1. An image processing method, comprising: when performing quantization processing on pixel values of an image, regarding each pixel of a plurality of pixels of the image, calculating a quantization error value of the pixel, wherein the quantization error value corresponds to a difference between a quantized value of the pixel after the quantization processing for the pixel and an original value of the pixel before the quantization processing for the pixel; and adjusting original values of a plurality of neighboring pixels of the pixel before the quantization processing for the neighboring pixels according to the quantization error value, a plurality of weighted values, and a plurality of random numbers, wherein the plurality of weighted values respectively correspond to relative locations of the plurality of neighboring pixels with respect to the pixel.