1. A weighted image enhancement method comprising: (a) receiving an original image, wherein the original image comprises a plurality of original pixels; (b) sharpening the original image to generate a sharpened image, wherein the sharpened image comprises a plurality of sharpened pixels; (c) performing edge detection with respect to the original image to generate a probability value corresponding to whether each original pixel is on an edge; (d) receiving an enhancement mode setting; (e) looking up a corresponding weight table corresponding to the enhancement mode setting to obtain a corresponding enhancement weight of each original pixel according to the probability of whether each original pixel is on an edge; (f) performing a weight calculation utilizing each original pixel and its corresponding sharpened pixel according to its corresponding enhancement weight to generate an enhanced image; and (g) displaying the enhanced image by a display unit.