Image segmentation based on contour extraction usually involves three stages of image operations: feature extraction, edge detection and edge linking. This paper is devoted to the first stage: a method to design feature extractors used to detect edges from noisy and/or blurred images. The method relies on a model that describes the existence of image discontinuities (e.g. edges) in terms of cov...

The present paper deals with the quantum coordinates of an event in spacetime, individuated by a quantum object. It is known that these observables cannot be described by selfadjoint operators. We describe them by means of a normalized positive operator valued (POV) measure in the Minkowski spacetime, satisfying a suitable covariance condition with respect to the Poincaré group. This POV measur...

Color Quantization of still images can be easily stated as a Clustering problem. Color Quantization of sequences of images becomes a Non-stationary Clustering Problem. In this paper we propose a very simple and e€ective Evolution-based Adaptive Strategy to perform the adaptive computation of the color representatives for each image in the sequence. Salient features of the algorithm proposed her...

I present an efficient new approach to simultaneously estimate two slopes from seismic data. I employ a Newton iteration to overcome the problem’s nonlinearity. In spite of my method’s theoretical inability to handle aliased data, it robustly estimates two independent slopes in many circumstances. I apply my method to the problem of signal/noise separation on synthetic and real data examples. T...

Communicated by (xxxxxxxxxx) Gaussian states — or, more generally, Gaussian operators — play an important role in Quantum Optics and Quantum Information Science, both in discussions about conceptual issues and in practical applications. We describe, in a tutorial manner, a systematic operator method for first characterizing such states and then investigating their properties. The central numeri...

We explicitly compute the complete three-loop (O(g 4)) contribution to the four-point function of chiral primary current-like operators˜q 2 q 2 ˜ q 2 q 2 in any finite N = 2 SYM theory. The computation uses N = 2 harmonic supergraphs in coordinate space. Dramatic simplifications are achieved by a double insertion of the N = 2 SYM linearized action, and application of supercon-formal covariance ...

The heavy mass limit of quark models based on the Bakamjian-Thomas construction reveals remarkable features. In addition to previously demonstrated properties of covariance and Isgur-Wise scaling, exact duality, leading to the Bjorken-Isgur-Wise sum rule, is proven, for the first time to our knowledge in relativistic quark models. Inelastic as well as elastic contributions to the sum rule are t...

We introduce a novel method for analyzing a well known class of adaptive algorithms. By combining recent developments from the theory of Markov processes and long existing results from t h e theory of Perturbations of Linear Operators we s tudy first the behavior and convergence properties of a class of products of random matrices. This i n t u r n allows for the analysis of t h e first a n d s...

We investigate permutation-invariant continuous variable quantum states and their covariance matrices. We provide a complete characterization of the latter with respect to permutation invariance and exchangeability and representing convex combinations of tensor power states. On the level of the respective density operators this leads to necessary criteria for all these properties which become n...