Dolby Laboratories Licensing Corporation

Hariharan Ganapathy Kathirvelu

Robin Atkins

Guan-Ming Su

Sheng Qu

Jaclyn Anne Pytlarz

Harshad Kadu

Gopi Lakshminarayanan

Per Jonas Andreas Klittmark

Tensor-Product B-splines (TPB) have been shown to improve video quality when used to represent reshaping functions to map reshaped standard dynamic range content into high dynamic range (HDR) content; however, TPB prediction is computationally intensive and may not be supported by legacy devices. Methods and systems for backwards-compatible signaling of TPB-related metadata and a fast TPB prediction method are presented to overcome both of these limitations. Computation overhead for a TPB-based 3D look-up table is reduced by using temporary two-dimensional arrays. A remapping of the most significant bits of a legacy bit-depth parameter allows for backwards compatibility.

Tensor-product B-spline prediction for HDR video in mobile applications

Methods are disclosed for ambient light-adaptive display management. Given an input image, image metadata, an ambient-light signal, and parameters characterizing a target display, a processor generates an ambient-light adjustment function which maps input luminance values in a reference viewing environment to output luminance values in a target viewing environment, wherein the target viewing environment is determined based on the ambient-light signal. The ambient-light adjustment function is applied to the input image and the input metadata to generate a virtual image and new metadata. A tone-mapping function based on the new metadata and target display parameters is applied to the virtual image to generate an output image. The parameters for the target display are computed based on the ambient-light signal, global dimming metadata, and the luminance characteristics of the target display.

Ambient light-adaptive display management

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Santa Clara, CA, United States of America

Hariharan Ganapathy Kathirvelu