Pixel modification to reduce energy consumption of a display device

Abstract

A method and device for reducing power consumption of display devices proposes to reduce the total amount of light emitted in a perceptually indistinguishable manner based on the on the human visual sensitivity at the position of a pixel. The visibility of the processing can be made to remain provably below threshold, whereas other techniques may not be able to provide such proof. This is achieved by determining a minimum detectable modulation or a corresponding just-noticeable difference based on frequency intensity information for a pixel representative of how much there is of a set of frequencies at the pixel and a contrast sensitivity function representative of a model of human vision that predicts which contrasts at which frequencies are visible to the human eye. Pixel values may be reduced based on this minimum detectable modulation or just-noticeable difference. The contrast sensitivity function may be given by Barten's model and the frequency intensity information may be based on a hierarchical map built using a discrete wavelet transform or a continuous wavelet transform.