System and method providing improved head motion estimations for animation
First Claim
1. A computing device to estimate head motion between two images of a face, the computing device comprising:
- a processor; and
a memory coupled to the processor, the memory comprising computer-program instructions executable by the processor for;
identifying locations of a plurality of distinct facial features in the two images, the locations corresponding to a number of unknowns determined upon estimation of head motion, the number of unknowns being determined by a number of equations;
converting the identified locations into a set of physical face parameters based on the symmetry of the distinct facial features, the set of physical face parameters reducing the number of unknowns as compared to the number of equations used to determine the unknowns;
adding an inequality constraint on a particular face parameter of the physical face parameters, such that the particular face parameter is constrained within a predetermined minimum and maximum value;
converting the inequality constraint to an equality constraint using a penalty function; and
estimating head motion from identified points in the two images, the identified points being based on the set of physical face parameters.
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Accused Products
Abstract
Systems and methods to estimate head motion between two images of a face are described. In one aspect, locations of a plurality of distinct facial features in the two images are identified. The locations correspond to a number of unknowns that are determined upon estimation of head motion. The number of unknowns are determined by a number of equations. The identified locations are converted into a set of physical face parameters based on the symmetry of the distinct facial features. The set of physical face parameters reduce the number of unknowns as compared to the number of equations used to determine the unknowns. An inequality constraint is added to a particular face parameter of the physical face parameters, such that the particular face parameter is constrained within a predetermined minimum and maximum value. The inequality constraint is converted to an equality constraint using a penalty function. Head motion is estimated from identified points in the two images. The identified points are based on the set of physical face parameters.
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Citations
51 Claims
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1. A computing device to estimate head motion between two images of a face, the computing device comprising:
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a processor; and a memory coupled to the processor, the memory comprising computer-program instructions executable by the processor for; identifying locations of a plurality of distinct facial features in the two images, the locations corresponding to a number of unknowns determined upon estimation of head motion, the number of unknowns being determined by a number of equations; converting the identified locations into a set of physical face parameters based on the symmetry of the distinct facial features, the set of physical face parameters reducing the number of unknowns as compared to the number of equations used to determine the unknowns; adding an inequality constraint on a particular face parameter of the physical face parameters, such that the particular face parameter is constrained within a predetermined minimum and maximum value; converting the inequality constraint to an equality constraint using a penalty function; and estimating head motion from identified points in the two images, the identified points being based on the set of physical face parameters. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A computer-readable medium comprising computer-program instructions executable by a processor to estimate head motion between two images of a face, the computer-program instructions comprising instructions for:
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identifying locations of a plurality of distinct facial features in the two images, the locations corresponding to a number of unknowns determined upon estimation of head motion, the number of unknowns being determined by a number of equations; converting the identified locations into a set of physical face parameters based on the symmetry of the distinct facial features, the set of physical face parameters reducing the number of unknowns as compared to the number of equations used to determine the unknowns; adding an inequality constraint on a particular face parameter of the physical face parameters, such that the particular face parameter is constrained within a predetermined minimum and maximum value; converting the inequality constraint to an equality constraint using a penalty function; and estimating head motion from identified points in the two images, the identified points being based on the set of physical face parameters. - View Dependent Claims (9, 10, 11, 12, 13, 14)
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15. A computing device to estimate head motion between two images of a face, the computing device comprising:
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identifying means to identify locations of a plurality of distinct facial features in the two images, the locations corresponding to a number of unknowns determined upon estimation of head motion, the number of unknowns being determined by a number of equations; converting means to convert the identified locations into a set of physical face parameters based on the symmetry of the distinct facial features, the set of physical face parameters reducing the number of unknowns as compared to the number of equations used to determine the unknowns; adding means to add an inequality constraint on a particular face parameter of the physical face parameters, such that the particular face parameter is constrained within a predetermined minimum and maximum value; converting means to change the inequality constraint to an equality constraint using a penalty function; and estimating means to estimate head motion from identified points in the two images, the identified points being based on the set of physical face parameters. - View Dependent Claims (16, 17, 18)
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19. A computing device to estimate head motion between two images of a face, the computing device comprising:
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a processor; and a memory coupled to the processor, the memory comprising computer-program instructions executable by the processor for; identifying locations of a plurality of distinct facial features in the two images, the locations corresponding to a number of unknowns determined upon estimation of head motion, the number of unknowns being determined by a number of equations; converting the identified locations into a set of physical face parameters based on the symmetry of the distinct facial features, the set of physical face parameters reducing the number of unknowns as compared to the number of equations used to determine the unknowns; and estimating head motion from identified points in the two images, the identified points being based on the set of physical face parameters; and wherein the operation of estimating head motion comprise operations of; calculating an estimation objective function to determine an initial estimate of head rotation, the estimation objective function comprising a set of terms to estimate;
(a) each of the set of physical face parameters, (b) a first head pose transform corresponding to the first image, and (c) a second head pose transform corresponding to the second image;placing an inequality constraint on a particular face parameter of the set of physical face parameters, such that the particular face parameter is constrained within a predetermined minimum and maximum value; converting the inequality constraint to an equality constraint using a penalty function; and adding the inequality constraint to the initial estimate.
