Image Processing Device

• US 20150220793A1
• Filed: 07/22/2013
• Published: 08/06/2015
• Est. Priority Date: 07/27/2012
• Status: Active Grant

• Current Assignee: Clarion Co., Ltd. (Faurecia SA), Nissan Motor Co., Ltd.
• Original Assignee: Clarion Co., Ltd. (Faurecia SA), Nissan Motor Co., Ltd.
• Inventors: Kiyohara, Masahiro, Nakamura, Katsuyuki, Takemura, Masayuki, Irie, Kota, Hayakawa, Yasuhisa, Fukata, Osamu
• Granted Patent: US 9,721,169 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06V 20/56 exterior to a vehicle by using sensors mounted on the vehicle
• CPC Class Codes: G06V 20/58 Recognition of moving objects or obstacles, e.g. vehicles or pedestrians; Recognition of traffic objects, e.g. traffic signs, traffic lights or roads
• CPC Class Codes: G08G 1/166 for active traffic, e.g. moving vehicles, pedestrians, bikes
• CPC Class Codes: G08G 1/167 Driving aids for lane monitoring, lane changing, e.g. blind spot detection
• CPC Class Codes: H04N 23/51 Housings
• CPC Class Codes: H04N 7/18 Closed-circuit television [CCTV] systems, i.e. systems in which the video signal is not broadcast
• CPC Class Codes: H04N 7/183 for receiving images from a single remote source

Abstract

An image processing device includes: an image acquisition unit that obtains a photographic image of an area outside of a vehicle captured and output by a camera; a sun decision unit that calculates a sun position which indicates, at least, a solar elevation and makes a decision as to whether or not the solar elevation is equal to or lower than a predetermined elevation; an opacity detection unit that detects clouding of a lens surface of the camera; a vehicle detection unit that detects another vehicle, different from the vehicle, based upon image information of a first image area in the photographic image; and a control unit that suspends detection of the other vehicle by the vehicle detection unit if the opacity detection unit detects opacity in, at least, the first image area and the sun decision unit decides that the solar elevation is equal to or lower than the predetermined elevation.

Claims

1. An image processing device, comprising:

an image acquisition unit that obtains a photographic image of an area outside of a vehicle captured and output by a camera;

a sun decision unit that calculates a sun position which indicates, at least, a solar elevation and makes a decision as to whether or not the solar elevation is equal to or lower than a predetermined elevation;

an opacity detection unit that detects clouding of a lens surface of the camera;

a vehicle detection unit that detects another vehicle, different from the vehicle, based upon image information of a first image area in the photographic image; and

a control unit that suspends detection of the other vehicle by the vehicle detection unit if the opacity detection unit detects opacity in, at least, the first image area and the sun decision unit decides that the solar elevation is equal to or lower than the predetermined elevation.

2. An image processing device according to claim 1, wherein:

the vehicle detection unit has a predetermined threshold value pertaining to detection sensitivity with which the other vehicle is detected; and

if clouding manifests at the lens surface over a range corresponding to an image range centered on the sun position, the control unit adjusts the threshold value so as to lower the detection sensitivity for detection of the other vehicle relative to the detection sensitivity set when no clouding manifests over said range at the lens surface.

3. An image processing device according to claim 1, wherein:

the sun decision unit calculates the sun position based upon a date/time, a latitude and a longitude of a position taken by the vehicle and an orientation of the vehicle.

4. An image processing device according to claim 1, wherein:

the sun decision unit calculates the sun position by executing image processing on the photographic image.

5. An image processing device according to claim 4, wherein:

the camera captures an image of at least a road surface outside the vehicle; and

the sun decision unit extracts a high luminance area formed due to road surface reflection from the photographic image and calculates the sun position based upon a position of a gravitational center of the high luminance area.

6. An image processing device according to claim 2, wherein:

the control unit detects clouding at the lens surface over the range corresponding to the image range centered on the sun position based upon a luminance gradient in said image range.

7. An image processing device according to claim 1, wherein:

an opacity detection area is set in the photographic image; and

the opacity detection unit calculates a histogram of edge intensity for the opacity detection area and detects an area where clouding manifests at the camera lens based upon an average value of the edge intensity calculated by using the histogram.

8. An image processing device according to claim 7, wherein:

the camera captures an image of at least a road surface outside the vehicle;

a plurality of opacity detection areas are set near a vanishing point of a white line painted on the road surface; and

the opacity detection unit calculates histograms of edge intensity, each in correspondence to one of the opacity detection areas, and detects an area where clouding manifests at the camera lens based upon average values of the edge intensity each calculated by using one of the histograms.

9. An image processing device according to claim 7, wherein:

the camera captures an image of at least a road surface outside the vehicle;

the opacity detection area includes a first opacity detection area set near a vanishing point of a white line painted on the road surface at a position further upward relative to a center of the photographic image and a second opacity detection area set near the vanishing point so as to range further downward relative to the first opacity detection area; and

the opacity detection unit detects an area where clouding manifests at the camera lens by using the first opacity detection area during daytime and detects an area where clouding manifests at the camera lens by using the second opacity detection area during nighttime.

10. An image processing device according to claim 1, further comprising:

a notification control unit that engages a specific notification unit to report that detection of the other vehicle by the vehicle detection unit has been suspended by the control unit.

11. An image processing device according to claim 2, wherein:

the opacity detection unit detects clouding at the lens surface of the camera when a degree of opacity at the lens surface of the camera exceeds a first opacity degree;

the vehicle detection unit sets the threshold value to a first threshold value when the degree of opacity at the lens surface of the camera is a second opacity degree at which no clouding manifests at the lens surface;

the vehicle detection unit sets the threshold value to a second threshold value greater than the first threshold value when the degree of opacity at the lens surface of the camera exceeds the first opacity degree; and

the vehicle detection unit sets a third opacity degree, in correspondence to which the threshold value is set to a third threshold value smaller than both the first threshold value and the second threshold value, between the second opacity degree and the first opacity degree.