1. A computing device, comprising: a processor; and a memory configured to maintain digital images and computer-readable instructions that are executable on the processor to implement a face detection application that is configured to perform operations comprising: learning weak classifiers of an adaboost technique as exemplars taken from example images, the weak classifiers of an exemplar being partitioned into partitions associated with a positive confidence score, a negative confidence score, and an uncertain confidence score, the partitions each corresponding to a range of similarity score values that result in a determination of the associated confidence score when a similarity score generated from the exemplar is within the range; applying each of the weak classifiers of the adaboost technique to an image of the digital images, including generating similarity scores from the exemplars; determining confidence scores for each of the weak classifiers as applied to the image based on comparison of the generated similarity scores to the ranges, the determined confidence scores of a weak classifier being an indication of whether a face is detected in the image based on the weak classifier; and generating a face detection score that indicates whether the image includes a face by summing all of the determined confidence scores of the weak classifiers.