US 12,125,183 B2
High dynamic range video color remapping
Johannes Yzebrand Tichelaar, Eindhoven (NL)
Assigned to Koninklijke Philips N.V., Eindhoven (NL)
Filed by KONINKLIJKE PHILIPS N.V., Eindhoven (NL)
Filed on Oct. 27, 2021, as Appl. No. 17/511,718.
Application 17/511,718 is a continuation of application No. 16/770,133, granted, now 11,170,478, previously published as PCT/EP2018/083856, filed on Dec. 6, 2018.
Claims priority of application No. 17206169 (EP), filed on Dec. 8, 2017.
Prior Publication US 2022/0124293 A1, Apr. 21, 2022
Int. Cl. G06K 9/00 (2022.01); G06T 5/92 (2024.01); G06T 7/90 (2017.01); G06T 9/00 (2006.01); H04N 9/64 (2023.01); H04N 9/68 (2023.01); H04N 9/77 (2006.01); H04N 23/88 (2023.01)
CPC G06T 5/92 (2024.01) [G06T 7/90 (2017.01); G06T 9/00 (2013.01); H04N 9/643 (2013.01); H04N 9/68 (2013.01); H04N 9/77 (2013.01); H04N 23/88 (2023.01); G06T 2207/10016 (2013.01); G06T 2207/10024 (2013.01); G06T 2207/20092 (2013.01)] 24 Claims
OG exemplary drawing
 
1. A luminance processor, comprising:
a gain determination circuit,
wherein the gain determination circuit is arranged to determine an initial multiplication factor,
wherein the initial multiplication factor is an output of a luminance mapping function divided by an input luminance of an input color of an input pixel of an input image,
wherein the output of the luminance mapping function is a result of applying the input luminance to the luminance mapping function,
wherein the input image has a first dynamic range,
wherein the first dynamic range has a first peak luminance,
wherein the luminance mapping function indicates how to adjust the input luminance to obtain an intermediate luminance of a second image,
wherein the second image has a second dynamic range,
wherein the second dynamic range has a second peak luminance,
wherein the second peak luminance divided is different from the first peak luminance;
an overflow determination circuit,
wherein the overflow determination circuit is arranged to determine an overflow,
wherein the overflow is determined as a product of the initial multiplication factor and a largest color component of the input color;
a gain factor modification circuit,
wherein the gain factor modification circuit is arranged to determine an alternative multiplication factor,
wherein the alternative multiplication factor is less than the initial multiplication factor,
wherein the gain factor modification circuit is arranged to output the alternative multiplication factor as a final multiplication factor when the overflow is greater than a threshold,
wherein the gain factor modification circuit is arranged to output the initial multiplication factor as the final multiplication factor when the overflow is less than or equal to the threshold; and
a multiplier circuit,
wherein the multiplier circuit is arranged to multiply input color components of the input color by the final multiplication factor so as to obtain an output color.