System and method for determining user input using polygons
Devices and method are provided that facilitate improved input device performance. Specifically, the systems and methods are configured to identify a portion of an image of sensor values as corresponding to at least one sensed object in the sensing region, determine a polygon corresponding to the identified portion of the image, and determine a contact characterization of the at least one sensed object based on the polygon. The determination of a polygon corresponding to a sensed object facilitates improved contact characterization of the sensed object. For example, the determined polygon may be used to determine if the sensed object is actually more than one object. As a second example, the determined polygon may be used to determine the orientation of the sensed object. In addition, determined polygons may be used to more accurately track changes in the position of the sensed object.
1. A processing system for a capacitive input device configured to sense in a sensing region, the processing system comprising:
a determination module configured to:
identify a portion of an image of sensor values as corresponding to at least one sensed object in the sensing region;
determine a polygon corresponding to the identified portion of the image; and
determine a characterization of the at least one sensed object based on the polygon by determining a count of input objects comprising the at least one sensed object based at least in part on a convexity of the polygon.
2. The processing system of claim 1 , wherein the determination module is configured to determine the polygon corresponding to the identified portion of the image by determining vertices of the polygon.
3. The processing system of claim 1 , wherein the determination module is configured to determine the polygon by determining a vertex of the polygon by comparing a sensor value from the identified portion of the image with at least one adjacent sensor value not from the identified portion of the image.
4. The processing system of claim 3 , wherein the at least one adjacent sensor value not in the identified portion of the image comprises at least one of an directly adjacent sensor value and a diagonally adjacent sensor value.
5. The processing system of claim 1 wherein the determination module is configured to determine the polygon by:
interpolating between at least one sensor value of a plurality of sensor values in the identified portion of the image and at least one adjacent sensor value not in the identified portion of the image.
6. The processing system of claim 1 wherein the determination module is configured to determine the polygon by:
for each sensor value of a plurality of sensor values in the identified portion of the image, interpolating between the sensor value and an adjacent sensor value not in the identified portion of the image.
7. The processing system of claim 1 wherein the determination module is configured to determine the characterization of the at least one sensed object based on a centroid, area, orientation, eccentricity, width, or aspect ratio of the polygon.
8. An input device comprising:
a plurality of capacitive sensor electrodes configured to sense in a sensing region; and
a processing system coupled to the plurality of capacitive sensor electrodes, the processing system configured to:
identify a portion of an image of sensor values corresponding to at least one sensed object in the sensing region;
determine a polygon corresponding to the identified portion of the image corresponding to the at least one sensed object in the sensing region; and
determine a characterization of the at least one sensed object based on the polygon by determining if the at least one sensed object comprises one sensed object or multiple sensed objects based at least in part on convexity of the polygon.
9. The input device of claim 8 , wherein the processing system is configured to determine the polygon corresponding to the identified portion of the image by determining vertices of the polygon.
10. The input device of claim 8 , wherein the processing system is configured to determine the polygon by determining a vertex of the polygon by comparing a sensor value from the identified portion of the image with at least one adjacent sensor value not from the identified portion of the image.
11. The input device of claim 10 , wherein the at least one adjacent sensor value not in the identified portion of the image comprises at least one of a directly adjacent sensor value and a diagonally adjacent sensor value.
12. The input device of claim 10 wherein the processing system is configured to determine the polygon by:
interpolating between at least one sensor value of a plurality of sensor values in the identified portion of the image and at least one adjacent sensor value not in the identified portion of the image.
13. The input device of claim 10 wherein the processing system is configured to determine the polygon by:
for each sensor value of a plurality of sensor values in the identified portion of the image, interpolating between the sensor value and an adjacent sensor value not in the identified portion of the image.
14. A method for determining input in a sensing region, the method comprising:
identifying a portion of an image of sensor values corresponding to at least one sensed object in the sensing region;
determining vertices of a polygon corresponding to the identified portion of the image corresponding to the at least one sensed object in the sensing region; and
determining a characterization of the at least one sensed object based on the polygon by determining if the at least one sensed object comprises one sensed object or multiple sensed objects based at least in part on convexity metric of the polygon.
15. The method of claim 14 wherein the determining the vertices of the polygon comprises comparing a sensor value from the identified portion of the image with at least one adjacent sensor value not from the identified portion of the image.
16. The method of claim 15 wherein the at least one adjacent sensor value not in the identified portion of the image comprises at least one of a directly adjacent sensor value and a diagonally adjacent sensor value.
17. The method of claim 14 wherein the determining the vertices of the polygon comprises interpolating each of a plurality of sensor values in the identified portion of the image with adjacent sensor values not in the identified portion of the image.