1. A method of detecting a face in a matrix of pixels representing an image, the method comprising: computing a vector having amplitude and direction for each of a plurality of sub-matrices, the sub-matrices having size estimated to be a facial feature size in the image; inspecting each sub-matrix to determine if the amplitude exceeds a threshold, wherein sub-matrices having amplitude exceeding the threshold are deemed facial feature candidate sub-matrices, establishing distance and angle criteria for relationships among candidate sub-matrices that match facial features; and identifying sets of candidate sub-matrices matching the distance and angle criteria to detect the presence of a face in the image.