78. A non-transitory computer-readable storage medium storing executable computer program instructions for recognizing a visual gesture, the computer program instructions comprising code for: receiving a visual gesture formed by a part of a human body, the visual gesture being captured in a video having a plurality of video frames; determining a region of interest (ROI) in the plurality of video frames of the video based on motion vectors associated with the part of the human body, a centroid of the ROI aligned to be a centroid of a cluster of the motion vectors; applying different visual gesture recognition processes to the plurality of video frames in parallel; merging results of the different visual gesture recognition processes to recognize the visual gesture; determining variations in the centroid, shape, and size of an object within the ROI of the plurality of video frames, the centroid, shape, and size of the object changing according to motion of the object in the plurality of video frames in an affine motion model, wherein said determination of the variations in the centroid, shape and size of the object within the ROI is performed by a track-learning-detection-type (TLD-type) process, wherein the TLD-type process is a signal processing scheme in which following functions are performed simultaneously: object tracking, by use of motion estimation in the affine motion model, either using optical flow, or block-based motion estimation and employing estimation error metrics comprising a sum of absolute differences (SAD) and normalized correlation coefficient (NCC); object feature learning, which automatically learns features of objects within the ROI, the features including size, centroids, statistics and edges; and object detection comprising: feature extraction employing edge analysis, spatial transforms, and background subtraction, feature analysis employing clustering and vector quantization, and feature matching employing signal matching using similarity metrics, neural networks, support vector machines, and maximum posteriori probability; and deriving three or more dimensional information and relationships of objects contained in the visual gesture from the plurality of video frames capturing the visual gesture based on the merged results of the different visual gesture recognition processes.
104. The computer-readable storage medium of claim 78 , wherein the computer program instructions for applying the different visual gesture recognition processes to the plurality of video frames comprise computer program instructions for: analyzing a plurality of features extracted from the plurality of video frames of the visual gesture; determining whether to apply a shape-based visual gesture recognition process or a motion-assisted visual gesture recognition process based on the analyzing of the plurality of the features; responsive to a determination of applying the shape-based visual gesture recognition process, applying the shape-based visual gesture recognition process to the plurality of the video frames capturing the visual gesture to recognize a shape gesture; and responsive to a determination of applying the motion-assisted visual gesture recognition process, applying the motion-assisted visual gesture recognition process to the plurality of the video frames capturing the visual gesture to recognize a motion gesture.