Distance measuring apparatus

• US 5,557,323 A
• Filed: 12/12/1994
• Issued: 09/17/1996
• Est. Priority Date: 12/14/1993
• Status: Expired due to Term

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Kajiwara, Yasuya
• Primary Examiner(s): Chin, Tommy P.
• Assistant Examiner(s): AU, AMELIA MEGAN
• Application Number:
  US08/354,483
• Time in Patent Office: 645 Days
• Field of Search: 348/116, 348/113, 348/140, 348/169, 348/170, 348/171, 348/172, 348/135, 348/142, 382/240, 382/270, 382/274, 382/106, 382/177, 382/205, 382/283, 382/282, 382/173, 382/291
• US Class Current: 348/140
• CPC Class Codes: G01S 11/12 using electromagnetic waves other than radio waves
• CPC Class Codes: H04N 13/10 Processing, recording or transmission of stereoscopic or multi-view image signals
• 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
• CPC Class Codes: H04N 2013/0092 Image segmentation from stereoscopic image signals

Abstract

A distance measuring apparatus sets a plurality of sub-windows in a picture plane so that the size of each sub-window having a contrast higher than a predetermined value is as small as possible but is greater than a minimum size. Therefore, it is possible to recognize the shape of an object and to measure a distance thereto with high resolution and high precision. For high speed processing, the sub-windows are successively updated in a predetermined cycle in such a manner that only those sub-windows which exist in a region in which a deviation of an image of the object last sensed relative to a previous image thereof is greater than a prescribed value are updated.

Claims

1. A distance measuring apparatus comprising:

image pick-up means for optically picking up an object at two different points to form a first and a second image;

window setting means for forming a window containing said first image and for successively splitting said window into a plurality of sub-windows in a repeated manner so that a contrast of each sub-window last split exceeds a predetermined value but the contrast thereof upon the next splitting becomes less than said predetermined value; and

distance calculation means for calculating a distance to said object through the principle of triangulation based on a deviation of said first and second images.

2. A distance measuring apparatus according to claim 1, wherein said window setting means ceases the splitting of said sub-windows when a size of each sub-window last split becomes less than a prescribed value.

3. A distance measuring apparatus according to claim 1, wherein said window setting means finds a deviation of an image of said object last pick up by said image pick-up means relative to a previous image thereof, and updates only those sub-windows which exist inside a region in which the deviation is greater than a prescribed value.

4. A distance measuring apparatus according to claim 2, wherein said window setting means finds a deviation of an image of said object last pick up by said image pick-up means relative to a previous image thereof, and updates only those sub-windows which exist inside a region in which the deviation is greater than a prescribed value.