METHODS AND SYSTEMS FOR DETECTION OF REPEATING PATTERNS OF FEATURES

• US 20080260259A1
• Filed: 06/24/2008
• Published: 10/23/2008
• Est. Priority Date: 07/21/2003
• Status: Active Grant

• Current Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Original Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Inventors: Paquette, Daniel R., Vanhall, Richard C.
• Granted Patent: US 7,583,840 B2
• Time in Patent Office: Days
• US Class Current: 382/203
• CPC Class Codes: G06V 10/44 Local feature extraction by analysis of parts of the pattern, e.g. by detecting edges, contours, loops, corners, strokes or intersections; Connectivity analysis, e.g. of connected components
• CPC Class Codes: G06V 30/424 Postal images, e.g. labels or addresses on parcels or postal envelopes

Abstract

Methods and system for automatic identification of repeating patterns of slanted stripe features (marks) on an item.

Claims

1. A computer program product comprising:

a computer usable medium having computer readable code embodied therein, the computer readable code capable of causing a computer system to;

obtain pixel data for a plurality of pixels in a digital image;

extract line segment data from the pixel data, said line segment data comprising line segment angle data;

identify a plurality of collinear line segments from the line segment data;

identify another plurality of line segments from the line segment data;

each line segment from said another plurality of line segments intersecting at least one line segment of said plurality of collinear line segments; and

identify, utilizing said another plurality of line segments and the plurality of collinear lines, a plurality of features, the identified plurality of features comprising said another plurality of lines segments and the plurality of collinear lines.

2. The computer program product of claim 1 wherein the computer readable code is further capable of causing the computer system to:

verify that each collinear line segment from the plurality of collinear line segments has characteristic properties of an element of the plurality of collinear line segments; and

remove from the plurality of collinear line segments each collinear line segment that does not have characteristic properties of an element of the plurality of collinear lines segments.

3. The computer program product of claim 1 wherein the computer readable code is further capable of causing the computer system to:

verify that the identified plurality of features is located at a preselected location on the item.

4. The computer program product of claim 1 wherein the computer readable code is further capable of causing the computer system to:

identify a subsequent plurality of collinear line segments from the line segment data;

identify a subsequent plurality of intersecting lines from the line segment data; and

identify a subsequent plurality of features comprising the subsequent plurality of intersecting lines and the subsequent plurality of collinear lines;

the intersecting lines from the subsequent plurality of intersecting lines intersecting the subsequent plurality of collinear lines.

5. The computer program product of claim 4 wherein the computer readable code is further capable of causing the computer system to:

determine whether the plurality of identified features and the subsequent plurality of identified features are substantially overlapping;

determine whether the plurality of identified features and the subsequent plurality of identified features have substantially similar collinearity; and

merge the plurality of identified features and the subsequent plurality of identified features if the plurality of identified features and the subsequent plurality of identified features are substantially overlapping and have substantially similar collinearity.