1. An image de-noising method, comprising: correcting an original image into an intermediate correction image, the original image having a plurality of pixels that are arranged two-dimensionally, each pixel in the original image having a pixel value, the intermediate correction image having a plurality of pixels that are arranged two-dimensionally with a one-to-one correspondence with the plurality of pixels of the original image, each pixel in the intermediate correction image having a corrected pixel value; determining a differential image between the original image and the intermediate correction image, the differential image having a plurality of pixels that are arranged two-dimensionally with a one-to-one correspondence with the plurality of pixels of the original image, the differential image having, for each pixel, a differential pixel value equal to a difference between the pixel value of the corresponding pixel in the original image and the corrected pixel value of the corresponding pixel in the intermediate correction image; and determining a pixel-dependent conversion parameter at each pixel based on the differential pixel value at the each pixel in the differential image and correcting the original image into a final correction image by using the pixel-dependent conversion parameter, the final correction image having a plurality of pixels that are arranged two-dimensionally with a one-to-one correspondence with the plurality of pixels of the original image.