US 2011/0033082 A1 · System and method for improved forensic analysis

Abstract

The present disclosure provides for a system and method for analyzing questioned documents. A sample document is illuminated to thereby generate a first plurality of interacted photons. The first plurality of interacted photons are detected at a first detector to thereby generate a digital image. The digital image is analyzed to thereby identify at least one region of interest of the sample document. This region of interest is illuminated to thereby generate a second plurality of interacted photons. This second plurality of interacted photons are passed through a tunable filter and detected at a second detector to thereby generate a hyperspectral image representative of the region of interest. The hyperpsectral image may then be analyzed to evaluate changes to or differentiate different inks present in the sample document. Chemometric techniques such as k-means clustering, PCA, and/or PLSDA may also be applied.

Claims51

Dependent claims

A system comprising:

a surface for placing a sample document;
an illumination source for illuminating said sample document to thereby generate a first plurality of interacted photons and a second plurality of interacted photons wherein said first and second plurality of interacted photons are selected from the group consisting of:
photons reflected by said sample, photons absorbed by said sample, photons scattered by said sample, photons emitted by said sample, and combinations thereof;
a collection optics for collecting said first plurality of interacted photons and said second plurality of interacted photons;
a first detector for detecting said first plurality of interacted photons and generating a digital image representative of said sample;
at least one tunable filter through which said second plurality of interacted photons are passed to thereby generate a plurality of filtered photons;
a second detector for detecting said plurality of filtered photons and generating a hyperspectral image representative of said sample.

4 more elements

A method comprising:

identifying at least one region of interest of a sample document wherein said region of interest comprises at least one ink type;
obtaining a hyperspectral image representative of said region of interest;
analyzing said hyperspectral image to thereby determine if two or more ink types are distinguishable in said region of interest:
if two or more ink types are distinguishable in said region of interest, reporting a result, and
if two or more ink types are not distinguishable in said region of interest, applying a first chemometric technique to said hyperspectral image to thereby generate a first processed image, wherein said chemometric technique comprises k-means clustering;
analyzing said first processed image to thereby determine if two or more ink types are distinguishable in said region of interest:
if two or more ink types are distinguishable in said region of interest, reporting a result, and
if two or more ink types are not distinguishable in said region of interest, applying a second chemometric technique to thereby generate a second processed image, wherein said chemometric technique comprises principal component analysis;
analyzing said second processed image to thereby determine if two or more ink types are distinguishable in said region of interest:
if two or more inks types are distinguishable in said region of interest, reporting a result, and
if two or more ink types are not distinguishable in said region of interest, reporting a result.

8 more elements

A method comprising:

identifying at least one region of interest of a sample document wherein said region of interest comprises at least one ink type;
obtaining a hyperspectral image representative of said region of interest;
analyzing said hyperspectral image to thereby determine if two or more ink types are distinguishable in said region of interest:
if two or more ink types are distinguishable in said region of interest, reporting a result, and
if two or more ink types are not distinguishable in said region of interest, applying a first chemometric technique to said hyperspectral image to thereby generate a first processed image, wherein said chemometric technique comprises k-means clustering;
analyzing said first processed image to thereby determine if two or more ink types are distinguishable in said region of interest:
if two or more ink types are distinguishable in said region of interest, reporting a result, and
if two or more ink types are not distinguishable in said region of interest, applying a second chemometric technique to thereby generate a second processed image, wherein said chemometric technique comprises partial least squares discriminate analysis;
analyzing said second processed image to thereby determine if two or more ink types are distinguishable in said region of interest:
if two or more inks types are distinguishable in said region of interest, reporting a result, and
if two or more ink types are not distinguishable in said region of interest, reporting a result.

8 more elements

A method comprising:

illuminating a sample document to thereby generate a first plurality of interacted photons wherein said first plurality of interacted photons are selected from the group consisting of:
photons reflected by said sample, photons absorbed by said sample, photons scattered by said sample, photons emitted by said sample, and combinations thereof;
detecting said first plurality of interacted photons at a first detector to thereby generate a digital image representative of a sample document;
analyzing said digital image to thereby identify at least one region of interest of said sample document;
illuminating said region of interest to thereby generate a second plurality of interacted photons wherein said second plurality of interacted photons are selected from the group consisting of:
photons reflected by said sample, photons absorbed by said sample, photons scattered by said sample, photons emitted by said sample, and combinations thereof;
detecting said second plurality of interacted photons to thereby generate a hyperspectral image representative of said region of interest;
analyzing said hyperspectral image to thereby determine if two or more ink types are distinguishable in said region of interest:
if two or more ink types are distinguishable in said region of interest, reporting a result, and
if two or more ink types are not distinguishable, applying a first chemometric technique to thereby generate a first processed image;
analyzing said first processed image to thereby determine if two or more ink types are distinguishable in said region of interest:
if two or more ink types are distinguishable in said region of interest, reporting a result, and
if two or more ink types are not distinguishable, applying a second chemometric technique to thereby generate a second processed image;
analyzing said second processed image to thereby determine if two or more ink types are distinguishable in said region of interest:
if two or more ink types are distinguishable in said region of interest, reporting a result, and
if two or more ink types are not distinguishable in said region of interest, applying a third chemometric technique to said second processed image to thereby generate a third processed image;
analyzing said third processed image to thereby determine if two or more ink types are distinguishable in said region of interest:
if two or more ink types are distinguishable in said region of interest, reporting a result, and
if two or more ink types are not distinguishable in said region of interest, reporting a result.

16 more elements

Dependencies are inferred from the claim text.

System and method for improved forensic analysis

Life of this patent

System and method for improved forensic analysis

Life of this patent

Abstract

Claims51