Irregular input identification

• US 9,411,468 B2
• Filed: 08/13/2012
• Issued: 08/09/2016
• Est. Priority Date: 01/03/2007
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Westerman, Wayne Carl
• Primary Examiner(s): MARINELLI, PATRICK
• Application Number:
  US13/584,725
• Publication Number:
  US 20120306800A1
• Time in Patent Office: 1,457 Days
• Field of Search: 345156-183, 345/104, 382/172, 382/312, 382/191, 382/181, 382/203, 382/210, 178 1801- 2004
• US Class Current: 1/1
• CPC Class Codes: G06F 2203/04101 2.5D-digitiser, i.e. digitiser detecting the X/Y position of the input means, finger or stylus, also when it does not touch, but is proximate to the digitiser's interaction surface and also measures the distance of the input means within a short range in the Z direction, possibly with a separate measurement setup
• CPC Class Codes: G06F 2203/04104 Multi-touch detection in digitiser, i.e. details about the simultaneous detection of a plurality of touching locations, e.g. multiple fingers or pen and finger
• CPC Class Codes: G06F 3/04166 Details of scanning methods, e.g. sampling time, grouping of sub areas or time sharing with display driving Synchronisation with the driving of the display or the backlighting unit to avoid interferences generated internally G06F3/04184
• CPC Class Codes: G06F 3/04182 Filtering of noise external to the device and not generated by digitiser components
• CPC Class Codes: G06F 3/04186 Touch location disambiguation
• CPC Class Codes: G06F 3/044 by capacitive means
• CPC Class Codes: G06F 3/0488 using a touch-screen or digitiser, e.g. input of commands through traced gestures
• CPC Class Codes: G06T 5/20 using local operators
• CPC Class Codes: G06T 5/70 Denoising; Smoothing
• CPC Class Codes: G06T 7/11 Region-based segmentation
• CPC Class Codes: G06T 7/41 based on statistical description of texture
• CPC Class Codes: G06V 40/107 Static hand or arm

Abstract

Techniques for identifying irregular objects in contact with, or in close proximity to, a touch-surface are described. An irregularity measure is determined based on the regions intrinsic characteristics (e.g., energy content) rather than on the shape (or pattern) of the pixels within the region.

Claims

1. A method to process a proximity image, comprising:

receiving a proximity image;

smoothing the proximity image to generate a filtered proximity image;

generating a dispersion image by subtracting the filtered proximity image from the proximity image;

determining an irregularity measure value for the dispersion image, the irregularity measure value indicating a degree of irregularity in the shape of the dispersion image; and

controlling an operation of a touch-surface device if the irregularity measure value is above a specified threshold.

2. The method of claim 1, wherein the specified threshold comprises a constant function.

3. The method of claim 1, wherein the specified threshold comprises a linear function.

4. The method of claim 1, wherein the specified threshold comprises a non-linear function.

5. The method of claim 1, wherein the specified threshold comprises two or more linear functions.

6. The method of claim 1, wherein the operation of the touch-surface device comprises causing the touch-surface device to obtain baseline touch-surface sensor values.

7. The method of claim 1, wherein the operation of the touch-surface device comprises:

utilizing multiple sampling frequencies for operation of the touch-surface device;

determining an irregularity measure value corresponding to each of the multiple sampling frequencies;

ignoring a touch-surface sensor sampling frequency during touch-surface device operations when a corresponding determined irregularity measure value is greater than the specified threshold.

8. The method of claim 1, wherein the operation of a touch-surface device comprises causing the touch-surface device to enter into a low-power state.

9. The method of claim 1, wherein the operation of a touch-surface device comprises causing the touch-surface device to exit a low-power state.

10. The method of claim 1, wherein the touch-surface device comprises one of the devices selected from the group of tablet computer system, notebook computer system, portable music player, portable video player, personal digital assistant and mobile telephone.

11. A non-transitory program storage device, readable by a programmable control device, comprising instructions stored thereon for causing the programmable control device to perform the method of claim 1.

12. A portable electronic device, comprising:

a touch input touch-surface component of the touch-surface device;

means for receiving a proximity image from the touch input touch-surface component; and

processing means for performing the acts of smoothing, generating, determining and controlling in accordance with claim 1.

13. The device in accordance with claim 12, wherein the processing means is operative for:

determining a far field image form the proximity image; and

controlling operation of the mobile telephone based on both the determined irregularity measure value and the far field image.

14. The device in accordance with claim 12, wherein the portable electronic device comprises is selected from the group consisting of a tablet computer system, a hand-held computer system, a portable music player system, a portable video player system and a mobile telephone.

35. The method of claim 1 wherein the irregularity measure indicates a general roughness or non-roundness in the dispersion image.

