Camera control device, control method, and program

Abstract

The purpose of the present disclosure is to provide: a camera control method with which the state of an image can be set to an optimal state for authentication in a shorter time even when the state of the image has changed drastically; a control method; and a non-transitory computer-readable medium. This camera control device (11) comprises: an area determining means (113) that determines, as a first area, a portion that includes an authentication target from a first image in which a surrounding environment is captured, determines, as a second area, a portion that includes the authentication target from a second image in which a control parameter of the camera control device (11) is set so that the state of the image of the authentication target is optimal for authenticating the authentication target, and determines, as a third area, a portion that includes the authentication target from a third image in which the surrounding environment has been captured further in the past than when the first image was captured; and a first difference calculating means (111) that calculates a first state difference that is the difference between a second state that represents the state of the image in the second area and a first state that represents the state of the image in the first area.

Claims

1. A region determination means that determines the portion containing the object to be authenticated as a first region from a first image taken of the surrounding environment, determines the portion containing the object to be authenticated as a second region from a second image taken after setting the optimal control parameters of the device so that the state of the image of the object to be authenticated is in the optimal state for authenticating the object to be authenticated, and determines the portion containing the object to be authenticated as a third region from a third image taken of the surrounding environment prior to when the first image was taken, A first difference calculation means calculates a first state difference, which is the difference between a second state indicating the state of the image in the second region and a first state indicating the state of the image in the first region. A second difference calculation means for calculating a second state difference, which is the difference between a third state representing the state of the image in the third region and the first state, When capturing the next first image, a control information determination means determines the value of the control parameter for capturing the next first image based on the sum of the first state difference and the second state difference, A camera control device equipped with the following features.

2. The second image is generated by capturing the surrounding environment with the optimal control parameters pre-set so that the state of the image of the object to be authenticated is in the optimal state for authenticating the object to be authenticated. The camera control device according to claim 1.

3. The state of the image includes at least one of the mean value of the brightness values ​​of the image, the variance of the brightness values, the standard deviation of the brightness values, and the histogram of the brightness values. The camera control device according to claim 1 or 2.

4. The system further comprises storage means for storing the state of the first image, the third image, and the second image of the image to be authenticated. A camera control device as described in claim 3.

5. Each of the control parameter and the optimal control parameter includes at least one of exposure time, sensitivity, and contrast. A camera control device according to any one of claims 1 to 4.

6. The control information determination means is Instead of the sum of the first state difference and the second state difference, we use the sum of the product of the first state difference and the first coefficient, and the product of the second state difference and the second coefficient. Based on the above sum, the value of the optimal control parameter is determined. A camera control device according to any one of claims 1 to 5.

7. The system further comprises a means for capturing the first image, the second image, and the third image. A camera control device according to any one of claims 1 to 6.

8. The authentication target is limited to a person's face. A camera control device according to any one of claims 1 to 7.

9. The first image, which captures the surrounding environment, determines the area containing the object to be authenticated as the first region, The optimal control parameters of the camera control device are set so that the state of the image to be authenticated is in the optimal state for authenticating the object to be authenticated, and the portion containing the object to be authenticated is determined as the second region from the captured second image. The third region is determined from a third image taken of the surrounding environment prior to the time the first image was taken, which includes the area to be authenticated. The first state difference is calculated as the difference between the second state, which indicates the state of the image in the second region, and the first state, which indicates the state of the image in the first region. The second state difference is calculated as the difference between the third state, which represents the state of the image in the third region, and the first state. When capturing the next first image, the value of the control parameter for capturing the next first image is determined based on the sum of the first state difference and the second state difference. A control method comprising the following features.

10. The first image, which captures the surrounding environment, determines the area containing the object to be authenticated as the first region, The optimal control parameters of the camera control device are set so that the state of the image to be authenticated is in the optimal state for authenticating the object to be authenticated, and the portion containing the object to be authenticated is determined as the second region from the captured second image. The third region is determined from a third image taken of the surrounding environment prior to the time the first image was taken, which includes the area to be authenticated. The first state difference is calculated as the difference between the second state, which indicates the state of the image in the second region, and the first state, which indicates the state of the image in the first region. The second state difference is calculated as the difference between the third state, which represents the state of the image in the third region, and the first state. When capturing the next first image, the value of the control parameter for capturing the next first image is determined based on the sum of the first state difference and the second state difference. A program that causes a computer to execute something.

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