Method for correcting skew in scanned documents
An apparatus and method for deskewing a scanned printed document is described. The original printed document is scanned with the scanner to obtain a first digital image, which contains skew (rotation) with respect to the original printed document. The first digital image is digitally flipped around a centerline to obtain a second digital image, which is printed to generate a second printed document. The second printed document is scanned using the same scanner to obtain a third digital image, which contains skew errors with respect to the second printed document. The third digital image is digitally flipped around the centerline to obtain a final digital image, which is substantially free of the skew introduced by the scanner.
1. A method for correcting skew introduced by a scanner when scanning an original printed document, comprising:
scanning the original printed document using the scanner to obtain a first digital image, the first digital image containing skew with respect to the original printed document;
digitally flipping the first digital image around a centerline to obtain a second digital image;
printing the second digital image to generate a second printed document;
scanning the second printed document using the scanner to obtain a third digital image, the third digital image containing skew with respect to the second printed document; and
digitally flipping the third digital image around the centerline to obtain a fourth digital image.
2. The method of claim 1 , wherein the centerline is a vertical centerline.
3. The method of claim 1 , further comprising displaying, storing or transmitting the fourth digital image.
4. A data processing system comprising:
a printing section for generating printed documents from digital images;
a scanning section for scanning printed documents to generate digital images; and
a control section for controlling the printing section and the scanning section,
wherein the control section is programmed to control the scanning section to scan an original printed document to obtain a first digital image which contains skew with respect to the original printed document, to digitally flip the first digital image around a centerline to obtain a second digital image, to control the printing section to print the second digital image to generate a second printed document, to control the scanning section to scan the second printed document to obtain a third digital image which contains skew with respect to the second printed document, and to digitally flip the third digital image around the centerline to obtain a fourth digital image.
5. The data processing system of claim 4 , wherein the centerline is a vertical centerline.