Device and method for position measurement

• US 7,860,273 B2
• Filed: 09/28/2007
• Issued: 12/28/2010
• Est. Priority Date: 09/29/2006
• Status: Active Grant

• Current Assignee: Topcon Corporation
• Original Assignee: Topcon Corporation
• Inventors: Sato, Hirokazu, Kochi, Nobuo, Anai, Tetsuji, Otani, Hitoshi
• Primary Examiner(s): AZARIAN, SEYED H
• Application Number:
  US11/905,404
• Publication Number:
  US 20080095402A1
• Time in Patent Office: 1,187 Days
• Field of Search: 382/100, 382/103, 382/104, 382/106, 382/107, 382/154, 382/168, 382/181, 382190-194, 382/199, 382/209, 382/232, 382/254, 382/274, 382/276, 382/286, 382291-295, 382/305, 382/312, 396/55, 348/218.1, 348/188, 348/207.99, 348/223.1, 348/187, 348/129, 340/435
• US Class Current: 382/103
• CPC Class Codes: G01C 11/00 Photogrammetry or videogrammetry, e.g. stereogrammetry; Photographic surveying
• CPC Class Codes: G01C 11/10 using computers to control the position of the pictures
• 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: G01C 21/1656 with passive imaging devices, e.g. cameras
• CPC Class Codes: G06T 2207/10021 Stereoscopic video; Stereoscopic image sequence
• CPC Class Codes: G06T 2207/30252 Vehicle exterior; Vicinity of vehicle
• CPC Class Codes: G06T 7/248 involving reference images or patches
• CPC Class Codes: G06T 7/593 from stereo images
• CPC Class Codes: G06T 7/74 involving reference images or patches

Abstract

A position measurement device is provided that can precisely measure the photographing position or posture of a photographing device or the coordinates of an object based on sequentially changing photographed images. A position measuring device 100 of the invention comprises: an image acquisition section 2 for acquiring a series of photographed images changing continuously or little by little along with position displacement relative to an object to be photographed; a positional relationship measurement section 9 for measuring position displacement and posture change of the image acquisition section 2; a feature extraction section 3 for extracting feature points from the photographed images obtained with the image acquisition section 2; a feature point tracking section 4 for tracking the feature points by searching corresponding points corresponding to the feature points on a plurality of the photographed images; an image selection section 61 for selecting an image to be processed from the series of photographed images based on a measurement result made with the positional relationship measurement section 9; and a position measurement section 7 for measuring the photographing position and the photographing posture of the image acquisition section 2 based on the image to be processed selected with the image selection section 61.

Claims

1. A position measuring device comprising:

an image acquisition section for acquiring a series of photographed images changing continuously or changing little by little along with position displacement relative to an object to be photographed;

a positional relationship measurement section for measuring position displacement and posture change of the image acquisition section;

a feature extraction section for extracting feature points from the photographed images obtained with the image acquisition section;

a feature point tracking section for tracking the feature points by searching corresponding points corresponding to the feature points on a plurality of the photographed images;

an image selection section for selecting an image to be precessed from the series of photographed images based on a measurement result made with the positional relationship measurement section; and

a position measurement section for measuring the photographing position and photographing posture of the image acquisition section or position of the photographed object based on the image to be processed selected with the image selection section.

2. The position measuring device of claim 1, wherein the image selection section selects the image to be processed based on the measurement data on the displacement direction and/or displacement amount obtained with the positional relationship measurement section.

3. The position measuring device of claim 2, wherein the image selection section selects the images to be processed between photographed image acquisition with the image acquisition section and feature point extraction with the feature extraction section.

4. The position measuring device of claim 1, wherein the positional relationship measurement section includes a gyroscope, an accelerometer, and a geomagnetism sensor.

5. The position measuring device of claim 1, wherein the feature point tracking section, when tracking feature points, is capable of changing search width direction or search width size.

6. The position measuring device of claim 1, comprising a display section for displaying on a screen displacement direction and displacement speed of feature points on the photographed image from a result of tracking made with the feature point tracking section.

7. The position measuring device of claim 1, comprising a comparing section for comparing the information on the photographing position and photographing posture measured with the position measurement section with the information on the photographing position and photographing posture obtained with the positional relationship measurement section, or for comparing the information on the position of the photographed object measured with the position measurement section with the information on the position of the photographed object obtained with the positional relationship measurement section.

8. A position measuring device comprising:

an image acquisition section for acquiring a series of photographed images changing continuously or changing little by little along with position displacement relative to an object to be photographed;

a positional relationship measurement section for measuring displacement and posture change of the image acquisition section;

a feature extraction section for extracting feature points from the photographed images obtained with the image acquisition section;

a feature point tracking section for tracking the feature points by searching corresponding points corresponding to the feature points on a plurality of the photographed images;

a feature point selection section for selecting feature points to be processed from the feature points extracted from the photographed images based on a measurement result made with the positional relationship measurement section; and

a position measurement section for measuring the photographing position and photographing posture of the image acquisition section or position of the photographed object based on the image to be processed selected with the image selection section.

