Patent ID: 9591176
Date: 2017-03-07
CPC Classifications: G06K,H04N

Claim:
1. An image skew angle determining method comprising: receiving image data representing an image of a document into an electronic memory; resolving an angle ambiguity caused by a false vertical edge of the image data using a window function on the image data, wherein the using the window function comprises applying a window to a first dimension of the image, rotating the image, and applying the window to a second dimension of the image, and wherein using the window function produces windowed image data; performing, after the resolving the angle ambiguity, a Fourier Transform on the windowed image data, wherein the performing the Fourier Transform on the windowed image data produces transformed image data; performing, after the performing the Fourier Transform, a radial line integration of the transformed image data, wherein the performing the radial line integration of the transformed image data produces integrated image data; determining the image skew angle based on a peak value from the integrated image data; and outputting an electronic signal that is indicative of the image skew angle.