1. A method of determining a portion of a document corresponding to a captured image, the method comprising: employing a processor that executes instructions retained in a computer-readable medium, the instructions when executed by the processor implement at least the following operations: receiving a captured image with an image capturing device of a portion of a document stored in electronic form, wherein the document has a pattern that uniquely identifies different positions in the document and wherein the captured image contains a portion of the pattern, and the portion of the pattern is at least partially obscured by overlaid printed content of the electronically stored document; determining obscured areas of the document in which the pattern is at least partially obscured; comparing the captured image with determined obscured areas of the electronically stored document; identifying the position of the portion of the document corresponding to the captured image; determining a spatial relationship between a reference pixel in the captured image and the pattern within the captured image, the determined spatial relationship is a shortest distance measured by a pixel offset between the reference pixel and an unobscured portion of the pattern; and identifying locations in the obscured areas of the document exhibiting a similar spatial relationship to the pattern in the obscured areas.