OBJECT DETECTION APPARATUS, VEHICLE-MOUNTED DEVICE CONTROL SYSTEM AND STORAGE MEDIUM OF PROGRAM OF OBJECT DETECTION

• US 20140254872A1
• Filed: 02/28/2014
• Published: 09/11/2014
• Est. Priority Date: 03/06/2013
• Status: Active Grant

• Current Assignee: Ricoh Company Limited
• Original Assignee: Ricoh Company Limited
• Inventors: GUAN, Haike
• Granted Patent: US 9,230,165 B2
• Time in Patent Office: Days
• US Class Current: 382/103
• CPC Class Codes: G06V 10/446 using Haar-like filters, e.g. using integral image techniques
• CPC Class Codes: G06V 10/50 by performing operations within image blocks; by using histograms, e.g. histogram of oriented gradients [HoG]; by summing image-intensity values; Projection analysis
• 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

Abstract

An object detection apparatus, using at least one processing circuit, for detecting an object in an image capturing area based on parallax information generated from a plurality of images captured by a plurality of image capturing units, includes a parallax histogram information generator to generate vertical-direction parallax histogram information indicating a frequency profile of parallax values in each of vertical row areas in a captured image based on the parallax information; and an object image area extraction unit to extract, among parallax values having frequency exceeding a given frequency threshold, a group of pixels having parallax values existing within proximity of a given parallax value and having a pixel-to-pixel interval in an image left-to-right direction within a given range as an object image area displaying an object based on the vertical-direction parallax histogram information.

Claims

1. An object detection apparatus, using at least one processing circuit, for detecting an object in an image capturing area based on parallax information generated from a plurality of images captured by a plurality of image capturing units, the object detection apparatus comprising;

a parallax histogram information generator to generate vertical-direction parallax histogram information based on the parallax information, the vertical-direction parallax histogram information indicating a frequency profile of parallax values in each of vertical row areas in a captured image, the vertical row area preparable by dividing the captured image in a plurality of areas in a left-right direction; and

an object image area extraction unit to extract, among parallax values having frequency exceeding a given frequency threshold, a group of pixels having parallax values existing within proximity of a given parallax value and having a pixel-to-pixel interval in an image left-to-right direction within a given range, as an object image area that includes an object for display, based on the vertical-direction parallax histogram information.

2. The object detection apparatus of claim 1, wherein the object image area extraction unit conducts Hough conversion to pixels having parallax values having frequency exceeding the given frequency threshold on a two dimensional coordinate system, defined by parallax values prepared from the vertical-direction parallax histogram information and image left-to-right direction positions, to extract a straight line extending in the image left-to-right direction,

wherein the object image area extraction unit extracts the group of pixels having parallax values existing within proximity of a given parallax value and having a pixel-to-pixel interval in the image left-to-right direction within a given range using the extracted straight line as a reference.

3. The object detection apparatus of claim 1, wherein the object image area extraction unit extracts the group of pixels as an object image area displaying an object on a parallax image prepared based on the parallax information.

4. The object detection apparatus of claim 1, further comprising a target object determination unit to determine whether an object, corresponded to the object image area extracted by the object image area extraction unit, is a target object.

5. The object detection apparatus of claim 4, further comprising:

an object width identifying unit to identify a width of an object, corresponded to the object image area, based on an image left-to-right direction length and parallax values of the object image area extracted by the object image area extraction unit,

wherein the target object determination unit determines whether the object, corresponded to the object image area extracted by the object image area extraction unit, is the target object based on the width of the object identified by the object width identifying unit.

6. The object detection apparatus of claim 4, wherein the target object determination unit determines whether the object, corresponded to the object image area extracted by the object image area extraction unit, is the target object based on luminance information of the object image area.

7. A vehicle-device control system comprising:

a plurality of image capturing units to capture an area outside a vehicle as an image capturing area;

the object detection apparatus of claim 1 to detect an object in the image capturing area based on a plurality of captured images captured by the plurality of image capturing units; and

a vehicle-device control unit to control one or more devices equipped to the vehicle based on a detection result of the object detection apparatus.

8. A method of detecting an object in an image capturing area based on parallax information, the method comprising the steps of:

1) generating parallax information based on a plurality of captured images captured by a plurality of image capturing units (generating step of parallax information);

2) generating vertical-direction parallax histogram information indicating a frequency profile of parallax values in each of vertical row areas in a captured image based on the parallax information, the vertical row area preparable by dividing the captured image in a plurality of areas in a left-right direction (generating step of vertical-direction parallax histogram information); and

3) extracting, among parallax values having frequency exceeding a given frequency threshold, a group of pixels having parallax values existing within proximity of a given parallax value and having a pixel-to-pixel interval in an image left-to-right direction within a given range as an object image area displaying an object, based on the vertical-direction parallax histogram information (extracting step of object image area).

9. A non-transitory computer-readable storage medium storing an object detection program that, when executed by a computer having a processing circuit, causes the computer to execute a method of detecting an object in an image capturing area based on parallax information, the method comprising the steps of:

1) generating parallax information based on a plurality of captured images captured by a plurality of image capturing units (generating step of parallax information);

2) generating vertical-direction parallax histogram information indicating a frequency profile of parallax values in each of vertical row areas in a captured image based on the parallax information, the vertical row area preparable by dividing the captured image in a plurality of areas in a left-right direction (generating step of vertical-direction parallax histogram information); and

3) extracting, among parallax values having frequency exceeding a given frequency threshold, a group of pixels having parallax values existing within proximity of a given parallax value and having a pixel-to-pixel interval in an image left-to-right direction within a given range as an object image area displaying an object, based on the vertical-direction parallax histogram information (extracting step of object image area).