Search results for "image resolution"
showing 10 items of 377 documents
Multitemporal fusion of Landsat/TM and ENVISAT/MERIS for crop monitoring
2013
Abstract Monitoring Earth dynamics using current and future satellites is one of the most important objectives of the remote sensing community. The exploitation of image time series from sensors with different characteristics provides new opportunities to increase the knowledge about environmental changes and to support many operational applications. This paper presents an image fusion approach based on multiresolution and multisensor regularized spatial unmixing. The approach yields a composite image with the spatial resolution of the high spatial resolution image while retaining the spectral and temporal characteristics of the medium spatial resolution image. The approach is tested using …
Resolution enhancement in integral microscopy by physical interpolation
2015
Integral-imaging technology has demonstrated its capability for computing depth images from the microimages recorded after a single shot. This capability has been shown in macroscopic imaging and also in microscopy. Despite the possibility of refocusing different planes from one snap-shot is crucial for the study of some biological processes, the main drawback in integral imaging is the substantial reduction of the spatial resolution. In this contribution we report a technique, which permits to increase the two-dimensional spatial resolution of the computed depth images in integral microscopy by a factor of √2. This is made by a double-shot approach, carried out by means of a rotating glass…
Multiframe image restoration in the presence of noisy blur kernel
2009
We wish to recover an original image u from several blurry-noisy versions f k , called frames. We assume a more severe degradation model, in which the image u has been blurred by a noisy (stochastic) point spread function. We consider the problem of restoring the degraded image in a variational framework. Since the recovery of u from one single frame f is a highly ill-posed problem, we formulate two minimization problems based on the multiframe approach proposed for image super-resolution by Marquina-Osher [13]. Several experimental results for image restoration are shown, illustrating that the proposed models give visually satisfactory results.
Light Sheet Fluorescence Microscopy (LSFM) for Two-Photon Excitation Imaging of Thick Samples.
2015
Over the last decades, fluorescence microscopy techniques have been developed in order to provide a deeper, faster and higher resolution imaging of three-dimensional biological samples. Within this framework, Light Sheet Fluorescence Microscopy (LSFM) became an increasingly useful and popular imaging technique able to answer several biological questions in the field of developmental biology [1]. Thanks to the spatial confinement of the excitation process within a thin sheet in the focal plane, it provides an intrinsic optical sectioning and a reduced phototoxicity. On the other side, Two-Photon Excitation (2PE), thanks to the use of IR wavelengths, has become an invaluable tool to improve i…
Three-dimensional superresolution by annular binary filters
1999
We present a new family of annular binary filters for improving the three-dimensional resolving power of optical systems. The filters, whose most important feature is their simplicity, permit to achieve a significant reduction, both in the transverse and in the axial direction, of the central lobe width of the irradiance point spread function of the system. The filters can be used for applications such as optical data storage or confocal scanning microscopy.
Enhancing spatial resolution in digital holographic microscopy by biprism structured illumination.
2014
A novel and efficient architecture of a structured-illumination digital holographic microscope (DHM) is presented. As the DHM operates at the diffraction limit, its spatial resolution on label-free imaging of transparent samples is improved by illuminating the sample with a structured illumination produced by a Fresnel's biprism. The theoretical analysis of the method forecasts a twofold improvement of the spatial resolution. The proposed method requires only two images to improve the spatial resolution, which eases the process of unmixing the high-resolution components by means of an unknown phase-shift procedure. Numerical modeling and experimental results validate the theoretical finding…
Combining hectometric and decametric satellite observations to provide near real time decametric FAPAR product
2017
Abstract A wide range of ecological, agricultural, hydrological and meteorological applications at local to regional scales requires decametric biophysical data. However, before the launch of SENTINEL-2A, only few decametric products are produced and most of them remain limited by the small number of available observations, mostly due to a moderate revisit frequency combined with cloud occurrence. Conversely, kilometric and hectometric biophysical products are now widely available with almost complete and continuous coverage, but the associated spatial resolution limits the application over heterogeneous landscapes. The objective of this study is to combine unfrequent decametric spatial res…
Near-Real-Time Estimation of Water Vapor Column From MSG-SEVIRI Thermal Infrared Bands: Implications for Land Surface Temperature Retrieval
2015
The Meteosat Second Generation-Spinning Enhanced Visible and Infrared Imager (MSG-SEVIRI) instrument provides observations of half the globe every 15 min, at low spatial resolution. These data are an invaluable tool to observe daily to yearly cycle of land surface temperature (LST), as well as for various early warning systems. However, advanced algorithms for LST estimation requires a previous estimation of the water vapor (WV) column above the observed pixel, for which no instantaneous retrieval methods are yet available, and therefore hinders their implementation in a near-real-time processing chain for MSG-SEVIRI data. This work analyzes three different formulations for such WV retrieva…
Validation of daily global solar irradiation images from MSG over Spain
2013
Abstract Daily irradiation images over Spain – area that embraces a highly heterogeneous landscape, climatic conditions and relief – are calculated from the down-welling surface short-wave radiation flux (DSSF) product derived from the MSG SEVIRI images. Their analysis and validation is carried out using two different station networks along the year 2008. The first network covers the peninsular Spain and Balearic islands. A denser one, covering the Catalonian territory and including many stations located in rugged terrain, is found useful to assess the elevation correction to be applied to the images. The statistics from the validation using the first network shows a relative mean bias of a…
Analysis of ASTER Emissivity Product Over an Arid Area in Southern New Mexico, USA
2011
The accuracy of thermal infrared emissivities derived from Advanced Spaceborne Thermal Emission and Reflectance radiometer (ASTER) was assessed in an arid area in southern New Mexico, which includes the White Sands National Monument (WSNM) during 2006-2008. ASTER emissivities retrieved by the temperature and emissivity separation (TES) algorithm were directly compared with laboratory measurements of samples from WSNM. Good agreement was found for the high spectral contrast of gypsum and for the low spectral contrast of water bodies. Furthermore, the day/night consistency of ASTER emissivities was checked, and day/night emissivity differences lower than ±0.013 were observed. However, unexpec…