Primax Electronics Ltd.

Visioneer, Inc.

Richard Clark Pasco

Pierre-Alain Cotte

Sorin Vasile Papuc

A document imaging system detects skew and/or size of a document. In one embodiment, a document imaging system generates scanning signals representing the documents, analyxes the scanning signals to detect one more edges of the document before the entire lenght of the document is scanned, establishes a skew angle between the detected edges and a reference orientation, and modifies the scanning signals to compensate for skew while the document is being scanned. In another embodiment, a document imaging system detects one or more edges of a document, defines a polygon having sides substantially congruent with the detected edges, and establishes the size of the document in response to the polygon.

Method and apparatus for near real-time document skew compensation

The present invention relates in general to optical scanning and image processing, and relates more particularly to a document imaging system which detects skew and/or detects size/shape of a document image. Preferred embodiments utilize a background with optical characteristics which contrast with those of the scanned document. In one embodiment, a document imaging system generates scanning signals in response to optical characteristics of a medium such as a sheet of paper, detects transitions in the scanning signal which define points along one or more edges of the medium, establishes a skew angle between the detected edges and a reference orientation, and compensates for skew by modifying the scanning signals as required such that the resultant skew angle is substantially equal to zero. In another embodiment, a document imaging system detects one or more edges of a document, defines a polygon having sides substantially congruent with the detected edges, and establishes the size of the document in response to the polygon.

Growing community of inventors

San Jose, CA, United States of America

Richard Clark Pasco