基于改进EMD和BM3D的底回波图像去噪方法研究OA

Multi-beam seafloor echosounder bottom echo are crucial information sources for reflecting changes in seafloor geomorphology and substrate distribution.However,the bottom echo signals received by echosounder often contain multiple types of noise,which seriously affect image quality and subsequent processing.To address this issue,this paper proposes a denoising method for bottom echo images based on improved Empirical Mode Decomposition(EMD)and Block-Matching 3D(BM3D):First,the improved Empirical Mode Decomposition(EMD)method is adopted to decompose the bottom echo signal into high-frequency and low-frequency Intrinsic Mode Function(IMF)components.Then,an improved wavelet transform is applied to the high-frequency IMF components for denoising in the signal domain.Next,the denoised high-frequency components are subsequently combined with the original low-frequency components for reconstruction to obtain a preliminarily denoised image.Finally,the improved BM3D algorithm is introduced to remove speckle noise,so as to obtain high-quality bottom echo image.The experimental results demonstrate that this method suppresses noise effectively while preserving detailed information in the image.It realizes comprehensive denoising of multi-beam bottom echo data in both the 1D signal domain and 2D image domain,and further promotes the application of multi-beam technology in marine surveying and mapping.