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; segmenting the proximity image to identify a plurality of patches; 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; determining a major axis radius value for at least one patch having a reducing or down-scaling peripheral patch pixel value; identifying the at least one patch as being associated with a large object when the determined major axis radius value of the at least one patch is above a first specified threshold; and using the identified patch to control an operation of the touch-surface device.