Imprint identification system

• US 6,181,804 B1
• Filed: 07/14/1998
• Issued: 01/30/2001
• Est. Priority Date: 01/31/1996
• Status: Expired due to Fees

• Current Assignee: Dudley Bryan Crossling
• Original Assignee: Dudley Bryan Crossling
• Inventors: Crossling, Dudley Bryan
• Primary Examiner(s): MEHTA, BHAVESH M
• Application Number:
  US09/101,486
• Time in Patent Office: 931 Days
• Field of Search: 382/115, 382/124-127, 382/100, 382/209
• US Class Current: 382/115
• CPC Class Codes: G06F 18/00 Pattern recognition
• CPC Class Codes: G06T 7/001 using an image reference approach

Abstract

A digital image is captured from an imprint left at the scene of a crime with a predetermined reproduction ratio. Suitable capture apparatus comprises a digital camera 1 supported in a stand 2 above the image 3. The captured image is displayed on a computer screen, cropped to a predetermined size, and the co-ordinates of any unique identification features in the image are recorded in computer memory, preferably together with information on the size and nature of such features. The sets of co-ordinates are stored in a database and compared to identify similar sets of co-ordinates likely to originate from the same article. The data can also be compared with a second database of co-ordinate data taken from the footwear of known offenders in order to link crimes with offenders.

Claims

1. A method of imprint identification which comprises:

producing, with a predetermined reproduction ratio, a digital image of an imprint produced by an article;

displaying said image on a computer screen;

recording in computer memory the co-ordinates of any unique identification features in said image caused by defects in said article;

storing the set of co-ordinates thereby produced in a database together with sets of co-ordinates similarly taken from other images; and

comparing said sets of co-ordinates to identify similar sets of co-ordinates likely to originate from the same article.

2. A method according to claim 1, in which the digital image is produced by recording a light image derived directly from the imprint.

3. A method according to claim 1, in which the image displayed on the computer screen is cropped to a selected one of a number of predetermined sizes.

4. A method according to claim 1, in which the nature of the identifying feature is recorded in association with each co-ordinate.

5. A method according to claim 1, in which the area of each feature is recorded in association with each co-ordinate.

6. A method according to claim 1, in which a stored set of coordinates is compared with other stored sets of co-ordinates a plurality of times, with the co-ordinates being incremented or decremented between comparisons.

7. A method according to claim 1, which comprises graphically displaying a set of stored co-ordinates mapped along two mutually perpendicular axes.

8. Apparatus for use in the identification of imprints, which comprises:

image recording means (1) for capturing an image of an imprint produced by an article, said recording means being provided with means (2) for producing a predetermined reproduction ratio between the imprint and the image;

a computer (30) for holding said image in digital form, said computer having a monitor (31) for displaying said image, and manual input means (32) for imputting the co-ordinates of characterising features of said image into computer memory; and

a database (33) which holds said characteristic co-ordinate data thereby obtained, and which includes the co-ordinates of unique identification features caused by defects in said article.

9. Apparatus according to claim 8, in which said means of producing a fixed reproduction ratio comprises a support structure (2) for positioning the recording means relative to an imprint.

10. Apparatus according to claim 8, comprising a screen (10) carrying positioning markers for superimposing on said imprint.