基于改进曲波变换的水面弱纹理提取方法  

Extraction Method of Water Surface Weak Texture Based on Improved Curvelet Transformation

作　　者：张祥翔[1,2] 陈永和 傅雨田[1] Zhang Xiangxiang;Chen Yonghe;Fu Yutian(Key Laboratory of Infrared System Detection and Imaging Technology,Shanghai Institute of Technology and Physics,Chinese Academy of Sciences,Shanghai 200083,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院上海技术物理研究所,红外探测与成像技术重点实验室,上海200083 [2]中国科学院大学,北京100049

出　　处：《光学学报》2021年第9期44-52,共9页Acta Optica Sinica

基　　金：中科院联合基金(6141A01130102)。

摘　　要：水下潜体的运动产生的内波使得水表形成一定的红外弱纹理信号,从而使得利用红外手段进行探测成为可能,但是这种纹理信号的对比度非常低,其与振幅很大的背景杂波混在一起,给信号的提取造成很大困难。以曲波变换为基础,根据弱纹理的对比度、频率特点等进行曲波尺度分量和方向分量的筛选,再结合阈值优化和边缘梯度算子得到了较清晰的纹理提取图像。该图像的信息熵和频率集中度与采用传统曲波变换所得结果相比分别有30%和11%的提高。当弱纹理的对比度大于5%,筛选频率的方向和弱纹理频率方向偏差小于12°时,该算法能够清晰地提取纹理信息。The internal wave generated by the movement of the underwater body makes the water surface form weak infrared texture signals,which makes it possible to use infrared means for detection.However,the contrast of texture signals is very low,and it is mixed with the background clutter with large amplitude,which causes great difficulty in signal extraction.Based on the curvelet transform,the curvelet scale component and direction component are screened according to the contrast and frequency characteristics of weak textures,and a clearer texture extraction image is obtained by combining with the threshold optimization and the edge gradient operator.Compared with the results of the traditional curvelet transform,the information entropy and frequency concentration of the image are improved by 30% and 11%,respectively.When the contrast of the weak texture is greater than 5% and the deviation between the direction of the screening frequency and the direction of the weak texture frequency is less than 12°,the algorithm can clearly extract texture information.

关 键 词：图像处理 弱纹理 曲波变换 灰度共生矩阵 先验频率 阈值优化 

分 类 号：P407.8[天文地球—大气科学及气象学]