Focus adjusting apparatus and method

• US 20100054723A1
• Filed: 06/29/2009
• Published: 03/04/2010
• Est. Priority Date: 09/04/2008
• Status: Active Grant

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Shiohara, Morito, Segawa, Eigo
• Granted Patent: US 7,873,268 B2
• Time in Patent Office: Days
• US Class Current: 396/128
• CPC Class Codes: G02B 7/36 using image sharpness techniques , e.g. image processing techniques for generating autofocus signals image data processing per se G06T; in cameras having a solid state image sensor H04N23/67
• CPC Class Codes: G03B 13/36 Autofocus systems
• CPC Class Codes: G06V 10/22 by selection of a specific region containing or referencing a pattern; Locating or processing of specific regions to guide the detection or recognition
• CPC Class Codes: G06V 20/54 of traffic, e.g. cars on the road, trains or boats
• CPC Class Codes: G06V 20/625 License plates
• CPC Class Codes: G06V 20/63 Scene text, e.g. street names
• CPC Class Codes: G08G 1/04 using optical or ultrasonic detectors
• CPC Class Codes: H04N 23/661 Transmitting camera control signals through networks, e.g. control via the Internet
• CPC Class Codes: H04N 23/673 based on contrast or high frequency components of image signals, e.g. hill climbing method

Abstract

A focus adjusting apparatus adjusts a focus of a camera imaging a moving object. The apparatus includes a calculating unit that calculates a first out-of-focus level of a portion corresponding to the moving object within a first region of an image picked up by the camera, and calculates a second out-of-focus level of a portion corresponding to the moving object within a second region of an image; and a focus adjusting unit that shifts the focus of the camera in a direction in which the camera is focused onto the portion corresponding to the moving object within the first region when the first out-of-focus level is larger than the second out-of-focus level, and that shifts the focus in a direction in which the camera is focused onto the portion corresponding to the moving object within the second region when the second out-of-focus level is larger than the first out-of-focus level.

Claims

1. A focus adjusting apparatus that adjusts a focus of a camera imaging a moving object, the focus adjusting apparatus comprising:

a calculating unit that calculates a first out-of-focus level of a portion corresponding to the moving object within a first region of an image picked up by the camera, and calculates a second out-of-focus level of a portion corresponding to the moving object within a second region of an image picked up by the camera; and

a focus adjusting unit that shifts the focus of the camera in a direction in which the camera is focused onto the portion corresponding to the moving object within the first region when the first out-of-focus level calculated by the calculating unit is larger than the second out-of-focus level calculated by the calculating unit, and that shifts the focus of the camera in a direction in which the camera is focused onto the portion corresponding to the moving object within the second region when the second out-of-focus level is larger than the first out-of-focus level.

2. The focus adjusting apparatus according to claim 1, wherein when both the first out-of-focus level calculated by the calculating unit and the second out-of-focus level calculated by the calculating unit are smaller than a certain reference, the focus adjusting unit adjusts the focus of the camera onto the same position as the current position.

3. The focus adjusting apparatus according to claim 1, wherein the calculating unit calculates the first out-of-focus level and the second out-of-focus level based on a high-frequency component of each of the portions corresponding to the moving object.

4. The focus adjusting apparatus according to claim 1, wherein the calculating unit calculates the first out-of-focus level and the second out-of-focus level based on contrast of each of the portions corresponding to the moving object.

5. The focus adjusting apparatus according to claim 1, wherein the calculating unit calculates the first out-of-focus level and the second out-of-focus level based on edge strength of each of the portions corresponding to the moving object.

6. A focus adjusting method of adjusting a focus of a camera imaging a moving object, the focus adjusting method comprising:

calculating a first out-of-focus level of a portion corresponding to the moving object within a first region of an image picked up by the camera;

calculating a second out-of-focus level of a portion corresponding to the moving object within a second region of an image picked up by the camera; and

shifting the focus of the camera in a direction in which the camera is focused onto the portion corresponding to the moving object within the first region when the first out-of-focus level calculated in the calculating of the first out-of-focus level is larger than the second out-of-focus level calculated in the calculating of the second out-of-level, and shifting the focus of the camera in a direction in which the camera is focused onto the portion corresponding to the moving object within the second region when the second out-of-focus level is larger than the first out-of-focus level.

7. A computer readable storage medium containing instructions for adjusting a focus of a camera imaging a moving object, wherein the instructions, when executed by a computer, causes the computer to perform:

calculating a first out-of-focus level of a portion corresponding to the moving object within a first region of an image picked up by the camera;

calculating a second out-of-focus level of a portion corresponding to the moving object within a second region of an image picked up by the camera; and

shifting the focus of the camera in a direction in which the camera is focused onto the portion corresponding to the moving object within the first region when the first out-of-focus level calculated in the calculating of the first out-of-focus level is larger than the second out-of-focus level calculated in the calculating of the second out-of-level, and shifting the focus of the camera in a direction in which the camera is focused onto the portion corresponding to the moving object within the second region when the second out-of-focus level is larger than the first out-of-focus level.