AN ALGORITHM FOR RAPID IMAGE SEGMENTING

As a first step in image processing applications it is often required to identify pixels above a threshold intensity level which contact one another. Sorting marker particles when the particle images cover many pixels is an obvious fluid mechanical application. With the present p rocedure, the image is scanned line by line once. The procedure is rap id, and can be continued across the boundary of the domain, for exampl e, when the data is a long time series which must be artificially brok en into ''image'' blocks for computer processing. The use of the algor ithm is demonstrated on a variety of complex shapes, and estimates of speed of execution are given. The timing results show that the increme ntal time per bright region scales roughly as the square root of the n umber of bright regions. In addition, if bright regions fill more than (roughly) ten per cent of the total array space, the execution time p er additional bright region becomes negligible.