US 12,444,033 B2
Encoder, decoder, system, and method for determining tone mapping curve parameters
Hu Chen, Munich (DE); Yichuan Wang, Beijing (CN); Weiwei Xu, Hangzhou (CN); Quanhe Yu, Beijing (CN); and Elena Alexandrovna Alshina, Munich (DE)
Assigned to Huawei Technologies Co., Ltd, Shenzhen (CN)
Filed by HUAWEI TECHNOLOGIES CO., LTD., Shenzhen (CN)
Filed on Nov. 7, 2022, as Appl. No. 17/982,221.
Application 17/982,221 is a continuation of application No. PCT/CN2020/089134, filed on May 8, 2020.
Prior Publication US 2023/0057829 A1, Feb. 23, 2023
Int. Cl. G06T 5/94 (2024.01); G06T 5/40 (2006.01)
CPC G06T 5/94 (2024.01) [G06T 5/40 (2013.01); G06T 2207/10016 (2013.01); G06T 2207/20208 (2013.01)] 19 Claims
OG exemplary drawing
 
1. A method for determining one or more curve parameters of a tone mapping curve, the method comprising:
obtaining a high dynamic range (HDR) video frame and metadata associated to the HDR video frame;
obtaining a pair of anchor points, wherein the pair of anchor points comprises a first anchor point and a second anchor point of the tone mapping curve, based on the HDR video frame and the metadata; and
generating the one or more curve parameters of the tone mapping curve based on the pair of anchor points, wherein the tone mapping curve comprises:
L ′=m_a((m_p×L (m_n))/((m_p−1)×L (m_n)+1)) (m_m)+m_b,
wherein L is a brightness of an input pixel of a HDR video frame, m_n is a first value, particularly m_n=1, m_m is a second value, particularly m_m=2.4, and m_b is a determined perception quantization, PQ, value, wherein m_p is a brightness control factor and m_a is a scaling factor defining a maximum brightness of an output pixel, and wherein the one or more curve parameters comprise m_p and m_a.