A real property document processing system can parse real property documents such as appraisal documents to extract useful information relating to real property assets. The system can extract images, text, and other information. Using the extracted information, the system can associate extracted images with portions of text as corresponding captions. Caption association can be performed based on results of directional analyses performed on each page of the real property document. In addition, caption associate can be performed based on results of context analyses—the system can determine appropriate captions by comparing the text of caption candidates against known keywords associated with contexts determined for the images. By analyzing the images and their associated captions, the system can detect one or more real property features depicted in each of the images. The real property features can be used to assign searchable tags to the images.