Picture level control method for bright regions of HDR images in power management of large AMOLED displays

Abstract

Herein, a picture control method designed to facilitate power management of large active‐matrix organic‐light‐emitting‐diode displays is proposed. In this method, Hybrid Log‐Gamma (HLG) pictures are presented simply by multiplying the upper half of the picture level by the gain corresponding to the power suppression. HLG is a standard for high‐dynamic‐range images. The controlled picture is processed by nominal luminance transformation, as well as by color conversion from red–green–blue into hue–saturation–value (HSV) imagery. Results obtained via simulations show that high‐contrast HLG pictures can be better simulated by our proposed method than by currently used conventional methods. The simulation results also demonstrate that when the picture is presented using the proposed power consumption management method, both the dark and bright regions show less deterioration. In addition, through an examination of image histograms created to elucidate detail descriptions of simulated pictures in the red–green–blue and HSV color spaces, we found that using HSV color conversion in conjunction with the proposed method mitigates chromaticity shift and that the feasibility of HSV color conversions could be quantitatively clarified by the evaluation of color differences defined by the Euclidean distance in a uniform color space.