Gesture judgment method used in an electronic device

1. A gesture judgment method used in an electronic device having a frame capturing function, the gesture judgment method comprising:

obtaining a plurality of motion history image (MHI) angles/directions from a plurality of MHIs;

judging whether a current gesture control is valid according to the MHI angles/directions; and

performing weight assignment on the MHI angles/directions to obtain a judgment result of the current gesture control if the current gesture control is valid.

2. The gesture judgment method according to claim 1 , wherein, the step of judging whether the current gesture control is valid comprises:

counting a continuous quantity of the MHI angles/directions; and

judging whether the current gesture control is valid according to the continuous quantity.

3. The gesture judgment method according to claim 2 , wherein if the continuous quantity is between a high threshold and a low threshold, then the current gesture control is judged as valid.

4. The gesture judgment method according to claim 2 , wherein, if the quantity of black MHIs occurring in the MHIs is larger than a predetermined value, then the continuous quantity is reset, wherein the black MHIs are MHIs caused by background IR calibration.

5. The gesture judgment method according to claim 2 , wherein, if a black MHI only occurs once in the MHIs, then the continuous quantity is not reset, wherein the black MHI is an MHI caused by background IR calibration.

6. The gesture judgment method according to claim 1 , wherein, the step of weight assignment comprises:

increasing a quantity of MHI angles/directions relating to a middle stage of a gesture;

maintaining or decreasing a quantity of MHI angles/directions relating to an initial gesture or a frame-entering gesture; and

maintaining or decreasing a quantity of MHI angles/directions relating to a finishing gesture or a frame-exiting gesture.

7. The gesture judgment method according to claim 6 , wherein, after assignment, the MHI angle/direction having largest quantity is a representative angle/direction of the current gesture control.

8. The gesture judgment method according to claim 1 , further comprising:

performing a next gesture judgment after a pre-determined period is elapsed, wherein a pre-determined number of MHIs are received in the pre-determined period and these received MHIs are excluded from said next gesture judgment.