1. A image processing method, comprising: computing a first adjusting value according to a first pixel of a current image and a plurality of first reference pixels nearby; computing a first weighted coefficient according to a gray-scale difference between the first pixel of the current image and a first pixel of a previous image; computing a first weighted adjusting value according to the first adjusting value and the first weighted coefficient; and adjusting the first pixel of the current image according to the first weighted adjusting value to generate a first pixel of an output image.