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 of an indicia-bearing surface;
• 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;
• generate a map of image angles, the map of image angles comprising, for each pixel of a plurality of pixels of the document image, a corresponding value reflecting an angle of image rotation caused by a deformation of the indicia-bearing surface in a vicinity of the pixel, the angle being measured with respect to a chosen text direction of the document image;
• define, based on the map of image angles, a reverse transformation 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 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 of an indicia-bearing surface;
• 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;
• generate a map of image angles, the map of image angles comprising, for each pixel of a plurality of pixels of the document image, a corresponding value reflecting an angle of image rotation caused by a deformation of the indicia-bearing surface in a vicinity of the pixel, the angle being measured with respect to a chosen text direction of the document image;
• define, based on the map of image angles, a reverse transformation 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 to the document image.