Commissariat a L'energie Atomique Et Aux Energies Alternatives

Thales

Institut D'optique

Centre National De La Recherche Scientifique

François Goudail

Daniel Dolfi

Gérard Berginc

Mehdi Alouini

Pierre Chavel

Patrick Mercier

Pierre-Antoine Frugier

Arnaud Beniere

A method of designing an imaging system including an optical system having a longitudinal optical axis, an image sensor and a spatial filter, the imaging system being configured to form an image of a focusing plane on the image sensor. The optical transfer function of the optical system combined with the spatial filter is calculated as a function of the image spatial frequencies, and of the focusing defect (&#x3a8;), so as to determine a contrast map and a phase map of the optical system combined with the pupil function of the spatial filter, the contrast map and the phase map being a function, of the spatial frequency (f), and of the focusing defect (&#x3a8;), and it is determined, based on these maps, a value of longitudinal extension (|P|) of the imaging system focusing depth domain in the useful range of spatial frequencies ([&#x2212;fc; fc]) and an average contrast.

Method of designing an imaging system, spatial filter and imaging system including such a spatial filter

Techniques for identifying images of a scene including illuminating the scene with a beam of 3 or more wavelengths, polarized according to a determined direction; simultaneously acquiring for each wavelength an image X(&#x3bb;) polarized according to said direction and an image X(&#x3bb;) polarized according to a direction perpendicular to said direction, X(&#x3bb;) being spatially distinct from X(&#x3bb;); calculating for each wavelength an intensity image which is a linear combination of X(&#x3bb;) and X(&#x3bb;), providing an intensity spectrum for each pixel; calculating for each wavelength a polarization contrast image on the basis of an intensity ratio calculated as a function of X(&#x3bb;) and of X(&#x3bb;), providing a polarization contrast spectrum for each pixel; and calculating a spectro-polarimetric contrast image of the scene, each pixel of this spectro-polarimetric contrast image calculated based on the intensity spectrum and the contrast spectrum of the pixel considered.

Method for identifying a scene from multiple wavelength polarized images

Growing community of inventors

Palaiseau, France

François Goudail