Patent ID: 7878402

Claim:
A method for decoding distorted symbols, the method comprising: at train-time: acquiring a training image of a two-dimensional (2D) code symbol disposed on a train-time surface using a camera with an optical axis having an incident angle with respect to the train-time surface; running a 2D code symbol reader that can detect and tolerate distortion so as to provide a correspondence between at least two 2D coordinates of points within the training image and at least two 2D coordinates of points within the 2D code symbol; using the correspondence to construct a coordinate transformation; at run-time: disposing a symbol on a run-time surface that is substantially parallel to the train-time surface; acquiring a run-time image of a symbol disposed on the run-time surface using a camera with an optical axis having substantially the incident angle with respect to the run-time surface; correcting distortion of the run-time image using the coordinate transformation to provide a corrected image; and running a run-time symbol reader on the corrected image.