Wrinkle detection method and electronic device

1. A wrinkle detection method, comprising:

rotating, according to some or all preset angles in a preset angle set, a region of a face image, in which a wrinkle will be detected, to obtain a plurality of to-be-detected images, wherein the preset angle set comprises a plurality of preset angles, and values of the preset angles are different;

determining wrinkle points from all pixel points of each to-be-detected image of the plurality of to-be-detected images based on grayscale values of the pixel points in each to-be-detected image of the plurality of to-be-detected images;

determining at least one wrinkle line from the plurality of to-be-detected images based on the wrinkle points, wherein each of the at least one wrinkle line indicates one wrinkle in each to-be-detected image of the plurality of to-be-detected images;

performing, for the at least one wrinkle line corresponding to each to-be-detected image, reverse rotation according to a preset angle based on which the to-be-detected image is obtained, to obtain rotated wrinkle lines;

fusing the rotated wrinkle lines into the region in which the wrinkle will be detected, to obtain a wrinkle line corresponding to the region in which the wrinkle will be detected;

displaying the wrinkle line in the region;

determining a wrinkle score corresponding to the region in which the wrinkle will be detected based on a feature set of the displayed wrinkle line, wherein the feature set comprises the following features: a length of the wrinkle line, a width of the wrinkle line, and a contrast ratio value of a pixel point on the wrinkle line, and an area proportion of the wrinkle line, wherein the contrast ratio value represents a contrast ratio of the pixel point on the wrinkle line, and the area proportion of the wrinkle line represents a proportion of a quantity of pixels on the wrinkle line to a quantity of all pixels in the to-be-detected image; and

outputting the wrinkle score, wherein the wrinkle score is determined according to the following formula:

H=A×ω 1+ B×ω 2+ C×ω 3+ D×ω 4+ω5, wherein

H is the wrinkle score, A is the length of the wrinkle line, B is the width of the wrinkle line, C is the contrast ratio value of the pixel point on the wrinkle line, D is the area proportion of the wrinkle line, ω1, ω2, ω3, and ω4 are preset parameters less than o, and ω5 is a preset parameter.

2. The method of claim 1 , wherein determining the wrinkle points from all the pixel points of each to-be-detected image of the plurality of to-be-detected images based on the grayscale values of the pixel points in each to-be-detected image of the plurality of to-be-detected images comprises:

setting a rectangular window;

controlling, according to a specified sliding step, the rectangular window to traverse each to-be-detected image of the plurality of to-be-detected images;

determining, at each window position in which the rectangular window is located, a central pixel point located at a central position of the rectangular window, and determining a confidence value of the central pixel point based on grayscale values of all pixel points in the rectangular window, to obtain a plurality of confidence values, wherein each confidence value indicates a possibility that the central pixel point is the wrinkle point; and

using a central pixel point corresponding to a confidence value not less than a threshold as the wrinkle point.

3. The method of claim 2 , wherein both a length and a width of the rectangular window are N pixels; and determining the central pixel point located at the central position of the rectangular window, and determining the confidence value of the central pixel point based on the grayscale values of all pixel points in the rectangular window comprises:

determining the confidence value of the central pixel point located at the central position of the rectangular window according to the following formula:

M

=

∑

i

,

j

=

1

N

⁢

⁢

P

ij

*

Q

ij

,

wherein

M represents the confidence value of the central pixel point at the central position of the rectangular window, P ij represents an element located in row i and column j in a first matrix, and Q ij represents an element located in row i and column j in a second matrix, wherein the first matrix is a preset N×N matrix, elements in each row in the first matrix are the same, and the element in row i and column j in the second matrix is a grayscale value of a pixel point in row i and column j in the rectangular window, wherein 1≤i≤N, 1≤j≤N, N is an odd number, and N is greater than or equal to 3.

4. The method of claim 3 , wherein an expression of the first matrix is:

P

=

[

n

1

n

1

n

1

n

0

n

0

n

0

n

1

n

1

n

1

]

,

wherein

P is the first matrix, and n o >n 1 ; or

P

=

[

n

1

n

1

n

1

n

0

n

0

n

0

n

1

n

1

n

1

]

,

wherein

P is the first matrix, and n o <n 1 ; or

P

=

[

n

x

n

x

n

x

…

n

x

n

x

-

1

n

x

-

1

n

x

-

1

…

n

x

-

1

…

…

…

…

…

n

0

n

0

n

0

…

n

0

…

…

…

…

…

n

x

-

1

n

x

-

1

n

x

-

1

…

n

x

-

1

n

x

n

x

n

x

…

n

x

]

,

wherein

P is the first matrix, n u >n u-1 , u is an integer and 1≤u≤x,

x

=

N

-

1

2

,

and N is greater than 3; or

P

=

[

n

x

n

x

n

x

…

n

x

n

x

-

1

n

x

-

1

n

x

-

1

…

n

x

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1

…

…

…

…

…

n

0

n

0

n

0

…

n

0

…

…

…

…

…

n

x

-

1

n

x

-

1

n

x

-

1

…

n

x

-

1

n

x

n

x

n

x

…

n

x

]

,

wherein

P is the first matrix, n u <n u-1 , u is an integer and 1≤u≤x,

x

=

N

-

1

2

,

and N is greater than 3.

5. The method of claim 2 , wherein the threshold is an average value of the plurality of confidence values.

6. The method of claim 1 , wherein determining the at least one wrinkle line from the plurality of to-be-detected images based on the wrinkle points comprises:

determining a contour line of at least two consecutive wrinkle points in the wrinkle points;

determining straight line segments in the contour line; and

using some or all of the straight line segments as the wrinkle line.

7. The method of claim 1 , wherein the wrinkle line meets one or more of the following conditions:

a size of the wrinkle line is not less than a preset pixel size; and

an included angle between a connection line of two farthest pixel points on the wrinkle line and a horizontal direction is not greater than a preset included angle.

