1. A method of detecting an orientation of a digital radiograph, comprising the steps of: accessing the radiograph; locating a region of interest in the radiograph; and using the located region of interest and a pre-trained classifier to detect the orientation of the radiograph; wherein the method further comprise the step of, prior to locating a region of interest in the radiograph, preprocessing the radiograph; wherein the step of preprocessing the radiograph comprises the steps of: sub-sampling the radiograph; segmenting the radiograph into foreground, background, and anatomy regions; removing the foreground region and the background region from the radiograph; and normalizing the intensity of the anatomy region of the radiograph.