APPROACHING OBJECT DETECTION SYSTEM

• US 20110228985A1
• Filed: 11/19/2009
• Published: 09/22/2011
• Est. Priority Date: 11/19/2008
• Status: Active Grant

• Current Assignee: Clarion Co., Ltd. (Faurecia SA)
• Original Assignee: Clarion Co., Ltd. (Faurecia SA)
• Inventors: Aoki, Toshiyuki, Uchida, Yoshitaka
• Granted Patent: US 8,712,097 B2
• Time in Patent Office: Days
• US Class Current: 382/103
• CPC Class Codes: G06T 2207/10016 Video; Image sequence
• CPC Class Codes: G06T 2207/20068 Projection on vertical or horizontal image axis
• CPC Class Codes: G06T 2207/20132 Image cropping
• CPC Class Codes: G06T 2207/30261 Obstacle
• CPC Class Codes: G06T 7/215 Motion-based segmentation

Abstract

An approaching object detection system, approaching object can be accurately detected while reducing the load on a calculation processing. A first moving region detection unit (30) detects (#3) only an optical flow substantially in horizontal direction in an image (P) captured by a camera (10) (#1) and sets (#4) a rectangular image portion (Q) containing a region moving in a substantially horizontal direction according to the detected optical flow. A second moving region detection unit (40) obtains a distribution (profile) of signal values of the set rectangular image portion (Q), (#5) in a vertical direction (longitudinal direction). Furthermore, the second moving region detection unit (40) correlates distributions of signal values of image portions (Q, Q) of two continuous images (P, P) in time series (#6) based on dynamic programming based processing to obtain an enlargement rate (#7). An approaching object determining unit (50) determines according to the enlargement rate whether the object is actually approaching.

Claims

1. An approaching object detection system comprising:

a camera which is mounted on a vehicle to capture an image in the vicinity of the vehicle;

a first moving region detection unit configured to perform, on a plurality of continuous images captured in time series by the camera, optical flow processing in which only a velocity vector in a certain direction in the images in time series is detected, to detect images portions of the images occupied by a moving object in the certain direction;

a second moving region detection unit configured to obtain distributions of image signal values of the image portions detected by the first moving region detection unit in a direction different from the certain direction and correlate the distributions of the continuous images in time series with each other to compute an enlargement rate of size of the image portions; and

an approaching object determining unit configured to determine, according to the enlargement rate, that a moving object corresponding to the image portions is an object approaching the camera, when the enlargement rate is increasing.

3. The approaching object detection system according to claim 1, wherein:

the certain direction is a direction within a predetermined range including a horizontal direction; and

the direction different from the certain direction is a vertical direction.

5. The approaching object detection system according to claim 1, wherein the first moving region detection unit is configured to exclude at least one of a sky region and a ground region from the image captured by the camera before detecting the image portion by the optical flow processing.

8. The approaching object detection system according to claim 1, further comprising:

a vehicle information acquiring unit configured to acquire vehicle information on a traveling condition of the vehicle including a vehicle speed; and

an image processing unit configured to correct, when the vehicle information indicates a movement of the vehicle, a size of the image in the continuous images in time series in such a direction as to reduce a change in size of an image according to the movement of the vehicle.

9. The approaching object detection system according to claim 8, wherein

the image processing unit is configured to change an enlargement rate of the image in the size correction according to a vehicle moving amount in the continuous images in time series.

10. The approaching object detection system according to claim 1,

wherein:

the first moving region detection unit includes a variation calculating unit configured to obtain a variation in shape of a region occupied by a moving object which has moved in the certain direction between continuous images in time series; and

the approaching object determining unit is configured to determine the moving object as a pedestrian when a variation in shape of the region is greater than a preset value.

11. The approaching object detection system according to claim 10, wherein

the variation calculating unit is configured to obtain a difference in area of regions occupied by a moving object which has moved in a certain direction in the continuous images in time series and set, as the variation, a value resulting from accumulation of the differences over the continuous images in time series.

2. (canceled)

4. (canceled)

6-7. -7. (canceled)