任务分配、从核执行JPEG2000图像压缩的设计方案。测试结果表明,该系统运行稳定可靠,且整体压缩性能优秀,能够满足对星载遥感图像压缩系统的性能要求。
With the continuous development of space-borne remote sensing technology, the remote sensing data has become increasingly large. At present, the limited bandwidth of communication can not meet the demand of remote sensing image data transmission. Therefore, the research of image compression technology for space-borne applications is of great significance to the development of space application technology. It is difficult to meet the performance requirements by adopting traditional single-core DSP ( Digital Signal Processor), and it is difficult to meet the power demand by adopting Field- Programmable Gate Array ( FPGA). In recent years, with the development of hardware technology, multi-core DSP technology has matured, and there are mature multi-core DSP image compression solutions in missile-borne scene for space-borne application reference. Based on multi-core DSP, TI's C6678 multi-core floating-point DSP platform, this paper constructed a parallel image compression system and made full use of the hardware resources of multi-core DSP. Considering the compression of space-borne remote sensing image has a high demand on compression quality, compression speed and other indicators, the system took the JPEG2000 standard as the image compression standard, using the main core responsible for external communication and internal task allocation, and using slave core to implement JPEG2000 image compression of the design. Test results show that the system is stable and reliable, and the overall compression performance is excellent, to meet the performance requirements of space-borne remote sensing image compression system.