8. The method of claim 1 , wherein displaying the at least one wrinkle line in the region comprises:

displaying, in the region, all wrinkle lines determined based on all the to-be-detected images.

9. An electronic device, comprising:

a non-transitory memory comprising instructions; and

a processor coupled to the non-transitory memory, the instructions being executed by the processor to cause the electronic device to:

rotate, according to some or all preset angles in a preset angle set, a region of a face image, in which a wrinkle will be detected, to obtain a plurality of to-be-detected images, wherein the preset angle set comprises a plurality of preset angles, and values of the preset angles are different;

determine wrinkle points from all pixel points of each to-be-detected image of the plurality of to-be-detected images based on grayscale values of the pixel points in each to-be-detected image of the plurality of to-be-detected images;

determine at least one wrinkle line from the plurality of to-be-detected images based on the wrinkle points, wherein each of the at least one wrinkle line indicates one wrinkle in each to-be-detected image of the plurality of to-be-detected images;

perform, for the at least one wrinkle line corresponding to each to-be-detected image, reverse rotation according to a preset angle based on which the to-be-detected image is obtained, to obtain rotated wrinkle lines;

fuse the rotated wrinkle lines into the region in which the wrinkle will be detected, to obtain a wrinkle line corresponding to the region in which the wrinkle will be detected;

display the wrinkle line in the region;

determine a wrinkle score corresponding to the region in which the wrinkle will be detected based on a feature set of the wrinkle line, wherein the feature set comprises the following features: a length of the wrinkle line, a width of the wrinkle line, and a contrast ratio value of a pixel point on the wrinkle line, and an area proportion of the wrinkle line, wherein the contrast ratio value represents a contrast ratio of the pixel point on the wrinkle line, and the area proportion of the wrinkle line represents a proportion of a quantity of pixels on the wrinkle line to a quantity of all pixels in the to-be-detected image; and

output the wrinkle score, wherein the wrinkle score is determined according to the following formula:

H=A×ω 1 +B×ω 2 +C×ω 3 +D×ω 4+ω5, wherein

H is the wrinkle score, A is the length of the wrinkle line, B is the width of the wrinkle line, C is the contrast ratio value of the pixel point on the wrinkle line, D is the area proportion of the wrinkle line, ω1, ω2, ω3, and ω4 are preset parameters less than o, and ω5 is a preset parameter.

10. The electronic device of claim 9 , wherein the instructions further cause the electronic device to:

set a rectangular window;

control, according to a specified sliding step, the rectangular window to traverse each to-be-detected image of the plurality of to-be-detected images;

determine, at each window position in which the rectangular window is located, a central pixel point located at a central position of the rectangular window, and determine a confidence value of the central pixel point based on grayscale values of all pixel points in the rectangular window, to obtain a plurality of confidence values, wherein the confidence value indicates a possibility that the central pixel point is the wrinkle point; and

use a central pixel point corresponding to a confidence value not less than a threshold as the wrinkle point.

11. A computer program product for speckle detecting, the computer program product being embodied in a non-transitory computer readable medium and comprising computer instructions for:

rotating, according to some or all preset angles in a preset angle set, a region of a face image, in which a wrinkle will be detected, to obtain a plurality of to-be-detected images, wherein the preset angle set comprises a plurality of preset angles, and values of the preset angles are different;

determining wrinkle points from all pixel points of each to-be-detected image of the plurality of to-be-detected images based on grayscale values of the pixel points in each to-be-detected image of the plurality of to-be-detected images;

determining at least one wrinkle line from the plurality of to-be-detected images based on the wrinkle points, wherein each of the at least one wrinkle line indicates one wrinkle in each to-be-detected image of the plurality of to-be-detected images;

performing, for the at least one wrinkle line corresponding to each to-be-detected image, reverse rotation according to a preset angle based on which the to-be-detected image is obtained, to obtain rotated wrinkle lines;

fusing the rotated wrinkle lines into the region in which the wrinkle will be detected, to obtain a wrinkle line corresponding to the region in which the wrinkle will be detected; and

displaying the wrinkle line in the region;

determining a wrinkle score corresponding to the region based on a feature set of the displayed wrinkle line, wherein the feature set comprises the following features: a length of the wrinkle line, a width of the wrinkle line, and a contrast ratio value of a pixel point on the wrinkle line, and an area proportion of the wrinkle line, wherein the contrast ratio value represents a contrast ratio of the pixel point on the wrinkle line, and the area proportion of the wrinkle line represents a proportion of a quantity of pixels on the wrinkle line to a quantity of all pixels in the to-be-detected image; and

outputting the wrinkle score, wherein the wrinkle score is determined according to the following formula:

H=A×ω 1 +B×ω 2 +C×ω 3 +D×ω 4+ω5, wherein

H is the wrinkle score, A is the length of the wrinkle line, B is the width of the wrinkle line, C is the contrast ratio value of the pixel point on the wrinkle line, D is the area proportion of the wrinkle line, ω1, ω2, ω3, and ω4 are preset parameters less than o, and ω5 is a preset parameter.

12. The computer program product of claim 11 , the computer program product further comprising computer instructions for:

setting a rectangular window;

controlling, according to a specified sliding step, the rectangular window to traverse each to-be-detected image of the plurality of to-be-detected images;

determining, at each window position in which the rectangular window is located, a central pixel point located at a central position of the rectangular window, and determining a confidence value of the central pixel point based on grayscale values of all pixel points in the rectangular window, to obtain a plurality of confidence values, wherein the confidence value indicates a possibility that the central pixel point is the wrinkle point; and

using a central pixel point corresponding to a confidence value not less than a threshold as the wrinkle point.