15. A method to identify an irregular input source to a touch-surface device, comprising:

obtaining a proximity image;

generating a dispersion image from the proximity image;

segmenting the proximity image to identify a plurality of patches;

determining an irregularity measure value for each of the plurality of patches based on the dispersion image, the irregularity measure value indicating a degree of irregularity in the space of each of the plurality of patches;

identifying one of the plurality of patches as being associated with an irregular object when the irregularity measure value of the one patch is above a specified threshold;

controlling an operation of the touch-surface device based on the identification of the irregular object;

smoothing the proximity image to generate a filtered proximity image;

wherein the act of generating the dispersion image comprises subtracting the filtered proximity image from the proximity image; and

wherein the act of determining an irregularity measure value for each of the plurality of patches comprises at least determining a total energy value for each of the plurality of patches.

16. The method of claim 15, wherein the act of determining comprises:

determining a spatial energy value for each of the plurality of patches;

determining a peak energy value for each of the plurality of patches; and

determining an irregularity measure value for each of the plurality of patches by dividing the difference between the spatial energy value and the peak energy value for each patch by the total energy value for each patch.

17. The method of claim 15, wherein the specified threshold comprises a constant function.

18. The method of claim 15, wherein the specified threshold comprises a linear function.

19. The method of claim 15, wherein the specified threshold comprises a non-linear function.

20. The method of claim 15, wherein the specified threshold comprises two or more linear functions.

21. The method of claim 15, wherein the irregular patch comprises a patch formed by an ear.

22. The method of claim 15, wherein the act of identifying comprises distinguishing a patch associated with an irregular object from a patch associated with a large object based on the irregularity measure value for the patch associated with the irregular object being greater than the specified threshold and the irregularity measure value for the patch associated with the large object being less than the specified threshold.

23. The method of claim 22, wherein the large object comprises a cheek, a chest or a leg.

24. The method of claim 22, wherein the irregular object comprises an ear, coin, or a key.

25. The method of claim 15, wherein the act of identifying comprises distinguishing a patch associated with an irregular object from a patch associated with a small regular object based on the irregularity measure value for the patch associated with the irregular object being greater than the specified threshold and the irregularity measure value for the patch associated with the small regular object being less than the specified threshold.

26. The method of claim 25, wherein the small regular object comprises a finger or a thumb.

27. The method of claim 15, wherein the plurality of patches have patch pixel values and the method further comprising:

compensating the proximity image for background noise;

filtering the proximity image; and

reducing or down-scalling peripheral patch pixel values for one or more of the plurality of patches based on the compensated proximity image and the filtered proximity image.

28. A non-transitory program storage device, readable by a programmable control device, comprising instructions stored thereon for causing the programmable control device to perform the method of claim 15.

29. A portable electronic device, comprising.

a touch input touch-surface component;

means for receiving the proximity image from the touch input touch-surface component; and

processing means for performing the acts of generating, segmenting, determining, identifying and controlling in accordance with claim 15.

30. The device in accordance with claim 29, wherein the portable electronic device comprises a tablet computer system.

31. The device in accordance with claim 29, wherein the portable electronic device comprises a hand-held computer system.

32. The device in accordance with claim 29, wherein the portable electronic device comprises a mobile telephone.

33. The device in accordance with claim 29, wherein the portable electronic device comprises a portable music player system.

34. The device in accordance with claim 29, wherein the portable electronic device comprises a portable video player system.

36. A device having a touch screen, the device operative to process a proximity image, comprising:

means for receiving a proximity image;

means for smoothing the proximity image to generate a filtered proximity image;

means for generating dispersion image from a difference between the proximity image and the filtered proximity image;

means for determining an irregularity measure value for the dispersion image, the irregularity measure value indicating a degree of irregularity in the shape of the dispersion image; and

means for controlling an operation of a touch-surface device if the irregularity measure value is above a specified threshold.

37. A method to process a proximity image to discriminate between ear and earlobe contacts as distinguished from other contacts in a mutual capacitance touch surface mobile telephone device, comprising:

obtaining a proximity image based on a disturbance in an electric field of a two dimensional array of sensing elements of the mutual capacitance touch surface mobile telephone device;

smoothing the proximity image to generate a filtered proximity image;

generating a dispersion image defined by the difference between the proximity image and the filtered proximity image;

segmenting the proximity image to identify a plurality of patches;

determining an irregularity measure value for each of the plurality of patches based on the identified patches and the dispersion image, wherein the irregularity measure value indicates a degree of irregularity in the shape of the dispersion image associated with the ear or earlobe positioned near or in contact with the mutual capacitance touch surface mobile telephone device;

identifying one of the plurality of patches as being associated with the ear or earlobe contact or near contact if the irregularity measure value of the one patch is above a specified threshold; and

controlling the operation of the mutual capacitance touch surface mobile telephone device based on the identification of the ear or earlobe contact.