US 7,145,699 B2 · System and method for digital document alignment

Abstract

A system and method are provided for aligning a scanned document in a digital scanner. The method comprises: scanning a document to create a matrix of pixel information; averaging pixel intensity information into a first plurality of row-mean buffer elements, where each row strip includes information from a second plurality of column elements; and, averaging pixel information into a third plurality of column-mean buffer elements, where each column strip includes information from a fourth plurality of row elements; comparing adjacent elements of matrix row information to generate a first set of edge positions; comparing adjacent elements of matrix column information to generate a second set of edge positions; generating a rotation angle in response to analyzing the first and second edge positions; and, rotating the scanned document by the rotation angle.

Claims35

Dependent claims

In a digital scanner, a method for aligning a scanned document, the method comprising:

scanning a document to create a matrix of pixel information;
averaging pixel intensity information into a first plurality of row-mean buffer elements, where each row strip includes information from a second plurality of column elements;
averaging pixel information into a third plurality of column-mean buffer elements, where each column strip includes information from a fourth plurality of row elements;
comparing adjacent elements of matrix row-mean buffer elements to generate a first set of edge positions;
comparing adjacent elements of matrix column-mean buffer elements to generate a second set of edge positions;
generating a rotation angle in response to analyzing the first and second edge positions;
and,
rotating the scanned document by the rotation angle.

5 more elements

A digital scanner system for aligning a scanned document with a predetermined axis, the system comprising:

a digital scanner having an interface to scan a supplied document and an output to supply a matrix of pixel information;
a first buffer having a port connected to the scanner output to store the matrix of pixel information
an averaging unit having a port connected to the buffer port, the averaging unit comparing adjacent elements of matrix row information to generate a first set of edge positions and comparing adjacent elements of matrix column information to generate a second set of edge positions;
a row-edge buffer having a port connected to the averaging unit to accept the first set of edge positions;
a column-edge buffer having a port connected to the averaging unit to accept the second set of edge positions;
a rotating unit having a port connected to the row-edge and column-edge buffer to generate a rotation angle, in response to analyzing the first and second edge positions, for aligning the matrix of pixel information in the first buffer with a predetermined axis;
wherein the averaging unit averages pixel intensity information into a first plurality of row-mean buffers, where each row includes information from a second plurality of column elements;
wherein the averaging unit averages pixel information into a third plurality of column-mean buffer elements, where each column includes information from a fourth plurality of row elements;
and,
wherein the averaging unit compares adjacent column elements in the row-mean buffer elements to generate a first set of edge positions and compares adjacent row elements in the column-mean buffer elements to generate a second set of edge positions.

7 more elements

Dependencies are inferred from the claim text.

System and method for digital document alignment

Life of this patent

System and method for digital document alignment

Life of this patent

Abstract

Claims35