1. A computer-implemented method for detecting and classifying gestures, comprising: receiving, by a processor, an unsegmented stream of data associated with a hand gesture, wherein the processor is configured as a three-dimensional convolutional neural network (3D-CNN) for unified detection and classification of gestures; extracting spatio-temporal features from the unsegmented stream by the 3D-CNN; and producing a class label for the hand gesture based on the spatio-temporal features.