1. An image processing method in an image processing apparatus, comprising: for a subject pixel in a subject image, determining a pixel corresponding to the subject pixel in the reference image, wherein one of a plurality of images matched in structure being selected as the reference image, and another of the images being selected as the subject image; calculating similarity values of at least part of pixels in the reference image with respect to the pixel corresponding to the subject pixel; establishing weight coefficients based on the similarity values, and weighted averaging the subject pixel in the subject image to obtain a processed pixel value.