Acharya, B., Mukherjee, Jayanta and Majumder, A.K. (1999):
Two-phase relaxation approach for extracting contours from noisy echocardiogram
images, proc. of 4th Int. Conf. on Advances in Pattern Recognition and
Digital Techniques, ISI, Calcutta, India, pp. 144-148. 
Abstract. 
In this work we present a technique for extracting contours from noisy echocardiogram images. In our technique, at first, an initial estimate of the boundary is obtained and then this initial contour is locally converged, in a number of steps, to the desired solution by minimising an energy function. This technique is applied to extract the contours of the heart-chambers from a sequence of echocardiogram images.
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