关键词: 矿区遥感图像, 双树复小波变换, 直方图均衡化, 多级中值滤波算法, 改进多级中值滤波算法

Abstract: Remote sensing image is easily influenced by the factors such as imaging environment,the inherent defects of imaging device during the process of imagining,the phenomenon of distortion with different degrees of the remote sensing image is appeared.Combing with the excellent characteristics of multi-scale image analysis of dual-tree complex wavelet transform(DTCWT),a adaptive filtering algorithm of remote sensing image is proposed.Firsly,the obtained remote sensing image with poor visual effect is processed by histogram equalization algorithm to improve the image contrast;then,the enhanced remote sensing image is conduct dual-tree complex wavelet transform,the low-frequency coefficients and high-frequency coefficients are obtained,the low-frequency coefficient is remained unchanged,the high-frequency coefficients are filtered by the improved multi-stage median filtering algorithm，the classical multi-stage median filtering algorithm is improved as follows:①the four direction filtering windows of the classical multi-stage median filtering algorithm are extended to seven direction filtering windows,which is more advantages to keep the multiple directions characteristics of the information in remote sensing image;②the new added three filtering windows are denoised by weighted median filtering algorithm,the filtering values of the above seven filtering windows are processed by a discriminant method based on image gray value relevance so as to eliminate the filtering values with poor correlation to the filtering values of the pixels points,the average value of the rest of the filtering values is regarded as the filtered value;finally,the low-frequency coefficient and the filtered high-frequency coefficients are conducted inverse dual-tree complex wavelet transform.The experimental results based on MATLAB software show that:the algorithm proposed in this paper maintain the integrity of the detail information of the remote sensing image of mining area during the process of filtering,the performance the algorithm has a certain degree of ascension related to the classical multi-stage median filtering algorithm，besides that,the performance of the algorithm has obvious advantages to the algorithms of median filtering and bilateral filtering

Key words: Remote sensing image of mining area, Dual-tree complex wavelet transform, Histogram equalization, Multi-tage median filtering algorithm, Improved multi-stage median filtering algorithm