نتایج جستجو برای: geometrical transform

تعداد نتایج: 142971  

2010
Chandrashekar M. Patil Sudarshan Patilkulkarni

Iris recognition a new biometric technology has great advantages such as variability, stability and security. In this paper we propose a feature extraction method for iris recognition based on contourlet transform. Contourlet transform captures the intrinsic geometrical structures of iris image. It decomposes the iris image into a set of directional subbands with texture details captured in dif...

2012
N. Suganthi

Region duplication is a common form of image manipulation where part of an image is pasted to another location to conceal undesirable contents. Mostly used region duplication detection methods are directly matching the block of image pixels. But it is not effective when the duplicated regions have geometrical and illumination distortions. The proposed method uses SR-PE (Scale rotation invariant...

2002
F. Meyer C. Vachier

The morphological approach to image segmentation is based on the watershed transform. It is a very powerful tool which presents many advantages: it is not parametric, computationally efficient... However, in comparison with energy-based methods as active contours, it does not allow to control the smoothness of the result. In order to introduce geometrical regularization constraints in the morph...

2007
John N. Ellinas

In this paper, a robust watermarking algorithm using the wavelet transform and edge detection is presented. The efficiency of an image watermarking technique depends on the preservation of visually significant information. This is attained by embedding the watermark transparently with the maximum possible strength. The watermark embedding process is carried over the subband coefficients that li...

Journal: :Pattern Recognition 1992
Ioannis Pitas Constantine Kotropoulos

-A new method is presented for the texture analysis and segmentation of seismic images. The texture of a seismic image is described in terms either of seismic horizons' features (e.g. length, reflection strength, geometrical appearance), or in terms of Hilbert transform features (magnitude, phase, instantaneous frequency) or in terms of features related to the generalized runs. Seismic image se...

2009
Amir Azizi Hamid Reza Pourreza

In different methods of Biometrics, recognition by iris images in recent years has been taken into consideration by researchers as one of the common methods of identification like passwords, credit cards or keys. Iris recognition a new biometric technology has great advantages such as variability, stability and security. In this paper we propose a new feature extraction method for iris recognit...

2007
Federico Esposti Jacopo Lamanna Maria Gabriella Signorini

A lot of methods were created in last decade for the spatio-temporal analysis of multi-electrode array (MEA) neuronal data sets. All these methods were implemented starting from a channel to channel analysis, with a great computational effort and onerous spatial pattern recognition task. Our idea is to approach the MEA data collection from a different point of view, i.e. considering all channel...

1997
J. Strom F. Davoine J. Ahlberg H. Li

In this paper we present two methods of enhancing the eigen face approach for the compression of images of human faces. In earlier work, a series of image basis functions (eigen faces) is created using the KarhunenLoeve transform on a large set of face images (the training set). The image to be encoded can then be approximated by a linear combination of these basis functions. We propose a rever...

Journal: :Journal of the Optical Society of America 2021

The metaplectic transform (MT), a generalization of the Fourier sometimes called linear canonical transform, is tool used ubiquitously in modern optics, for example, when calculating transformations light beams paraxial optical systems. MT also an essential ingredient geometrical-optics modeling caustics that was recently proposed by authors. In particular, this application relies on near-ident...

Journal: :Symmetry 2021

The Raychaudhuri equation is derived by assuming geometric flow in space–time M of n+1 dimensions. turns into a harmonic oscillator form under suitable transformations. Thereby, relation between geometrical entropy and mean geodesic deviation established. This has connection to chaos theory where the trajectories diverge exponentially. We discuss its application cosmology black holes. Thus, we ...

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