A seismic processing workflow based on iterative ray+Born migration/inversion and targetoriented post-processing of the migrated image is developed for fine-scale quantitative characterization of reflectors. The first step of the workflow involves linear iterations of the ray+Born migration/inversion. The output of the first step is a true-amplitude migrated image parameterized by velocity pert...

Polycapillary devices focus X-rays by means of multiple reflections of X-rays in arrays of bent glass capillaries. The size of the focal spot (typically 10-100 μm) limits the resolution of scanning, absorption and phase-contrast X-ray imaging using these devices. At the expense of a moderate resolution, polycapillary elements provide high intensity and are frequently used for X-ray micro-imagin...

We report results of an 18 ks exposure with the ACIS instrument on Chandra of the powerful z = 0.62 radio galaxy 3C 220.1. The X-ray emission separates into cluster gas of emission-weighted kT ∼ 5 keV and 0.7-12 keV luminosity (to a radius of 45 arcsec) 5.6 × 10 44 ergs s −1 , and unresolved emission (coincident with the radio core). While the extended X-ray emission is clearly thermal in natur...

In the context of the classical study of optical systems within the geometrical Gauss approximation, the cardinal elements are efficiently obtained with the aid of the transfer matrix between the input and output planes of the system. In order to take into account the geometrical aberrations, a ray tracing approach, using the Snell-Descartes laws, has been implemented in an interactive software...

Evaluation of solar heat gain and daylight distribution through complex window and shading systems requires the determination of the Bi-directional Transmission Distribution Function (BTDF). Measurement of BTDF can be time-consuming, and inaccuracies are likely because of physical constraints and experimental adjustments. A general calculation methodology, based on more easily measurable compon...

Background: Intraoperative Radiotherapy (IORT) is a method by which a critical radiation dose is delivered to the tumour bed immediately after surgical excision. It is being investigated whether a single high dose of radiation will impart the same clinical benefit as a standard course of external beam therapy. Our centre has four Photon Radiosurgery Systems (PRS) currently used to irradiate bre...

Classical ray-tracing algorithms compute radiance returning to the eye along one or more sample rays through each pixel of an image. The output of a ray-tracing algorithm, although potentially photorealistic, is a two-dimensional quantity { an image array of radiance values { and is not directly useful from any viewpoint other than the one for which it was computed. This paper makes several con...

Classical ray-tracing algorithms compute radiance returning to the eye along one or more sample rays through each pixel of an image. The output of a ray-tracing algorithm, although potentially photoreal-istic, is a two-dimensional quantity { an image array of radiance values { and is not directly useful from any viewpoint other than the one for which it was computed. This paper makes several co...

Printing with custom inks is of interest both for artistic purposes and for printing security documents such as banknotes. However, in order to create designs with only a few custom inks, a general purpose high-quality gamut reduction technique is needed. Most existing gamut mapping techniques map an input gamut such as the gamut of a CRT display into the gamut of an output device such as a CMY...

Calibration of the output device used for the reproduction of digital colour images a color CRT in most cases can either be achieved through conventional techniques involving mathematical modeling of the CRT, or through a novel neural-network-based scheme, introduced in this work. A Java-based system for CRT remote calibration is also presented, which allows the user to get rid of the computati...