TEXT ENHANCEMENT OF A TEXTUAL IMAGE UNDERGOING OPTICAL CHARACTER RECOGNITION
First Claim
1. A method for enhancing a textual image for undergoing optical character recognition, comprising:
- receiving an image that includes native lines of text;
determining a background line profile that represents an average background intensity along the native lines in the image;
determining a foreground line profile that represents an average foreground background intensity along the native lines in the image;
assigning pixels in the image to either a background or foreground portion of the image based at least in part on the background line profile and the foreground line profile; and
adjusting an intensity of the pixels designated to the background portion of the image to a prescribed intensity representing a portion of the image that does not include text.
3 Assignments
0 Petitions
Accused Products
Abstract
A method for enhancing a textual image for undergoing optical character recognition begins by receiving an image that includes native lines of text. A background line profile is determined which represents an average background intensity along the native lines in the image. Likewise, a foreground line profile is determined which represents an average foreground background intensity along the native lines in the image. The pixels in the image are assigned to either a background or foreground portion of the image based at least in part on the background line profile and the foreground line profile. The intensity of the pixels designated to the background portion of the image is adjusted to a maximum brightness so as to represent a portion of the image that does not include text.
35 Citations
20 Claims
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1. A method for enhancing a textual image for undergoing optical character recognition, comprising:
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receiving an image that includes native lines of text; determining a background line profile that represents an average background intensity along the native lines in the image; determining a foreground line profile that represents an average foreground background intensity along the native lines in the image; assigning pixels in the image to either a background or foreground portion of the image based at least in part on the background line profile and the foreground line profile; and adjusting an intensity of the pixels designated to the background portion of the image to a prescribed intensity representing a portion of the image that does not include text. - View Dependent Claims (2, 3, 4, 6, 7, 8, 9, 10)
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5. The method of 1 further comprising estimating an average or median stroke width of connected components representing text in the image.
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11. A method for enhancing a textual image for undergoing optical character recognition, comprising:
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receiving an image that includes native lines of text; determining a background line profile that represents an average background intensity along the native lines in the image; determining a foreground line profile that represents an average foreground background intensity along the native lines in the image; estimating an average or median stroke width of connected components representing text in the image; and enhancing text quality if the average or median stroke width is less than a threshold value. - View Dependent Claims (12, 13, 14, 15, 16)
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17. A system that enhances a textual image undergoing optical character recognition, comprising:
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an input component for receiving an input image having native lines of text; a background and foreground line profiling component for determining background and foreground line profiles which respectively represent average background and foreground intensities in the image; an image quality detection component for determining if the quality of the image is sufficient to assign pixels to the background or foreground portion of the image; a thresholding component 208 for assigning pixels to either a background or foreground portion of the image based on the background and foreground line profiles; and a stroke enhancement component 210 for enhancing strokes of connected components representing text in the image if the image quality detection component determines that the quality of the image is below a threshold value. - View Dependent Claims (18, 19, 20)
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Specification