Method and apparatus for managing display limitations in color grading and content approval

Patent metadata

Field	Value
Publication number	US-9319652-B2
Application number	US-201113989736-A
Country	US
Kind code	B2
Filing date	Nov 16, 2011
Priority date	Dec 12, 2010
Publication date	Apr 19, 2016
Grant date	Apr 19, 2016

Abstract

Methods and apparatus are provided for ensuring consistency in the appearance of video data displayed on displays having different capabilities than a target display. Some embodiments comprising modifying at least one pixel of input video data such that the modified pixel represents the appearance of the at least one pixel when displayed by a target display. In some embodiments, modifying the at least one pixel comprises replacing an original pixel value of the at least one pixel with a replacement pixel value representing a modeled display of the original pixel value by the target display.

First claim

What is claimed is:

1. A color grading tool for producing color-graded display video data from input video data, the color grading tool comprising:
a color grading adjustment module operable to color-grade the input video data to yield color-graded video data while displaying the color-graded video data on a color-grading display; and
a display conformer configured to modify the color-graded video data for display on a target display and having a greater fidelity range than the color-grading display, by:
modeling the display of all or part of the color-graded video data on the color-grading display by a computational display model of the target display to determine one or more modified pixel values that represent the appearance of one or more corresponding pixels of the color-graded video data when displayed on the color-grading display;
identifying at least one pixel having values outside the fidelity range of the color-grading display; and
modifying the color-graded video data by replacing such pixel values of one or more identified pixels of the color-graded video data for which the identified pixel values are outside a fidelity range of the color-grading display with the corresponding ones of the modified pixel values, wherein the modified pixel values include substitute chromaticities and/or luminances related to the target display, and wherein
the display conformer is configured to apply the input video data to the computational display model of the target display, the computational display model configured to determine said substitute chromaticities and/or luminances with which the target display would display such pixels of the input video data which are outside said fidelity range of the color-grading display.

2. The color grading tool according to claim 1 , wherein the target display comprises an illumination source and spatial light modulator configured to modulate light emitted by the illumination source, and the display conformer is further configured to:
determine a pattern of illumination produced on the spatial light modulator by the illumination source in response to the video data; and
determine a fidelity limit of the fidelity range of the target display based on the pattern of illumination,
wherein the pixels values to be replaced are identified based on the determined fidelity limit.

3. The color grading tool according to claim 2 , wherein the display conformer is configured to determine the fidelity limit by determining a chromaticity space that can be achieved by the spatial light modulator modulating the determined illumination at one or more pixels of the spatial light modulator.

4. The color grading tool according to claim 2 , wherein the display conformer is configured to determine the fidelity limit by determining a luminance range that can be achieved by the spatial light modulator modulating the illumination at one or more pixels of the spatial light modulator.

5. The color grading tool according to claim 3 , wherein the display conformer is configured to determine the fidelity limit by determining a luminance range that can be achieved by the spatial light modulator modulating the illumination at one or more pixels of the spatial light modulator.

6. A method for managing display limitations related to a target display in the distribution of color-graded video data, the color-graded video data viewed on a color-grading display during color grading thereof, the color-grading display having a smaller fidelity range than the target display, the method comprising:
obtaining the color-graded video data;
generating display video data related to the target display by modifying the color-graded video data, the modifying comprising:
modeling the display of all or part of the color-graded video data on the color-grading display to determine one or more modified pixel values representing the appearance of one or more corresponding pixels of the color-graded video data when displayed by the color-grading display;
identifying at least one pixel having values outside the fidelity range of the color-grading display; and
in the color-graded video data, replacing pixel values of one or more identified pixels of the color-graded video data for which the pixel values are outside the fidelity range of the color-grading display with substitute pixel values including substitute chromaticities and/or luminances with which the target display would display such pixels of the input video data which are outside the fidelity range of the color-grading display; and
making the display video data available to an end-user, wherein said substitute chromaticities and/or luminances are determined by a computational display model of the target device.

7. A system configured to execute the method according to claim 6 .

8. A color grading tool for producing color-graded display video data from input video data, the color grading tool comprising:
a color grading adjustment module operable to color-grade the input video data to yield color-graded video data while displaying the color-graded video data on a color-grading display; and
a display conformer configured to modify the color-graded video data for display on a target display and having a greater fidelity range than the color-grading display, by:
modeling the display of all or part of the color-graded video data on the color-grading display by a computational display model of the target display to determine one or more modified pixel values that represent the appearance of one or more corresponding pixels of the color-graded video data when displayed on the color-grading display;
identifying at least one pixel having values outside the fidelity range of the color-grading display; and
modifying the color-graded video data by replacing such pixel values of one or more identified pixels of the color-graded video data for which the identified pixel values are outside a fidelity range of the color-grading display with the corresponding ones of the modified pixel values, wherein the modified pixel values include substitute chromaticities and/or luminances related to the target display, and wherein
the display conformer is configured to apply the input video data to the computational display model of the target display, the computational display model configured to determine said substitute chromaticities and/or luminances with which the target display would display such pixels of the input video data which are outside said fidelity range of the color-grading display, wherein
the target display comprises an illumination source and spatial light modulator configured to modulate light emitted by the illumination source, and the display conformer is further configured to:
determine a pattern of illumination produced on the spatial light modulator by the illumination source in response to the video data; and
determine a fidelity limit of the fidelity range of the target display based on the pattern of illumination, wherein the pixels values to be replaced are identified based on the determined fidelity limit.

Assignees

• Atkins Robin
• Wan Chun C
• Webster Anne
• Dolby Lab Licensing Corp

Inventors

• Atkins Robin
• Wan Chun C
• Webster Anne

Classifications

• G09G5/02 Primary

  characterised by the way in which colour is displayed {(details of colour display specific for CRTs G09G1/28; specific for flat matrix panels other than liquid crystal displays G09G3/2003; specific for liquid crystal displays G09G3/3607)} · CPC title

• H04N23/841

  to modify gamut · CPC title

• H04N23/56

  provided with illuminating means · CPC title

• H04N25/134

  based on three different wavelength filter elements · CPC title

• H04N9/67

  for matrixing (camera processing pipelines for matrixing of colour signals H04N23/85) · CPC title