Vision-based user interface and related method

1. A vision-based user interface comprising:

an image input unit for capturing frame images;

an image processor for recognizing a posture in at least one of the captured frame images, and generating a recognized gesture according to the posture; the image processor comprising:

a hand area localization unit for limiting range for recognizing the posture to a limited range of the at least one captured frame images;

a feature extraction unit for obtaining candidate color blocks within the limited range, fitting the candidate color blocks into rectangular windows, and extracting variant features from each rectangular window; and

a model matching unit for transferring the variant features into parallel classifiers to generate a matching calculation result, and determining each rectangular window to be a posture-containing window or a none window, wherein each parallel classifier has a pre-built model corresponding to at least one predefined posture; and

a control unit for generating a control command corresponding to the recognized gesture.

2. The vision-based user interface of claim 1 , wherein the image processor further comprises:

an area merging unit for merging two or more posture-containing windows into a merged block according to distribution of the two or more posture-containing windows.

3. The vision-based user interface of claim 2 , wherein the image processor further comprises:

a feature tracking unit for searching possible positions in the current frame image according to features extracted from pre-gestures to generate a position; and

a motion prediction unit for predicting the position according to previous velocity of a hand over the at least one captured frame images.

4. The vision-based user interface of claim 3 , wherein the image processor further comprises:

an information fusion unit for combining outputs of the feature tracking unit and the motion prediction unit.

5. The vision-based user interface of claim 4 , wherein the image processor further comprises:

a gesture recognition unit electrically connected to the hand posture detection unit and the hand gesture tracking unit for outputting the recognized gesture according to a hand posture type outputted by the hand posture detection unit and a hand movement outputted by the hand gesture tracking unit.

6. A method of controlling a device according to a gesture, the gesture performed by a user, the method comprising:

capturing frame images by an image input unit;

limiting range for recognizing the posture to a limited range of the at least one captured frame images;

obtaining candidate color blocks within the limited range;

fitting the candidate color blocks into rectangular windows;

extracting variant features from each rectangular window;

transferring the variant features into parallel classifiers to generate a matching calculation result, wherein each parallel classifier has a pre-built model corresponding to at least one predefined posture;

determining each rectangular window to be a posture-containing window or a none window;

recognizing a posture in at least one of the captured frame images by an image processor;

generating a recognized gesture according to the posture by the image processor; and

generating a control command corresponding to the recognized gesture by a control unit.

7. The method of claim 6 , further comprising:

merging two or more posture-containing windows into a merged block according to distribution of the two or more posture-containing windows.

8. The method of claim 7 , further comprising:

(a) searching possible positions in the current frame image according to features extracted from pre-gestures to generate a position; and

(b) predicting the position according to previous velocity of a hand over the at least one captured frame images.

9. The method of claim 8 , further comprising:

combining results of steps (a) and (b) to generate a tracking result.

10. The method of claim 9 , further comprising:

outputting the recognized gesture according to a hand posture type and a hand movement.