1. An article of manufacture comprising a non-transitory computer-readable medium with instructions encoded thereon, the instructions configured to cause one or more processors to perform a method comprising: obtaining an image based on a document capture process performed on a rendered document; identifying a portion of the image, the portion comprising a sequence of text units; segmenting the portion of the image into a sequence of segmented sub-images, each segmented sub-image comprising a single text unit of the sequence of text units; for each segmented sub-image of the sequence of segmented sub-images: determining that one or more features of the segmented sub-image are classified as being similar to one or more corresponding features of a stored sub-image; and based on determining that one or more features of the segmented sub-image are classified as being similar to one or more corresponding features of the stored sub-image, assigning to the segmented sub-image a text unit identity that is associated with the stored sub-image; generating a representation of the portion of the image, based on the assigned text unit identities; and identifying the sequence of segmented sub-images, based on the generated representation.