Ambient headroom adaptation

Patent metadata

Field	Value
Publication number	US-11473971-B2
Application number	US-201916586411-A
Country	US
Kind code	B2
Filing date	Sep 27, 2019
Priority date	Sep 27, 2019
Publication date	Oct 18, 2022
Grant date	Oct 18, 2022

Abstract

A device comprises memory, a display characterized by a display characteristic, and processors coupled to the memory. The processors execute instructions causing the processors to receive data indicative of the display characteristic, data indicative of ambient lighting, and data indicative of content characteristics for a content item; determine a tone mapping curve for the content item based on the data indicative of content characteristics; determine a first, so-called “anchor” point along the tone mapping curve; modify a first portion of the tone mapping curve below the anchor point based on the data indicative of ambient lighting; modify a second portion of the tone mapping curve above the anchor point based on the data indicative of the display characteristic; perform tone mapping for the content item based on the modified toned mapping curve to obtain a tone mapped content item; and cause the display to display the tone mapped content item.

First claim

What is claimed is:

1. A method, comprising:
receiving data indicative of a characteristic of a display device, data indicative of ambient light conditions, and data indicative of content characteristics for a content item;
determining a tone mapping curve for the content item based on the data indicative of content characteristics;
determining a first point along the tone mapping curve;
modifying a first portion of the tone mapping curve below an input signal data value corresponding to the first point based on the data indicative of ambient light conditions;
modifying a second portion of the tone mapping curve above the input signal data value corresponding to the first point based on the data indicative of the characteristic of the display device;
performing tone mapping for the content item based on modified tone mapping curve to obtain a tone mapped content item; and
displaying the tone mapped content item.

2. The method of claim 1 , wherein determining the first point comprises determining at least one of: a mid-tone of the content item; or a reference white value.

3. The method of claim 1 , wherein modifying the first portion comprises adjusting the first point.

4. The method of claim 1 , wherein modifying the first portion comprises adjusting a slope of the first portion.

5. The method of claim 1 , wherein modifying the second portion comprises stretching the second portion.

6. The method of claim 5 , wherein stretching the second portion is based on the data indicative of the characteristic of the display device and the first point.

7. The method of claim 6 , wherein the data indicative of the characteristic of the display device comprises a peak brightness level of the display device, and wherein stretching the second portion comprises stretching the second portion to fit a range of brightness levels between the first point and the peak brightness level of the display device.

8. The method of claim 1 , wherein the data indicative of content characteristics for the content item comprises at least one of: a minimum brightness, a maximum brightness, and a mid-tone.

9. A non-transitory program storage device comprising instructions stored thereon to cause one or more processors to:
receive data indicative of a characteristic of a display device, data indicative of ambient light conditions, and data indicative of content characteristics for a content item;
determine a tone mapping curve for the content item based on the data indicative of content characteristics;
determine a first point along the tone mapping curve;
modify a first portion of the tone mapping curve below an input signal data value corresponding to the first point based on the data indicative of ambient light conditions;
modify a second portion of the tone mapping curve above the input signal data value corresponding to the first point based on the data indicative of the characteristic of the display device;
perform tone mapping for the content item based on modified tone mapping curve to obtain a tone mapped content item; and
cause the display device to display the tone mapped content item.

10. The non-transitory program storage device of claim 9 , wherein the instructions to determine the first point comprise instructions to determine at least one of a mid-tone of the content item and a reference white.

11. The non-transitory program storage device of claim 9 , wherein the instructions to modify the first portion comprise instructions to adjust the first point.

12. The non-transitory program storage device of claim 9 , wherein the instructions to modify the first portion comprise instructions to adjust a slope of the first portion.

13. The non-transitory program storage device of claim 9 , wherein the instructions to modify the second portion comprise instructions to stretch the second portion.

14. The non-transitory program storage device of claim 13 , wherein the data indicative of the characteristic of the display device comprises a peak brightness level of the display device, and wherein the instructions to stretch the second portion further comprise instructions to stretch the second portion to fit a range of brightness levels between the first point and the peak brightness level of the display device.

15. A device, comprising:
a memory;
a display, wherein the display is characterized by a characteristic; and
one or more processors operatively coupled to the memory, wherein the one or more processors are configured to execute instructions causing the one or more processors to:
receive data indicative of the characteristic of the display, data indicative of ambient light conditions, and data indicative of content characteristics for a content item;
determine a tone mapping curve for the content item based on the data indicative of content characteristics;
determine a first point along the tone mapping curve;
modify a first portion of the tone mapping curve below an input signal data value corresponding to the first point based on the data indicative of ambient light conditions;
modify a second portion of the tone mapping curve above the input signal data value corresponding to the first point based on the data indicative of the characteristic of the display;
perform tone mapping for the content item based on modified tone mapping curve to obtain a tone mapped content item; and
cause the display to display the tone mapped content item.

16. The device of claim 15 , wherein the instructions to determine the first point comprise instructions causing the one or more processors to determine at least one of a mid-tone of the content item and a reference white.

17. The device of claim 15 , wherein the instructions to modify the first portion comprise instructions causing the one or more processors to adjust the first point.

18. The device of claim 15 , wherein the instructions to modify the first portion comprise instructions causing the one or more processors to adjust a slope of the first portion.

19. The device of claim 15 , wherein the instructions to modify the second portion comprise instructions causing the one or more processors to stretch the second portion.

20. The device of claim 19 , wherein the data indicative of the characteristic of the display comprises a peak brightness level of the display, and wherein the instructions to stretch the second portion further comprise instructions causing the one or more processors to stretch the second portion to fit a range of brightness levels between the first point and the peak brightness level of the display.

Assignees

• Apple Inc

Inventors

• Yang Xiaohua
• Hu Ruiqi
• Pan Hao
• Mani Vaidyanath
• Wang Qiang
• He Haiyan
• Wang Xin
• Xie Gui
• Chang Jin Wook

Classifications

• H04N1/6027

  Correction or control of colour gradation or colour contrast (H04N1/6058 takes precedence) · CPC title

• G06T7/11

  Region-based segmentation · CPC title

• G06T7/90

  Determination of colour characteristics · CPC title

• H04N1/60

  Colour correction or control {(H04N1/54 takes precedence)} · CPC title

• G01J1/4204 Primary

  with determination of ambient light (solar light G01J2001/4266) · CPC title