Method for recognizing and tracing gesture

• US 8,270,670 B2
• Filed: 12/25/2008
• Issued: 09/18/2012
• Est. Priority Date: 12/25/2008
• Status: Active Grant

• Current Assignee: Jess-Link Products Company Limited
• Original Assignee: Topseed Technology Corp.
• Inventors: Hsu, Che-Hao, Chen, Shoei-Lai
• Primary Examiner(s): Wang, Claire X
• Application Number:
  US12/344,234
• Publication Number:
  US 20100169840A1
• Time in Patent Office: 1,363 Days
• Field of Search: 382/103, 382/107, 382/115, 382/173, 382/288, 345/156, 345/158
• US Class Current: 382/103
• CPC Class Codes: G06F 3/017 Gesture based interaction, e.g. based on a set of recognized hand gestures interaction based on gestures traced on a digitiser G06F3/04883

Abstract

A method for recognizing and tracing a gesture fetches a gesture image by an image sensor. The gesture image is processed for recognizing and tracing, and a corresponding action is performed according to the processed result. The gesture image is pre-processed and then a moved image is detected. The moved image is analyzed to obtain a gesture feature. When the gesture feature is corresponding to a moved gesture, a center coordinate of the moved gesture is detected and outputted to control a cursor. When the gesture feature is corresponding to a command gesture, a relevant action command is outputted. Therefore, the method provides cursor movement and command input by user gesture.

Claims

1. A method for recognizing and tracing a gesture to provide an image sensor (10) to fetch a gesture image, the method comprising the steps of:

(a) pre-processing the gesture image;

(b) detecting a largest moved block of the gesture image and defining the largest moved block as a gesture block, (b1) calculating moved portions of the gesture image by utilizing an analysis of dynamic image difference;

(b2) calculating a largest moved area of the gesture image by gathering statistically horizontal projections and vertical projections of the gesture image;

(b3) filling empty holes of the gesture block by utilizing a dilation method; and

(b4) calculating a largest connected area to detect the largest moved block by labeling connected areas;

(c) analyzing a feature of the gesture block to determine the gesture block is a moved verification gesture or a command gesture;

(d) determining whether the gesture block is successively changed to a moved gesture when the gesture block is the moved verification gesture;

(e) detecting and tracing a center coordinate of the moved gesture when the gesture block successively changes to the moved gesture, and the moved gesture does not stop moving with duration over an action time; and

(f) outputting the center coordinate of the moved gesture and re-performing the step (a).

2. The method in claim 1, wherein the step (a) comprising:

(a1) adjusting processed size of the gesture image;

(a2) transferring colors of the gesture image; and

(a3) filtering speckle noises of the gesture image.

3. The method in claim 1, wherein the step (e) comprising:

(e1) detecting the center coordinate of the moved gesture by utilizing the circular Hough transfer; and

(e2) tracing the center coordinate of the moved gesture by utilizing the sum of accumulator table.

4. The method in claim 1, the step (d) further comprising:

re-performing the step (a) when the gesture block is the moved verification gesture and the gesture block is successively changed to be not a moved gesture.

5. The method in claim 1, the step (d) further comprising:

outputting an action command corresponded to the command gesture and then re-performing the step (a) when the gesture block is the command gesture.

6. The method in claim 1, the step (d) further comprising:

re-performing the step (a) when the gesture block is an undefined gesture.

7. The method in claim 1, the step (e) further comprising:

re-performing the step (a) when the moved gesture stops moving with duration over the action time.

8. The method in claim 1, the step (e) further comprising:

re-detecting the center coordinate of the moved gesture when the center coordinate of the moved gesture is not detected or traced.

9. The method in claim 1, wherein the action time is set to be one second.

10. The method in claim 1, wherein the moved verification gesture is defined as a V-shaped gesture formed by an index finger and a middle finger.

11. The method in claim 1, wherein the moved gesture is defined as a circle-shaped gesture formed by clenching a fist.

12. The method in claim 1, wherein the command gesture is defined as a “

l”

-shaped gesture formed by the index finger.