Multi-touch input discrimination
AssigneeApple Inc.
InventorWayne Carl Westerman
Life of this patent
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Abstract
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.
Claims34
A method to discriminate input sources to a touch-surface device, comprising:
- obtaining a proximity image;
- segmenting the proximity image to identify a plurality of patches;
- determining a eccentricity value for each of the plurality of patches;
- identifying a first patch as a thumb contact if the eccentricity value of the first patch is greater than a first threshold;
- determining a minor radius value for each of the plurality of patches;
- ignoring each patch having a minor radius value greater than a second threshold:
- and
- using the identified patch to control an operation of a touch-surface device.
A method to discriminate input sources to a touch-surface device, comprising:
- obtaining a proximity image;
- segmenting the proximity image to identify a plurality of patches, each patch having one or more pixels, each pixel having a value;
- reducing the value of each pixel in a non-linear fashion;
- determining a minor radius value for each of the plurality of patches;
- identifying a first patch as a palm contact if the minor radius of the first patch is greater than a specified threshold;
- and
- using the identified patch to control an operation of a touch-surface device.
A method to discriminate input sources to a touch-surface device, comprising:
- obtaining a proximity image;
- segmenting the proximity image to identify one or more patches, each patch having a plurality of pixels, each pixel have a value;
- reducing the value of each pixel in a non-linear fashion;
- determining an eccentricity value for each of the plurality of patches;
- determining a minor radius value for each of the plurality of patches;
- identifying each patch having a minor radius value greater than a first threshold as a palm contact, said patches associated with a first group of patches;
- identifying each patch having a minor radius value less than the first threshold and an eccentricity value greater than a second threshold as a thumb contact, said patches associated with a second group of patches;
- identifying each patch having a minor radius value less than the first threshold and an eccentricity value less than the second threshold as a fingertip contact, said patches associated with a third group of patches;
- and
- using the identified patches to control an operation of a touch-surface device.
Dependencies are inferred from the claim text.