作者：吴岚

近日，国产卫星遥感影像压缩质量评价技术研究及应用项目通过国家测绘局组织的专家鉴定。以中国工程院院士刘先林为组长的鉴定委员会一致认为，国产卫星遥感影像压缩质量评价技术作为卫星重大工程和卫星遥感产业的重要技术支撑，填补了国内空白。该成果具有面向实际应用、适应国情的技术集成创新特色，其技术达到国际先进水平。

　　随着卫星影像数据规模的日益增长，有限的卫星信道容量与传输大量遥感数据的需求之间的矛盾日益突出，影像压缩技术作为解决这一问题的有效途径，其必要性和经济社会效益越来越明显。影像压缩是对影像数据按照一定的规则进行变换和组合，用尽可能少的数据量来表示影像，形象地说，就是对影像数据“瘦身”。由于遥感卫星影像数据量巨大，受限于星上存储能力的大小和卫星下行链路的带宽，几乎所有卫星影像都要进行星上压缩后才能下传。卫星影像压缩是影响影像质量的一个重要原因，直接关系到卫星影像的应用能力和应用范围，对于卫星研制和应用有深远的影响。

　　长期以来，我国民用遥感卫星的影像压缩一直由航天部门直接研制，应用领域基本没有介入，卫星研制和应用严重脱节。为了改变我国遥感卫星重发射、轻应用的局面，2005年国家有关部门组织开展了卫星影像压缩质量评价技术研究，成立了以中国测绘科学研究院唐新明研究员为首的遥感影像压缩质量评价项目组，立足于空间科学技术前沿，以压缩质量评价为纽带，围绕我国卫星的实际应用需求，针对我国卫星传感器的实际特点，以我国资源卫星的遥感影像压缩技术为基础，提出了一套面向测绘、土地和地质等重要卫星行业应用的遥感影像压缩质量评价方法，自主设计了影像构像质量的综合性评价指标，建立了我国遥感影像压缩质量评价体系，构建了包含不同地区、不同地形类别和不同分辨率的压缩标准测试影像集，研发了影像压缩失真度量系统，实现了快速、全面和准确地对压缩影像的失真程度进行评价；从影像分类、影像分割、灰度剖面分析、影像匹配、自动生成数字表面模型和摄影测量点定位等方面，深入研究了影像有损压缩和影像应用的关系，为国产卫星压缩算法的使用范围和应用能力提供了重要依据，直接促进了国产卫星从试验应用型向应用服务型的转变。

　　国产卫星遥感影像压缩质量评价技术为确保卫星发挥应用潜力奠定了重要基础，标志着我国遥感影像压缩质量评价有了可靠的自主技术保障。该项目研究成果已经在国防科技工业局、中国空间技术研究院、中国空间技术研究院西安分院、航天东方红卫星有限公司等卫星研制部门以及国家测绘局资源三号卫星项目办公室等卫星应用单位得到了广泛应用，获得了较好的评价。

Recently, domestic satellite remote sensing image compression quality evaluation technology research and application projects organized through the national mapping agency experts. The Chinese Academy of Engineering, Xian-Lin Liu as head of the evaluation committee agreed that the China-made satellite remote sensing image compression quality evaluation of technology as a major engineering and satellite remote sensing satellite industry, an important technical support to fill the domestic blank. This result has a practical application-oriented, integrated innovation of technology to adapt to national conditions and characteristics, its technology has reached the international advanced level.

With the growing size of satellite image data, limited satellite channel capacity and transmit large amounts of remote sensing data needs of the contradiction between the increasingly prominent video compression technology as an effective way to solve this problem, its necessity and economic and social benefits Yue Lai more obvious. Image compression is the image data according to certain rules, transformation and combination of the amount of data to use as little as possible to represent the image, the image that is the right image data "downsizing." As the huge volume of remote sensing satellite image data, limited by the size of the onboard storage capacity and satellite downlink bandwidth, almost all the satellite images should be compressed before the satellite downlink. Satellite image compression affecting the image quality of an important reason for a direct bearing on the application of satellite imaging capabilities and range of applications, for satellite development and application of far-reaching impact.


For a long time, China's civilian remote sensing satellite image compression has been developed by the space sector directly, applications basically no involvement, satellite development and application of seriously out of line. In order to change the emphasis of China's remote sensing satellite, launch, light application of the situation in 2005, relevant state departments has embarked on a satellite image compression quality evaluation of technical studies, set up the Chinese Academy of Surveying and Mapping researchers led by Tang Xin-ming remote sensing image compression quality evaluation of the project team, based on in the forefront of space science and technology, quality evaluation as a link to compress around the needs of the practical application of our satellites for the actual characteristics of China's satellite sensors, to the country's resources satellite remote sensing image compression technology based on a set for the mapping, land - and geological and other important industrial applications of satellite remote sensing image compression quality evaluation method, self-designed image structure such as a comprehensive assessment of the quality indicators, the quality of our remote sensing image compression evaluation system was constructed with different regions and terrain types and in different resolution rate video compression standard test collection, research and development of image compression distortion measurement system to achieve a rapid, comprehensive and accurate distortion of compressed images to assess the extent; from image classification, image segmentation, gray profile analysis, image matching, automatic generation of digital surface models and photogrammetric point positioning, etc., in-depth study of the image lossy compression and video applications, relations, China-made satellite compression algorithm and application of the use of the ability to provide an important basis for the direct promotion of home-made satellite from experimental application type to Application service-oriented transformation.


Chinese-made satellite remote sensing image compression technology to ensure the quality evaluation of potential applications of satellite play an important foundation laid, marking China's remote sensing image compression quality evaluation of a reliable technical support for the autonomy. The project has been in defense science and technology research the Industrial Development Bureau, the Chinese Academy of Space Technology, Xi'an Branch of China Academy of Space Technology, Aerospace Dongfanghong Satellite Co., Ltd., satellite development departments and the National Mapping Agency resources satellite project offices on the 3rd unit of satellite applications such as has been widely applied to obtain a better evaluation.