一维小波变换在侧扫声纳图像去噪中的应用

摘要

Aimed at the speckle noise of SSS Ping-signals,1D DWT was used to decompose the sigal on different scales.After non-maxima suppression on wavelet coefficients,the modulus maximum of wavelet coefficients was gained.The signal denoising was implemented by threshold processing of the modulus maximum and effects of different thresholds on denoising were discussed.The results indicated that the selection of scale factor and threshold influenced little on the maintenance of the original data energy,but influenced a lot on the noise effect.After denoising,the examples with edge preserve index(EPI) above 0.5 could preserve edges well.%针对侧扫声纳呯信号中的斑点噪声问题,采用一维离散小波变换对信号在各尺度分解,采用非极大值抑制技术平滑信号,并对各层小波系数模极大值进行阈值化处理抑制噪声,讨论了不同阈值对去噪效果的影响.结果表明,尺度因子和阈值的选择对原数据能量保持影响不大,但对噪声抑制效果影响大.文中算例均能较好地保持边缘,边缘保持指数均在0.5以上.