Detection of document security marks using run profiles
First Claim
1. A method of digital image processing for a printed document potentially including a security mark defined by a plurality of actual mark constituents each having a known color, size, shape, and run profile, and said actual mark constituents having a select spatial arrangement relative to each other, said method comprising:
- (a) scanning said printed document to obtain digital image data corresponding to said printed document, said digital image data defined in terms of a plurality of color input pixel values;
(b) processing said digital image data to identify all portions representing potential mark constituents of a security mark, wherein said processing comprises;
(i) determining a run profile for features represented in said digital image data;
(ii) comparing said run profile for each feature to the known run profile of an actual mark constituent to identify suspect components, wherein only features having said known run profile are identified as suspect components; and
, (iii) examining each suspect component to identify any suspect components that are potential mark constituents;
(c) for each potential mark constituent represented by said digital image data, determining if said potential mark constituent, together with at least one other potential mark constituent represented by said digital image data, defines a potential security mark;
(d) for each potential security mark represented in said digital image data, determining if said potential security mark represents an actual security mark present in said printed document.
2 Assignments
0 Petitions
Accused Products
Abstract
A method and apparatus for preventing or inhibiting effective reproduction of documents such as currency, checks, stock certificates, and any other printed document including a pre-defined security mark printed therein. The method and apparatus operate to effect a multi-step review of all digital image data acquired from a printed document to be reproduced for purposes of locating any potential security marks and further examining same for purposes of positively identifying a potential security mark as an actual security mark. If a mark is located and verified to be an authentic security mark, effective reproduction of the printed document will not be permitted and/or other security measures will be taken. Processing speed is improved by using run profile analysis to limit the image features that are subjected to computationally intensive template matching operations. Run profiles are tracked using a finite automaton.
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Citations
20 Claims
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1. A method of digital image processing for a printed document potentially including a security mark defined by a plurality of actual mark constituents each having a known color, size, shape, and run profile, and said actual mark constituents having a select spatial arrangement relative to each other, said method comprising:
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(a) scanning said printed document to obtain digital image data corresponding to said printed document, said digital image data defined in terms of a plurality of color input pixel values;
(b) processing said digital image data to identify all portions representing potential mark constituents of a security mark, wherein said processing comprises;
(i) determining a run profile for features represented in said digital image data;
(ii) comparing said run profile for each feature to the known run profile of an actual mark constituent to identify suspect components, wherein only features having said known run profile are identified as suspect components; and
, (iii) examining each suspect component to identify any suspect components that are potential mark constituents;
(c) for each potential mark constituent represented by said digital image data, determining if said potential mark constituent, together with at least one other potential mark constituent represented by said digital image data, defines a potential security mark;
(d) for each potential security mark represented in said digital image data, determining if said potential security mark represents an actual security mark present in said printed document. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A digital image processing method for preventing unauthorized reproduction of a printed document including a security mark defined in terms of a plurality of actual mark constituents having a known quantity, a known color, known dimensions, a known run profile, and arranged in a known pattern relative to each other, said method comprising:
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a. scanning said printed document to derive color digital data representing said printed document, said color digital data defined in terms of a plurality of pixels each having a color value;
b. identifying all pixels of said color digital data having a color value representing a color at least approximating said known color of said plurality of actual mark constituents;
c. constructing a binary map of said color digital data defined in terms of “
on” and
“
off”
pixels, said “
on”
pixels corresponding to said identified pixels of said color digital data having color values at least approximating said known color of said plurality of actual mark constituents;
d. (i) processing said binary map to identify all suspect components, wherein a suspect component is an image feature having said known run profile of a security mark; and
, (ii) examining each suspect component to determine if the suspect component is a potential mark constituent;
e. using said binary map, identifying at least one neighborhood of plural potential mark constituents together defining a potential security mark;
f. identifying said potential security mark as an actual security mark if said potential mark constituents thereof are uniform relative to each other; and
g. preventing effective duplication of said printed document if an actual security mark is identified. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18)
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19. A document reproduction apparatus comprising:
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means for scanning a printed document to derive color digital image data representative of said printed document;
means for identifying all features represented by said digital image data as having a color encompassed by a select color range used to define a security mark in said printed document;
means for identifying said features as suspect component features only if said features define a select run profile;
means for identifying a suspect component feature as a potential mark constituent if said suspect component feature has both a size and shape corresponding to a known size and shape of an actual mark constituent used to define the security mark in said printed document;
means for establishing a neighborhood of a select size about each potential mark constituent;
means for identifying as a potential security mark all neighborhoods comprising a number of potential mark constituents greater than or equal to a minimum number of said actual mark constituents required to define a security mark, with said potential mark constituents arranged relative to each other in a manner corresponding to the actual mark constituents defining said security mark in said printed document;
means for processing said digital image data of each neighborhood identified as a potential security mark to identify said potential security mark as an actual security mark if said potential mark constituents in said neighborhood are uniform in terms of at least size and color; and
,means for preventing effective reproduction of said printed document if said digital image data comprises an actual security mark. - View Dependent Claims (20)
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Specification