Method of verifying a triggered alert and alert verification processing apparatus

• Main Authors: Alberto Baldacci, Marco Cappelletti
• Format: Patent
• Language: English
• Published: 15.11.2017
• Subjects: ALARM SYSTEMS; CALCULATING; COMPUTING; COUNTING; ELECTRIC COMMUNICATION TECHNIQUE; ELECTRICITY; EQUIPMENT FOR DWELLING OR WORKING UNDER WATER; IMAGE DATA PROCESSING OR GENERATION, IN GENERAL; LAUNCHING, HAULING-OUT, OR DRY-DOCKING OF VESSELS; LIFE-SAVING IN WATER; MEANS FOR SALVAGING OR SEARCHING FOR UNDERWATER OBJECTS; ORDER TELEGRAPHS; PERFORMING OPERATIONS; PHYSICS; PICTORIAL COMMUNICATION, e.g. TELEVISION; RELATED EQUIPMENT; SHIPS OR OTHER WATERBORNE VESSELS; SIGNALLING; SIGNALLING OR CALLING SYSTEMS; TRANSPORTING

Verifying a triggered alert in a man overboard detection system where: sequential frames of image data associated with the triggered alert are received followed by the creation of difference frames 730, 732, 734, 736 which are generated from the differences between successive frames. Motion compensation is applied to the difference frames 746, 748, 750. A summation of the motion compensated difference frames is then generated 752. The summation image is then analysed and the detection associated therewith is classified in response to identification of a cluster of pixels corresponding to a predetermined size range. Preferably the alert is triggered in response to the detection of movement of an object. Preferably the rate of vertical movement of the object is determined in units of rate of change of pixels. Preferably ranging track data corresponding to the movement of the object is received and, using this data and a knowledge of the positioning of the camera used to capture the image frames in order to translate a calculated three dimensional movement of the object into a two dimensional pixel domain.