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## ‣ Modelo computacional baseado em técnicas wavelets para relacionar imagens digitais obtidas em diferentes escalas e resoluções; Computational model based on wavelet techniques for linking digital images obtained at different scales and resolutions

Minatel, Edson Roberto
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
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## ‣ Uma Abordagem fuzzy na detecção automática de mudanças do uso do solo usando imagens de fração e de informações de contexto espacial; A fuzzy approach to land use automatic change detection using fraction images and spatial context information

Zanotta, Daniel Capella
Tipo: Dissertação Formato: application/pdf
Português
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## ‣ Sub-pixel estimation of tree cover and bare surface densities using regression tree analysis

Toneli,Carlos Augusto Zangrando; Carvalho,Luis Marcelo Tavares de
Tipo: Artigo de Revista Científica Formato: text/html
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Sub-pixel analysis is capable of generating continuous fields, which represent the spatial variability of certain thematic classes. The aim of this work was to develop numerical models to represent the variability of tree cover and bare surfaces within the study area. This research was conducted in the riparian buffer within a watershed of the São Francisco River in the North of Minas Gerais, Brazil. IKONOS and Landsat TM imagery were used with the GUIDE algorithm to construct the models. The results were two index images derived with regression trees for the entire study area, one representing tree cover and the other representing bare surface. The use of non-parametric and non-linear regression tree models presented satisfactory results to characterize wetland, deciduous and savanna patterns of forest formation.

## ‣ PSICIC: Noise and Asymmetry in Bacterial Division Revealed by Computational Image Analysis at Sub-Pixel Resolution

Guberman, Jonathan M.; Fay, Allison; Dworkin, Jonathan; Wingreen, Ned S.; Gitai, Zemer
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Português
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Live-cell imaging by light microscopy has demonstrated that all cells are spatially and temporally organized. Quantitative, computational image analysis is an important part of cellular imaging, providing both enriched information about individual cell properties and the ability to analyze large datasets. However, such studies are often limited by the small size and variable shape of objects of interest. Here, we address two outstanding problems in bacterial cell division by developing a generally applicable, standardized, and modular software suite termed Projected System of Internal Coordinates from Interpolated Contours (PSICIC) that solves common problems in image quantitation. PSICIC implements interpolated-contour analysis for accurate and precise determination of cell borders and automatically generates internal coordinate systems that are superimposable regardless of cell geometry. We have used PSICIC to establish that the cell-fate determinant, SpoIIE, is asymmetrically localized during Bacillus subtilis sporulation, thereby demonstrating the ability of PSICIC to discern protein localization features at sub-pixel scales. We also used PSICIC to examine the accuracy of cell division in Esherichia coli and found a new role for the Min system in regulating division-site placement throughout the cell length...

## ‣ Color Capable Sub-Pixel Resolving Optofluidic Microscope and Its Application to Blood Cell Imaging for Malaria Diagnosis

Lee, Seung Ah; Leitao, Ricardo; Zheng, Guoan; Yang, Samuel; Rodriguez, Ana; Yang, Changhuei
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
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Miniaturization of imaging systems can significantly benefit clinical diagnosis in challenging environments, where access to physicians and good equipment can be limited. Sub-pixel resolving optofluidic microscope (SROFM) offers high-resolution imaging in the form of an on-chip device, with the combination of microfluidics and inexpensive CMOS image sensors. In this work, we report on the implementation of color SROFM prototypes with a demonstrated optical resolution of 0.66 µm at their highest acuity. We applied the prototypes to perform color imaging of red blood cells (RBCs) infected with Plasmodium falciparum, a particularly harmful type of malaria parasites and one of the major causes of death in the developing world.

