The data describing a process of echo-image formation in bottlenose dolphin sonar perception were accumulated in our experimental explorations. These data were formalized mathematically and used in the computational model, comparative testing of which in echo-discrimination tasks revealed no less capabilities then those of bottlenose dolphins.

We investigate the problem of speciation and coexistence in simple ecosystems when the competition among individuals is included in the Eigen model for quasispecies. By suggesting an analogy between the competition among strains and the diffusion of a chemical inhibitor in a reaction-diffusion system, the speciation phenomenon is considered the analogous of chemical pattern formation in genetic...

Date of publication: 13 June 2014 T his article presents a survey of recent research on sparsity-driven synthetic aperture radar (SAR) imaging. In particular, it reviews 1) the analysis and synthesis-based sparse signal representation formulations for SAR image formation together with the associated imaging results, 2) sparsity-based methods for wide-angle SAR imaging and anisotropy characteriz...

A method is proposed for calibrating Catadioptric Omnidirectional Vision Systems. This method, similarly to classic camera calibration, makes use of a set of fiducial points to find the parameters of the geometric image formation model. The method makes no particular assumption regarding the shape of the mirror or its position with respect to the camera. Given the camera intrinsic parameters an...

? Abstract. Image formation is described by means of modern geometry in terms of curvatures. These curvatures are a quantisation of the set of rules for constructing the image. A simpliication of this set of rules is proposed by applying dynamic scale-space theory.

Coherent image formation in step transform algorithm is realized by overlapped subapertures in both range and cross range direction. Subaperture formation principle is treated as multiplication of target backscatter signature with a set of overlapped and shifted complex, conjugate reference functions and subsequent spectral analysis. A polyphase filter bank interpretation of step transform is p...

We present an approach to easily remove the effects of haze from images. It is based on the fact that usually airlight scattered by atmospheric particles is partially polarized. Polarization filtering alone cannot remove the haze effects, except in restricted situations. Our method, however, works under a wide range of atmospheric and viewing conditions. We analyze the image formation process, ...

We present a novel method of imaging multiple moving targets using a SAR system transmitting ultra-narrowband continuous waveforms. Our method comprises of a new forward model that relates the velocity as well as re ectivity information at each location to a correlated received signal; and a novel image formation method based on ltered-backprojection and image-contrast optimization. The method ...

The fractal geometry is the most appropriate mathematical instrument to describe the irregularity of a natural scene, by means of few effective and reliable parameters. Therefore, fractal concepts can be used to model and to identify geometrical changes occurred in areas hit by disasters. An overall framework employing fractal based models, algorithms and tools to support identification of natu...

A geometrical optical model for the image formation of Makyoh (or magic-mirror) topography is presented. General relations are given on the optical settings. The basic equations of the imaging are derived. Fundamental features of the imaging are pointed out, and optimum working conditions are established. Simulations of the image of an isolated defect (hillock or depression) and a periodic (sin...