Object detection apparatus, object detection method, object detection program and device control system for moveable apparatus

• US 9,330,320 B2
• Filed: 04/09/2015
• Issued: 05/03/2016
• Est. Priority Date: 04/10/2014
• Status: Active Grant

• Current Assignee: Ricoh Company Limited
• Original Assignee: Ricoh Company Limited
• Inventors: Takahashi, Sadao, Yokota, Soichiro, Ishigaki, Tomoko
• Primary Examiner(s): Alavi, Amir
• Application Number:
  US14/682,496
• Publication Number:
  US 20150294160A1
• Time in Patent Office: 390 Days
• US Class Current: 1/1
• CPC Class Codes: G06T 11/206 Drawing of charts or graphs
• CPC Class Codes: G06T 2207/10012 Stereo images
• CPC Class Codes: G06T 2207/10021 Stereoscopic video; Stereoscopic image sequence
• CPC Class Codes: G06T 2207/30256 Lane; Road marking
• CPC Class Codes: G06T 2207/30261 Obstacle
• CPC Class Codes: G06T 7/20 Analysis of motion motion estimation for coding, decoding, compressing or decompressing digital video signals H04N19/43, H04N19/51
• CPC Class Codes: G06T 7/70 Determining position or orientation of objects or cameras camera calibration G06T7/80
• CPC Class Codes: G06V 20/56 exterior to a vehicle by using sensors mounted on the vehicle
• CPC Class Codes: H04N 13/204 using stereoscopic image cameras stereoscopic photography G03B35/00
• CPC Class Codes: H04N 13/239 using two 2D image sensors having a relative position equal to or related to the interocular distance H04N13/243 takes precedence
• CPC Class Codes: H04N 2013/0081 Depth or disparity estimation from stereoscopic image signals

Abstract

An object detection apparatus mountable to a moveable apparatus for detecting an object existing outside the moveable apparatus by capturing a plurality of images using a plurality of imaging devices mounted to the moveable apparatus and generating a disparity image from the captured images includes a map generator to generate a map indicating a frequency profile of disparity values correlating a horizontal direction distance of the object with respect to a movement direction of the moveable apparatus, and a distance to the object in the movement direction of the moveable apparatus based on the disparity image, an isolated area detection unit to detect an isolated area based on the frequency profile, an isolated area divider to divide the isolated area into two or more isolated areas based on the frequency profile in the isolated area, and an object detector to detect an object based on the divided isolated area.

Claims

1. An object detection apparatus mountable to a moveable apparatus for detecting an object existing outside the moveable apparatus by capturing a plurality of images using a plurality of imaging devices mounted to the moveable apparatus and generating a disparity image from the captured images, the object detection apparatus comprising:

a map generator to generate a map indicating a frequency profile of disparity values correlating a horizontal direction distance of the object with respect to a movement direction of the moveable apparatus, and a distance of the movable apparatus to the object in the movement direction of the moveable apparatus based on the disparity image;

an isolated area detection unit to detect an isolated area based on the frequency profile;

an isolated area divider to divide the isolated area into two or more isolated areas based on the frequency profile in the isolated area; and

an object detector to detect an object based on the divided isolated area.

2. The object detection apparatus of claim 1, wherein the isolated area divider includes a movement direction divider that divides the isolated area in the movement direction when a length of the isolated area in the movement direction is greater than a given value.

3. The object detection apparatus of claim 2, wherein the movement direction divider estimates an actual width of the object in the isolated area based on the frequency profile when the length of the isolated area in the movement direction is greater than a length variably settable depending on the distance of the movable apparatus to the object in the movement direction, and the movement direction divider determines a position used for dividing the isolated area based on the actual width and the disparity values of the frequency profile.

4. The object detection apparatus of claim 3, wherein the movement direction divider adds frequency values in the isolated area along the horizontal direction to detect a position in the movement direction corresponding to the maximum value of frequency based on the added frequency values, and estimates the maximum length of frequency connected at the detected position as the actual width of the object.

5. The object detection apparatus of claim 1, wherein the isolated area divider includes a horizontal direction divider that divides the isolated area in the horizontal direction when a length of the isolated area in the horizontal direction is greater than a given value.

6. The object detection apparatus of claim 5, wherein the map generator generates a map indicating a height profile of the disparity values, and the horizontal direction divider adds values of products, obtained by multiplying values of each of points on the real frequency U map and values of each of corresponding points on the real height U map of the isolated area along the movement direction, and determines one or more positions used for dividing the isolated area based on the added values.

7. The object detection apparatus of claim 1, wherein the map generator generates a map indicating a height profile of the disparity values, and the isolated area divider includes a peripheral area excluder that excludes one or more peripheral areas each having a low height in the isolated area.

8. A device control system mountable to a moveable apparatus, comprising;

the object detection apparatus of claim 1 to detect an object existing outside the moveable apparatus based on a disparity image generated from a plurality of images captured by a plurality of imaging devices mounted to the moveable apparatus; and

one or more device controllers to control one or more devices mounted to the moveable apparatus based on a result obtained by the object detection apparatus.

9. A method of detecting an object, existing outside a moveable apparatus by capturing a plurality of images using a plurality of imaging devices mounted to the moveable apparatus and generating a disparity image from the captured images, the method comprising the steps of:

generating a map indicating a frequency profile of disparity values correlating a horizontal direction distance of the object with respect to a movement direction of the moveable apparatus, and a distance to the object in the movement direction of the moveable apparatus based on the disparity image;

detecting an isolated area based on the frequency profile;

dividing the isolated area into two or more isolated areas based on the frequency profile in the isolated area; and

detecting an object based on the divided isolated area.

10. A non-transitory computer-readable storage medium storing a program that, when executed by a computer, causes the computer to execute a method of detecting an object, existing outside a moveable apparatus by capturing a plurality of images using a plurality of imaging devices mounted to the moveable apparatus and generating a disparity image from the captured images, the method comprising the steps of:

generating a map indicating a frequency profile of disparity values correlating a horizontal direction distance of the object with respect to a movement direction of the moveable apparatus, and a distance to the object in the movement direction of the moveable apparatus based on the disparity image;

detecting an isolated area based on the frequency profile;

dividing the isolated area into two or more isolated areas based on the frequency profile in the isolated area; and

detecting an object based on the divided isolated area.