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20. A computer-readable medium comprising computer-program instructions to estimate head motion between two images of a face, the computer-program instructions comprising instructions for:
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identifying locations of a plurality of distinct facial features in the two images, the locations corresponding to a number of unknowns determined upon estimation of head motion, the number of unknowns being determined by a number of equations; converting the identified locations into a set of physical face parameters based on the symmetry of the distinct facial features, the set of physical face parameters reducing the number of unknowns as compared to the number of equations used to determine the unknowns; and estimating head motion from identified points in the two images, the identified points being based on the set of physical face parameters; and wherein the operation of estimating head motion comprise operations of; calculating an estimation objective function to determine an initial estimate of head rotation, the estimation objective function comprising a set of terms to estimate;
(a) each of the set of physical face parameters, (b) a first head pose transform corresponding to the first image, and (c) a second head pose transform corresponding to the second image;placing an inequality constraint on a particular face parameter of the set of physical face parameters, such that the particular face parameter is constrained within a predetermined minimum and maximum value; converting the inequality constraint to an equality constraint using a penalty function; and adding the inequality constraint to the initial estimate.
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21. A computing device to estimate head motion between two images of a face, the computing device comprising:
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identifying means to identify locations of a plurality of distinct facial features in the two images, the locations corresponding to a number of unknowns determined upon estimation of head motion, the number of unknowns being determined by a number of equations; converting means to convert the identified locations into a set of physical face parameters based on the symmetry of the distinct facial features, the set of physical face parameters reducing the number of unknowns as compared to the number of equations used to determine the unknowns; and estimating means to estimate head motion from identified points in the two images, the identified points being based on the set of physical face parameters; and wherein the estimating means further comprise; calculating means to calculate an estimation objective function to determine an initial estimate of head rotation, the estimation objective function comprising a set of terms to estimate;
(a) each of the set of physical face parameters, (b) a first head pose transform corresponding to the first image, and (c) a second head pose transform corresponding to the second image;placing means to associate an inequality constraint on a particular face parameter of the set of physical face parameters, such that the particular face parameter is constrained within a predetermined minimum and maximum value; converting means to convert the inequality constraint to an equality constraint using a penalty function; and adding means to add the inequality constraint to the initial estimate.
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22. A method to estimate motion between two images, the method comprising:
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determining locations of a plurality of distinct features in the two images; converting the identified locations into a set of parameters based on the symmetry of the distinct features; and estimating motion between the two images based on the set of physical face parameters by; (1) calculating an estimation objective function comprising a set of terms to estimate;
(a) each of the parameters, (b) a first transform corresponding to the first image, and (c) a second transform corresponding to the second image; and(2) multiplying each term of the estimation objective function by a weighted contribution factor based on the confidence of data corresponding to the estimation objective function. - View Dependent Claims (23, 24, 25, 26, 27, 28)
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29. A computing device comprising:
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a processor; and a memory coupled to the processor, the memory comprising computer-program instructions executable by the processor to estimate motion between two images, the computer-program instructions comprising instructions for; determining locations of a plurality of distinct features in the two images; converting the identified locations into a set of parameters based on the symmetry of the distinct features; and estimating motion between the two images based on the set of physical face parameters by; (1) calculating an estimation objective function comprising a set of terms to estimate;
(a) each of the parameters, (b) a first transform corresponding to the first image, and (c) a second transform corresponding to the second image; and(2) multiplying each term of the estimation objective function by a weighted contribution factor based on the confidence of data corresponding to the estimation objective function. - View Dependent Claims (30, 31, 32, 33, 34, 35)
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36. A computing device comprising:
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determining means to determine locations of a plurality of distinct features in the two images; converting means to convert the identified locations into a set of parameters based on the symmetry of the distinct features; and estimating means to estimate motion between the two images based on the set of physical face parameters by; (1) calculating an estimation objective function comprising a set of terms to estimate;
(a) each of the parameters, (b) a first transform corresponding to the first image, and (c) a second transform corresponding to the second image; and(2) multiplying each term of the estimation objective function by a weighted contribution factor based on the confidence of data corresponding to the estimation objective function. - View Dependent Claims (37, 38, 39, 40, 41)
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42. A computer-readable medium to estimate head motion between two images of a face, the computer-readable medium comprising computer program instructions for:
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identifying locations of a plurality of distinct facial features in the two images, the locations corresponding to a number of unknowns determined upon estimation of head motion, the number of unknowns being determined by a number of equations; converting the locations into set of physical face parameters based on the symmetry of the identified distinct facial features, the set of physical face parameters reducing the number of unknowns as compared to the number of equations used to determine the unknowns; determining an initial estimation of head motion between the two images using the set of physical face parameters as follows; (1) calculating an estimation objective function comprising a number of terms to estimate each of;
(a) the set of coordinates, (b) a first head pose transform corresponding to the first image, and (c) a second head pose transform corresponding to the second image; and(2) multiplying each term of the estimation objective function by a weighted contribution factor based on the confidence of data corresponding to the estimation objective function; and refining the initial estimation of head motion by incorporating the initial estimation into a feature matching algorithm. - View Dependent Claims (43, 44, 45, 46, 47, 48, 49, 50)
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51. A computing device to estimate head motion between two images of a face, the computing device comprising:
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identifying means to identify locations of a plurality of distinct facial features in the two images, the locations corresponding to a number of unknowns determined upon estimation of head motion, the number of unknowns being determined by a number of equations; converting means to convert the locations into set of physical face parameters based on the symmetry of the identified distinct facial features, the set of physical face parameters reducing the number of unknowns as compared to the number of equations used to determine the unknowns; determining means to determine an initial estimation of head motion between the two images using the set of physical face parameters as follows; calculating an estimation objective function comprising a number of terms to estimate each of;
(a) the set of coordinates, (b) a first head pose transform corresponding to the first image, and (c) a second head pose transform corresponding to the second image; andmultiplying each term of the estimation objective function by a weighted contribution factor based on the confidence of data corresponding to the estimation objective function; and refining the initial estimation of head motion by incorporating the initial estimation into a feature matching algorithm.
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Specification