Iteratively adjusting estimated touch geometries of estimated touches to sequential estimated actual touches

1. A method comprising:

measuring, at a processing device, a first set of actual touch data from an actual response of a low-resolution sense array;

determining that the first set of actual touch data represents two or more concurrent actual touches proximate to the sense array, each of the concurrent actual touches having a respective actual touch geometry including a touch position and a touch size, wherein the actual touch geometries associated with the concurrent actual touches are obscured in the first set of actual test data from the low-resolution sense-array;

obtaining estimated touch geometries of two or more concurrent simulated touches proximate to the sense array that correspond to the two or more actual touches with the associated actual touch geometries;

sequentially estimating the actual touch geometries of the two or more concurrent actual touches by iteratively computing an estimated response of the sense array to the two or more concurrent simulated touches and adjusting the estimated touch geometries to approximate the actual touch geometries based on an error between the estimated response and the actual response, wherein the estimated touch geometries include a set of estimated touch sizes and estimated touch positions of the two or more concurrent simulated touches, and wherein the actual touch geometries are distinct from the estimated touch geometries and the two or more actual touches are distinct from the two or more concurrent simulated touches; and

outputting the actual touch geometries of the two or more actual touches based on the estimated touch geometries when the error is less than a specified threshold, thereby resolving the actual touch geometries associated with the concurrent actual touches that were obscured in the first set of actual test data.

2. The method of claim 1 , wherein the sequentially estimating the actual touch geometries comprises:

determining a second set of estimated touch data based on the estimated response;

determining the error based on a difference between the first set of actual touch data and the second set of estimated touch data; and

adjusting the estimated touch geometries of the two or more concurrent simulated touches when the difference is greater than the specified threshold.

3. The method of claim 2 , wherein the sequentially estimating the actual touch geometries further comprises:

determining a subsequent set of estimated touch data based on the adjusted estimated touch geometries when the difference is greater than the specified threshold;

determining a subsequent difference between the subsequent set of estimated touch data and a previous set of estimated touch data; and

iteratively updating the estimated touch geometries of the two or more estimated touches until the subsequent difference is less than the specified threshold.

4. The method of claim 2 , further comprising:

determining actual touch orientations of the two or more actual touches based on the first set of actual touch data and the second set of estimated touch data; and

outputting the actual touch orientations when the error between the two or more estimated touches and the two or more actual touches is less than the specified threshold.

5. The method of claim 1 , wherein the sense array is a capacitive sense array, and wherein the actual response and the estimated response each include a plurality of cells each with a capacitance value of an intersection of sense elements of the capacitive sense array.

6. The method of claim 5 , wherein at least two of the two or more actual touches overlap on at least one of the intersections.

7. A method comprising:

obtaining, at a processing device, a first capacitive image of a low-resolution capacitive sense array, wherein the capacitive image comprises a plurality of cells each with a capacitance value of an intersection of sense elements of the capacitive sense array;

identifying existence of at least two concurrent actual touches proximate to the capacitive sense array based on the first capacitive image, each of the concurrent actual touches having a respective actual touch geometry including a touch position and a touch size, wherein the actual touch geometries associated with the concurrent actual touches are obscured in the first set of actual test data from the low-resolution sense-array;

computing an estimated capacitive image based on estimated touch geometries of at least two concurrent simulated touches that correspond to the at least two actual touches with the associated actual touch geometries;

iteratively adjusting the estimated touch geometries of the at least two concurrent simulated touches and iteratively determining the estimated capacitive image based on the adjusted estimated touch geometries until an error between the estimated capacitive image and the first capacitive image is less than a specified threshold; and

outputting the actual touch geometries of the at least two concurrent actual touches, wherein the actual touch geometries include a set of touch sizes and touch positions of the at least two actual touches, and wherein the actual touch geometries are different from the estimated touch geometries and the at least two actual touches are different from the at least two concurrent simulated touches, thereby resolving the actual touch geometries associated with the concurrent actual touches that were obscured in the first set of actual test data.