## ‣ Sub-pixel Area Calculation Methods for Estimating Irrigated Areas

Thenkabail, Prasad S.; Biradar, Chandrashekhar M.; Noojipady, Praveen; Cai, Xueliang; Dheeravath, Venkateswarlu; Li, Yuanjie; Velpuri, Manohar; Gumma, MuraliKrishna; Pandey, Suraj
Fonte: Molecular Diversity Preservation International (MDPI) Publicador: Molecular Diversity Preservation International (MDPI)
Tipo: Artigo de Revista Científica
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The goal of this paper was to develop and demonstrate practical methods for computing sub-pixel areas (SPAs) from coarse-resolution satellite sensor data. The methods were tested and verified using: (a) global irrigated area map (GIAM) at 10-km resolution based, primarily, on AVHRR data, and (b) irrigated area map for India at 500-m based, primarily, on MODIS data. The sub-pixel irrigated areas (SPIAs) from coarse-resolution satellite sensor data were estimated by multiplying the full pixel irrigated areas (FPIAs) with irrigated area fractions (IAFs). Three methods were presented for IAF computation: (a) Google Earth Estimate (IAF-GEE); (b) High resolution imagery (IAF-HRI); and (c) Sub-pixel de-composition technique (IAF-SPDT). The IAF-GEE involved the use of “zoom-in-views” of sub-meter to 4-meter very high resolution imagery (VHRI) from Google Earth and helped determine total area available for irrigation (TAAI) or net irrigated areas that does not consider intensity or seasonality of irrigation. The IAF-HRI is a well known method that uses finer-resolution data to determine SPAs of the coarser-resolution imagery. The IAF-SPDT is a unique and innovative method wherein SPAs are determined based on the precise location of every pixel of a class in 2-dimensional brightness-greenness-wetness (BGW) feature-space plot of red band versus near-infrared band spectral reflectivity. The SPIAs computed using IAF-SPDT for the GIAM was within 2 % of the SPIA computed using well known IAF-HRI. Further the fractions from the 2 methods were significantly correlated. The IAF-HRI and IAF-SPDT help to determine annualized or gross irrigated areas (AIA) that does consider intensity or seasonality (e.g....

## ‣ Sub-pixel estimation of tree cover and bare surface densities using regression tree analysis; Estimativa subpixel da cobertura arbórea e superfície esposta utilizando análise por árvore de regfressão

Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
47.3974%
Sub-pixel analysis is capable of generating continuous fi elds, which represent the spatial variability of certain thematic classes. The aim of this work was to develop numerical models to represent the variability of tree cover and bare surfaces within the study area. This research was conducted in the riparian buffer within a watershed of the São Francisco River in the North of Minas Gerais, Brazil. IKONOS and Landsat TM imagery were used with the GUIDE algorithm to construct the models. The results were two index images derived with regression trees for the entire study area, one representing tree cover and the other representing bare surface. The use of non-parametric and non-linear regression tree models presented satisfactory results to characterize wetland, deciduous and savanna patterns of forest formation.

## ‣ Sub-pixel estimation of tree cover and bare surface densities using regression tree analysis; Estimativa subpixel da cobertura arbórea e superfície exposta utilizando análise por árvore de regressão

Tipo: Artigo de Revista Científica Formato: text/html
Português
Relevância na Pesquisa
47.3974%
Sub-pixel analysis is capable of generating continuous fields, which represent the spatial variability of certain thematic classes. The aim of this work was to develop numerical models to represent the variability of tree cover and bare surfaces within the study area. This research was conducted in the riparian buffer within a watershed of the São Francisco River in the North of Minas Gerais, Brazil. IKONOS and Landsat TM imagery were used with the GUIDE algorithm to construct the models. The results were two index images derived with regression trees for the entire study area, one representing tree cover and the other representing bare surface. The use of non-parametric and non-linear regression tree models presented satisfactory results to characterize wetland, deciduous and savanna patterns of forest formation.

