1. A image processing method, comprising: obtaining a first set of characterization values, which represents a first group of pixels that are associated with a denoising pixel in a filter window of an image, wherein obtaining the first set of characterization values includes determining a component in the first set of characterization values based on a value associated with one or more pixels in a first neighborhood block formed by the first group of pixels; obtaining a second set of characterization values, which represents a second group of pixels that are associated with a denoising reference pixel in the filter window; wherein obtaining the second set of characterization values includes determining a component in the second set of characterization values based on a value associated with one or more pixels in a second neighborhood block formed by the second group of pixels; and using the first set of characterization values and the second set of characterization values to determine a similarity between the denoising pixel and the denoising reference pixel.