双边滤波（Bilateral filter）是一种可以保边去噪的滤波器。之所以可以达到此去噪效果，是因为滤波器是由两个函数构成。一个函数是由几何空间距离决定滤波器系数。另一个由像素差值决定滤波器系数。-Bilateral filtering (as the filter) is a kind of filter can protect and denoising. Can achieve the denoising effect, because filter is made up of two functions. A function is determined by the geometrical distance filter coefficient. Another is determined by the pixel difference filter coefficient.