A UNIFIED APPROACH TO NOISE REMOVAL, IMAGE-ENHANCEMENT, AND SHAPE RECOVERY

We present a unified approach to noise removal, image enhancement, and shape recovery in images. The underlying approach relies on the level set formulation of curve and surface motion, which leads to a class o f PDE-based algorithms. Beginning with an image, the first stage of th is approach removes noise and enhances the image by evolving the image under flow controlled by min/max curvature and by the mean curvature. This stage is applicable to both salt-and-pepper grey-scale noise and full-image continuous noise present in black and white images, grey-s cale images, texture images, and color images. The noise removal/enhan cement schemes applied in this stage contain only one enhancement para meter, which in most cases is automatically chosen. The other key adva ntage of our approach is that a stopping criteria is automatically pic ked from the image; continued application of the scheme produces no fu rther change. The second stage of our approach is the shape recovery o f a desired object; we again exploit the level set approach to evolve an initial curve/surface toward the desired boundary, driven by an ima ge-dependent speed function that automatically stops at the desired bo undary.