Method for identifying individuals from analysis of elemental shapes derived from biosensor data

• US 5,163,094 A
• Filed: 03/20/1991
• Issued: 11/10/1992
• Est. Priority Date: 03/20/1991
• Status: Expired due to Term

• Current Assignee: Infrared Indentification Incorporated, Mikos Limited
• Original Assignee: Francine J. Prokoski
• Inventors: Prokoski, Francine J., Coffin, Jeffrey S., Riedel, Robert B.
• Primary Examiner(s): Couso, Jose L.
• Application Number:
  US07/672,320
• Time in Patent Office: 601 Days
• Field of Search: 382/2, 382/1, 382/8, 382/6, 358/113, 250/334
• US Class Current: 382/118
• CPC Class Codes: A61B 5/015 By temperature mapping of body part
• CPC Class Codes: A61B 5/1171 based on the shapes or appearances of their bodies or parts thereof
• CPC Class Codes: G06V 40/10 Human or animal bodies, e.g. vehicle occupants or pedestrians; Body parts, e.g. hands
• CPC Class Codes: G06V 40/16 Human faces, e.g. facial parts, sketches or expressions
• CPC Class Codes: G07C 9/253 visually

Abstract

A method and apparatus for identifying individuals is characterized by the analysis of elemental shapes derived from biosensor data presented in n dimensions, particularly facial thermograms. A thermal image of the individual'"'"'s face is generated in accordance with the thermal energy patterns thereof. The thermal image is converted to a digital representation comprising a matrix of pixels, the intensity of each pixel corresponding with the level of thermal energy of a corresponding portion of the image. The digital representation of the image is normalized for size and equalized to a standard histogram to produce an image containing elemental shapes comprising contours corresponding with unique structural features of the individual.

Claims

1. A method for identifying individuals from biosensor data, comprising the steps of

(a) generating a thermal image of a portion of an individual'"'"'s body in accordance with the thermal energy patterns thereof;

(b) processing said thermal image to produce a digital representation thereof, said digital representation comprising a matrix of pixels, the intensity of each pixel corresponding with the level of thermal energy of a corresponding portion of said image;

(c) normalizing said image in order to eliminate variables therefrom, thereby to produce an image containing elemental shapes comprising contours corresponding with unique structural features of the individual; and

(d) storing said normalized digital representation of said image, whereby a unique digital representation is created and stored for every individual for subsequent identification.

2. A method as defined in claim 1, wherein said normalizing step includes cropping said image to an area of minimum thermal variation over time and maximum uniqueness.

3. A method as defined in claim 2, wherein said cropped image area comprises a portion of the individual'"'"'s face containing the eyes and nose.

4. A method as defined in claim 2, wherein said cropping step is performed by

(1) detecting the edges of said image;

(2) defining vertical and horizontal axes of said image with respect to intensity levels thereof; and

(3) deleting excess portions of said image.

5. A method as defined in claim 2, wherein said normalizing step further includes the step of standardizing said image for size by measuring a field of interest and scaling said field to preserve and reconstruct said image to a standard size.

6. A method as defined in claim 5, wherein said normalizing step further includes the step of equalizing said image to a standard histogram in accordance with specific feature areas of said image.

7. A method as defined in claim 1, and further comprising the step of identifying regions of said image containing elemental shapes of interest.

8. A method as defined in claim 7, and further comprising the step of storing at least a portion of each region containing an elemental shape with respect to its location on the image in a memory.

9. A method as defined in claim 8, wherein each of said regions is defined by one of geometry, mathematics, and as a bit-map replica of said region, thereby to provide a signature of the individual.

10. A method as defined in claim 9, and further comprising the step of comparing a previously defined reference signature of an individual with a currently defined signature of the individual to confirm the individual'"'"'s identity.

11. A method as defined in claim 10, wherein said comparison step is accomplished using correlation techniques.

12. A method as defined in claim 10, wherein said comparison step comprises matching the location and configuration of each of said elemental shapes.

13. A method as defined in claim 12, and further comprising the step of adaptively establishing a threshold level of match to confirm the individual'"'"'s identity, whereby the threshold level must be met in order to confirm the individual'"'"'s identity.

14. A method as defined in claim 13, wherein said portion of the individual'"'"'s body comprises the face, and further wherein said normalized image contains elemental shapes corresponding with at least the eyes and nose of the individual.