In this paper it is founding that at the aspect of extracting characteristic information of the pulse signals , the usual algorithm of the cwt has better superiority than the algorithm based on the discrete mellin transform 在分析中发现,在提取吸毒者脉象信号中病变的异常信息方面,连续小波变换的一般算法比借助离散梅林变换的算法具有更好的效果。
The feature parameter extraction methods of the underwater target are studied which can improve the performance of the underwater acoustic countermeasure equipments . several feature extraction methods such as the scale invariance feature extraction , target pole extraction fourier - mellin transform etc are investigated by computer simulations . the experimental results demonstrated the efficiency of these feature extraction methods in the applications of underwater target recognition 对多种特征提取方法如目标相对不变尺度特征提取、目标极点特征提取、目标信号的傅里叶?梅林变换特征提取等进行了仿真研究,结果表明了这些特征参数提取方法的有效性,具有良好的应用前景。
First , resistance to geometrical distortion was obtained by using moment normalization ; second , we focus on the phase of fourier - mellin transform . before detecting watermark , synchronization could be retrieved by using the phase information . to eliminate the influence of pixel value distortion generated during print / scan process , a dft - based robust watermark algorithm was designed , which could successfully detect watermark from a severe distorted image 另一种思路是根据图像经过旋转、缩放、平移后,其傅立叶?梅林变换域只有相位受到影响的特点,从其相位中提取几何失真信息,然后再进行相应的失真补偿,从而消除几何失真的影响;对于打印扫描过程产生的像素值失真,本文也提出了一种基于dft的鲁棒性算法,能在较严重的图像失真情况下,成功检测水印。