Granted Patent B2

US 12,249,054 · App. 18/411,985 · Granted Mar 11, 2025

Inventors: Sheng Yuan Chiu (San Jose, CA); Kunlung Wu (San Jose, CA)

Assignee: Roku, Inc.

G06T5/92G06T5/40G06T5/50G06T7/0002H04N5/20G06T2200/24G06T2207/10016G06T2207/20208

Abstract

Claims (40)

1. A computer-implemented method for dynamic tone mapping of video content, comprising:

receiving, by at least one computer processor, histogram data associated with a first video signal representing a video program, wherein the first video signal has a first dynamic range and static metadata describing one or more brightness characteristics of the video program, wherein the histogram data comprises color values for a plurality of frames in the first video signal outputted by a display device;

determining a cumulative histogram for a scene in the video program based on the histogram data;

determining a near-brightest pixel for the scene in the video program based on the cumulative histogram, wherein the near-brightest pixel is a representative pixel value that defines a maximum target brightness value for proper display of the scene;

modifying a tone mapping curve based on the near-brightest pixel and characteristics of the display device to generate a modified tone mapping curve; and

converting the first video signal based on the modified tone mapping curve to generate a second video signal having a second dynamic range that is less than the first dynamic range.

2. The computer-implemented method of claim 1 , wherein the modifying the tone mapping curve comprises:

modifying the tone mapping curve based on a user setting.

3. The computer-implemented method of claim 2 , further comprising:

adapting the second video signal to the user setting.

4. The computer-implemented method of claim 1 , wherein the modifying the tone mapping curve comprises:

temporally filtering the modified tone mapping curve.

5. The computer-implemented method of claim 1 , wherein the determining the near-brightest pixel for the scene in the video program comprises:

determining the near-brightest pixel for the scene in the video program by identifying, using the cumulative histogram, a pixel value in the scene that belongs to a top percentage value of brightest pixels in the scene, wherein the top percentage value is defined by a threshold value.

6. The computer-implemented method of claim 1 , further comprising:

generating video quality enhancement data based on the histogram data associated with the first video signal, and

wherein the converting the first video signal comprises:

converting the first video signal based on the video quality enhancement data.

7. The computer-implemented method of claim 6 , wherein the video quality enhancement data comprises dark scene adjustment data, bright scene adjustment data, or detail enhancement data.

8. A system for dynamic tone mapping of video content, comprising:

one or more memories; and

at least one processor each coupled to at least one of the memories and configured to perform operations comprising:

receiving histogram data associated with a first video signal representing a video program, wherein the first video signal has a first dynamic range and static metadata describing one or more brightness characteristics of the video program, wherein the histogram data comprises color values for a plurality of frames in the first video signal outputted by a display device;

determining a cumulative histogram for a scene in the video program based on the histogram data;

determining a near-brightest pixel for the scene in the video program based on the cumulative histogram, wherein the near-brightest pixel is a representative pixel value that defines a maximum target brightness value for proper display of the scene;

modifying a tone mapping curve based on the near-brightest pixel and characteristics of the display device to generate a modified tone mapping curve; and

converting the first video signal based on the modified tone mapping curve to generate a second video signal having a second dynamic range that is less than the first dynamic range.

9. The system of claim 8 , wherein the modifying the tone mapping curve comprises:

modifying the tone mapping curve based on a user setting.

10. The system of claim 9 , wherein the operations further comprise:

adapting the second video signal to the user setting.

11. The system of claim 8 , wherein the modifying the tone mapping curve comprises:

temporally filtering the modified tone mapping curve.

12. The system of claim 8 , wherein the determining the near-brightest pixel for the scene in the video program comprises:

determining the near-brightest pixel for the scene in the video program by identifying, using the cumulative histogram, a pixel value in the scene that belongs to a top percentage value of brightest pixels in the scene, wherein the top percentage value is defined by a threshold value.

13. The system of claim 8 , wherein the operations further comprise:

generating video quality enhancement data based on the histogram data associated with the first video signal; and

wherein the converting the first video signal comprises:

converting the first video signal based on the video quality enhancement data.

14. The system of claim 13 , wherein the video quality enhancement data comprises dark scene adjustment data, bright scene adjustment data, or detail enhancement data.

Assignments (2)

Continuity (3)

References Cited (79)