1. A method of analysis, comprising: registering a target image to define a plurality of keypoints arranged in sets corresponding to polygons or linear segments in the target image; accessing a database of registered and annotated images, and employing a polygon-wise comparison between the target image and each database image; and using said comparison for projecting annotated locations from said database images into the target image; wherein the target image is an image of a craniofacial complex of a subject, wherein said annotated locations correspond to cephalometric landmarks and wherein the method further comprises extracting cephalometric features from the target image based on said annotated locations and calculating characteristic pharyngeal airflow resistance, based, at least in part, on said cephalometric features.