基于小波的SPIHT雷达图像压缩算法

雷达在现代航海导航中占据着很重要的地位,在综合船桥系统和船舶交通管理系统里,雷达图像需要通过网络传送给其他导航系统如ECDIS或远程图像监视系统。由于雷达图像数据量非常大,为了保证图像的实时性,通过网络传输雷达图像时,先要对雷达图像进行压缩。雷达天线的扫描速度大约为20 RPM,所以一幅雷达图像的数据压缩、数据传输和数据重建必须在3 s内完成,这对雷达图像的压缩和重建提出了很高的要求。论文采用基于小波变换的SPIHT算法对雷达图像进行压缩.在追求高压缩比率情况下,保证了较低的均方误差和较高的信噪比,最后用C 实现了算法并给出了实验对比数据。

Radar Image Compression Using Wavelet Based on SPIHT Algorithm

Radar image is large in size and it is essential to compress this image before it is transmitted through the LAN network to other navigational aids such as ECDIS(Electronic Chart Display and Information System) and VTS(Vessel Traffic Service).The Marine Radar Scanner rotates at about 20 RPM,i.e.,it takes about 3 seconds to get a complete image.For the real time transmission purposes,the total time of compression,transmission and reconstruction of a Radar image must be limited within 3 seconds before the next cycle starts.Therefore,while maintaining the radar image quality as good as possible for the HVS(Human Visual System),it is increasingly demanded to gain high compression ratio for the purpose of reducing transmission time.In this paper,Wavelet Transform based on SPIHT(Set Partitioning in Hierarchical Trees) coding algorithm is used to gain higher compression ratio while maintaining least MSE(Mean Square Error) and higher PSNR(Peak Signal to Noise Ratio).Experiments illustrate that SPIHT coding algorithm outperforms Embedded Zero Tree Wavelet(EZW) algorithm in many aspects.