尽量保留图像细节特征的条件下对目标图像的噪声进行抑制，是图像预处理中不可缺少的操作，其处理效果的好坏将直接影响到后续图像处理和分析的有效性和可靠性。(It is an indispensable operation in image pre-processing to suppress the noise of target image under the condition of preserving the details of the image. The processing effect will directly affect the effectiveness and reliability of subsequent image processing and analysis.)