VIRTUAL RULER

• US 20130201210A1
• Filed: 07/31/2012
• Published: 08/08/2013
• Est. Priority Date: 01/13/2012
• Status: Abandoned Application

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Vaddadi, Sundeep, Hong, John H., Lee, Chong U., Chimalamarri, Krishnakanth S.
• Application Number:
  US13/563,330
• Publication Number:
  US 20130201210A1
• Time in Patent Office: Days
• US Class Current: 345/632
• CPC Class Codes: G01B 11/25 by projecting a pattern, e.g. one or more lines, moiré fringes on the object G01B11/255 takes precedence ; image analysis for depth or shape recovery G06T7/50
• CPC Class Codes: G06T 19/006 Mixed reality object pose determination, tracking or camera calibration for mixed reality G06T7/00

Abstract

In some embodiments, first information indicative of an image of a scene is accessed. One or more reference features are detected, the reference features being associated with a reference object in the image. A transformation between an image space and a real-world space is determined based on the first information. Second information indicative of input from a user is accessed, the second information identifying an image-space distance in the image space corresponding to a real-world distance of interest in the real-world space. The real-world distance of interest is then estimated based on the second information and the determined transformation.

Claims

1. A method for estimating a real-world distance, the method comprising:

accessing first information indicative of an image of a scene;

detecting one or more reference features associated with a reference object in the first information;

determining a transformation between an image space and a real-world space based on the image;

accessing second information indicative of input from a user, the second information identifying an image-space distance in the image space corresponding to a real-world distance of interest in the real-world space; and

estimating the real-world distance of interest based on the second information and the determined transformation.

2. The method of claim 1, wherein the second information comprises a start point and an endpoint, and the real-world distance of interest comprises a distance between real-world locations associated with the start point and the endpoint.

3. The method of claim 1, further comprising superimposing a virtual ruler on the image.

4. The method of claim 3, wherein the second information comprises a position where at least part of the superimposed virtual ruler is to be located on the image.

5. The method of claim 1, wherein the transformation at least partly accounts for perspective distortion.

6. The method of claim 1, wherein the transformation comprises a homography matrix.

7. The method of claim 1, wherein the method is performed in its entirety on a mobile device.

8. The method of claim 7, wherein the mobile device comprises a cellular phone.

9. The method of claim 1, wherein the reference object comprises a substantially flat and substantially rectangular object.

10. The method of claim 1, further comprising:

determining at least one first spatial property in the image space associated with the one or more of the reference features;

determining at least one second spatial property in the real-world space associated with the one or more of the reference features; and

determining the transformation based on the at least one first spatial property and the at least one second spatial property.

11. The method of claim 1, wherein both the estimated real-world distance of interest and a surface of the reference object lie along a same plane.

12. The method of claim 1, wherein estimating the real-world distance of interest comprises applying an inverse of the transformation.

13. A system for estimating a real-world distance, the system comprising:

an imaging device for accessing first information indicative of an image of a scene;

a reference-feature detector for detecting one or more reference features associated with a reference object in the first information;

a transformation identifier for determining a transformation between an image space and a real-world space based on the detected one or more reference features;

a user input component for accessing second information indicative of input from a user of a mobile device that identifies an image-space distance in the image space corresponding to a real-world distance of interest in the real-world space; and

a distance estimator for estimating the real-world distance of interest based on the second information and the determined transformation.

14. The system of claim 13, wherein the second information comprises a rotation of a ruler superimposed on a presentation of the image.

15. The system of claim 13, wherein the distance estimator comprises a ruler generator for generating a virtual ruler to be presented by a display.

16. The system of claim 13, wherein a display simultaneously presents the estimated real-world distance of interest and the image.

17. The system of claim 13, wherein the reference-feature detector comprises an edge detector.

18. The system of claim 13, wherein the user input component and the display are integrated as a touchscreen display.

19. A system for estimating a real-world distance, the system comprising:

means for accessing first information indicative of an image of a scene;

means for detecting one or more reference features associated with a reference object in the image;

means for determining a transformation between an image space and a real-world space based on the first information;

means for accessing second information indicative of input from a user, the second information identifying an image-space distance in the image space corresponding to a real-world distance of interest in the real-world space; and

means for estimating the real-world distance of interest based on the second information and the determined transformation.

20. The system of claim 19, wherein the means for accessing the first information comprise a camera in a mobile phone.

21. The system of claim 19, wherein the means for detecting the one or more reference features comprise an edge detector.

22. The system of claim 19, wherein the means for accessing the second information indicative of the input from the user comprise a touchscreen display.

23. The system of claim 19, wherein the means for estimating the real-world distance of interest comprise a ruler generator.

24. The system of claim 19, further comprising means for presenting the estimated real-world distance of interest.

25. A computer-readable medium containing a program which executes steps of:

accessing first information indicative of an image of a scene;

detecting one or more reference features associated with a reference object in the image;

determining a transformation between an image space and a real-world space based on the first information;

accessing second information indicative of input from a user, the second information identifying an image-space distance in the image space corresponding to a real-world distance of interest in the real-world space; and

estimating the real-world distance of interest based on the second information and the determined transformation.

26. The computer-readable medium of claim 25, wherein the program further executes a step of:

identifying real-world spatial properties associated with the reference object from a database.

27. The computer-readable medium of claim 25, wherein the transformation comprises a homography.

28. The computer-readable medium of claim 25, wherein the second information comprises a start point and a stop point.