Monitoring system and camera device

• US 10,277,805 B2
• Filed: 05/29/2015
• Issued: 04/30/2019
• Est. Priority Date: 05/30/2014
• Status: Active Grant

• Current Assignee: Hitachi Kokusai Electric Incorporated (Hitachi, Ltd.)
• Original Assignee: Hitachi Kokusai Electric Incorporated (Hitachi, Ltd.)
• Inventors: Emi, Hirofumi, Aikawa, Tomohiro, Fujii, Masaru, Saotome, Naoki, Takahashi, Kei, Murata, Shigeyuki, Honda, Atsushi
• Primary Examiner(s): Camargo, Marly S
• Application Number:
  US15/314,663
• Publication Number:
  US 20170195556A1
• Time in Patent Office: 1,432 Days
• Field of Search: 348241, 348 25- 30, 348131, 348132, 348153, 348234, 348235, 348159, 348143, 348246, 348247, 3482113, 3482118, 34821113, 3482221, 3482961, 34833301, 3484211, 348687, 348619, 382164, 382171, 382173, 382272, 382274
• CPC Class Codes: G06T 2207/20172 Image enhancement details
• CPC Class Codes: G08B 13/19604 involving reference image or background adaptation with time to compensate for changing conditions, e.g. reference image update on detection of light level change
• CPC Class Codes: G08B 13/1961 Movement detection not involving frame subtraction, e.g. motion detection on the basis of luminance changes in the image
• CPC Class Codes: G08B 25/00 Alarm systems in which the location of the alarm condition is signalled to a central station, e.g. fire or police telegraphic systems
• CPC Class Codes: G08B 29/00 Checking or monitoring of signalling or alarm systems; Prevention or correction of operating errors, e.g. preventing unauthorised operation
• CPC Class Codes: H04N 17/002 for television cameras
• CPC Class Codes: H04N 19/154 Measured or subjectively estimated visual quality after decoding, e.g. measurement of distortion use of rate-distortion criteria H04N19/147
• CPC Class Codes: H04N 21/218 Source of audio or video content , e.g. local disk arrays details of retrieval in video databases G06F16/739
• CPC Class Codes: H04N 21/21805 enabling multiple viewpoints, e.g. using a plurality of cameras
• CPC Class Codes: H04N 21/23418 involving operations for analysing video streams, e.g. detecting features or characteristics television picture signal circuitry for scene change detection H04N5/147; filtering for image enhancement G06T5/00; methods or arrangements for recognising scenes G06V20/00; arrangements characterised by components specially adapted for monitoring, identification or recognition of video in broadcast systems H04H60/59
• CPC Class Codes: H04N 21/44008 involving operations for analysing video streams, e.g. detecting features or characteristics in the video stream arrangements characterised by components specially adapted for monitoring, identification or recognition of video in broadcast systems H04H60/59
• CPC Class Codes: H04N 23/00 Cameras or camera modules comprising electronic image sensors; Control thereof
• CPC Class Codes: H04N 23/56 provided with illuminating means
• CPC Class Codes: H04N 23/64 Computer-aided capture of images, e.g. transfer from script file into camera, check of taken image quality, advice or proposal for image composition or decision on when to take image
• CPC Class Codes: H04N 7/18 Closed-circuit television [CCTV] systems, i.e. systems in which the video signal is not broadcast
• CPC Class Codes: H04N 7/181 for receiving images from a plurality of remote sources

Abstract

In a monitoring system, each individual camera device divides image data acquired by an image sensor unit into a plurality of areas, and detects video-image abnormality from an average luminance signal value in each area or from a change thereof. The camera device that has detected video abnormality transmits video-image abnormality detection information to a server. In the plurality of areas, it is possible to use different detection algorithms such as a first algorithm in which it is determined that an abnormality has occurred when there is no change in the average luminance value, a second algorithm in which it is determined that an abnormality has occurred when there is a change in the average luminance value, and a third algorithm for observing a change in the video captured while a change is made to an aperture, exposure time, or the like.

Claims

1. A camera device comprising:

an image sensor unit; and

a measurement unit configured to;

divide image data acquired by the image sensor unit into a plurality of areas;

measure a change in a mean value of a luminance signal in each of the areas for a predetermined time period,

store a longest time period during which a state where there is no change in the mean value of the luminance signal is maintained, and a minimum value and a maximum value of the mean value of the luminance signal for the predetermined time period after the predetermined time period has lapsed;

when the longest time period is equal to or less than a preset threshold, determine that the change constantly occurs and specify a corresponding area as a first measurement area, wherein the first measurement area is determined to have a video-image abnormality when there is no change in the mean value of the luminance signal in the first measurement area; and

when a ratio of the maximum value and the minimum value is equal to or smaller than a preset value, specify a corresponding area as a second measurement area, wherein the second measurement area is determined to have a video-image abnormality when there is a change in the mean value of the luminance signal in the second measurement area.

2. A monitoring system comprising:

a plurality of the camera devices described in claim 1; and

a server connected to the camera devices through a network,

wherein each of the camera devices is configured to transmit information of the video-image abnormality to the server when the measurement unit determines that the video-image abnormality has occurred.