8. The method of claim 7 , wherein the iteratively adjusting the estimated touch geometries comprises adjusting at least one parameter of at least one of the estimated touches.

9. The method of claim 7 , further comprising selecting a set of two or more circles of a predefined size for the at least two estimated touches.

10. The method of claim 7 , further comprising:

selecting a first circular touch for one of the at least two concurrent simulated touches;

estimating a first diameter or radius of the first circular touch based on the first capacitive image;

selecting a second circular touch for one of the at least two concurrent simulated touches; and

estimating a second diameter or radius of the second circular touch based the first capacitive image.

11. The method of claim 10 , further comprising:

estimating a first coordinate of the first circular touch based on the first capacitive image; and

estimating a second coordinate of the second circular touch based on the first capacitive image.

12. The method of claim 11 , wherein the iteratively adjusting the estimated touch geometries comprises adjusting at least one of the first diameter or radius, second diameter or radius, first coordinate or second coordinate.

13. The method of claim 11 , wherein the iteratively adjusting the estimated touch geometries comprises adjusting at least one of a first aspect ratio of first circular touch or a second aspect ratio of the second circular touch.

14. The method of claim 13 , wherein the iteratively adjusting the estimated touch geometries comprises adjusting at least one of a first touch orientation of first circular touch or a second touch orientation of the second circular touch.

15. An apparatus comprising:

a memory; and

a processing element coupled to the memory, wherein the processing element is configurable to:

obtain a first set of actual touch data of a low-resolution sense array;

determine that the first set of actual touch data represents two or more concurrent actual touches proximate to the sense array, each of the concurrent actual touches having a respective actual touch geometry including a touch position and a touch size, wherein the actual touch geometries associated with the concurrent actual touches are obscured in the first set of actual test data from the low-resolution sense-array;

obtain estimated touch geometries of two or more concurrent simulated touches proximate to the sense array that correspond to the two or more actual touches with the associated actual touch geometries;

sequentially estimate the actual touch geometries of the two or more concurrent actual touches by iteratively computing an estimated response of the sense array to the two or more concurrent simulated touches and adjusting the estimated touch geometries to approximate the actual touch geometries based an error between the estimated response and the actual response and adjusting the estimated touch geometries to approximate the actual touch geometries based an error between the estimated response and the actual response, wherein the estimated touch geometries include a set of estimated touch sizes and estimated touch positions of the two or more concurrent simulated touches, and wherein the actual touch geometries are distinct from the estimated touch geometries and the two or more actual touches are distinct from the two or more concurrent simulated touches; and

output the actual touch geometries of the two or more concurrent actual touches based on the estimated touch geometries when the error is less than a specified threshold, thereby resolving the actual touch geometries associated with the concurrent actual touches that were obscured in the first set of actual test data.

16. The apparatus of claim 15 , wherein the processing element is further configurable to:

determine a second set of estimated touch data based on the estimated touch estimated response;

determine the error based on a difference between the first set of actual touch data and the second set of estimated touch data; and

adjust the estimated touch geometries of the two or more concurrent simulated touches when the difference is greater than the specified threshold.

17. The apparatus of claim 16 , wherein the processing element is further configurable to:

determine a subsequent set of estimated touch data based on the adjusted estimated touch geometries when the difference is greater than the specified threshold;

determine a subsequent difference between the subsequent set of estimated touch data and a previous set of estimated touch data; and

iteratively update the estimated touch geometries of the two or more estimated touches until the subsequent difference is less than the specified threshold.

18. The apparatus of claim 16 , wherein the processing element is further configurable to:

determine actual touch orientations of the two or more actual touches based on the first set of actual touch data and the second set of estimated touch data; and

output the actual touch orientations when the error between the two or more estimated touches and the two or more actual touches is less than the specified threshold.

19. The apparatus of claim 15 , further comprising the sense array, wherein the sense array is a capacitive sense array, and wherein the capacitive image comprises a plurality of cells each with a capacitance value of an intersection of sense elements of the capacitive sense array.

20. The apparatus of claim 15 , further comprising the sense array, wherein the sense array is an optical sense array.