Multi-touch input discrimination

摘要

Techniques for identifying and discriminating between different types of contacts to a multi-touch touch-screen device are described. Illustrative contact types include fingertips, thumbs, palms and cheeks. By way of example, thumb contacts may be distinguished from fingertip contacts using a patch eccentricity parameter. In addition, by non-linearly deemphasizing pixels in a touch-surface image, a reliable means of distinguishing between large objects (e.g., palms) from smaller objects (e.g., fingertips, thumbs and a stylus) is described.

主权项

1. A method to discriminate input sources to a touch-surface device, comprising:
obtaining a proximity image; compensating the proximity image for background noise; filtering the proximity image to reduce spurious peaks, the filtering being distinct from the compensating; segmenting the proximity image to identify a plurality of patches having patch pixel values; reducing or down-scaling peripheral patch pixel values for one or more of the plurality of patches based on the compensated proximity image and the filtered proximity image, the reducing or down-scaling being distinct from the compensating and filtering; determining an eccentricity value for one or more of the reduced or down-scaled peripheral patch pixel values of the plurality of patches; identifying a first patch having an eccentricity value greater than a first threshold; and using the identified patch to control an operation of a touch-surface device.