Dot-matrix video enhancement for optical character recognition
AssigneeEastman Kodak Company
InventorsPeter Rudak, George A. Hadgis
Life of this patent
Estimating the term…
Abstract
A method and apparatus for eliminating discontinuities inherent to binary digital image data when hard copy text is generated by a dot-matrix printer. An M.times.M matrix is moved over a bit-mapped image of said text one pixel at a time, and for each pixel position, pixels are selectively converted from white to black based on a predetermined set of rules.
Claims5
A method for use in an apparatus for improving optical character recognition of printed draft quality dot-matrix characters of an image to be scanned, comprising the steps of:
- scanning an image with an electronic scanning device and generating signals representing the scanned image as rows and columns of pixels;
- sending the signals of the scanned image to a binary digital filter that performs the following steps;
- locating kernel of a first integer, M, M pixel rows and a second integer, N, N pixel columns in particular position in said scanned image where M and N are integers greater than two;
- modifying the scanned image by moving said kernel between adjacent pixel positions and applying the following set of rules:
- a) if two black pixels are separated by no more than N-2 white pixels in the horizontal direction, convert signals representing the white pixels to black;
- b) if two black pixels are separated by no more than M-2 white pixels in the vertical direction, convert signals representing the white pixels to black;
- c) if two black pixels are separated by no more than M-2 white pixels in the first diagonal direction, convert signals representing the white pixels to black;
- d) if two black pixels are separated by more than M-2 white pixels in the second diagonal direction convert signals representing the white pixels to black;
- applying the above steps to all pixels in said image;
- outputting the modified image for optical character recognition.
A method for use in an apparatus for improving character recognition of printed draft quality dot-matrix characters of an image to be scanned, comprising the steps of:
- scanning an image with an electronic scanning device an generating signals representing a scanned image as rows and columns of pixels;
- sending the signals of the scanned image to a binary digital filter that performs the following steps;
- locating a kernel of M pixel rows and N pixel columns in a particular position in said image where M and N are integers greater than two;
- moving said kernel to the next adjacent pixel position and applying the following set of rules;
- a) if two black pixels are separated by no more than M-2 white pixels in the horizontal direction and the two end pixels in the vertical direction are not black, convert signals representing the white pixels to black;
- b) if two black pixels re separated by no more than N-2 white pixels in the vertical direction and the two end pixels in the horizontal direction are not black, convert signals representing the white pixels to black;
- c) if two black pixels are separated by no more than N-2 white pixels in either diagonal direction are not black, convert signals representing the white pixels to black;
- applying the above steps to all pixels in the image;
- outputting the modified image for optical character recognition.
A method for use in an apparatus for improving the optical character recognition of printed draft quality dot matrix characters of an image to be scanned, comprising the steps of:
- scanning an image with an electronic scanning device and generating signals representing the scanned image as rows and columns of pixels;
- sending the signals representing the scanned image to a binary digital filter that performs the following steps;
- locating a kernel of M pixel rows and M pixel columns in a particular position in said image where M is an integer greater than two;
- modifying the scanned image by moving said kernel to the next adjacent pixel position and applying the following set of rules:
- a) if two black pixels are separated by no more than M-2 white pixels in either the horizontal or vertical direction, convert signals representing the intervening white pixels in that direction to black;
- b) if two black pixels are separated by no more than M-2 white pixels in either diagonal direction, convert signals representing the intervening white pixels in that direction to black;
- applying the above steps to all pixels in the image;
- outputting the modified image for optical character recognition.
Dependencies are inferred from the claim text.