Method for detecting a document boundary
AssigneeKodak Alaris Inc.
InventorsLouis James Beato, John J. Alescio
Life of this patent
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Abstract
A method for detecting a document boundary in a captured digital image depicting a hardcopy document on a background. Each color channel of the captured digital image is analyzed to determine a corresponding busyness metric representing a complexity level of the image data. The color channel having a lowest busyness level is selected and analyzed to detect a document boundary of the depicted hardcopy document. The detected document boundary can be used to perform a perspective correction process to determine a corrected digital image where the depicted document has a substantially rectangular boundary
Claims19
A method for detecting a document boundary in a captured digital image of a document, the method implemented at least in part by a data processing system and comprising:
- receiving a color digital image captured using a digital imaging system that depicts a hardcopy document on a background, wherein the color digital image includes image data for a plurality of color channels;
- for each of the color channels analyzing the image data to determine a corresponding busyness metric, the busyness metric representing a complexity level of the image data;
- selecting the color channel having a lowest busyness level;
- analyzing the image data for the selected color channel to detect the document boundary of the depicted hardcopy document;
- and
- storing an indication of the detected document boundary in a processor-accessible memory.
A document imaging system for capturing a digital image of a document, comprising:
- an image capture system adapted to capture a color digital image of a hardcopy document on a background, wherein the captured color digital image includes image data for a plurality of color channels;
- a data processing system;
- and
- a memory system communicatively connected to the data processing system and storing instructions configured to cause the data processing system to implement a method for correcting perspective distortion in the captured color digital image, wherein the method includes:
- transforming the captured color digital image to an analysis color space having a plurality of analysis color channels;
- for each of the analysis color channels analyzing the image data to determine a corresponding busyness metric, the busyness metric representing a complexity level of the image data;
- selecting the analysis color channel having a lowest busyness level;
- analyzing the image data for the selected analysis color channel to detect the document boundary of the depicted document;
- applying a perspective correction process to the captured color digital image based on the detected document boundary to determine a corrected digital image where the depicted document has a substantially rectangular boundary;
- and
- storing the corrected digital image in a processor-accessible memory.
Dependencies are inferred from the claim text.