And smoothing the picture in order to getting rid of the noise which is produced by gathering and transmitting, so that we can detect the edge easily.
并对图像进行平滑处理，去除图像采集和传输中混入的噪声，以利于图像的边缘检测。
2
The system can take a picture of the user's face, "without a flash, any noise, or any indication that a picture is being taken to prevent the current user from knowing he is being photographed";
此系统能为用户面部照相，“无声无息无闪光，也没有任何提示，当前用户根本不知道自己已经被留影了”；
3
By applying wavelet analysis method to image edge detection, multi scale operator of wavelet analysis functions well for noise resisting ability and picture edge reserving.