Granted Patent B2

US 7,020,328 · App. 10/235,015 · Granted Mar 28, 2006

Abstract

Claims (34)

1. A method for electronic color dropout utilizing spatial context to enhance accuracy comprising:

a) scanning a document to produce a color digital image;

b) applying a thresholding process to said color digital image to produce a bitonal image;

c) select a region of said color digital image corresponding to a feature of said bitonal image;

d) compute an average color for said region;

e) compared said average color of said region to one or more predetermined dropout colors;

f) if said average color matches any of said predetermined dropout colors, erase said region from said bitonal image;

g) determine if all features of said bitonal image have been examined; and

h) if all features of said bitonal image have not been examined go to step c) if all features have been examined, the process is complete.

2. A method for electronic color dropout as in claim 1 wherein said thresholding process is an adaptive thresholding process.

3. A method for electronic color dropout as in claim 1 wherein said matching of said average color and said predetermined dropout color is within a predetermined tolerance.

4. A method for electronic color dropout utilizing spatial context to enhance accuracy comprising:

a) scanning a document to produce a color digital image;

b) applying a thresholding process to said color digital image to produce a bitonal image;

c) utilizing a contour following algorithm applied to said bitonal image to select a region of said color digital image corresponding to a feature of said bitonal image;

d) compute an average color for said region;

e) compare said average color of said region to one or more predetermined dropout colors;

f) if said average color matches any of said predetermined dropout colors, erase said region from said bitonal image;

g) determine if all regions of said bitonal image have been examined; and

h) if all features of said bitonal image have not been examined go to step c) and if all regions have been examined, the process is complete.

5. A method for electronic color dropout as in claim 4 wherein said thresholding process is an adaptive thresholding process.

6. A method for electronic color dropout as in claim 4 wherein said matching of said average color and said predetermined dropout color is within a predetermined tolerance.

7. A method for electronic color dropout utilizing spatial context to enhance accuracy comprising:

a) scanning a document to produce a color digital image;

b) applying a thresholding process to said color digital image to produce a bitonal image;

c) establishing an evaluation window surrounding a pixel of said bitonal image;

d) locating the connected pixels within said evaluation window of said bitonal image, to select a region of said color digital image, corresponding to the connected pixels of said bitonal image;

e) compute an average color for said region;

f) compared said average color of said region to one or more predetermined dropout colors;

g) if said average color matches any of said predetermined dropout colors, erase said region from said bitonal image; and

h) repeat steps c) through f), for each pixel in said color digital image.

8. A method for electronic color dropout as in claim 7 wherein said thresholding process is an adaptive thresholding process.

9. A method for electronic color dropout as in claim 7 wherein said matching of said average color and said predetermined dropout color is within a predetermined tolerance.

10. A method for electronic color dropout as in claim 7 said computation of an average color for said region is accomplished on a pixel by pixel basis.

Assignments (11)