The problems of recognizing blobs (the result of connected component analysis), classifying them as representing potential collections of interest such as text strings, and applying techniques such as are described in the patent application, have been known and practised for decades. In fact, if faced with this problem, it's impossible not to do what these gentlemen describe, and wish to patent, or a close facsimile thereof.
As mentioned in a comment, this is a patent application that as of today (Feb. 20, 2013) has not yet been examined. All of what it describes is not what it desires to claim and the broadest claims found in a published patent application are usually narrowed in the course of prosecution. As published the claim 1 is:
- A method for correcting a distortion in an image including text, the method comprising:
generating a first set of substantially straight lines corresponding to a first direction for a quadrangle for the image;
generating a second set of substantially straight lines corresponding to a second direction for the quadrangle for the image;
finding a first vanishing point based on said first set of substantially straight lines;
finding a second vanishing point based on said second set of substantially straight lines;
identifying the quadrangle for the image based on the first vanishing point and the second vanishing point;
determining a parameter for a rectangle of a corrected image; and
reducing the distortion in the image including text by generating the corrected image based on the rectangle at least partially in a memory of a computer device.
Since this is published but not yet subject to an office action on the merits it is in the time window allowing 3rd parties to submit prior art into the case. The mechanics for this are on several other Ask Patents posts. This is the USPTO press release on the topic. Up to three documents per submitter, with limited comments, can be filed at no cost. It is possible to do yourself. If done through a registered practitioner it can even be done with anonymity.
Please look up this application in USPTO Public PAIR to see that the applicant themselves have already made the examiner aware of several prior art patent documents.