Signature verification method and apparatus

• US 4,286,255 A
• Filed: 05/02/1980
• Issued: 08/25/1981
• Est. Priority Date: 02/22/1979
• Status: Expired due to Term

• Current Assignee: Unisys Corporation
• Original Assignee: Burroughs Corp (Unisys Corporation)
• Inventors: Siy, Pepe
• Primary Examiner(s): Boudreau, Leo H.
• Application Number:
  US06/146,134
• Time in Patent Office: 480 Days
• Field of Search: 340/146.3 SY, 340/146.3 SG, 340/146.3 H, 340/146.3 AE, 340/149 A, 358/93, 364/200
• US Class Current: 382/123
• CPC Class Codes: G06V 40/30 Writer recognition; Reading and verifying signatures
• CPC Class Codes: G07C 9/35 by means of a handwritten signature

Abstract

A method and apparatus for determining whether a newly-signed signature and a previously recorded signature were made by the same person. The method and apparatus include the steps of and apparatus for scanning a document containing the newly-signed signature to provide an electrical signal representative of the reflectivity of the newly-signed signature and the document and generating a signature envelope from the electrical signal with the envelope being formed of selected points on the signature. A plurality of characteristics of the newly-signed signature are then calculated based on the location and magnitude of the selected points forming the signature envelope with respect to a reference line. The calculated characteristics of the newly-signed signature are then compared with corresponding characteristics of a standard signature formed from a group of previously recorded signatures and a signature verification decision is generated based on the degree with which the compared characteristics match.

Claims

1. Apparatus for use in signature verification by comparing features of a signature to be validated against features of a signature standard recorded in binary form, comprising:

scanning means for scanning a document bearing a signature to be validated, said scanning means providing a first plurality of signals representative of the reflectivity of the signature and the document;

first means coupled to receive said first plurality of signals and, in response to said signals, generate mode signals, write enable signals, and field indicator signals;

second means coupled to receive said first plurality of signals and extract a plurality of digital signals representing the electrical values of an envelope formed by a reference line founding the lower part of a signature and a line founding the upper part of the signature where the scanning means scans across the lines of the envelope; and

a data router coupled responsive to a first set of said mode signals to direct said digital signals for recording in a memory device;

said data router responding to a second set of said mode signals to direct digital signals recorded in said memory device to a computer for comparison against features of a standard signature recorded therein.

2. The invention as claimed in claim 1, in which:

the scanning means includes a television camera employing an interlaced scan in which two interlaced scanning fields are provided per picture frame and the first plurality of signals are raw video signals;

the first means including means for separating blanking pulses from the raw video signals and means for distinguishing valid blanking pulses from spurious high amplitude video signals of short duration.

3. The invention as claimed in claim 1, in which:

the first means includes a field detector coupled responsive to characteristics of successive valid blanking pulses to distinguish between scanning fields and to generate field indicator signals; and

the first means includes an envelope complete detector responsive to field indicator signals to generate said mode signals indicating when an envelope is being generated and when an envelope is complete and ready for transmission.

4. The invention as claimed in claim 2, in which:

the first means includes a field detector responsive to characteristics of successive blanking pulses to distinguish between scanning fields and to generate field indicator signals; and

the first means includes an envelope complete detector responsive to field indicator signals to generate said mode signals indicating when an envelope is being generated and when an envelope is complete and ready for transmission.

5. The invention as claimed in claims 1, 2, 3 or 4 in which, the computer:

includes in an internal memory a digital representation of a plurality of distinct features of a signature standard prerecorded therein;

receives digital signals, from said memory device, representing the envelope;

processes the digital signals to produce distinct signals representing features of the signature to be validated; and

evaluates said distinct signals against the digital representation in its memory to effect an evaluation of the signature.

6. Apparatus for generating a plurality of electrical signals for use in determining whether a newly-signed signature and a previously recorded signature were made by the same person, said electrical signals representing selected points forming the envelope of a signature, comprising:

scanner means for scanning a document bearing a signature to provide a first plurality of signals representative of the reflectivity of the signature and the document;

comparator means coupled responsive to said first plurality of signals to separate blanking pulses from among said signals and advance the blanking pulses in the system;

valid blank pulse detector means coupled to receive said blanking pulses and distinguish valid blanking pulses of minimum duration from spurious high amplitude pulses having durations shorter than a minimum period;

write enable means coupled responsive to valid blanking pulses to receive said pulses;

field detector means coupled responsive to valid blanking pulses to distinguish a first scanning field of the scanning means from a second field and to provide distinct signals identifying the two fields; and

an envelope complete detector coupled to receive said distinct signals and generate mode signals indicating by first mode signals that an envelope is being generated and by second mode signals that an envelope is complete and the start of transmission.

7. The invention as claimed in claim 6, including:

additional means coupled to receive said first plurality of signals and extract a plurality of digital signals representing the electrical values of an envelope formed by a reference line founding the lower part of a signature and a line founding the upper part of the signature where the scanning means scans across the lines of the envelope;

a data router coupled responsive to first mode signals to direct said digital signals for recording in a memory device; and

said data router responding to second mode signals to direct said digital signals recorded in said memory device to a computer for comparison against features of a standard signature recorded therein.

8. The invention as claimed in claim 7, in which:

the digital signals are compared in a computer with corresponding signals representing the signature envelope of a previously recorded signature; and

the computer generates a signature verification decision based on the degree with which said compared characteristics match.

9. Apparatus for use in signature verification employing a reference signature consisting of a signature envelope generated from a plurality of samples of a signature, said reference signature serving as a signature standard against which a newly recorded signature may be compared, said apparatus comprising:

TV scanner means for scanning a sample signature on a document to produce video signals representative of reflectivity of the scanned documents and the signature;

comparator means coupled to the scanner means for comparing said video signals with a reference potential to transmit blanking pulses;

a valid blanking pulse detector coupled to the comparator to distinguish valid blanking pulses from spurious high amplitude signals at video frequencies which are of short duration;

a field detector coupled responsive to characteristics of successive valid blanking pulses to distinguish between scanning fields and to generate field indicator signals;

an envelope complete detector coupled responsive to said field indicator signals to generate mode signals indicating when an envelope is being generated and when an envelope is complete and ready for transmission;

a gate generator coupled responsive to said valid blanking pulses to provide gate signals;

envelope generator means coupled to said scanner means responsive to said video signals and coupled to said gate generator responsive to said gate signals to provide pulses representing a signature envelope; and

means coupled responsive to said mode signals and said pulses representing a signature envelope to route signals representing a complete envelope to a computer for comparison against features of the reference signature stored therein.