基于改进零树小波的图像压缩算法在舰船故障远程诊断中的应用

结合舰船故障远程诊断中图像压缩、传输存在的问题和特点,提出对故障诊断图像实现感兴趣区域无损编码与背景区域高压缩比压缩相结合的思路。比较JPEG和JPEG2000算法的编码过程及缺陷,利用小波变换具有多分辨率分析的特点,提出了基于改进零树小波算法。以离散小波变换为基础,产生嵌入式码流,利用较粗尺度系数来预测较细尺度系数。针对某型燃气轮机的零级动叶部位破损的故障,完成了舰船故障远程诊断中机电设备故障图像的压缩应用研究。研究表明:原始图像压缩后能有效降低数据量;重构图像中的感兴趣区域清晰,说明改进零树小波算法完全能满足远程诊断需求。

Application of an improved embedded zerotree wavelets encoded algorithm in warship remote fault diagnosis system

With a view to the image compression and transport problems and characteristics,the scheme that fault diagnosis image is compressed with the lossless coding algorithm in the region of interest and compression the image in the background with high ratio was given.By comparing the encoding process and defects of JPEG and JPEG2000 algorithm,an improved embedded zerotree wavelets(EZW) encoded algorithm was proposed based on the ability of achieving topical characteristics of image by the wavelet transform.At last,according to zero rotor blade fault of some gas turbine,the compression encoding experiment of the fault diagnosis image of the navy marine machinery equipment was studied.The research results show that the data size of original picture can be effectively reduced after compression and the interested region after reconstruction becomes clear,thus the improved zerotree wavelets algorithm can completely satisfy the need of remote fault diagnosis.