Regulation method, terminal equipment and non-transitory computer-readable storage medium for automatic exposure control of region of interest

1. A regulation method for automatic exposure control (AEC) of a region of interest, comprising:

obtaining a luminance histogram of each color channel in a region of interest based on statistics on luminance of a plurality of sub-region blocks in the region of interest, a luminance histogram of a color channel comprising a corresponding relationship between a luminance and a number of sub-region blocks of the color channel;

determining a first luminance of the each color channel according to the luminance histogram of the each color channel in the region of interest and the corresponding relationship between the luminance and the number of the sub-region blocks, the first luminance being associated with a present AEC luminance;

determining a reference luminance based on the first luminance of the each color channel, the reference luminance corresponding to a reference color channel;

obtaining a target luminance corresponding to the present AEC luminance; and

performing a luminance regulation on the reference color channel according to the target luminance.

2. The method as claimed in claim 1 , further comprising:

obtaining an area of the region of interest;

determining a total number of the plurality of sub-region blocks corresponding to the area of the region of interest according to division granularity information, the division granularity information comprising a correspondence between a total number of sub-region blocks and an area of a region of interest, or according to division ratio information, the division ration information comprising a first ratio of a total number of sub-region blocks to an area of a region of interest; and

dividing the region of interest into the plurality of sub-region blocks according to the total number of the plurality of sub-region blocks.

3. The method as claimed in claim 1 , wherein determining the first luminance of the each color channel comprises:

determining a lowest luminance of the each color channel which meets a requirement of the present AEC luminance according to the luminance histogram of the each color channel in the region of interest and the corresponding relationship between the luminance and the number of the sub-region blocks.

4. The method as claimed in claim 3 , wherein determining the lowest luminance of the each color channel which meets the requirement of the present AEC luminance according to the luminance histogram of the each color channel in the region of interest and the corresponding relationship between the luminance and the number of the sub-region blocks comprises:

determining a total luminance value of the each color channel within a luminance range according to a descending order of the luminance based on the luminance histogram of the each color channel and the corresponding relationship between the luminance and the number of the sub-region blocks; and

determining the lowest luminance of the each color channel which meets the requirement of the present AEC luminance according to the total luminance value, the luminance range and the present AEC luminance.

5. The method as claimed in claim 4 , wherein determining the lowest luminance of the each color channel which meets the requirement of the present AEC luminance according to the total luminance value, the luminance range and the present AEC luminance comprises:

determining a minimum luminance in the luminance range within which the total luminance value is equal to the present AEC luminance or is larger than the present AEC luminance for a first time to be the lowest luminance of the each color channel which meets the requirement of the present AEC luminance.

6. The method as claimed in claim 1 , wherein determining the reference luminance based on the first luminance of the each color channel comprises:

determining a maximum value in the first luminance of the each color channel as the reference luminance.

7. The method as claimed in claim 1 , wherein obtaining the target luminance corresponding to the present AEC luminance comprises:

obtaining a second luminance corresponding to the present AEC luminance based on first preset AEC information, the second luminance serving as the target luminance.

8. The method as claimed in claim 7 , wherein the method further comprises:

obtaining third luminance corresponding to the second luminance by adopting a gamma curve corresponding to the second luminance.

9. The method as claimed in claim 1 , wherein obtaining the target luminance corresponding to the present AEC luminance comprises:

determining a sum of the numbers of sub-region blocks corresponding to respective luminance between the reference luminance and a luminance peak;

determining a second ratio of the sum to a total number of the plurality of sub-region blocks in the region of interest; and

obtaining fourth luminance corresponding to the second ratio based on third preset AEC information, the fourth luminance serving as the target luminance.

10. The method as claimed in claim 1 , wherein performing the luminance regulation on the reference color channel according to the target luminance comprises:

performing luminance convergence regulation on the reference color channel according to the target luminance.

