Measuring apparatus

• US 20020181764A1
• Filed: 07/15/2002
• Published: 12/05/2002
• Est. Priority Date: 05/22/1997
• Status: Active Grant

• Current Assignee: Kabushiki Kaisha Topcon
• Original Assignee: Kabushiki Kaisha Topcon
• Inventors: Kochi, Nobuo, Otani, Hitoshi
• Granted Patent: US 7,016,528 B2
• Time in Patent Office: Days
• US Class Current: 382/154
• CPC Class Codes: G01C 21/005 with correlation of navigation data from several sources, e.g. map or contour matching G01C21/30 takes precedence
• CPC Class Codes: G06T 2207/10012 Stereo images
• CPC Class Codes: G06T 7/593 from stereo images
• 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

A preferred shape measuring apparatus comprises a characteristic pattern extracting portion, in accordance with a pair of first images of a subject for measurement having characteristic patterns serving as references provided thereon in different angles and a pair of second images of the subject for measurement having no characteristic patterns serving as references provided thereon in the same angles as with the fist images, for calculating the difference between the first image and the second image taken in each direction thereby obtaining the characteristic patterns, positional relationship calculating portion for obtaining a positional relationship between the pair of the first images or the pair of the second images on the basis of the difference images obtained in the characteristic pattern extracting portion, a stereo model forming portion, in accordance with the positional relationship obtained in the positional relationship calculating portion, for mutually relating the fist images or the second images so that a stereo model capable of being stereoscopically viewed is formed, and a shape measuring portion for obtaining the shape of the subject in accordance with the stereo model formed in the stereo model forming portion.

Claims

1. A shape measuring apparatus comprising:

a characteristic pattern extracting portion, in accordance with a pair of first images of a subject for measurement having characteristic patterns serving as references provided thereon in different angles and a pair of second images of the subject for measurement having no characteristic patterns serving as references provided thereon in the same angles as with the fist images, for calculating the difference between the first image and the second image taken in each direction thereby obtaining the characteristic patterns;

positional relationship calculating portion for obtaining a positional relationship between the pair of the first images or the pair of the second images on the basis of the difference images obtained in said characteristic pattern extracting portion;

a stereo model forming portion, in accordance with the positional relationship obtained in said positional relationship calculating portion, for mutually relating the fist images or the second images so that a stereo model capable of being stereoscopically viewed is formed; and

a shape measuring portion for obtaining the shape of the subject in accordance with the stereo model formed in said stereo model forming portion.

2. A shape measuring apparatus according to claim 1, wherein said characteristic pattern extracting portion is adapted to extract the characteristic pattern image through comparison of the difference image constituted of the difference between the first image and the second image taken in each direction with a reference characteristic pattern image previously stored.

3. A shape measuring apparatus according to claim 1, wherein said characteristic pattern extracting portion is adapted to extract the characteristic pattern image through comparison, according to a template matching method, of the difference image constituted of the difference between the first image and the second image taken in each direction with a reference characteristic pattern image previously stored.

4. A shape measuring apparatus according to claim 1, wherein said characteristic pattern extracting portion is adapted to extract the characteristic pattern image first by making coarse detection according to a template matching method and then making precise detection by applying predetermined processing to an image in the vicinity of a characteristic pattern.

5. An image forming apparatus for shape measurement comprising:

a characteristic pattern forming portion for selectively forming characteristic patterns serving as references on a subject for measurement; and

an image forming portion for taking images of a subject for measurement having characteristic patterns serving as references provided thereon in different directions thereby obtaining a pair of first images and taking images of the subject for measurement having no characteristic patterns serving as references provided thereon in the same directions as with the first images thereby obtaining a pair of second images.

6. An image forming apparatus for shape measurement according to claim 5, wherein said characteristic pattern forming portion is constituted of a characteristic pattern projecting portion for selectively projecting characteristic patterns serving as references onto a subject for measurement.

7. An image measuring apparatus comprising:

an approximate position measuring portion for approximately obtaining, from a pair of images of a subject for measurement in different directions, positional information of the subject for measurement in each of the images;

a data setting portion, having one image of the pair of images set as a reference image and the other image as a searched image, for setting up, in accordance with the positional information obtained in said approximate position measuring portion, reference data blocks in the reference image and setting up searched areas in the searched image and searched data blocks in the searched area; and

a correspondence determining portion for obtaining correspondence between the searched data block set up in the searched area and the reference data block, wherein

said data setting portion is adapted, in accordance with the positional information obtained in said approximate position measuring portion, to perform at least either setting up of the reference data blocks in the reference image or setting up of the searched areas and setting up of the searched data blocks in the searched image.

8. An image measuring apparatus according to claim 7, wherein

said pair of images include a characteristic pattern image of which positional information is previously known, and

said approximate position measuring portion is adapted, in accordance with the position of the characteristic pattern image in the reference image and the positional information of the characteristic pattern image in the searched image, to approximately obtain the positional information of the subject for measurement in each of the pair of images.

9. An image measuring apparatus according to claim 8, wherein said data setting portion is adapted to set up the range of the searched area in the searched image in accordance with the position of the characteristic pattern image in the searched image.

10. An image measuring apparatus according to claim 8, wherein said data setting portion is adapted to set up the range of the searched area in the searched image in accordance with its relationship with the position of the characteristic pattern image and the position of the searched area in the searched image or with the position of the characteristic pattern image and the position of the reference data block in the reference image.

11. An image measuring apparatus according to claim 8, wherein said data setting portion is adapted to set up the magnitude of the range of the searched area in the searched image in accordance with its relationship with the position of the characteristic pattern image and the position of the searched area in the searched image or with the position of the characteristic pattern image and the position of the reference data block in the reference image.

12. An image measuring apparatus according to claim 11, wherein said data setting portion is adapted to set up in the searched image the range of the searched area having a larger width or area according as the characteristic pattern image and the searched area in the searched image, or the characteristic pattern image and the reference data block in the reference image, are more distant from each other.

13. An image measuring apparatus according to claim 9, 10, 11, or 12, wherein said data setting portion is adapted to set up a plurality of searched areas differing in size.

14. An image measuring apparatus according to claim 8, wherein said data setting portion is adapted to set up the reference data block in the reference image in accordance with the position of the characteristic pattern image in the reference image.

15. An image measuring apparatus according to claim 8, wherein said data setting portion is adapted to set up the magnitude of the reference data block in the reference image in accordance with the position of the characteristic pattern image and the position of the reference data block in the reference image.

16. An image measuring apparatus according to claim 8, wherein said data setting portion is adapted to set up in the reference image the reference data block larger in height or width according as the position of the characteristic pattern image and the position of the reference data block in the reference image are more distant from each other.

17. An image measuring apparatus according to claim 14, 15, or 16, wherein said data setting portion is adapted to set up a plurality of reference data blocks differing in size in accordance with the characteristic pattern image in the reference image.