Variable skew correction system and method

• US 20080267502A1
• Filed: 04/30/2007
• Published: 10/30/2008
• Est. Priority Date: 04/30/2007
• Status: Active Grant

• Current Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Original Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Inventors: Pilu, Maurizio, Youngers, Kevin
• Granted Patent: US 7,991,244 B2
• Time in Patent Office: Days
• US Class Current: 382/176
• CPC Class Codes: G06V 10/243 by compensating for image skew or non-uniform image deformations

Abstract

A variable skew correction system comprises a de-skew application executable to transform scanned image data of a document exhibiting a variable skew condition to an output model representing a de-skewed image of the document by transferring pixel data for each of a plurality of raster lines of the scanned image data to the output model, wherein a variable spacing between at least two adjacent raster lines of the scanned image data is modified in the output model to correct non-linear distortion of the scanned image data.

Claims

1. A variable skew correction system, comprising:

a de-skew application executable to transform scanned image data of a document exhibiting a variable skew condition to an output model representing a de-skewed image of the document by transferring pixel data for each of a plurality of raster lines of the scanned image data to the output model, wherein a variable spacing between at least two adjacent raster lines of the scanned image data is modified in the output model to correct non-linear distortion of the scanned image data.

2. The system of claim 1, wherein the de-skew application is configured to transform the scanned image data to the output model at a variable pixel-by-pixel ratio between at least two opposing sides of the scanned image data.

3. The system of claim 1, wherein the de-skew application is configured to perform edge detection on the scanned image data to generate the output model.

4. The system of claim 1, wherein the de-skew application is configured to partition and group linear segments of the scanned image data to determine sides for the output model.

5. The system of claim 1, wherein the de-skew application is configured to analyze intersections of linear segments of the scanned image data to determine sides for the output model.

6. The system of claim 1, wherein the de-skew application is configured to position the at least two adjacent raster lines in the output model with a uniform spacing therebetween.

7. The system of claim 1, wherein the de-skew application is configured to generate another model deformed to the scanned image data to determine at least one dimension of the output model.

8. A variable skew correction method, comprising:

generating an output model representing a de-skewed image of a document based on scanned image data of the document, the scanned image data indicating a variable skew condition;

deforming another model to conform to the scanned image data; and

transforming the scanned image data from the deformed model to the output model to correct non-linear distortion of the scanned image data.

9. The method of claim 8, further comprising transforming the scanned image data to the de-skewed model at a variable pixel-by-pixel ratio between at least two opposing sides of the scanned image data.

10. The method of claim 8, further comprising performing edge detection on the scanned image data to generate the output model.

11. The method of claim 8, further comprising partitioning and grouping linear segments of the scanned image data to determine sides for the output model.

12. The method of claim 8, further comprising analyzing intersections of linear segments of the scanned image data to determine sides for the output model.

13. The method of claim 8, further comprising transferring raster lines of the scanned image data from the deformed model to the output model.

14. The method of claim 8, wherein deforming the another model comprises deforming at least one side of the another model to a side of the scanned image data exhibiting a curvature.

15. A variable skew correction system, comprising:

an imaging device having a de-skew application executable by a processor to;

generate an output model representing a de-skewed image of a document based on scanned image data of the document, the scanned image data indicating a variable skew condition;

deform another model to conform to the scanned image data; and

transform the scanned image data from the deformed model to the output model to correct non-linear distortion of the scanned image data.

16. The system of claim 15, wherein the de-skew application is configured to transform the scanned image data to the output model at a variable pixel-by-pixel ratio between at least two opposing sides of the scanned image data.

17. The system of claim 16, wherein the de-skew application is configured to perform edge detection on the scanned image data to generate the output model.

18. The system of claim 16, wherein the de-skew application is configured to partition and group linear segments of the scanned image data to determine sides for the output model.

19. The system of claim 16, wherein the de-skew application is configured to analyze intersections of linear segments of the scanned image data to determine sides for the output model.

20. The system of claim 16, wherein the de-skew application is configured to transfer raster lines of the scanned image data from the deformed model to the output model: