Multipoint tracking method and related device

• US 8,135,171 B2
• Filed: 08/19/2008
• Issued: 03/13/2012
• Est. Priority Date: 08/19/2008
• Status: Active Grant

• Current Assignee: Optronic Sciences LLC
• Original Assignee: AU Optronics Corporation
• Inventors: Ho, Chen-Hsiang, Yang, Chia-Feng, Hsu, Yu-Min
• Primary Examiner(s): CHANG, JON CARLTON
• Application Number:
  US12/194,530
• Publication Number:
  US 20100046850A1
• Time in Patent Office: 1,302 Days
• Field of Search: 382/103, 382/257, 382/180, 382/199, 382/258, 382/260, 382/264, 382/288, 348169-172, 345/173, 345/174, 345/178
• US Class Current: 382/103
• CPC Class Codes: G06F 2203/04808 Several contacts: gestures triggering a specific function, e.g. scrolling, zooming, right-click, when the user establishes several contacts with the surface simultaneously; e.g. using several fingers or a combination of fingers and pen
• CPC Class Codes: G06F 3/04883 for inputting data by handwriting, e.g. gesture or text
• CPC Class Codes: G06T 7/12 Edge-based segmentation
• CPC Class Codes: G06T 7/155 involving morphological operators
• CPC Class Codes: G06T 7/246 using feature-based methods, e.g. the tracking of corners or segments
• CPC Class Codes: G06T 7/66 of image moments or centre of gravity

Abstract

Multipoint tracking is performed by receiving raw data of an image, calculating line average values for a plurality of lines of the raw data, filtering the raw data according to the line average values to generate filtered data, performing a dilation algorithm on the filtered data to generate dilated data, performing an erosion algorithm on the dilated data to generate eroded data, performing edge detection on the eroded data for identifying touch regions of the raw data, performing a labeling algorithm on the touch regions, calculating centers of gravity for the touch regions, and generating a multipoint tracking result according to the centers of gravity.

Claims

1. A method of performing multipoint tracking, the method comprising:

receiving raw data of an image;

calculating line average values for a plurality of lines of the raw data;

filtering the raw data according to the line average values to generate filtered data;

performing a dilation algorithm on the filtered data to generate dilated data;

performing an erosion algorithm on the dilated data to generate eroded data;

performing edge detection on the eroded data for identifying touch regions of the eroded data;

performing a labeling algorithm on the touch regions;

calculating centers of gravity for the touch regions; and

generating a multipoint tracking result according to the centers of gravity.

2. The method of claim 1, wherein performing edge detection for identifying the touch regions of the raw data is performing a logical AND on a result of the dilation algorithm and an inverted result of the erosion algorithm.

3. The method of claim 1, wherein performing the dilation algorithm on the filtered data is assigning a first predetermined value to a point of the filtered data when an adjacent point is of the first predetermined value.

4. The method of claim 3, wherein assigning the first predetermined value to the point of the filtered data when the point or the adjacent point is of the first predetermined value is assigning the first predetermined value to the point of the filtered data when a horizontally adjacent point or a vertically adjacent point is of the first predetermined value.

5. The method of claim 1, wherein performing the erosion algorithm on the dilated data is assigning a second predetermined value to a pixel of the dilated data when part of horizontally adjacent pixels and all vertically adjacent pixels are of a first predetermined value.

6. The method of claim 1, wherein filtering the raw data comprises:

setting a threshold value for each of the line average values;

comparing each point with the threshold value of the line average for the line of the point;

determining points as touch points according to the threshold value; and

combining the touch points to determine the touch regions.

7. The method of claim 1, wherein performing the labeling algorithm on the touch regions is applying different marks to edges corresponding to each touch region.

8. The method of claim 1, wherein performing the labeling algorithm on the touch regions comprises determining number of the touch regions.

9. The method of claim 1, wherein calculating the center of gravity for each of the touch regions is determining a coordinate pair for each of the touch regions according to a center of gravity algorithm.

10. The method of claim 9, wherein generating the multipoint tracking result is outputting the coordinate pairs corresponding to the touch regions.

11. A multipoint tracking device comprising:

a receiver module for receiving raw data of an image;

a line average module for calculating a line average value for each of a plurality of lines of the raw data;

a filter module for filtering the raw data to generate filtered data;

a dilation module for performing a dilation algorithm on the filtered data to generate dilated data;

an erosion module for performing an erosion algorithm on the dilated data to generate eroded data;

an edge detection module for performing edge detection for identifying touch regions of the eroded data;

a labeling module for performing a labeling algorithm on the touch regions;

a center of gravity module for calculating a center of gravity for each of the touch regions; and

an output module for outputting a multipoint tracking result based on the centers of gravity calculated for each of the touch regions.

12. The multipoint tracking device of claim 11, wherein the edge detection module comprises an AND module for performing an AND operation on a result of the dilation algorithm and a result of the erosion algorithm.

13. The multipoint tracking device of claim 11, wherein the dilation module comprises a dilation comparison module for comparing a point of the filtered data with adjacent points of the filtered data.

14. The multipoint tracking device of claim 13, wherein the dilation comparison module is for comparing the point of the filtered data with horizontally adjacent points and vertically adjacent points.

15. The multipoint tracking device of claim 11, wherein the erosion module comprises an erosion comparison module for comparing a pixel of the dilated data with horizontally adjacent pixels and vertically adjacent pixels.

16. The multipoint tracking device of claim 11, wherein the filtering module comprises:

a threshold generation module for setting a threshold value for each of the line average values;

a threshold comparison module for comparing each point with the threshold value of the line average for the line of the point;

a touch point identification module for determining points under the threshold value as touch points; and

a touch region generation module for combining the touch points to determine the touch regions.

17. The multipoint tracking device of claim 11, wherein the labeling module is for applying different marks to edges corresponding to each touch region.

18. The multipoint tracking device of claim 11, wherein the labeling module comprises a summing module for determining number of the touch regions.

19. The multipoint tracking device of claim 11, wherein the center of gravity module comprises a coordinate determination module for determining a coordinate pair for each of the touch regions according to a center of gravity algorithm.