arXiv subjects

Leonid Yaroslavsky

Publications and source records attributed to Leonid Yaroslavsky.

6 recordsLinked to original sources

arXiv2017

How can one sample images with sampling rates close to the theoretical minimum?

A problem is addressed of minimization of the number of measurements needed for digital image acquisition and reconstruction with a given accuracy. A sampling theory based method of image sampling and reconstruction is suggested that allows to draw near the minimal rate of image sampling defined by the sampling theory. Presented and discussed are also results of experimental verification of the method and its possible applicability extensions.

cs.CV↗

arXiv2014

Compression, Restoration, Re-sampling, Compressive Sensing: Fast Transforms in Digital Imaging

Transform image processing methods are methods that work in domains of image transforms, such as Discrete Fourier, Discrete Cosine, Wavelet and alike. They are the basic tool in image compression, in image restoration, in image re-sampling and geometrical transformations and can be traced back to early 1970-ths. The paper presents a review of these methods with emphasis on their comparison and relationships, from the very first steps of transform image compression methods to adaptive and local adaptive transform domain filters for image restoration, to methods of precise image re-sampling and image reconstruction from sparse samples and up to "compressive sensing" approach that has gained popularity in last few years. The review has a tutorial character and purpose.

cs.CV↗

arXiv2013

Self-controlled growth, coherent shrinkage, eternal life in a self-bounded space and other amazing evolutionary dynamics of stochastic pattern formation and growth models inspired by Conways Game of Life

Results of experimental investigation are presented of evolutionary dynamics of several stochastic pattern formation and growth models designed by modifications of the famous mathematical Game of Life. The modifications are two-fold: Game of Life rules are made stochastic and mutual influence of neighboring cells is made non-uniform. The results reveal a number of new phenomena in the evolutionary dynamics of the models: - Ordering of chaos to maze-like patterns: evolutionary formation, from arbitrary seed patterns, of stable maze-like patterns with chaotic dislocations that resemble natural patterns frequently found in the nature, such as skin patterns of some animals. The remarkable property of these patterns is their capability of unlimited growth, self-healing and transplantation. - Self-controlled growth of chaotic live formations into communities bounded, depending on the model, by a square, hexagon or octagon, until they reach a certain critical size, after which the growth stops. - Coherent shrinkage of mature, after reaching a certain size, communities into one of stable or oscillating patterns preserving in this process isomorphism of their bounding shapes until the very end. - Eternal life in a self-bounded space of communities: seemingly permanent birth/death activity of communities after they reach a certain size and shape.

nlin.CG↗

arXiv2013

The amazing dynamics of stochastic pattern formation and growth models inspired by the Conway's Game of Life

Several modifications of the famous mathematical Game of Life are introduced by making Game of Life rules stochastic and mutual influence of cells in their 8-neighborhood on a rectangular lattice spatially non-uniform. Results are reported of experimental investigation of evolutionary dynamics of the introduced models. A number of new phenomena in the evolutionary dynamics of the models and collective behavior of patterns they generate are revealed, described and illustrated: formation of maze-like patterns as fixed points of the models, "self-controlled growth", "eternal life" in a bounded space and "coherent shrinkage".

nlin.CG↗

arXiv2008

Optics-less smart sensors and a possible mechanism of cutaneous vision in nature

Optics-less cutaneous (skin) vision is not rare among living organisms, though its mechanisms and capabilities have not been thoroughly investigated. This paper demonstrates, using methods from statistical parameter estimation theory and numerical simulations, that an array of bare sensors with a natural cosine-law angular sensitivity arranged on a flat or curved surface has the ability to perform imaging tasks without any optics at all. The working principle of this type of optics-less sensor and the model developed here for determining sensor performance may be used to shed light upon possible mechanisms and capabilities of cutaneous vision in nature.

physics.optics↗

arXiv2007

Computational Vision in Nature and Technology

It is hard for us humans to recognize things in nature until we have invented them ourselves. For image-forming optics, nature has made virtually every kind of lens humans have devised. But what about lensless "imaging"? Recently, we showed that a bare array of sensors on a curved substrate could achieve resolution not limited by diffraction- without any lens at all provided that the objects imaged conform to our a priori assumptions. Is it possible that somewhere in nature we will find this kind of vision system? We think so and provide examples that seem to make no sense whatever unless they are using something like our lensless imaging work.

physics.optics↗