9. The position measuring device of claim 8, wherein the feature point selection section selects feature points, with their displacement direction and displacement amount obtained from tracking data with the feature point tracking section falling within a specified range including the displacement direction and displacement amount obtained with the positional relationship measurement section, as the object points to be processed.

10. The position measuring device of claim 9, comprising an image selection section for selecting images to be processed from the series of photographed images based on a measurement result made with the positional relationship measurement section, wherein the image selection section selects an image having relatively many feature points to be processed, as the image to be processed.

11. The position measuring device of claim 9, wherein the feature point selection section selects the feature points to be processed during feature point tracking with the feature point tracking section, or between feature point tracking with the feature point tracking section and position measurement with the position measurement section.

12. The position measuring device of claim 8, wherein the feature point selection section selects feature points, with the approximate distance between the image acquisition section and the feature point determined from measurement data obtained with the positional relationship measurement section falling within a specified range, as the feature points to be processed.

13. The position measuring device of claim 12, comprising an image selection section for selecting images to be processed from the series of photographed images based on a measurement result made with the positional relationship measurement section, wherein the image selection section selects an image having relatively many feature points to be processed, as the image to be processed.

14. The position measuring device of claim 12, wherein the feature point selection section selects the feature points to be processed either during feature point tracking with the feature point tracking section, between feature point extraction with the feature extraction section and feature point tracking with the feature point tracking section, or between feature point tracking with the feature point tracking section and position measurement with the position measurement section.

15. The position measuring device of claim 8, wherein the positional relationship measurement section includes a gyroscope, an accelerometer, and a geomagnetism sensor.

16. The position measuring device of claim 8, wherein the feature point tracking section, when tracking feature points, is capable of changing search width direction or search width size.

17. The position measuring device of claim 8, comprising a display section for displaying on a screen displacement direction and displacement speed of feature points on the photographed image from a result of tracking made with the feature point tracking section.

18. The position measuring device of claim 8, comprising a comparing section for comparing the information on the photographing position and photographing posture measured with the position measurement section with the information on the photographing position and photographing posture obtained with the positional relationship measurement section, or for comparing the information on the position of the photographed object measured with the position measurement section with the information on the position of the photographed object obtained with the positional relationship measurement section.

19. A position measuring device comprising:

an image acquisition section for acquiring a series of photographed images changing continuously or changing little by little along with position displacement relative to an object to be photographed;

a positional relationship measurement section for measuring position displacement and posture change of the object to be photographed;

a feature extraction section for extracting feature points from the photographed images obtained with the image acquisition section;

a feature point tracking section for tracking the feature points by searching corresponding points corresponding to the feature points on a plurality of the photographed images;

an image selection section for selecting an image to be processed from the series of photographed images based on a measurement result made with the positional relationship measurement section; and

a position measurement section for measuring the photographing position and photographing posture of the image acquisition section or position of the photographed object based on the image to be processed selected with the image selection section.

20. The position measuring device of claim 19, wherein the image selection section selects the image to be processed based on the measurement data on the displacement direction and/or displacement amount obtained with the positional relationship measurement section.

21. The position measuring device of claim 20, wherein the image selection section selects the images to be processed between photographed image acquisition with the image acquisition section and feature point extraction with the feature extraction section.

22. The position measuring device of claim 19, wherein the positional relationship measurement section includes a gyroscope, an accelerometer, and a geomagnetism sensor.

23. The position measuring device of claim 19, wherein the feature point tracking section, when tracking feature points, is capable of changing search width direction or search width size.

24. The position measuring device of claim 19, comprising a display section for displaying on a screen displacement direction and displacement speed of feature points on the photographed image from a result of tracking made with the feature point tracking section.

25. The position measuring device of claim 19, comprising a comparing section for comparing the information on the photographing position and photographing posture measured with the position measurement section with the information on the photographing position and photographing posture obtained with the positional relationship measurement section, or for comparing the information on the position of the photographed object measured with the position measurement section with the information on the position of the photographed object obtained with the positional relationship measurement section.

26. A position measuring device comprising:

an image acquisition section for acquiring a series of photographed images changing continuously or changing little by little along with position displacement relative to an object to be photographed;

a positional relationship measurement section for measuring position displacement and posture change of the object to be photographed;

a feature extraction section for extracting feature points from the photographed images obtained with the image acquisition section;

a feature point tracking section for tracking the feature points by searching corresponding points corresponding to the feature points on a plurality of the photographed images;

a feature point selection section for selecting processing feature point to be processed from the photographed images based on a measurement result made with the positional relationship measurement section; and

a position measurement section for measuring the photographing position and photographing posture of the image acquisition section or position of the photographed object based on the feature point to be processed selected with the feature point selection section.

