Ranging device utilizing image processing

• US 7,266,221 B2
• Filed: 09/24/2002
• Issued: 09/04/2007
• Est. Priority Date: 09/25/2001
• Status: Active Grant

• Current Assignee: Fujitsu Ten Limited (DENSO Corporation)
• Original Assignee: Fujitsu Ten Limited (DENSO Corporation)
• Inventors: Oka, Kenji, Oota, Akihiro, Shima, Nobukazu
• Primary Examiner(s): Johns; Andrew W.
• Assistant Examiner(s): MACKOWEY, ANTHONY M
• Application Number:
  US10/254,035
• Publication Number:
  US 20030081815A1
• Time in Patent Office: 1,806 Days
• Field of Search: 382/104, 382/105, 382/106, 382/154, 382/174, 382/206, 348/113, 348/118, 348/119, 348/148, 340/901, 340/903, 340/933, 340/934, 340/937
• US Class Current: 382/106
• CPC Class Codes: B60W 2420/403 Image sensing, e.g. optical camera
• CPC Class Codes: G06T 7/97 Determining parameters from multiple pictures depth or shape recovery from multiple images G06T7/55; stereo camera calibration G06T7/85
• CPC Class Codes: G06V 10/255 Detecting or recognising potential candidate objects based on visual cues, e.g. shapes
• 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: G06V 2201/08 Detecting or categorising vehicles

Abstract

An image size changing section obtains a size-changed image by changing the size of one of two original images captured by a pair of cameras. If an edge of an object has many oblique components, the edge is difficult to detect as a vertical edge but, when the image is horizontally reduced, an oblique edge becomes close to a vertical edge. For this reason, a feature end points are extracted with reliability by a feature extracting section and, thereby, an object is recognized and the distance to the object is determined reliably.

Claims

1. A ranging device utilizing image processing for recognizing an object in front of said ranging device to determine the distance to said object by processing images captured by a camera facing forward, comprising:

a density summing section for obtaining the sum of densities in the vertical direction of each of an image and a subsequent image captured by said camera;

a comparing section for comparing the sum of densities in the vertical direction of each of an image and a subsequent image;

a determining section for determining that the image of an object which causes an erroneous ranging is included, in one of said image and said subsequent image, when the difference between said sum of densities in the vertical direction of each of said image and said subsequent image is larger than a predetermined value, to output a signal; and

a ranging section for recognizing an object in front of said ranging device to determine the distance to said object while omitting images for which said signal is output.

2. The ranging device utilizing image processing of claim 1, wherein the object which causes said erroneous ranging is a windshield wiper.