Dolby Laboratories Licensing Corporation

Thaddeus Beier

Robin Atkins

Raymond Yeung

Patrick Griffis

Tao Chen

Timo Kunkel

Ali Zandifar

Anustup Kumar Atanu Choudhury

Ian Godin

Robert Atkins

A method for generating metadata for use by a video decoder for displaying video content encoded by a video encoder includes: (1) accessing a target tone mapping curve; (2) accessing a decoder tone curve corresponding to a tone curve used by the video decoder for tone mapping the video content; (3) generating a plurality of parameters of a trim-pass function used by the video decoder to apply after applying the decoder tone curve to the video content, wherein the parameters of the trim-pass function are generated to approximate the target tone curve with the combination of the trim-pass function and the decoder tone curve, and (4) generating the metadata for use by the video decoder, including said plurality of parameters of the trim-pass function.

Tone-curve optimization method and associated video encoder and video decoder

An existing metadata set that is specific to a color volume transformation model is transformed to a metadata set that is specific to a distinctly different color volume transformation model. For example, source content metadata for a first color volume transformation model is received. This source metadata determines a specific color volume transformation, such as a sigmoidal tone map curve. The specific color volume transformation is mapped to a color volume transformation of a second color volume transformation model, e.g., a B&#xe9;zier tone map curve. Mapping can be a best fit curve, or a reasonable approximation. Mapping results in metadata values used for the second color volume transformation model (e.g., one or more B&#xe9;zier curve knee points and anchors). Thus, devices configured for the second color volume transformation model can reasonably render source content according to received source content metadata of the first color volume transformation model.

Transformation of dynamic metadata to support alternate tone rendering

A display management processor receives an input image with enhanced dynamic range to be displayed on a target display which has a different dynamic range than a reference display. The input image is first transformed into a perceptually-corrected IPT color space. A non-linear mapping function generates a first tone-mapped signal by mapping the intensity of the input signal from the reference dynamic range into the target dynamic range. The intensity (I) component of the first tone-mapped signal is sharpened to preserve details, and the saturation of the color (P and T) components is adjusted to generate a second tone-mapped output image. A color gamut mapping function is applied to the second tone-mapped output image to generate an image suitable for display onto the target display. The display management pipeline may also be adapted to adjust the intensity and color components of the displayed image according to specially defined display modes.

Display management for high dynamic range video

Growing community of inventors

Lafayette, CA, United States of America

Thaddeus Beier