Fire detection system utilizing relationship of correspondence with regard to image overlap

Patent 5926280 Issued on July 20, 1999. Estimated Expiration Date:

July 28, 2017. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.

Abstract Claims Description Full Text

Patent References

Surveillance monitor system using image processing for monitoring fires and thefts Patent #: 5289275
Issued on: 02/22/1994
Inventor: Ishii, et al.

Inventors

Assignee

Nohmi Bosai Ltd.

Application

No. 901074 filed on 07/28/1997

US Classes:

356/390, With two images of single article compared356/328Having diffraction grating means

Examiners

Primary: Kim, Robert H.

Attorney, Agent or Firm

Wenderoth, Lind & Ponack, L.L.P.

International Class

G01B 011/00

Foreign Application Priority Data

1996-07-29 JP

Abstract

A fire detection system extracts fire (flame) portions from images produced by a monitoring camera while eliminating portions depicting artificial light sources. Portions depicting a light source that emits light are extracted from images produced by the monitoring camera. The system judges whether or not pairs of the extracted portions of images produced with the passage of time have a relationship of correspondence. If the extracted portions are contained in images produced for a given period of time, the light source is judged not to be the lamps of a moving vehicle, and is therefore identified as a fire. An area of an overlapping part of the extracted portions of images produced at different time instants, and an overall area of the extracted portions are computed, and the ratio of the area of the overlapping part to the overall area, that is, the area ratio between the extracted portions is computed. Incorrect alarming due to a vehicle at a standstill or a rotating lamp can be prevented.