27. The position measuring device of claim 26, wherein the feature point selection section selects feature points, with their displacement direction and displacement amount obtained from tracking data with the feature point tracking section falling within a specified range including the displacement direction and displacement amount obtained with the positional relationship measurement section, as the object points to be processed.

28. The position measuring device of claim 27, comprising an image selection section for selecting images to be processed from the series of photographed images based on a measurement result made with the positional relationship measurement section, wherein the image selection section selects an image having relatively many feature points to be processed, as the image to be processed.

29. The position measuring device of claim 27, wherein the feature point selection section selects the feature points to be processed during feature point tracking with the feature point tracking section, or between feature point tracking with the feature point tracking section and position measurement with the position measurement section.

30. The position measuring device of claim 26, wherein the feature point selection section selects feature points, with the approximate distance between the image acquisition section and the feature point determined from measurement data obtained with the positional relationship measurement section falling within a specified range, as the feature points to be processed.

31. The position measuring device of claim 30, comprising an image selection section for selecting images to be processed from the series of photographed images based on a measurement result made with the positional relationship measurement section, wherein the image selection section selects an image having relatively many feature points to be processed, as the image to be processed.

32. The position measuring device of claim 30, wherein the feature point selection section selects the feature points to be processed either during feature point tracking with the feature point tracking section, between feature point extraction with the feature extraction section and feature point tracking with the feature point tracking section, or between feature point tracking with the feature point tracking section and position measurement with the position measurement section.

33. The position measuring device of claim 26, wherein the positional relationship measurement section includes a gyroscope, an accelerometer, and a geomagnetism sensor.

34. The position measuring device of claim 26, wherein the feature point tracking section, when tracking feature points, is capable of changing search width direction or search width size.

35. The position measuring device of claim 26, comprising a display section for displaying on a screen displacement direction and displacement speed of feature points on the photographed image from a result of tracking made with the feature point tracking section.

36. The position measuring device of claim 26, comprising a comparing section for comparing the information on the photographing position and photographing posture measured with the position measurement section with the information on the photographing position and photographing posture obtained with the positional relationship measurement section, or for comparing the information on the position of the photographed object measured with the position measurement section with the information on the position of the photographed object obtained with the positional relationship measurement section.

37. A position measuring method comprising:

An image acquisition step, with an image acquisition section, of acquiring a series of photographed images changing continuously or changing little by little along with position displacement relative to an object to be photographed;

a positional relationship measurement step of measuring position displacement and posture change of the image acquisition section;

a feature extracting step of extracting feature points from photographed images obtained in the image acquisition step;

a feature point tracking step of tracking the feature points by searching corresponding points corresponding to the feature points on a plurality of the photographed images;

an image selection step of selecting images to be processed from the series of photographed images based on a measurement result made with the positional relationship measurement step; and

a position measurement step of measuring the photographing position and photographing posture of the image acquisition section or position of the photographed object based on the images to be processed selected in the image selection step.

38. A position measuring method comprising:

an image acquisition step, with an image acquisition section, of acquiring a series of photographed images changing continuously or little by little along with position displacement relative to an object to be photographed;

a positional relationship measurement step of measuring position displacement and posture change of the image acquisition section;

a feature extraction step of extracting feature points from photographed images obtained in the image acquisition step;

a feature point tracking step of tracking the feature points by searching corresponding points corresponding to the feature points on a plurality of the photographed images;

a feature point selection step of selecting feature points to be processed from the feature points extracted from the photographed images based on a measurement result made in the positional relationship measurement step; and

a position measurement step of measuring the photographing position and photographing posture of the image acquisition section based on the feature points to be processed selected in the feature point selection step.

39. A position measuring method comprising:

an image acquisition step of acquiring a series of photographed images changing continuously or little by little along with position displacement relative to an object to be photographed;

a positional relationship measurement step of measuring position displacement and posture change of the object to be photographed;

a feature extraction step of extracting feature points from the photographed images obtained in the image acquisition step;

a feature point tracking step of tracking the feature points by searching corresponding points corresponding to the feature points on a plurality of the photographed images;

an image selection step of selecting images to be processed from the series of photographed images based on a measurement result made in the positional relationship measurement step; and

a position measurement step of measuring the photographing position and the photographing posture of the image acquisition section or the position of the photographed object based on the images to be processed selected in the image selection step.

40. A position measuring method comprising:

an image acquisition step of acquiring a series of photographed images changing continuously or little by little along with position displacement relative to an object to be photographed;

a positional relationship measurement step of measuring position displacement and posture change of the object to be photographed;

a feature extraction step of extracting feature points from the photographed images obtained in the image acquisition step;

a feature point tracking step of tracking the feature points by searching corresponding points corresponding to the features points on a plurality of the photographed images;

a feature point selection step of selecting feature points to be processed from the feature points extracted from the photographed images based on a measurement result made in the positional relationship measurement step; and

a position measurement step of measuring the photographing position and photographing posture of the image acquisition section or the position of the photographed object based on the feature points to be processed selected in the feature point selection step.