Method, tool, and device for determining the coordinates of points on a surface by means of an accelerometer and a camera

• US 20120026322A1
• Filed: 08/01/2010
• Published: 02/02/2012
• Est. Priority Date: 08/01/2010
• Status: Active Grant

• Current Assignee: Sensopia, Inc.
• Original Assignee: Mr. Francis Ruben Malka, Mr. Gilles Jean Desforges
• Inventors: Malka, Francis Ruben, Desforges, Gilles Jean
• Granted Patent: US 9,041,796 B2
• Time in Patent Office: Days
• US Class Current: 348/142
• CPC Class Codes: G01C 11/02 Picture taking arrangements specially adapted for photogrammetry or photographic surveying, e.g. controlling overlapping of pictures

Abstract

A method, tool, and device for determining the coordinates or a plurality of points on a substantially plane surface by means of an accelerometer and a camera. The coordinates of each point are computed by determining a perpendicular projection of the camera onto the surface, identifying each point, measuring an inclination (the angle between the line of sight of the camera and gravity) using the accelerometer, and determining an azimuth (the angle of the line of sight of the camera around gravity).

Claims

1. A method for determining the coordinates of a plurality of points P_i on a substantially plane surface S by means of a device comprising an accelerometer, a camera, and a processor, the method comprising, for each point P_i:

determining a perpendicular projection C_i of the location of the camera onto S;

identifying the point Pi by means of the device;

measuring an inclination I_i (the angle between the line of sight of the camera and gravity) by means of the accelerometer;

determining an azimuth A_i (the angle of the line of sight of the camera around gravity);

computing the coordinates of the point P_i using A_i, I_i, and C_i by means of the processor.

2. The method of claim 1, wherein the azimuth A_i is determined by at least one of the following:

analyzing at least one image captured by the camera while aiming at P_i;

capturing a user input by means of an input unit;

using a gyroscope;

using a compass;

using a known angle formed by P<sub>i−

2</sub>, P<sub>i−

1</sub>, and P_i;

using predetermined values.

3. The method of claim 1, wherein the perpendicular projection C_i is determined by at least one of the following:

analyzing at least one image captured by the camera while aiming at P_i;

capturing a user input by means of an input unit;

using a gyroscope;

using the accelerometer;

placing all projections C_i on a known path;

rotating the camera around a center of rotation that is substantially the same for all points P_i;

using a biomechanical model of the user holding the device;

using predetermined values.

4. The method of claim 1, further comprising a calibration phase determining at least one calibration parameter for at least one of the following:

correcting the image captured by the camera by taking into account its optical characteristics;

determining at least one biometric parameter of the user;

adjusting the values read by means of the accelerometer to an environment in which the device is being used.

5. A device for determining the coordinates of a plurality of points P_i on a substantially plane surface S, the device comprising:

a camera for capturing a video stream;

a screen for displaying the video stream;

an accelerometer for measuring an inclination I_i (the angle between the line of sight of the camera and gravity) for each point P_i;

a point determination unit for;

identifying each point P_i;

determining the inclination I_i by means of the accelerometer for each point P_i;

determining an azimuth A_i(the angle of the line of sight of the camera around gravity) for each point P_i;

a coordinates computation unit for;

determining a perpendicular projection C_i of the location of the camera onto S;

computing the coordinates of each point P_i using A_i, I_i, and C_i.

6. The device of claim 5, further comprising:

a gyroscope for determining the azimuth A_i of each point P_i.

7. The device of claim 5, further comprising:

a compass for determining the azimuth A_i of each point P_i.

8. The device of claim 5, wherein the azimuth A_i is determined by at least one of the following:

analyzing at least one image captured by the camera while aiming at P_i;

capturing a user input by means of an input unit;

using a known angle formed by P<sub>i−

2</sub>, P<sub>i−

1</sub>, and P_i;

using predetermined values.

9. The device of claim 5, wherein the coordinates computation unit determines the perpendicular projection C_i by at least one of the following:

analyzing at least one image captured by the camera while aiming at P_i;

capturing a user input by means of an input unit;

using a gyroscope;

using the accelerometer;

placing all projections C_i on a known path;

placing all projections C_i such as the lines of sight of the camera for all points P_i intersect at a single point;

using a biomechanical model of the user holding the device;

using predetermined values.

10. The device of claim 5, wherein the point determination unit further performs image analysis on at least one image for each point P_i.

11. The device of claim 5, further comprising a calibration unit for determining at least one calibration parameter for at least one of the following:

correcting the image captured by the camera by taking into account its optical characteristics;

determining at least one biometric parameter of the user;

adjusting the values read from the accelerometer to an environment in which the device is being used.

12. A tool for determining coordinates of a plurality of points P_i on a substantially plane surface S, adapted to run on a device comprising an accelerometer and a camera, the tool comprising:

a point determination unit being adapted for;

receiving a video stream by means of the camera;

reading the inclination I_i (the angle between the line of sight of the camera and gravity) from the accelerometer for each point P_i;

determining an azimuth A_i (the angle of the line of sight of the camera around gravity) for each point P_i;

a coordinates computation unit being adapted for;

determining a perpendicular projection C_i of the location of the camera onto S;

computing the coordinates of each point P_i using A_i, I_i, and C_i.

13. The tool of claim 12, wherein the point determination unit determines the azimuth A_i by at least one of the following:

analyzing at least one image captured by the camera while aiming at P_i;

displaying the video stream on a screen;

capturing a user input by means of an input unit;

using a gyroscope;

using a compass;

rotating the camera around a center of rotation that is substantially the same for all points P_i;

using a known angle formed by P<sub>i−

2</sub>, P<sub>i−

1</sub>, and P_i;

using predetermined values.

14. The tool of claim 12, wherein the coordinates computation unit determines the perpendicular projection C_i by at least one of the following:

analyzing at least one image captured by the camera while aiming at P_i;

capturing a user input by means of an input unit;

using a gyroscope;

using the accelerometer;

placing all projections C_i on a known path;

placing all projections C_i such as the lines of sight of the camera for all points P_i substantially intersect at a single point;

using a biomechanical model of the user holding the device;

using predetermined values.

15. The tool of claim 12, further comprising a calibration unit for determining at least one calibration parameter for at least one of the following:

correcting the image captured by the camera by taking into account its optical characteristics;

determining at least one biometric parameter of the user;

adjusting the values read from the accelerometer to an environment in which the device is being used.