Fingerprint image transmission system utilizing reversible and non-reversible data compression coding techniques

• US 5,644,645 A
• Filed: 08/22/1994
• Issued: 07/01/1997
• Est. Priority Date: 08/20/1993
• Status: Expired due to Fees

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Osuga, Yoshikazu
• Primary Examiner(s): Razavi, Michael T.
• Assistant Examiner(s): Patel, Jayanti K.
• Application Number:
  US08/294,726
• Time in Patent Office: 1,044 Days
• Field of Search: 382/116, 382/124, 382/125, 382/233, 382/234, 382/237, 382/243, 382/259, 382/257, 382/258, 382/232, 382/244, 382/240, 358/405, 358/435
• US Class Current: 382/124
• CPC Class Codes: G06T 9/00 Image coding bandwidth or redundancy reduction for static pictures H04N1/41; coding or decoding of static colour picture signals H04N1/64; methods or arrangements for coding, decoding, compressing or decompressing digital video signals H04N19/00

Abstract

A fingerprint image transmission system includes a remote computer system and a central computer system. In the remote computer system, a gray image of a fingerprint image sampled by an image scanner portion (10) is compressed by a non-reversible (lossy) coding by a non-reversible coding mechanism (202) and a skeleton pattern generated by a skeleton generating mechanism (201) by inputting the gray image, is compressed by a reversible (lossless) coding by a reversible coding mechanism (203). The compressed gray image and the compressed skeleton pattern are transmitted to the central computer system through a transmission mechanism (31). In the central computer system, a receiver mechanism (41) receives the gray image and the skeleton pattern transmitted from the remote computer system. A skeleton editing portion (60) performs correction of the skeleton pattern decompressed by a skeleton decompressing mechanism (502) with reference to the gray image decompressed by a gray image decompressing mechanism (501), and extracts feature points in the skeleton pattern to record in a database (80).

Claims

1. A fingerprint image transmission system for transmitting a fingerprint image from a remote computer system which samples the fingerprint image to a central computer system which performs analysis of a fingerprint, wherein:

said remote computer system comprises an image scanner portion, an image compressing portion and a transmitting portion;

said image scanner portion being input with a fingerprint image and comprising means for generating a gray image as data indicative of tone of respective pixels of said fingerprint image;

said image compressing portion comprising a non-reversible coding mechanism, a skeleton generating mechanism and a reversible coding mechanism;

said non-reversible coding mechanism being input with said gray image and comprising means for compressing the gray image and eliminating a high frequency band;

said skeleton generating mechanism being input with the gray image generated by said image scanner portion and comprising means for generating a skeleton pattern as data indicative of ridge portions of the minutiae of the fingerprint from the reproduced gray image, said skeleton pattern being generated from an entire non-blank area of said gray image;

said reversible coding mechanism comprising means for compressing said skeleton pattern generated by said skeleton generating mechanism in such a manner that no information will be lost upon decompression of said skeleton pattern;

said transmitting portion of said remote computer system comprising a transmitter mechanism;

said transmitter mechanism comprising means for feeding the gray image compressed by said non-reversible coding mechanism together with said skeleton pattern compressed by said reversible coding mechanism to a transmission path; and

wherein

said central computer system comprises a receiving portion, an image decompressing portion, a skeleton editing portion and a database recording portion;

said receiving portion of said central computer system comprising a receiver mechanism;

said receiver mechanism comprising means for receiving said gray image and said skeleton pattern transmitted from said remote side computer system via said transmission path and means for separating said gray image and said skeleton pattern;

said image decompressing portion comprising a gray image decompression mechanism and a skeleton decompression mechanism;

said gray image decompression mechanism being input with the gray image received and separated by said receiver mechanism for reproducing a decompressed gray image;

said skeleton decompression mechanism being input with the skeleton pattern received and separated by said receiver mechanism and comprising means for reproducing the original skeleton pattern existing before compression;

said skeleton editing portion being input with a skeleton pattern decompressed by said skeleton decompression mechanism and the gray image decompressed by said gray image decompressing mechanism, and comprising means for providing an editing screen for a user for correction of said skeleton pattern with reference to said decompressed gray image for enabling correction, and means for extracting feature points from the corrected skeleton pattern; and

said database recording portion comprising means for recording the feature points of said skeleton pattern extracted by said skeleton editing portion and said gray image in a database.

2. A fingerprint image transmission system as claimed in claim 1, wherein said non-reversible coding mechanism comprises means for compressing approximately 164 Kbytes of gray image into approximately 10 Kbytes;

said skeleton generating mechanism comprises means for generating the skeleton pattern having an information amount of approximately 32 Kbytes from the gray image having an information amount of approximately 164 Kbytes; and

said reversible mechanism comprises means for compressing approximately 32 Kbytes of the information amount of said skeleton pattern into an information amount of approximately 7 Kbytes.

3. An image data transmission system in a data communication network including an image source system and an image data processing system, said image data transmission system comprising:

an image scanner portion provided in said image source system and comprising means for sampling an image of an object and generating image data indicative of tone of respective pixels of the sampled image;

an image compressing portion in said image source system comprising a skeleton generating mechanism, an image data compressing mechanism, and a skeleton compressing mechanism;

said skeleton generating mechanism comprising means for generating, from image data corresponding to an entire non-blank area of said image of said object, a skeleton pattern as data indicative of characteristics of said image;

said image data compressing mechanism being input with said image data and comprising means for compressing said image data utilizing a first data compression method which achieves a high data compression rate while sacrificing exactness of a restored image data upon decompression;

said skeleton compressing mechanism being input with said skeleton pattern from said skeleton generating mechanism and comprising means for compressing said skeleton pattern utilizing a data compression method which permits complete restoration of an original skeleton pattern, for generating a compressed skeleton pattern;

a data communication path comprising means for connecting, through a communication channel, said image source system and said image data processing system for transmitting said compressed image data together with said compressed skeleton pattern from said image source system to said image data processing system;

an image decompressing portion in said image data processing system comprising an image decompression mechanism and a skeleton decompression mechanism;

said image decompression mechanism being input with said compressed image data received from said data communication path, and comprising means for decompressing said compressed image data;

said skeleton decompression mechanism being input with said compressed skeleton pattern received from said data communication path, and comprising means for decompressing said compressed skeleton pattern for restoring said original skeleton pattern;

a skeleton editing portion being input with said restored original skeleton pattern and said decompressed image data, and comprising means for providing an editing screen image for a user for correction of said original skeleton pattern with reference to said decompressed image data for enabling correction, and means for extracting feature points from the corrected skeleton pattern; and

a database recording portion in said image data processing system comprising means for recording the feature points of said skeleton pattern extracted by said skeleton editing portion and said image data in a database.