Systems and methods for exposure control

Patent metadata

Field	Value
Publication number	US-10924684-B2
Application number	US-201916395615-A
Country	US
Kind code	B2
Filing date	Apr 26, 2019
Priority date	Oct 26, 2016
Publication date	Feb 16, 2021
Grant date	Feb 16, 2021

Abstract

The present disclosure relates to systems and methods for determining the exposure setting of an imaging device having a set of exposure parameters. A target luma of the imaging device may be determined. A correspondence table may be obtained. The correspondence table may relate to a plurality of reference luma values and a plurality of groups of operation values of the set of exposure parameters, a group of operation values corresponding to a reference luma value. A reference luma value and a group of operation values of the set of exposure parameters may be identified based on the target luma and the correspondence table. An adjustment of at least one exposure parameter of the imaging device may be determined based on the identified group of operation values. The at least one exposure parameter of the imaging device may be adjusted based on the determined adjustment.

First claim

What is claimed is:

1. A system, comprising:
at least one processor;
at least one non-transitory computer-readable storage medium storing a set of instructions, the set of instructions, when executed by the at least one processor, cause the system to:
identify that an imaging device switches from a first exposure mode to a second exposure mode;
determine a current luma of the first exposure mode based on a first correspondence table associated with the first exposure mode and a current group of operation values of a set of exposure parameters of the imaging device in the first exposure mode;
determine a target luma of the imaging device corresponding to the second exposure mode based on the current luma of the first exposure mode;
obtain a correspondence table associated with the second exposure mode relating to a plurality of reference luma values and a plurality of groups of operation values of a set of exposure parameters of the imaging device, a group of operation values of the set of exposure parameters of the imaging device corresponding to a reference luma value;
identify, based on the target turns and the correspondence table, a reference luma value, and a group of operation values with respect to the set of exposure parameters corresponding to the reference luma value, the identified reference luma value and the identified group of operation values being associated with the target luma of the second exposure mode;
determine, based on the group of operation values, an adjustment of at least one exposure parameter of the imaging device; and
adjust, based on the determined adjustment, the at least one exposure parameter of the imaging device.

2. The system of claim 1 , wherein the imaging device includes at least one exposure mode of an auto exposure mode, a gain priority mode, a shutter priority mode, an aperture priority mode, or an anti-ghosting mode.

3. The system of claim 1 , wherein the set of exposure parameters of the imaging device include at least one exposure parameter of a gain, a shutter speed, or an aperture size.

4. The system of claim 1 , wherein to identify, based on the target luma and the correspondence table, a reference luma value, and a group of operation values with respect to the set of exposure parameters corresponding to the reference luma value, the system is caused to:
for each of the plurality of reference luma values in the corresponding table, determine a difference between the reference luma value and the target luma; and
identify, from the plurality of reference luma values, the reference luma value that has the smallest difference with respect to the target luma.

5. The system of claim 1 , wherein the second exposure mode is an auto exposure mode, and to obtain a correspondence table associated with the second exposure mode, the system is caused to:
maintain the imaging device to operate with an initial shutter speed, an initial gain, and an initial aperture size;
determine a first range of a luma by adjusting the initial aperture size to a first aperture size;
determine a second range of the luma by adjusting the initial shutter speed to a first shutter speed;
determine a third range of the luma by adjusting the initial gain to a first gain;
determine a fourth range of the luma by adjusting the first shutter speed to a final shutter speed;
determine a fifth range of the luma by adjusting the first gain to a final gain; and
determine a sixth range of the luma by adjusting the first aperture size to a final aperture size.

6. The system of claim 1 , wherein the second exposure mode is a gain priority mode, and to obtain a correspondence table associated with the second exposure mode, the system is caused to:
maintain the imaging device to operate with an initial shutter speed, an initial gain, and an initial aperture size;
determine a seventh range of a luma by adjusting the initial aperture size to a final aperture size:
determine an eighth range of the luma by adjusting the initial gain to a final gain; and
determine a ninth range of the luma by adjusting the initial shutter speed to a final shutter speed.

7. The system of claim 1 , wherein the second exposure mode is a shutter priority mode, and to obtain a correspondence table associated with the second exposure mode, the system is caused to;
maintain the imaging device to operate with an initial shutter speed, an initial gain, and an initial aperture size;
determine a tenth range of a luma by adjusting the initial aperture size to a final aperture size;
determine an eleventh range of luma by adjusting the initial shutter speed to a final shutter speed; and
determine a twelfth range of the luma by adjusting the initial gain to a final gain.

8. The system of claim 1 , wherein the second exposure mode is an aperture priority mode, and to obtain a correspondence table associated with the second exposure mode, the system is caused to:
maintain the imaging device to operate with an initial shutter speed, an initial gain, and an initial aperture size;
determine a thirteenth range of a luma by adjusting the initial aperture size to a first aperture size;
determine a fourteenth range of the luma by adjusting the initial shutter speed to a final shutter speed;
determine a fifteenth range of the luma by adjusting the initial gain to a final gain; and
determine a sixteenth range of the luma by adjusting the first aperture size to a final aperture size.

9. A method, comprising:
identifying that an imaging device switches from a first exposure mode to a second exposure mode;
determining a current luma of the first exposure mode based on a first correspondence table associated with the first exposure mode and a current group of operation values of a set of exposure parameters of the imaging device in the first exposure mode;
determining a target luma of the imaging device corresponding to the second exposure mode based on the current luma of the first exposure mode;
obtaining a correspondence table associated with the second exposure mode relating to a plurality of reference luma values and a plurality of groups of operation values with respect to a set of exposure parameters of the imaging device; a set of exposure parameters of the imaging device corresponding to a reference luma value:
identifying, based on the target luma and the correspondence table, a reference luma value and a group of operation values with respect to the set of exposure parameters corresponding to the reference luma value, the identified reference luma value and the identified group of operation values being associated with the target luma of the second exposure mode;
determining, based on the group of operation values, an adjustment to at least one exposure parameter of the imaging device; and
adjusting, based on the determined adjustment, the at least one exposure parameter of the imaging device.

10. The method of claim 9 , wherein the imaging device includes at least one exposure mode of an auto exposure mode, a gain priority mode, a shutter priority mode, an aperture priority mode, or an anti-ghosting mode.

11. The method of claim 9 , wherein the set of exposure parameters of the imaging device include at least one exposure parameter of a gain, a shutter peed, or an aperture size.

12. The method of claim 9 , wherein the identifying, based on the target luma and the correspondence table, a reference luma value, and a group of operation values with respect to the set of exposure parameters corresponding to the reference luma value comprises:
for each of the plurality of reference luma values in the corresponding table, determining a difference between the reference luma va

Assignees

• Zhejiang Dahua Technology Co

Inventors

• Qu Erping
• Huang Qianfeng
• Pan Runfa
• Li Liangcheng

Classifications

• H04N23/71

  Circuitry for evaluating the brightness variation · CPC title

• H04N23/76

  by influencing the image signals · CPC title

• H04N23/72

  Combination of two or more compensation controls · CPC title

• H04N23/667 Primary

  Camera operation mode switching, e.g. between still and video, sport and normal or high- and low-resolution modes · CPC title

• H04N23/75

  by influencing optical camera components · CPC title