1. A system comprising: one or more computers; and a memory storage apparatus in data communication with the one or more computers, the memory storage apparatus storing instructions executable by the one or more computers and that upon such execution cause the one or more computers to perform operations comprising: receiving a digital image that depicts a document that includes words; performing a first optical character recognition operation on the digital image to extract, from the digital image, a portion of the words included in the document, the portion including fewer words than the document; determining a document type of the document based on the portion of the words; selecting between at least two dictionary based language models according to the document type of the document; performing a second optical character recognition operation on the digital image to extract, from the digital image, the words included in the document; processing the words extracted by the second optical character recognition operation in accordance with the selected dictionary based language model; indexing the digital image based on the processed words; and storing the digital image for later retrieval based on one or more received search terms.