An Original Method for Spot Detection and Analysis for Large Surveys of Videos in JET

An original spot detection method for large surveys of videos in Joint European Torus (JET) is presented. The method can be used for the automatic identification of spots in JET infra-red (IR) videos and for the assessment of the long-term trends in their evolution. This method has been applied to the analysis of a large database of JET IR images collected during the last campaigns of operation with the International Thermonuclear Experimental Reactor-like wall. The evolution of the spots and their properties, such as size and distribution, can be correlated with macroscopic events, in particular series of intentional disruptions. On the other hand, care must be taken in the interpretation of the results because there is some evidence of toroidal asymmetries in the spot distribution.