A method of reducing noise in an image, comprising: a) for each pixel being examined in the image, selecting a set of search pixels b) calculating a value of one or more features of a neighborhood of each search pixel, and a value of corresponding features of a neighborhood of the pixel being examined and c) calculating a reduced noise grey value for each pixel being examined, based on raw or transformed grey values of its search pixels, with greater sensitivity to those with one or more feature values similar to those of the pixel being examined wherein calculating the value of at least one feature comprises calculating a characteristic of a distribution of raw or transformed grey values of pixels in the neighborhood, other than a mean grey value of all pixels in the neighborhood.