In this article we consider the anisotropic Calderón problem and related inverse problems. The approach is based on limiting Carleman weights, introduced in [13] in the Euclidean case. We characterize those Riemannian manifolds which admit limiting Carleman weights, and give a complex geometrical optics construction for a class of such manifolds. This is used to prove uniqueness results for ani...

This work proposes a novel technique for the extraction of descriptors of a texture image. The method consists in modeling the image through a complex network, based on the distribution of gray-level intensities. Therefore, we process the adjacency matrix as a geometrical object and compute its fractal dimension. Thus we apply a multiscale transform over the powerlaw fractal curve, obtaining th...

In this paper we present a new blind separation of sources (BSS) algorithm based on second order statistics (SOS) and geometrical approaches. The new algorithm can separate multisources from their instantaneous mixtures obtained by multisensors. In the case of p sources and p sensors, the algorithm can be decomposed into p steps: First, one should transform the mixing signals to orthogonal sign...

This manuscript introduces the concept of self similar watermarks for the purpose of counterfeiting geometrical attacks on copyright protected still images. Geometrical transformations result in the de-synchronization of watermark detection mechanisms enforcing the adoption of exhaustive search strategies for optimizing the algorithm’s efficiency. The self-similar structure attained by the pres...

Retrieval of texture images, especially those with different orientation and scale changes, is a challenging and important problem in image analysis. This paper adopts spiking cortical model (SCM) to explore geometrical invariant texture retrieval schemes based on Discrete Cosine Transform (DCT) coefficients of pulse images. The series of pulse images, outputs of SCM, have a robust talent for e...

The paper presents a general paradigm of semiautomatic house extraction from aerial stereo image pair. In the semiautomatic extraction system, the house model is defined as the one with multi right angles roof, then under the knowledge of the roof type, low-level and mid-level processing including edge detection, straight line segments extraction and obtaining initial house corners are used to ...

We propose a new approach for detecting ellipses. The approach is based on the geometrical property that five points on an ellipse can determine the parameters of the ellipse, and the symmetry of ellipses is used to obtain these points. Using symmetry, we classify the edge points in an input image into several subimages. Ellipses with different symmetric axes will lie in different subimages. In...

Image degradation occurs while acquisition because of so many reasons for example low illumination, noise, occlusion etc. Geometric distortion and radiometric degradations are also one of the widespread difficulties in computer vision. This paper presents a system to classify multi class images deformed due to geometrical transform, blur contamination or the combination of both. Different blur ...

We describe a novel continuous medial representation for describing object geometry and a deformable templates method for fitting the representation to images. Our representation simultaneously describes the boundary and medial loci of geometrical objects, always maintaining Blum’s symmetric axis transform (SAT) relationship. Cubic b-splines define the continuous medial locus and the associated...

We propose a discretization of two dimensional Euclidean Yang-Mills theories with N = 2 supersymmetry which preserves exactly both gauge invariance and an element of supersymmetry. The approach starts from the twisted form of the continuum super Yang Mills action which we show may be written in terms of two real Kähler-Dirac fields whose components transform into each other under the twisted su...