AUTOMATIC CORRECTION OF SKEWING OF DIGITAL IMAGES

摘要

A method and system for automatic correction of skewing of digital images. A captured digital image s provided. An initial angle of rotation is determined by sampling test angles of rotation of the input image and analyzing resultant rotated images to determine a resultant rotated image with a highest number of substantially empty lines. The input image is rotated by the initial angle of rotation to generate a first rotated image which is processed to determine a refining angle of rotation as follows: determining text line areas of the first rotated image; generating a representative line of each text line area; calculating a slope of each representative line; and determining an aggregated slope of all the representative lines. The aggregated slope is converted to the refining angle of rotation. The first rotated image is rotated by the refining angle of rotation to result in a final rotated image.

主权项

1. A method, said method comprising:
receiving a captured digital image for processing as an input image; determining an initial angle of rotation by sampling a plurality of test angles of rotation of the input image and analyzing resultant rotated images to determine a resultant rotated image with a highest number of substantially empty lines; rotating the input image by the initial angle of rotation to generate a first rotated image; processing the first rotated image to determine a refining angle of rotation, said processing including:
determining text line areas of the first rotated image;generating a representative line of each text line area;calculating a slope of each representative line; anddetermining an aggregated slope of all the representative lines in the first rotated image, wherein the aggregated slope is converted to the refining angle of rotation; validating the refining angle of rotation by finding points of intersection of lines connecting opposing ends of adjacent representative lines, and estimating a substantially vertical line through the point of intersection, wherein the difference between the substantially vertical line and a line perpendicular to the aggregated slope indicates the accuracy of the refining angle of rotation; and rotating the first rotated image by the refining angle of rotation to result in a final rotated image.