Search results for "Pixel"
showing 10 items of 421 documents
The wide-field imager for IXO: status and future activities
2010
The Wide Field Imager (WFI) of the International X-ray Observatory (IXO) is an X-ray imaging spectrometer based on a large monolithic DePFET (Depleted P-channel Field Effect Transistor) Active Pixel Sensor. Filling an area of 10 x 10 cm2 with a format of 1024 x 1024 pixels it will cover a field of view of 18 arcmin. The pixel size of 100 x 100 μm2 corresponds to a fivefold oversampling of the telescope's expected 5 arcsec point spread function. The WFI's basic DePFET structure combines the functionalities of sensor and integrated amplifier with nearly Fano-limited energy resolution and high efficiency from 100 eV to 15 keV. The development of dedicated control and amplifier ASICs allows for…
ATHENA WFI optical blocking filters development status toward the end of the instrument phase-A
2018
Copyright 2018 Society of Photo-Optical Instrumentation Engineers (SPIE). One print or electronic copy may be made for personal use only. Systematic reproduction and distribution, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper are prohibited. The Wide Field Imager (WFI) is one of the two instruments of the ATHENA astrophysics space mission approved by ESA as the second large mission in the Cosmic Vision 2015-2025 Science Programme. The WFI, based on a large array of depleted field effect transistors (DEPFET), will provide imaging in the 0.2-15 keV band over a 40'x40' field of view, simultaneously with spectrally an…
Comparison of Bathymetric estimation using different satellite images in coastal sea waters
2009
Bathymetric estimation can be obtained from multispectral satellite images for shallow waters. The method is based on the rotation of a pair of spectral bands. One of the resulting images is depth-dependent. Therefore several pixels corresponding to different depths are required to numerically evaluate the linear relation between the pixel values and the real depth for a training area. The aim of this study is to compare, for one bathymetric estimation method and one mesotrophic site, the results of depth estimation with a large panel of satellite and aerial images: CASI, QUICKBIRD, CHRIS PROBA, ETM, HYPERION and MeRIS. For each image the pair of spectral bands chosen to compute the bathyme…
Multispectral Imaging using a Stereo Camera: Concept, Design and Assessment
2011
This paper proposes a one-shot six-channel multispectral color image acquisition system using a stereo camera and a pair of optical filters. The two filters from the best pair selected from among readily available filters such that they modify the sensitivities of the two cameras in such a way that they produce optimal estimation of spectral reflectance and/or color are placed in front of the two lenses of the stereo camera. The two images acquired from the stereo camera are then registered for pixel-to-pixel correspondence. The spectral reflectance and/or color at each pixel on the scene are estimated from the corresponding camera outputs in the two images. Both simulations and experiments…
Spatially variant dimensionality reduction for the visualization of multi/hyperspectral images
2011
International audience; In this paper, we introduce a new approach for color visu- alization of multi/hyperspectral images. Unlike traditional methods, we propose to operate a local analysis instead of considering that all the pixels are part of the same population. It takes a segmentation map as an input and then achieves a dimensionality reduction adaptively inside each class of pixels. Moreover, in order to avoid unappealing discon- tinuities between regions, we propose to make use of a set of distance transform maps to weigh the mapping applied to each pixel with regard to its relative location with classes' centroids. Results on two hyperspec- tral datasets illustrate the efficiency of…
Smart camera design for realtime High Dynamic Range imaging
2011
International audience; Many camera sensors suffer from limited dynamic range. The result is that there is a lack of clear details in displayed images and videos. This paper describes our approach to generate high dynamic range (HDR) from an image sequence while modifying exposure times for each new frame. For this purpose, we propose an FPGA-based architecture that can produce a real-time high dynamic range video from successive image acquisition. Our hardware platform is build around a standard low dynamic range CMOS sensor and a Virtex 5 FPGA board. The CMOS sensor is a EV76C560 provided by e2v. This 1.3 Megapixel device offers novel pixel integration/readout modes and embedded image pre…
HDR-ARtiSt: High Dynamic Range Advanced Real-Time Imaging System
2012
International audience; This paper describes the HDR-ARtiSt hardware platform, a FPGA-based architecture that can produce a real- time high dynamic range video from successive image acquisition. The hardware platform is built around a standard low dynamic range (LDR) CMOS sensor and a Virtex 5 FPGA board. The CMOS sensor is a EV76C560 provided by e2v. This 1.3 Megapixel device offers novel pixel integration/readout modes and em- bedded image pre-processing capabilities including multiframe acquisition with various exposure times. Our approach consists of a hardware architecture with different algorithms: double exposure control during image capture, building of an HDR image by combining the…
Scene-based noise reduction on a smart camera
2012
International audience; Raw output data from CMOS image sensors tends to exhibit significant noise called Fixed-Pattern Noise (FPN) due to on-die variations between pixel photodetectors. FPN is often corrected by subtracting its value, estimated through calibration, from the sensor's raw signal. This paper introduces an on-line scene-based technique for an improved FPN compensation which does not rely on calibration, and hence is more robust to the dynamic changes in the FPN which may occur slowly over time. Development has been done with a special emphasis on real-time hardware implementation on a FPGA-based smart camera. Experimental results on different scenes are depicted showing that t…
3D Displacements and Strains Solid Measurement based on the Surface Texture with a Scanner Laser
2013
International audience; The developments of non-contact measurement are today widely due to the unprecedented progress of optronic. The applications of these techniques are wide and varied for the 3D measurement of industrial products. In addition to the forms and dimensions, we show in this paper that the devices of laser scanning permit to measure displacements and deformations. In this case, it is necessary to follow a solid particle in its motion. It is then necessary to identify the particle between two configurations of the body before and after displacement. The method of greyscale patterns, obtained by applying a spray, is generally used. The originality of the proposed method is ba…
Multi-Kernel Implicit Curve Evolution for Selected Texture Regions Segmentation in VHR Satellite Images
2014
Very high resolution (VHR) satellite images provide a mass of detailed information which can be used for urban planning, mapping, security issues, or environmental monitoring. Nevertheless, the processing of this kind of image is timeconsuming, and extracting the needed information from among the huge quantity of data is a real challenge. For some applications such as natural disaster prevention and monitoring (typhoon, flood, bushfire, etc.), the use of fast and effective processing methods is demanded. Furthermore, such methods should be selective in order to extract only the information required to allow an efficient interpretation. For this purpose, we propose a texture region segmentat…