1. An image processing method, for adjusting an edge pixel value of an image, comprising: calculating an intersection point formed by an edge of the image and a pixel scan line; estimating a relative ratio of the image within a pixel block corresponding to the intersection point, and accordingly generating an adjustment parameter; and adjusting a pixel value of the pixel block according to the adjustment parameter, wherein the generating the adjustment parameter step comprises: determining a relative position relationship between the image and intersection point; and estimating the relative ratio of the image within the pixel block according to the relative position relationship and the intersection point to generate the adjustment parameter, and wherein the pixel scan line is a horizontal scan line, and the generating the adjustment parameter step further comprises: estimating a ratio of a horizontal distance from the intersection point to a border of the pixel block to a horizontal width of the pixel block to generate the adjustment parameter.