数字图像处理中的图像去噪部分，用低通去噪和non-local means两种方法，其中用non-local means，可把信噪比提高10dB左右。-Digital image processing, image denoising part of the low-pass de-noising and non-local means are two ways in which non-local means to signal to noise ratio increased by about 10dB.