US 11,935,492 B2
Image-dependent contrast and brightness control for HDR displays
Jaclyn Anne Pytlarz, Santa Clara, CA (US)
Assigned to Dolby Laboratories Licensing Corporation, San Francisco, CA (US)
Appl. No. 17/920,115
Filed by Dolby Laboratories Licensing Corporation, San Francisco, CA (US)
PCT Filed Apr. 27, 2021, PCT No. PCT/US2021/029476
§ 371(c)(1), (2) Date Oct. 20, 2022,
PCT Pub. No. WO2021/222310, PCT Pub. Date Nov. 4, 2021.
Claims priority of provisional application 63/016,363, filed on Apr. 28, 2020.
Claims priority of application No. 20171788 (EP), filed on Apr. 28, 2020.
Prior Publication US 2023/0169930 A1, Jun. 1, 2023
Int. Cl. G09G 3/34 (2006.01)
CPC G09G 3/3406 (2013.01) [G09G 2320/0238 (2013.01); G09G 2320/0626 (2013.01); G09G 2320/0646 (2013.01); G09G 2320/066 (2013.01); G09G 2360/16 (2013.01)] 11 Claims
OG exemplary drawing
 
1. A computer-implemented method for providing an image-dependent brightness control based on a user-defined value of a peak luminance adjustment parameter to reduce brightness in bright image portions relatively stronger than in dark image portions, the method comprising:
receiving an input image in an image dynamic range;
receiving a minimum display luminance value and a maximum display luminance value defining a display dynamic range of a target display;
generating (420) a first adjusted luminance value for the target display based on the peak luminance adjustment parameter and the maximum display luminance value, wherein the first adjusted luminance value is lower than the maximum display luminance value;
generating (430) a tone-mapped image with a tone-mapping function and the input image, wherein the tone-mapping function maps the image dynamic range to the minimum display luminance value and the first adjusted luminance value; and
generating (415) an output image for the target display based on the tone-mapped image; wherein generating the first adjusted luminance value (TmaxAdj1) comprises computing

OG Complex Work Unit Math
wherein Tmax denotes the maximum display luminance value and β denotes the peak luminance adjustment parameter.