Content-based retrieval and real time detection from video sequences acquired by surveillance systems

A surveillance system devoted to detect abandoned objects in unattended environments is presented; image processing content based retrieval capabilities have been added to make the inspection task of operators easier. Video based surveillance systems generally employ one or more cameras connected to a set of monitors. This kind of system needs the presence of a human operator, who interprets the acquired information and controls the evolution of the events in a surveyed environment. During the last years, efforts have been made to develop systems supporting human operators in their surveillance task, in order to focus the attention of operators when unusual situations are detected. Image sequence databases are also managed by the proposed surveillance system in order to provide operators with the possibility of retrieving in a second time the interesting sequences that may contain useful information for discovering causes of an alarm. Experimental results are shown in terms of the probability of correct detection of abandoned objects and examples concerning retrieval sequences