Processing images of deformed indicia-bearing surfaces

A system comprising:

• a memory;
• and
• a processing device operatively coupled to the memory, the processing device configured to:
• receive a document image;
• detect, within the document image, a plurality of image fragments, wherein each image fragment of the plurality of image fragments contains a respective sequence of alphabet symbols;
• group the plurality of image fragments by lines of text to be reconstructed in the document image;
• generate a map of isolines associated with the document image, wherein an isoline identifies a set of points that lie on a straight line of an undistorted image corresponding to the document image;
• generate, based on the map of isolines, a reverse transformation matrix that defines a set of transformations to be applied to the document image in order to remove image distortions caused by deformations of an indicia bearing surface;
• and
• generate an undistorted document image by applying the reverse transformation matrix to the document image.

A non-transitory computer-readable storage medium comprising executable instructions that, when executed by a processing device, cause the processing device to:

• receive a document image;
• detect, within the document image, a plurality of image fragments, wherein each image fragment of the plurality of image fragments contains a respective sequence of alphabet symbols;
• group the plurality of image fragments by lines of text to be reconstructed in the document image;
• generate a map of isolines associated with the document image, wherein an isoline identifies a set of points that lie on a straight line of an undistorted image corresponding to the document image;
• generate, based on the map of isolines, a reverse transformation matrix that defines a set of transformations to be applied to the document image in order to remove image distortions caused by deformations of an indicia bearing surface;
• and
• generate an undistorted document image by applying the reverse transformation matrix to the document image.