Detection System for Jellyfish Inflow using Images from Monitor Video Cameras

In order to strengthen the surveillance of jellyfishes interrupting the intake of cooling water in power stations, we have developed the system that detects an inflow of jellyfish by image recognition using existing monitor cameras. Monitor cameras are set on land in the way to look down the surface of the sea. Their images are changing by various factors, such as wave patterns, shadows and reflections of structures affected by the sun and the weather. We developed the image processing method to detect jellyfishes in distinction from other phenomena. Jellyfish candidate regions are extracted by edge enhancement and thresholding, and are divided into jellyfishes and the others by their shapes and histogram features. This process features the automatic masking operation that exclude regions of image which are inappropriate for jellyfish detection such as regions except sea-surface from the object region of processing. We have tested experimental system at two thermal stations and confirmed that the system is of practical use.