IMAGING APPARATUS

• US 20200137313A1
• Filed: 10/29/2019
• Published: 04/30/2020
• Est. Priority Date: 10/30/2018
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Sato, Natsuko, Chino, Shunsuke
• Granted Patent: US 11,343,432 B2
• Time in Patent Office: Days
• CPC Class Codes: H04N 23/58 Means for changing the camera field of view without moving the camera body, e.g. nutating or panning of optics or image sensors
• CPC Class Codes: H04N 23/673 based on contrast or high frequency components of image signals, e.g. hill climbing method
• CPC Class Codes: H04N 23/675 comprising setting of focusing regions
• CPC Class Codes: H04N 23/695 Control of camera direction for changing a field of view, e.g. pan, tilt or based on tracking of objects

Abstract

An imaging apparatus includes a controller configured to change a tilt angle between an image sensor and a plane orthogonal to an optical axis of an optical system by adjusting a tilt of the image sensor or the optical system, an evaluation value acquirer configured to acquire contrast evaluation values of a plurality of areas in an image by changing the tilt angle through the controller, and a determiner configured to determine the tilt angle for each of the plurality of areas based on the contrast evaluation values of the plurality of areas acquired by the evaluation value acquirer, and to determine the tilt angle based on the tilt angle of each determined area. The controller adjusts the tilt of the image sensor or the optical system based on the tilt angle determined by the determiner.

Claims

1. An imaging apparatus comprising:

a controller configured to change a tilt angle between an image sensor and a plane orthogonal to an optical axis of an optical system by adjusting a tilt of the image sensor or the optical system;

an evaluation value acquirer configured to acquire contrast evaluation values of a plurality of areas in an image by changing the tilt angle through the controller; and

a determiner configured to determine the tilt angle for each of the plurality of areas based on the contrast evaluation values of the plurality of areas acquired by the evaluation value acquirer, and to determine the tilt angle based on the tilt angle of each determined area,

wherein the controller adjusts the tilt of the image sensor or the optical system based on the tilt angle determined by the determiner.

2. The imaging apparatus according to claim 1, wherein each of the plurality of areas includes one or more pixels.

3. The imaging apparatus according to claim 2, wherein the determiner acquires an optimal tilt angle for each of the plurality of areas corresponding to a maximum evaluation value among the evaluation values of the plurality of areas, and determines an optimal tilt angle having the most types among the plurality of optimal tilt angles, and determines the optimal tilt angle that is determined to be the optimal tilt angle having the most types.

4. The imaging apparatus according to claim 3, wherein the determiner determines a plurality of optimal tilt angles within a predetermined angular range as the same type of optimal tilt angle.

5. The imaging apparatus according to claim 4, wherein the predetermined angular range is determined based on a depth of focus calculated using at least one of a focal length, an object distance, a size of the image sensor, a light source, a temperature, and a humidity.

6. The imaging apparatus according to claim 3, wherein the determiner determines the optimal tilt angle having the most types among the plurality of optimal tilt angles.

7. The imaging apparatus according to claim 3, wherein the determiner determines a tilt angle belonging to a predetermined angular range in which the most optimal tilt angles are present among the plurality of optimal tilt angles.

8. The imaging apparatus according to claim 7, wherein the determiner calculates the tilt angle based on at least one of a minimum value, a maximum value, an average value, and a tilt angle corresponding to an absolute value larger than a predetermined value of the maximum evaluation value among the predetermined angular range.

9. The imaging apparatus according to claim 8, wherein the average value is calculated by weighting such that a tilt angle corresponding to an evaluation value having a difference larger than a predetermined value between the maximum value and the minimum value can be advantageous.

10. The imaging apparatus according to claim 9, wherein an average value is calculated by weighting such that a tilt angle corresponding to an evaluation value having a steep peak shape can be advantageous.

11. The imaging apparatus according to claim 3, wherein the controller excludes from the area determined by the determiner an area where an optimal tilt angle with a low reliability is obtained among the plurality of areas.

12. The imaging apparatus according to claim 11, wherein the controller determines an area near a rotational axis of the image sensor as the area where the optimal tilt angle with the low reliability is obtained.

13. The imaging apparatus according to claim 11, wherein the controller determines an area where a difference value between a maximum value and a minimum value of the evaluation value is determined to be smaller than a predetermined value, as the area where the optimal tilt angle with the low reliability is obtained.

14. The imaging apparatus according to claim 11, wherein the controller determines an area determined to have a plurality of peaks of the evaluation value, as the area where the optimal tilt angle with the low reliability is obtained.

15. The imaging apparatus according to claim 11, wherein the controller determines an area determined to have an object having a luminance value equal to or higher than a predetermined value, as the area where the optimal tilt angle with the low reliability is obtained.