Results 261 to 270 of about 178,783 (273)
Some of the next articles are maybe not open access.
Phase singularities in scale-space
Image and Vision Computing, 1991Abstract This paper concerns the use of phase information from band-pass signals for the measurement of binocular disparity, optic flow and image orientation. Towards this end, one of the important properties of band-pass phase information is its stability with respect to small geometric deformations and contrast changes.
Allan D Jepson, David J Fleet
openaire +1 more source
Laser beams with phase singularities
Optical and Quantum Electronics, 1992Phase singularities in an optical field appear as isolated dark spots and can be generated in active laser cavities or by computer generated holograms. Detection and categorization of these singularities can easily be achieved either by interferometry or Fourier transform pattern recognition using a computer generated hologram.
Heckenberg, N. R. +4 more
openaire +2 more sources
Scale-Space Phase Singularities
1992Chapter 9 discussed the stability of phase information using quantitative bounds on the expected variation of phase as a function of small scale perturbations of the input. But from Figure 9.1 it is also clear that phase stability is not uniform throughout scale-space; some regions exhibit much greater instability in that the phase contours are nearly ...
openaire +1 more source
Singular beams based on tangential phase warp
Optics Letters, 2019We introduce a new kind of singular beam with a controllable topological charge. These beams are created by modulating the spatial phase using a tangent function on the angular coordinate, and a linear function on the radial coordinate. While the angular function controls the topological charge of the beam, the radial function generates a warped ...
Eduardo Peters +2 more
openaire +2 more sources
Phase-sensitive structured singular value
1999Given Γ ∈ C n ×n with Γ + Γ* ≥ 0, define the phase Φ(Γ) of Γ by $$\Phi \left( \Gamma \right) = {\cot ^{ - 1}}\left( {\sup \left\{ {b:\Gamma + \Gamma * - \frac{\beta }{j}\left( {\Gamma - \Gamma *} \right) \geqslant 0\forall \beta \in \left\{ { - b,\,b} \right\}} \right\}} \right).$$
André L. Tits, V. Balakrishnan
openaire +1 more source
Analyticity, Singularity and Phase Transitions
2004There are various instances in which the construction of the Gibbs distributions can be performed in great detail, almost completely explicitly, allowing us to answer satisfactorily questions concerning, for instance, mixing rates of Gibbs states and smoothness of their dependence on the potential.
Giovanni Gallavotti +2 more
openaire +1 more source
Phase singularities in microscopic imaging
SPIE Proceedings, 2011In this paper the concept of optical vortex scanning microscope (OVSM) is presented. In the OVSM a sample is scanned by the focused laser beam with optical vortex. The beam possessing an optical vortex contains a line along which the phase is undetermined. At image plane this line is seen as the single point.
openaire +1 more source
Stress Singularities in Cracked Phases
1987The previous chapter described the stress concentrations and stress singularities developed in the composite because of geometric discontinuities in the inclusions. We now concentrate on singularities developed in the matrix. Since in the preparation of the composite the viscous matrix is generally cast around the solid inclusions, the matrix material ...
openaire +1 more source
Phase Singularity Crystals in Transverse Laser Patterns
1991BRAMBILLA M +4 more
openaire +2 more sources