18. The computer program product of claim 11 , where aligning the candidate text regions comprises aligning pixels of the candidate text regions using block matching.
11. A computer program product, encoded on a computer-readable medium, operable to cause data processing apparatus to perform operations comprising: receiving a plurality of images each including a corresponding version of an identified candidate text region; aligning each candidate text region from the plurality of images to a high resolution grid; compositing the aligned candidate text regions to create a single superresolution image; and performing character recognition on the superresolution image to identify text.