RECONSTRUCTION OF ORIGINAL TOUCH IMAGE FROM DIFFERENTIAL TOUCH IMAGE

• US 20130271427A1
• Filed: 04/16/2012
• Published: 10/17/2013
• Est. Priority Date: 04/16/2012
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: William Matthew Vieta
• Inventors: Vieta, William Matthew, Westerman, Wayne Carl, Hotelling, Steven Porter, BENBASAT, Ari Y.
• Granted Patent: US 9,329,723 B2
• Time in Patent Office: Days
• US Class Current: 345/175
• CPC Class Codes: G06F 3/0418 for error correction or compensation, e.g. based on parallax, calibration or alignment

Abstract

Reconstruction of an original touch image from a differential touch image is disclosed. Reconstruction can include aligning columns of the differential touch image relative to each other and aligning the image to a baseline DC value. The column and baseline alignment can be based on the differential image data indicative of no touch or hover, because such data can more clearly show the amount of alignment needed to reconstruct the original image. The reconstruction can be performed using the differential image data alone. The reconstruction can also be performed using the differential image data and common mode data indicative of the missing image column average.

Claims

1. A method for reconstructing a first image from a second image comprising:

capturing the second image on a touch sensitive device;

aligning columns of image data in the second image with each other; and

aligning the column-aligned image data with a baseline value of the first image to reconstruct the first image.

2. The method of claim 1, wherein the reconstruction is based on the image data alone.

3. The method of claim 1, wherein aligning columns of image data comprises calculating an offset for each column, the offset indicative of the amount of misalignment of the column with the other columns.

4. The method claim 1, wherein aligning the column-aligned image data comprises calculating a global offset for the column-aligned image data, the offset indicative of the amount of alignment to reach the baseline value of the first image.

5. The method of claim 1, further comprising:

capturing common mode data associated with the second image, wherein the reconstruction is based on the image data and the common mode data.

6. The method of claim 5, wherein aligning columns of image data comprises:

estimating a baseline value for each column based on the common mode data; and

calculating an offset for each column based on the estimated baseline value, the offset indicative of the amount of alignment for the column with the other columns.

7. The method of claim 5, wherein aligning the column-aligned image data comprises:

estimating a baseline value for each column based on the common mode data; and

calculating a global offset for the column-aligned image data based on the estimated baseline value, the offset indicative of the amount of alignment to reach the baseline value of the first image.

8. The method of claim 5, wherein aligning columns of image data comprises:

selectively utilizing the common mode data; and

calculating an offset for each column based on the selectively utilized common mode data, the offset indicative of the amount of misalignment of the column with other columns.

9. The method of claim 5, wherein aligning the column-aligned image data comprises:

selectively utilizing the common mode data; and

calculating a global offset from the column-aligned image data based on the selectively utilized common mode data, the offset indicative of the amount of alignment to reach the baseline value of the first image.

10. The method of claim 1, further comprising:

detecting an erroneous baseline value from the image data of the second image.

11. A method for reconstructing an original touch image from a differential touch image comprising:

capturing the differential touch image at a touch sensitive device;

performing a column alignment to align columns of the differential touch image with each other; and

performing a baseline alignment to align the column-aligned differential touch image with a baseline value of the original touch image, resulting in the reconstructed original touch image.

12. The method of claim 11, wherein capturing the differential touch image comprises performing a differential scan of the device to provide image data in each column of the differential touch image has a sum of approximately zero.

13. The method of claim 11, wherein performing a column alignment comprises utilizing image data of the differential touch image corresponding to untouched regions of the device.

14. The method of claim 11, wherein performing a baseline alignment comprises utilizing image data of the differential touch image corresponding to untouched regions of the device.

15. A method for reconstructing an original touch image from a differential touch image, comprising:

capturing the differential touch image at a touch sensitive device;

capturing common mode data at the device;

performing a column alignment to align columns of the differential touch image to each other based on the captured common mode data; and

performing a baseline alignment to align the column-aligned differential touch image with a baseline value of the original touch image based on the captured common mode data, resulting in the reconstructed original touch image.

16. The method of claim 15, comprising:

estimating a second baseline value for the differential touch image based on the captured common mode data; and

utilizing the estimated second baseline value for the column and baseline alignments.

17. The method of claim 16, wherein utilizing a histogram comprises:

sorting image data of the differential touch image having the captured common mode data applied thereto among bins of the histogram; and

identifying the bins having highest counts, the identified bins indicative of the second baseline value.

18. A method for reconstructing an original touch image from a differential touch image, comprising:

capturing the differential touch image at a touch sensitive device;

capturing common mode data at the device;

weighting the captured common mode data;

performing a column alignment to align columns of the differential touch image to each other based on the weighing; and

performing a baseline alignment to align the column-aligned differential touch image with a baseline value of the original touch image based on the weighting, resulting in the reconstructed original touch image.

19. The method of claim 18, comprising:

estimating a second baseline value for the differential touch image based on the captured common mode data; and

weighting the second baseline value along with the captured common mode data.

20. The method of claim 19, wherein weighting the captured common mode data comprises:

weighting the captured common mode data more heavily when non-touch image data in the differential touch image is limited, the non-touch data indicative of lack of a proximate object.

21. A method for reconstructing an original touch image from a differential touch image, comprising:

capturing the differential touch image at a touch sensitive device;

calculating a parameter associated with at least some column data of the differential touch image; and

applying the parameter to the differential touch image to reconstruct the original touch image.

22. The method of claim 21, wherein the parameter is at least one of a minimum, a median, a mode, a mean, or a weighted mean of the at least some column data.

23. A touch sensitive device comprising:

a touch panel capable of sensing a proximate object;

scan logic couplable to the touch panel and capable of performing a scan of the touch panel so as to capture a first touch image; and

a processor capable of reconstructing a second touch image from the first touch image, the reconstructing including;

calculating first alignments for portions of the first touch image, each portion having a different first alignment,

aligning the portions with each other according to the first alignments to form an aligned first image,

calculating a second alignment for the aligned first image, and

aligning the aligned first image according to the second alignment to meet a baseline value of the second touch image so as to form the reconstructed second touch image.

24. The device of claim 23, wherein the first image is a differential touch image and the second image is an original touch image.

25. The device of claim 23 comprising at least one of a computer, a media player, or a mobile telephone.