Zero-crossing contour construction for scale-space filtering

The description of a signal or an image is only meaningful over a limited range of resolutions. The interest in and perception of different features of a signal depends not only on the signal, but on the scale of observation. Witkin (1983) has developed a multi-resolution method that looks at a signal over a continuum of scales in the course of describing it by finding the zero-crossing contour of a signal-fingerprint-and plotting the signal´s scale-space image. In this paper we present a fast and adaptive procedure for constructing the zero-crossing contours of a signal. We present two algorithms for finding the optimum smoothing scales and relating the zero-crossing of adjacent scales by our developed similarity measure.