“祝融号”火星车图像压缩软件的设计与实现

Image Compression Software Design for Zhurong Mars Exploration Rover

针对火星图像传输信道极其有限,误码率较高等问题,给出了一种火星车图像压缩软件的设计与实现方法:分析了火星车图像管理的特点,归纳出火星车图像压缩软件需具备的三项能力(文件统一管理能力、高效压缩能力、高容错能力);针对文件统一管理能力,提出了一种针对多类型图像数据的统一化管理的文件系统;针对压缩算法高效性和高容错性要求,在基于首1游程的图像位面并行编码算法基础上,扩展了多载荷图像统一化处理、彩色图像预处理和分段位平面编码三个重要过程,进一步提高算法压缩性能和容错能力,并形成一整套图像压缩软件设计方案,使用FPGA(Field Programmable Gate Array)+DSP(Digital Signal Process)方式实现了整套软件;最后采用仿真验证系统对压缩效果进行了验证,仿真结果表明了算法的有效性。本软件经“祝融号”火星车在轨验证,可有效满足火星探测任务需求,软件设计方案可作为后续超远距离深空探测图像压缩的参考。

Because of the limited number of information transmission channels and high bit error rate in Mars image transmission,a method of image compression software design and realization of Mars rover was proposed.The characteristics of rover image data management were analyzed,and the three capabilities that the rover image compression software needed to have were concluded:uniform file management capability,high-efficiency compression capability,and high fault tolerance capability.For uniform file management capability,a file system for uniform management of multiple types of image data was proposed.To meet the high efficiency and high fault tolerance requirements of the compression algorithm,based on run-length coding algorithm of first-1 bit,the three important processes of multi-load image unification processing,color image preprocessing,and segmented bit-plane image coding were expanded,to improve compression performance and fault tolerance.Then a complete set of image compression software design schemes was formed,using FPGA+DSP,and the complete set of software was realized.Finally a simulation verification system was used to verify the compression effect.Verification results show the effectiveness of the algorithm.This software has been verified by China’s Zhurong Mars rover and can effectively meet the needs of Mars exploration missions.The software design can be used as a reference for image compression in subsequent ultra-long-distance deep space explorations.