Original-discrimination system for discriminating special document, and image forming apparatus, image processing apparatus and duplicator using the original-discrimination system

• US 6,272,248 B1
• Filed: 03/02/1998
• Issued: 08/07/2001
• Est. Priority Date: 08/03/1992
• Status: Expired due to Fees

• Current Assignee: Ricoh Company Limited
• Original Assignee: Ricoh Company Limited
• Inventors: Yamakawa, Shinji, Hikita, Toshiya, Kaneko, Yoshio, Ukai, Takeshi, Hashiguchi, Tadato, Sakano, Yukio, Ishigaki, Kouji, Aida, Midori, Murai, Kazuo, Fukuda, Haruhiko, Takahashi, Hiroshi, Saitoh, Takashi, Sumida, Hiroyasu, Kurotaka, Shigeo, Omi, Kyoji, Okubo, Hiromi, Tachikawa, Michiyoshi
• Primary Examiner(s): Couso, Jose L.
• Application Number:
  US09/032,991
• Time in Patent Office: 1,254 Days
• Field of Search: 382/218, 382/271, 382/272, 382/273, 382/274, 382/275, 382/165, 382/176, 382/286
• US Class Current: 382/218
• CPC Class Codes: G06T 2207/10008 from scanner, fax or copier
• CPC Class Codes: G06T 2207/10024 Color image
• CPC Class Codes: G06T 2207/30144 Printing quality
• CPC Class Codes: G06T 2207/30176 Document
• CPC Class Codes: G06T 7/0002 Inspection of images, e.g. flaw detection
• CPC Class Codes: G06T 7/001 using an image reference approach
• CPC Class Codes: G06V 10/40 Extraction of image or video features
• CPC Class Codes: G07D 7/12 Visible light, infrared or ultraviolet radiation
• CPC Class Codes: H04N 1/00843 based on recognising a copy prohibited original, e.g. a banknote pattern authentication and markers therefor, forgery detection G06V20/95; character recognition G06V30/10; document-oriented image-based pattern recognition G06V30/40; testing paper currency or similar valuable papers for genuineness G07D7/00
• CPC Class Codes: H04N 1/00846 based on detection of a dedicated indication, e.g. marks or the like
• CPC Class Codes: H04N 1/00848 by detecting a particular original
• CPC Class Codes: H04N 1/00875 Inhibiting reproduction, e.g. by disabling reading or reproduction apparatus

Abstract

An original image comprises a printed region on which a predetermined printed matter is realized and a background region on which no printed matter is realized. The shape of a peripheral zone in the original image comprises the shape of the background region, which shape exists particularly at the peripheral region of said original image. It is determined whether or not the original image comprises the special document by detecting the peripheral zone. Further, the original image has an outer-frame region, having a predetermined shape at the peripheral region of the original image. The determination is carried out using a result of measuring the width of the outer-frame region. Further, the width of the outer-frame region comprises a width along a direction substantially perpendicular to a direction extending along the outline of the original image.

Claims

1. An original discrimination system for determining whether or not an original image is identical to a predetermined reference image, in response to data concerning said original image being input, duplication of said reference image being inadmissible, the determination comprising the steps of:

a) removing extremely fine lines and isolated dots from the original image,

b) determining whether in a predetermined area fine lines have been recognized in a number which exceeds a predetermined limit to be allocated to the original image;

c) interrupting the copying operation when the number equals or exceeds the predetermined limit, and continuing the copying operation when the number falls below the predetermined limit;

d) determining whether in the predetermined area fine lines are present with equal or unequal distance; and

e) interrupting the copy operation if the fine lines are recognized with unequal distance.

2. An original discrimination system according to claim 1, wherein said step a) comprises the substeps of:

a1) scanning the original image as to density;

a2) allocating image data with a density below a threshold value to the extremely fine lines and removing or setting isolated dots at a density value of 0;

a3) setting image data with a density above the threshold value which are adjacent to image data with a high density to a high density.