Multi camera, high data rate SPAD imaging for computation-intensive applications

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Recently, we have proposed a new image device called gigavision camera whose most important characteristic is that pixels have binary response. The response function of a gigavision sensor is non-linear and similar to a logarithmic function, which makes the camera suitable for high dynamic range imaging. One important parameter in the gigavision camera is the threshold for generating binary pixels. Threshold T relates to the number of photo-electrons necessary for the pixel output to switch from "0" to "1".

Most digital cameras employ a spatial subsampling process, implemented as a color filter array (CFA), to capture color images. The choice of CFA patterns has a great impact on the performance of subsequent reconstruction (demosaicking) algorithms. In this work, we propose a quantitative theory for optimal CFA design. We view the CFA sampling process as an encoding (low- dimensional approximation) operation and, correspondingly, demosaicking as the best decoding (reconstruction) operation. Finding the optima

Fourier domain Optical coherence microscopy (FDOCM) offers excellent sensitivity and high axial resolution to image the structure of biological tissue. The depth information is extracted in parallel and allows very high volume acquisition rates. An illumination scheme employing an axicon lens produces a Bessel-like interference pattern to obtain a laterally highly confined illumination needle, extending over a long axial range. High lateral resolution is provided over an extended depth of field (xf). For in

Digital holographic microscopy (DHM) is an interferometric technique, providing quantitative mapping of the phase shift induced by semi- transparent microscopic specimens, such as cells, with sub-wavelenght resolution along the optical axis. Thanks to actual PCs and CCDs, DHM provides nowadays cost-effective instruments for real-time measurements at very high acquisition rates, with sub-micron transverse resolution. However, DHM phase images do not reveal the three-dimensional (3D) internal distribution of

In digital holographic microscopy, shot noise is an intrinsic part of the recording process with a digital camera. We present a study based on simulations describing how shot noise influences the quality of the reconstructed phase images under different beams intensities configurations. A model for image quality estimation based on the decision statistical theory proposed by Wagner and Brown (R.F. Wagner and D.G. Brown, "Unified SNR Analysis of Medical Imaging-Systems," Phys. Med. Biol. 30, 489-518 (1985))

The height and/or deformation of a surface of an object (10) defined in terms of x, y and z coordinates is measured by projecting a divergent beam of light 21) onto the surface to produce a periodic pattern of fringes (30. A CCD camera (40) views the surface from another angle and images the reflected light. Phase information is extracted from at least one image to produce an optical print (36) of the object containing phase information and image-coordinates information both being related to camera pixel po

A set of seven twin slit cameras, each containing two 20-element linear absolute extreme ultraviolet photodiode arrays, has been installed on the Tokamak a Configuration Variable. One array in each camera will operate as a bolometer and the second as a Lyman-alpha (L-alpha) emission monitor for estimating the recycled neutral flux. The camera configuration was optimized by simulations of tomographic reconstructions of the expected L-alpha emission. The diagnostic will provide spatial and temporal resolution

New methods and apparatus for authenticating security documents such as banknotes, passports, etc. which may be printed on any support, including transparent synthetic materials and traditional opaque materials such as paper. The invention is based on moire patterns occuring between superposed dot-screens. By using a specially designed basic screen and master screen, where at least the basic screen is comprised in the document, a moire intensity profile of a chosen shape becomes visible in their superpositi

Current spectroscopic optical coherence tomography (OCT) methods rely on a posteriori numerical calculation. We present an experimental alternative for accessing spectroscopic information in OCT without post-processing based on wavelength de-multiplexing and parallel detection using a diffraction grating and a smart pixel detector array. Both a conventional A-scan with high axial resolution and the spectrally resolved measurement are acquired simultaneously. A proof-of-principle demonstration is given on a

The advent of scanning near-field optical microscopy (SNOM) has augmented at the microscopic level the usefulness of IR spectroscopy. Two-dimensional imaging of chemical constituents makes this a very attractive and powerful new approach. In this paper we present SNOM results on boron-doped silicon and on biological growth medium by means of shear-force, reflectivity and photocurrent measurements. Such experiments allowed us to identify boron clusters embedded in silicon and the distribution of growth mediu

Digital imaging brings a new set of possibilities to photography. For example, little pictures can be assembled to form a large panorama, and digital cameras are trying to mimic the human visual system to produce better pictures. This manuscript aims at developing the algorithms required to stitch a set of pictures together to obtain a bigger and better image. This thesis explores three important topics of panoramic photography: The alignment of images, the matching of the colours, and the rendering of the

We report on new developments of a technique, called Digital Holographic Microscopy (DHM), for the numerical reconstruction of digital holograms taken in microscopy, which allows simultaneous amplitude and quantitative phase contrast imaging. The reconstruction method computes the propagation of the complex optical wavefront diffracted by the object and is used to determine the refractive index and/or shape of the object with accuracies in the nanometer range along the optical axis. The method requires the

Multi camera, high data rate SPAD imaging for computation-intensive applications

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On Pixel Detection Threshold in the Gigavision Camera

Optimal Color Filter Array Design: Quantitative Conditions and an Efficient Search Procedure

Towards in vivo small animal imaging

Sub-cellular quantitative optical diffraction tomography with digital holographic microscopy

Shot noise perturbations in digital holographic microscopy phase images

Shape and deformation measurements of large objects by fringe projection

AXUV bolometer and Lyman-alpha camera systems on the TCV tokamak

New methods and apparatus for authentication of documents by using the intensity profile of moire patterns

Spectroscopic optical coherence tomography based on wavelength de-multiplexing and smart pixel array detection

Optical nanospectroscopy study of ion-implanted silicon and biological growth medium

Perspectives on panoramic photography

Digital holography applied to microscopy