Handheld device and positioning method thereof
First Claim
1. A positioning method performed in a handheld device, comprising:
- obtaining a first image position of a reference;
computing a first pointing coordinate according to the first image position and a first tilt angle indicative of a rotation angle of the handheld device;
computing a second pointing coordinate according to the first image position and a second tilt angle that is rendered based on a movement of the first image position of the reference;
computing a first displacement vector between the first pointing coordinate and the second pointing coordinate, and generating a unit displacement;
obtaining a second image position of the reference;
computing a third pointing coordinate according to the second image position and the second tilt angle; and
obtaining an output pointing coordinate according to the third pointing coordinate and the unit displacement, wherein the step of obtaining the output pointing coordinate further includes;
a) setting a number of calibrations as N, a compensation vector as C and a calibration coordinate, wherein the calibration coordinate is the third pointing coordinate;
b) determining whether the first displacement vector is greater than a predetermined threshold;
c) setting N equal to the first displacement vector divided by C when it is determined that the first displacement vector is greater than the predetermined threshold, wherein C is a predetermined compensation value;
setting C equal to the first displacement vector divided by N when it is determined that the first displacement vector is less than the predetermined threshold, wherein N is a predetermined number of calibrations;
d) computing a sum of the calibration coordinate and C to generate a compensated pointing coordinate;
e) executing N-1 and determining whether N is equal to zero; and
f) setting a fourth pointing coordinate to be the calibration coordinate and returning to step d) upon determined that N is not equal to zero;
wherein the forth pointing coordinate is computed according to an image position of the reference and the second tilt angle.
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Accused Products
Abstract
A positioning method and a handheld device for performing the method are disclosed. In the method, a handheld device captures images corresponding to positions of a reference when the handheld device points toward the reference. A first image position, a first tilt angle indicative of a rotation angle of the handheld device, and a first pointing coordinate of the reference can obtained. A second pointing coordinate according to the first image position and a second tilt angle are obtained. Therefore, a first displacement vector between the first pointing coordinate and the second pointing coordinate can be computed. A third pointing coordinate can also be obtained. When a substantial movement of the positions of the reference revealed in the images captured by the handheld device is found, an output pointing coordinate is obtained. The output can be outputting a cursor parameter for controlling a cursor controlled by the handheld device.
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Citations
20 Claims
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1. A positioning method performed in a handheld device, comprising:
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obtaining a first image position of a reference; computing a first pointing coordinate according to the first image position and a first tilt angle indicative of a rotation angle of the handheld device; computing a second pointing coordinate according to the first image position and a second tilt angle that is rendered based on a movement of the first image position of the reference; computing a first displacement vector between the first pointing coordinate and the second pointing coordinate, and generating a unit displacement; obtaining a second image position of the reference; computing a third pointing coordinate according to the second image position and the second tilt angle; and obtaining an output pointing coordinate according to the third pointing coordinate and the unit displacement, wherein the step of obtaining the output pointing coordinate further includes; a) setting a number of calibrations as N, a compensation vector as C and a calibration coordinate, wherein the calibration coordinate is the third pointing coordinate; b) determining whether the first displacement vector is greater than a predetermined threshold; c) setting N equal to the first displacement vector divided by C when it is determined that the first displacement vector is greater than the predetermined threshold, wherein C is a predetermined compensation value;
setting C equal to the first displacement vector divided by N when it is determined that the first displacement vector is less than the predetermined threshold, wherein N is a predetermined number of calibrations;d) computing a sum of the calibration coordinate and C to generate a compensated pointing coordinate; e) executing N-1 and determining whether N is equal to zero; and f) setting a fourth pointing coordinate to be the calibration coordinate and returning to step d) upon determined that N is not equal to zero;
wherein the forth pointing coordinate is computed according to an image position of the reference and the second tilt angle. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A handheld device, comprising:
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an image capturing unit configured to capture images of frames containing a reference; a processing unit, coupled to the image capturing unit, configured to perform a positioning method for; obtaining a first image position of the reference; computing a first pointing coordinate according to the first image position and a first tilt angle indicative of a rotation angle of the handheld device; computing a second pointing coordinate according to the first image position and a second tilt angle that is rendered based on a movement of the first image position of the reference; computing a first displacement vector between the first pointing coordinate and the second pointing coordinate, and generating a unit displacement; obtaining a second image position of the reference; computing a third pointing coordinate according to the second image position and the second tilt angle; and obtaining an output pointing coordinate according to the third pointing coordinate and the unit displacement, wherein the step of obtaining the output pointing coordinate in the positioning method further includes; a) setting a number of calibrations as N, a compensation vector as C and a calibration coordinate, wherein the calibration coordinate is the third pointing coordinate; b) determining whether the first displacement vector is greater than a predetermined threshold; c) setting N equal to the first displacement vector divided by C when it is determined that the first displacement vector is greater than the predetermined threshold, wherein C is a predetermined compensation value;
setting C equal to the first displacement vector divided by N when it is determined that the first displacement vector is less than the predetermined threshold, wherein N is a predetermined number of calibrations;d) computing a sum of the calibration coordinate and C to generate a compensated pointing coordinate; e) executing N-1 and determining whether N is equal to zero; and f) setting a fourth pointing coordinate to be the calibration coordinate and returning to step d) upon determined that N is not equal to zero;
wherein the forth pointing coordinate is computed according to an image position of the reference and the second tilt angle. - View Dependent Claims (15, 16, 17, 18, 19, 20)
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Specification