1. A system, comprising a computing device that includes a processor and a memory, the memory storing instructions executable by the processor, the instructions including instructions for: using image metadata to perform a first sub-classification of an image, wherein the first sub-classification is deterministic; using a combination of image data and the image metadata to perform a second sub-classification, and in a third sub-classification, using image data to make a probabilistic classification of an image according to a likely phantom type.