Method and apparatus for adjusting the contrast of an image

摘要

A method and apparatus for adjusting the contrast of an image is provided. Each of the pixels in the image has an initial brightness level that is within a range of brightness levels between a minimum brightness level and a maximum brightness level. For each of the brightness levels within said range, the number of pixels that have the same initial brightness level is counted (10). The pixels are divided (11) into at least two types by identifying the or each set of pixels having initial brightness levels in which each of a plurality of adjacent ones of said brightness levels has more pixels than a threshold number. The pixels of said plurality of adjacent ones of said brightness levels are treated as a first type. The remaining pixels are treated as a second type. For the or each set of pixels of the first type, contrast enhancement (14) is carried out separately on the pixels that make up the or each set of pixels of the first type.