US 12,452,464 B2
Film grain parameters adaptation based on viewing environment
Guan-Ming Su, Fremont, CA (US); Harshad Kadu, Santa Clara, CA (US); and Peng Yin, Ithaca, NY (US)
Assigned to Dolby Laboratories Licensing Corporation, San Francisco, CA (US)
Appl. No. 18/721,054
Filed by Dolby Laboratories Licensing Corporation, San Francisco, CA (US)
PCT Filed Dec. 19, 2022, PCT No. PCT/US2022/053410
§ 371(c)(1), (2) Date Jun. 17, 2024,
PCT Pub. No. WO2023/122039, PCT Pub. Date Jun. 29, 2023.
Claims priority of provisional application 63/292,654, filed on Dec. 22, 2021.
Claims priority of application No. 22152455 (EP), filed on Jan. 20, 2022.
Prior Publication US 2025/0063203 A1, Feb. 20, 2025
Int. Cl. H04N 19/80 (2014.01); H04N 19/85 (2014.01)
CPC H04N 19/80 (2014.11) [H04N 19/85 (2014.11)] 11 Claims
OG exemplary drawing
 
1. A method to process film grain metadata, the method comprising:
receiving an input video bitstream and associated input film grain information;
parsing the input film grain information to generate input film grain parameters (301) for generating film noise for a target display;
accessing measured viewing parameters (312) for the target display, wherein the viewing parameters comprise an ambient light value, a pixels per inch value, and a viewing distance value;
accessing reference viewing parameters for a reference display;
adjusting (315) one or more of the input film grain parameters based on the measured viewing parameters and the reference viewing parameters to generate adjusted film grain parameters, wherein the adjusting comprises:
generating ratio values between corresponding parameters in the measured and reference viewing parameters;
adjusting film grain size and/or strength proportionally to a ratio of measured ambient luminance over reference ambient luminance;
adjusting film grain size and/or strength proportionally to a ratio of measured viewing distance over reference viewing distance; and
adjusting film grain size and/or strength proportionally to a ratio of measured pixels per inch over a reference pixels per inch;
generating output film noise based at least on the adjusted film grain parameters;
decoding the input video bitstream to generate decoded video pictures; and
blending (320) the output film noise with the decoded video pictures to generate output video pictures on the target display.