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US-12621474-B2 - Scalable systems for controlling color management comprising varying levels of metadata

US12621474B2US 12621474 B2US12621474 B2US 12621474B2US-12621474-B2

Abstract

Several embodiments of scalable image processing systems and methods are disclosed herein whereby color management processing of source image data to be displayed on a target display is changed according to varying levels of metadata.

Inventors

  • Neil W. Messmer
  • Robin Atkins
  • Steve Margerm
  • Peter W. Longhurst

Assignees

  • DOLBY LABORATORIES LICENSING CORPORATION

Dates

Publication Date
20260505
Application Date
20251016

Claims (4)

  1. 1 . An apparatus for decoding a bitstream, the apparatus comprising: an input to receive a bitstream comprising image data and two or more sets of metadata; and a processor, wherein the processor; decodes the image data and the two or more sets of metadata, wherein: a first set of metadata describes characteristics of a reference display device that is used to produce the image data, the first set of metadata comprising: a) a white point for the reference display device, and b) three primaries for the reference display device, a second set of metadata describes tone-mapping parameters to display the image data on a display; and a third set of metadata describes ambient light conditions at the reference display that is used to produce the image data.
  2. 2 . The apparatus of claim 1 , wherein the first set of metadata, the second set of metadata, and the third set of metadata in the bitstream can be decoded independently of each other.
  3. 3 . The apparatus of claim 1 , wherein the second set of metadata defines a tone-mapping sigmoidal curve.
  4. 4 . The apparatus of claim 3 , wherein the metadata for the tone-mapping sigmoidal curve comprise a minimum signal value, a sigmoidal mid value, and a max signal value to be used in tone-mapping the image data to a target display.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application is a continuation of U.S. patent application Ser. No. 19/308,110, filed Aug. 22, 2025, which is a continuation application of U.S. patent application Ser. No. 19/268,800, filed Jul. 14, 2025, which is a continuation of U.S. patent application Ser. No. 19/049,625, filed Feb. 10, 2025, now U.S. Pat. No. 12,363,326, which is a continuation of U.S. patent application Ser. No. 18/957,187, filed Nov. 22, 2024, now U.S. Pat. No. 12,418,666, which is a continuation of U.S. patent application Ser. No. 18/731,860, filed Jun. 3, 2024, now U.S. Pat. No. 12,432,364, which is a continuation of U.S. patent application Ser. No. 18/413,720, filed Jan. 16, 2024, now U.S. Pat. No. 12,231,660, which is a continuation of U.S. patent application Ser. No. 18/219,344, filed Jul. 7, 2023, now U.S. Pat. No. 11,917,171, which is a continuation of U.S. patent application Ser. No. 17/353,519, filed Jun. 21, 2021, now U.S. Pat. No. 11,736,703, which is a continuation of U.S. patent application Ser. No. 14/740,862, filed on Jun. 16, 2015, now U.S. Pat. No. 11,218,709, which is a continuation of U.S. patent application Ser. No. 14/003,097, filed Sep. 4, 2013, now U.S. Pat. No. 9,111,330, which is a Section 371 National Stage Application of International Application No. PCT/US2012/038448, filed May 17, 2012, which claims priority to U.S. Provisional Ser. No. 61/491,014, filed May 27, 2011, each of which are hereby incorporated by reference in their entirety. TECHNICAL FIELD The present invention relates to image processing and, more particularly, to the encoding and decoding of image and video signals employing metadata, and more particularly, in various layers of metadata. BACKGROUND Known scalable video encoding and decoding techniques allow for the expansion or contraction of video quality, depending on the capabilities of the target video display and the quality of the source video data. Improvements in image and/or video rendering and the experience to the viewers may be made, however, in the use and application of image metadata in either a single level or in various levels of metadata. SUMMARY Several embodiments of scalable image processing systems and methods are disclosed herein whereby color management processing of source image data to be displayed on a target display is changed according to varying levels of metadata. In one embodiment, a method for processing and rendering image data on a target display through a set of levels of metadata is disclosed wherein the metadata is associated with the image content. The method comprises inputting the image data; ascertaining the set of levels of metadata associated with the image data; if no metadata is associated with the image data, performing at least one of a group of image processing steps, said group comprising: switching to default values and adaptively calculating parameter values; if metadata is associated with the image data, calculating color management algorithm parameters according to set of levels of metadata associated with the image data. In yet another embodiment, a system for decoding and rendering image data on a target display through a set of levels of metadata is disclosed. The system comprises: a video decoder, said video decoder receiving input image data and outputting intermediate image data; a metadata decoder, said metadata decoder receiving input image data wherein said metadata decoder capable of detecting a set of levels of metadata associated with said input image data and outputting intermediate metadata; a color management module, said color management module receiving intermediate metadata from said metadata decoder, receiving intermediate image data from said video decoder, and performing image processing upon intermediate image data based upon said intermediate metadata; and a target display, said target display receiving and displaying the image data from said color management module. Other features and advantages of the present system are presented below in the Detailed Description when read in connection with the drawings presented within this application. BRIEF DESCRIPTION OF THE DRAWINGS Exemplary embodiments are illustrated in referenced figures of the drawings. It is intended that the embodiments and figures disclosed herein are to be considered illustrative rather than restrictive. FIGS. 1A, 1B and 1C show one embodiment of a current video pipeline from creation, to distribution, to consumption of a video signal. FIG. 2A depicts one embodiment of a video pipeline that comprises a metadata pipeline in accordance with the teachings of the present application. FIG. 2B depicts one embodiment of a metadata prediction block. FIG. 3 shows one embodiment of a sigmoidal curve that employs Level 1 metadata. FIG. 4 shows one embodiment of a sigmoidal curve that employs Level 2 metadata. FIG. 5 shows one embodiment of a histogram plot based on image/scene analysis that may be used to adjust the