Due to the impact of the equipment and the environment

poor quality images could be generated inevitably in the process of image acquisition

which makes the later processing more difficult.In this paper

an edge preserving denoising method for color images through a controlling gradient vector is proposed.In order to make better use of the color image information

information loss is analyzed by transforming color images to gray image in the first step.Furthermore

the calculation method of a gradient vector in RGB space is proposed.Second

by analyzing regional structure differences of the noise gradient vector in a neighborhood and the edge gradient vector in a neighborhood

the inadequacy with diffusion equation is pointed out

and a method for controlling the diffusion matrix is proposed.Finally

PM equation in RGB space is proposed through the edge function derived by vector images

normal diffusion is removed by decomposition of model and improved edge stopping function with the controlling the diffusion matrix can make better control.The results show the proposed method has higher signal to noise ratio

and the effectiveness of it is verified.This method can denoise image

and it could keep the image contrast and edge information at the same time

so it has some practicability.