11. The method as claimed in claim 1 , wherein the region of interest comprises at least one of: a face region, a sky region or a building region.

12. The method as claimed in claim 1 , wherein the method further comprises:

determining the region of interest.

13. The method as claimed in claim 12 , wherein determining the region of interest comprises:

performing subject identification on an image to identify the region of interest where a subject is positioned.

14. The method as claimed in claim 12 , wherein determining the region of interest comprises:

performing contour extraction on an image to identify the region of interest where a subject is positioned.

15. The method as claimed in claim 14 , wherein performing contour extraction on the image to identify the region of interest where the subject is positioned comprises:

performing a depth information extraction on the image based on corresponding depth information, and determining a contour where the region of interest is positioned according to the different depth information of the region of interest and other regions to determine a position of the contour as the region of interest where the subject is positioned.

16. The method as claimed in claim 12 , wherein determining the region of interest comprises:

displaying a preview image in an image previewing region and receiving a selection over the region of interest in the image previewing region.

17. Terminal equipment, comprising:

at least one processor; and

a computer readable storage, coupled to the at least one processor and storing at least one computer executable instructions thereon, which when the at least one computer executable instructions is executed by the at least one processor, cause the at least one processor to carry out following actions:

dividing the region of interest into a plurality of sub-region blocks, and obtaining a luminance histogram of each color channel in the region of interest based on statistics on luminance of the plurality of sub-region blocks in the region of interest, a luminance histogram of a color channel comprising a corresponding relationship between a luminance and a number of sub-region blocks of the color channel;

determining lowest luminance of each color channel which meets present automatic exposure control (AEC) luminance according to the luminance histogram of the each color channel and the corresponding relationship between the luminance and the number of the sub-region blocks;

obtaining a maximum value from the lowest luminance of respective color channels to determine reference luminance, and obtaining a reference color channel corresponding to the reference luminance;

obtaining a target luminance corresponding to the present AEC luminance; and

performing luminance convergence regulation on the reference color channel according to the target luminance.

18. The terminal equipment as claimed in claim 17 , wherein obtaining the target luminance corresponding to the present AEC luminance comprises:

querying first preset AEC information to obtain a second luminance corresponding to the present AEC luminance, the second luminance serving as the target luminance; or,

calculating a sum of the numbers of sub-region blocks corresponding to respective luminance between the reference luminance and a luminance peak; calculating a second ratio of the sum to a total number of the plurality of sub-region blocks in the region of interest; and querying third preset AEC information to obtain fourth luminance corresponding to the second ratio, the fourth luminance serving as the target luminance.

19. A non-transitory computer-readable storage medium, on which a computer program is stored, wherein the computer program is executed by a processor to carry out following actions:

obtaining a luminance histogram of each color channel in a region of interest based on statistics on luminance of a plurality of sub-region blocks in the region of interest, a luminance histogram of a color channel comprising a corresponding relationship between a luminance and a number of sub-region blocks of the color channel;

determining a first luminance of the each color channel according to the luminance histogram of the each color channel in the region of interest and the corresponding relationship between the luminance and the number of the sub-region blocks, the first luminance being associated with a present automatic exposure control (AEC) luminance;

determining a reference luminance based on the first luminance of the each color channel, the reference luminance corresponding to a reference color channel;

obtaining a target luminance corresponding to the present AEC luminance; and

performing a luminance regulation on the reference color channel according to the target luminance.

20. The non-transitory computer-readable storage medium as claimed in claim 19 , further comprising:

obtaining an area of the region of interest;

determining a total number of the plurality of sub-region blocks corresponding to the area of the region of interest according to division granularity information, the division granularity information comprising a correspondence between a total number of sub-region blocks and an area of a region of interest, or according to division ratio information, the division ration information comprising a first ratio of a total number of sub-region blocks to an area of a region of interest; and

dividing the region of interest into the plurality of sub-region blocks according to the total number of the plurality of sub-region blocks.