Image analysis at the Institute of Marine Research, Norway

Computer-aided analysis of images is a technology gaining importance and utilization in marine science. Whereas analyses by eye are often tedious, slow and inaccurate, state-of-the-art image analysis is rapid, accurate, permits operator intervention and produces data in the form of tables as well as graphic presentations. In addition to image-analytic expertise on otoliths at the institute's biological station at Flødevigen, the Institute of Marine Research in Bergen has developed an image-analysis system called Zeus to aid scientists in routine and specialized investigations. In its simplest form the system consists of a Zeus computer, a Macintosh computer, a high-resolution monitor and high-resolution black-and-white camera. Zeus is user-friendly, can be run in the laboratory or in the field and can analyze images from video tapes, still photographs, computer pictures, directly from a camera or from digitized images stored on diskette. Zeus has been applied for objects ranging in size from bacteria to ice floes. Research includes investigations on autotrophic as well as heterotrophic plankton, fish otoliths and swimming behavior, bioturbation in sediments, seal sizing from aerial photography and even distribution of drift ice. Development of applications continues. The pinpose of this paper is to provide a brief description of the image-analysis system developed at IMR, an overview of some of the major projects using Zeus, key findings and references for additional reading