Automated Boundary-Extraction and Region-Growing Techniques Applied to Solar Magnetograms

We present an automated approach to active region extraction from full disc MDI longitudinal magnetograms. This uses a region-growing technique in conjunction with boundary-extraction to define a number of enclosed contours as belonging to separate regions of magnetic significance on the solar disc. This provides an objective definition of active regions and areas of plage on the Sun. A number of parameters relating to the flare-potential of each region is discussed.