1. A computer readable medium embedded with a computer program for performing an adaptive image sharpening method, for generating a sharpened image area corresponding to an original image area, the original image area including a plurality of original pixels, wherein the computer program readable medium performs the following steps: blurring the original image area to generate a plurality of blurred pixels corresponding to the plurality of original pixels respectively; calculating a plurality of characteristic values based on the values of the plurality of original pixels, wherein each of the pixels has one corresponding characteristic value; for each original pixel, statistically analyzing the plurality of characteristic values corresponding to the plurality of original pixels to generate a plurality of weighting values that respectively correspond to the plurality of original pixels; and generating a plurality of sharpened pixels according to the plurality of original pixels, the plurality of weighting values, and the plurality of blurred pixels; wherein the plurality of sharpened pixels constitute the sharpened image area.