Granted Patent B2

US 12,608,783 · App. 19/042,231 · Granted Apr 21, 2026

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 (58)

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;

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 ambient light measurement, thereby generating a modified tone mapping curve; and

converting the first video signal based on the modified tone mapping curve, thereby generating 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;

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 ambient light measurement, thereby generating a modified tone mapping curve; and

converting the first video signal based on the modified tone mapping curve, thereby generating 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.

15 . A non-transitory computer-readable medium having instructions stored thereon that, when executed by at least one computing device, cause the at least one computing device 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;

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 ambient light measurement, thereby generating a modified tone mapping curve; and

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

16 . The non-transitory computer-readable medium of claim 15 , wherein the modifying the tone mapping curve comprises:

modifying the tone mapping curve based on a user setting.

17 . The non-transitory computer-readable medium of claim 16 , the operations further comprising:

adapting the second video signal to the user setting.

18 . The non-transitory computer-readable medium of claim 15 , wherein the modifying the tone mapping curve comprises:

temporally filtering the modified tone mapping curve.

19 . The non-transitory computer-readable medium of claim 15 , 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.

20 . The non-transitory computer-readable medium of claim 15 , the operations 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.

Assignments (1)

Continuity (4)

References Cited (77)