Display screen image contrasts that are supposed to be the same at different locations on the screen should appear the same.
Additional Information: Contrast uniformity can be important if proper recognition or presentation of information depends critically on proper scene or pattern rendering. It is expressed as a percentage: contrast (C) uniformity = 100 % (Cmin / Cmax), where Cmin and Cmax are the minimum and maximum contrast, respectively, of the sampled contrast set on the screen. The contrast uniformity should be as high as possible and, in general, should be commensurate to the user’s task. See IDMS (2012) for measurement information. 8 9241-303
© ISO. This material is excerpted from ISO 9241-303: 2011 with the permission of ANSI on behalf of ISO. All rights reserved.