Abstract:
Methods and systems for detecting and characterizing a pattern (or patterns) of interest in a low signal-to-noise ratio (SNR) data set are disclosed. One method is a two-stage Likelihood pipeline analysis that takes advantage of the benefits of a full Likelihood analysis while providing computational tractability. The two-stage Likelihood pipeline may include, at either stage, the calculation and use of one or more of a false positive rate, a standard error, and a multi-factor landscape involving a gradient and/or Hessian of a Likelihood ratio.
Abstract:
Image-sensing devices include odd-symmetry gratings that cast interference patterns over a photodetector array. Grating features offer considerable insensitivity to the wavelength of incident light, and also to the manufactured distance between the grating and the photodetector array. Photographs and other image information can be extracted from interference patterns captured by the photodetector array. Images can be captured without a lens, and cameras can be made smaller than those that are reliant on lenses and ray-optical focusing.
Abstract:
The invention relates to encoding phase information in micro-grating-based anti-counterfeit devices such as diffractive optically variable identification devices (DOVID). The invention utilizes that alignment of grating line positions in different micro-gratings having common line spacing and orientation, can be used as a new, additional information channel in DOVIDs. By displacing grating line positions in different pixels relative to a common reference grating, relative shifts in alignment are introduced that do not affect the visual effects encoded in the DOVID. The relative shifts in line position alignment induce relative shifts in the phase of light diffracted by the DOVID, so as to introduce a spatial phase shift distribution corresponding to the distribution of position shifts over the DOVID. Such spatial phase shift distribution is not visible, and the phase encoded information is thereby invisible unless a reader based on e.g. generalized phase contrast is applied. The phase encoded information can further be phase encrypted so that a spatial phase modulator decryption key is required to read the encoded information.
Abstract:
Zoom lens systems and methods for imaging incoming rays over a range of ray angles are disclosed. The incoming rays are characterized by at least phase. The zoom lens system includes an optical axis and is characterized by a plurality of modulation transfer functions (MTFs) corresponding at least to the range of ray angles. The zoom lens system includes an optical group disposed along the optical axis, including at least one variable optical element that has a variable focal length selectable between at least two distinct focal length values. The optical group also includes a wavefront coding element. The wavefront coding element alters at least the phase of the incoming rays, such that the plurality of MTFs corresponding to the range of ray angles, for each one of the two distinct focal length values, are less sensitive to misfocus-like aberrations than a corresponding system without the wavefront coding element.
Abstract:
Die Erfindung bezieht sich auf eine Ortsfrequenzfiltervorrichtung zur Ortsfrequenzfilterung von Laserstrahlung. Diese weist einen für die Laserstrahlung zumindest teilweise transparenten Transmissionskörper und ein an dem Transmissionskörper angrenzend angeordnetes oder in den Transmissionskörper integriertes, Pinhole bildendes bzw. eine Apertur aufweisendes Element auf, wobei das Pinhole bildende Element eine diffraktive und/oder eine refraktive lblenkstruktur aufweist.
Abstract:
A method of controlling the point spread function of an image projected with said image being diffused by a filter; said point spread function is a result of the application of spatial filter(s) on said image; with said control of the point spread function effected by varying the distance between such image and said spatial filter(s) and varying the bidirectional scattering transmission function of the spatial filter(s). Said spatial filter may be a holographic diffuser, which by method of manufacture has a well defined bi-directional scattering transmission spread function. Control of said spread function is particularly useful to maintain image quality while abating moiré interference in situations where two periodic patterns are layered causing moiré interference.