1. A computer-implemented method for training a specialized recognition engine to recognize a preselected attribute of a facial image, the specialized recognition engine specialized for a range of head poses, the method comprising: for each of a plurality of facial images of heads that are within the range of head poses for the specialized recognition engine: identifying a pair comprising a known good facial image and a known good specialized recognition metric, wherein the known good facial image is for a same head as said facial image and has the same preselected attribute as said facial image but for a head pose within a range of head poses that is different than the range of head poses for the specialized recognition engine, and the known good specialized recognition metric is indicative of the preselected attribute of the known good facial image; and associating a specialized recognition metric with said facial image, wherein the specialized recognition metric is derived from the known good specialized recognition metric; and training the specialized recognition engine by using pairs comprising the plurality of facial images and the associated specialized recognition metrics as a training set for supervised learning.