Display apparatus

A display apparatus for presenting an image frame divided into a plurality of subfields (SF1-SF8) based on time, comprises a gradation level converter (10) arranged to convert a brightness level of the input image into a gradation level selected from a group of predetermined gradation levels. The group is defined such the number of corresponding subfields within adjacent gradation levels that indicate different light-emitting states does not exceed a predetermined number, e.g. 1 or 2, in order to reduce unwanted brightness differences caused by the variations in the number of pixels emitting light during successive subfields. The display apparatus may comprise a motion detector (40) to determine whether the input image is a still or moving picture, so that the gradation level can be selected from a group configured for the appropriate type of image, and a pixel detector (50) arranged to detect the number pixels sharing a common gradation level from the input image, so that the group of gradation levels can be compiled based on said common gradation level.