The invention provides a method of image filtering and a filter. The method of image filtering comprises confirming at least one selected direction and an opposite direction of at least one selected direction from the center point of a given window in the given window, wherein the window is used for confirming a current image area to be processed; carrying out collection of image sample points, and confirming the average value of the image sample points collected in at least one selected direction and the opposite direction of at least one selected direction and a weight corresponding to the average value; and carrying out a filtering operation on images in the image area to be processed, carrying out weighted averaging on the average value of all the selected directions and the opposite directions of all the selected directions and the weight corresponding to the average value, and obtaining a filtered image. The method of image filtering skillfully combines the number of the directions and the length of the directions in the limited window, can achieve gradual reduction of the number of the directions, maintains high accuracy, and meanwhile is simple in hardware implementation.