1. A non-transitory program storage device, readable by a processor and comprising instructions stored thereon to cause one or more processors to: acquire a depth image of a scene in the vicinity of an intelligent system, the first depth image having a first plurality of pixels, each pixel having a value indicative of a distance; store the depth image in a memory; develop a scene geometry based upon the depth image; determine that a user is engaging the intelligent system; identify a human hand in a region of space based on the first plurality of values; identify a three-dimensional region about the human hand, wherein the three-dimensional region includes at least some of the first plurality of pixels; partition the three-dimensional region about the hand into a second plurality of sub-regions, each sub-region having a corresponding value; generate a feature vector for the hand based on the second plurality of corresponding values; apply the feature vector to a classifier; determine the hand as making an identified gesture based on output from the classifier; and cause an action to be taken based upon the identified gesture and the scene geometry.