Patent ID: 9628649
Date: 2017-04-18
CPC Classifications: H04N

Claim:
1. A scanning apparatus, comprising: a conveyer configured to convey an original document; a scanning device configured to scan an image on the original document conveyed by the conveyer; and a controller, the controller being configured to execute: an extraction process which causes the scanning apparatus to extract edges of the original document from the image scanned by the scanning device; an end obtaining process which causes the scanning apparatus to obtain a leading end of the original document and a trailing end of the original document based on the extracted edges in the extraction process; an inclination obtaining process which causes the scanning apparatus to obtain a first inclination of the leading end of the original document and a second inclination of the trailing end, the first inclination indicating an inclination angle and an inclination direction of the leading end with respect to a direction orthogonal to a conveying direction of the original document, the second inclination indicating an inclination angle and a direction of the trailing end with respect to the direction orthogonal to the conveying direction of the original document; a calculating process which causes the scanning apparatus to obtain an angle difference between an inclination angle of the first inclination and an inclination angle of the second inclination; and a determination process which causes the scanning apparatus to determine that a rotational skew has occurred when the angle difference is greater than a rotational skew threshold value, the rotational skew being a change of inclination of the original document during conveyance of the original document, wherein the controller is configured to further execute a rotation compensation process which causes the scanning apparatus to extract an output image from the scanned image of the scanning device and applies rotation to the output image, when it is determined in the determination process that the rotational skew has occurred.