## ‣ Estimating Sub-pixel to Regional Winter Crop Areas using Neural Nets

ATZBERGER Clement; REMBOLD Felix
Fonte: International Society for Photogrammetry and Remote Sensing (ISPRS) Publicador: International Society for Photogrammetry and Remote Sensing (ISPRS)
Tipo: Contributions to Conferences Formato: Online
Português
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The current work aimed at testing a methodology which can be applied to low spatial resolution satellite data to assess inter-annual crop area variations on sub-pixel to regional scales. The methodology is based on the assumption that within mixed pixels land cover variations are reflected by changes in the related hyper-temporal profiles of the Normalised Difference Vegetation Index (NDVI). We evaluated if changes in the fractional winter crop coverage are reflected in changing shapes of annual NDVI profiles and can be detected by using neural networks. The neural nets were trained on reference data obtained from high resolution Landsat TM/ETM images and additional ancillary data readily available (CORINE land cover). The proposed methodology was applied in a study region in central Italy to estimate winter crop areas between 1988 and 2002 from 1 km resolution NOAA-AVHRR profiles. The accuracy of the estimates was assessed by comparison to official agricultural statistics using a bootstrap approach. The method showed promise for estimating crop area variation on sub-pixel (cross-validated R2 between 0.7 and 0.8) to regional scales (normalized RMSE: 10%) and proved to have a significantly higher forecast capability than other methods used previously for the same study area.; JRC.DG.G.3-Monitoring agricultural resources

## ‣ Mapping the Spatial Distribution of Winter Crops at Sub-Pixel Level Using AVHRR NDVI Time Series and Neural Nets

ATZBERGER Clement; REMBOLD Felix
Tipo: Articles in Journals Formato: Online
Português
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For large areas, it is difficult to assess the spatial distribution and inter-annual variation of crop acreages through field surveys. Such information, however, is of great value for governments, land managers, planning authorities, commodity traders and environmental scientists. Time series of coarse resolution imagery offer the advantage of global coverage at low costs, and are therefore suitable for large-scale crop type mapping. Due to their coarse spatial resolution, however, the problem of mixed pixels has to be addressed. Traditional hard classification approaches cannot be applied because of sub-pixel heterogeneity. We evaluate neural networks as a modeling tool for sub-pixel crop acreage estimation. The proposed methodology is based on the assumption that different cover type proportions within coarse pixels prompt changes in time profiles of remotely sensed vegetation indices like the Normalized Difference Vegetation Index (NDVI). Neural networks can learn the relation between temporal NDVI signatures and the sought crop acreage information. This learning step permits a non-linear unmixing of the temporal information provided by coarse resolution satellite sensors. For assessing the feasibility and accuracy of the approach...

## ‣ Detection of Spatially Unresolved (Nominally Sub-Pixel) Submerged and Surface Targets Using Hyperspectral Data

Burt, Christopher B.
Português
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Due to the United States dependency on maritime travel, the proliferation of efficient and inexpensive naval mines poses a tremendous risk. Current MCM technologies have narrow FOVs, preventing timely, wide-area searches. These technologies require the operator to be in proximity to the targets, a dangerous scenario made worse when in denied territory. In an effort to mitigate these risks, the use of a high altitude hyperspectral sensor is proposed. The operational ability of a hyperspectral sensor to detect sub-pixel surface and submerged mines in non-littoral environments was evaluated using visual inspection and two common anomaly detectors Mixture Tuned Matched Filtering (MTMF) and Reed-Xiaoli (RX). Due to the unavailability of the DoDs Spectral Infrared Imaging Technology Testbed (SPIRITT), ProSpecTIR-VS3, a sensor similar spatially and spectrally to SPIRITT was flown over a range offshore California. This experiment included three surface and three submerged targets, each with a 0.8 meter diameter. Both 0.5 and 1 meter spatial resolution data were collected, allowing for both a resolved and unresolved analysis. While both anomaly detection techniques have their flaws, the success of this study is in proving the usefulness of hyperspectral data for sub-pixel mine detection.

## ‣ Spectral Unmixing Applied to Desert Soils for the Detection of Sub-Pixel Disturbances

(Howard), Jessica Stuart
Português
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Desert areas cover approximately one-fifth of the Earth, making it important to understand how disturbance affects arid regions on a spectral level. Remote sensing technology can be used to detect and characterize surface disturbance both literally (visually) and non-literally (analytically). Non-literal approaches may even allow detection of anthropogenic-related surface disturbances that are not visible in individual images or color composites. This is achievable through identification of differences in spectral reflectance among like soil components, both chemical and biological. Previous research suggests that surface disturbances cause alteration of soil properties, making it feasible to detect variation in reflectance signatures. This research supports that assumption and has determined that disturbance-related changes do have unique spectral characteristics in hyperspectral imagery that are detectable, even at the sub-pixel level and using endmembers from geographically different yet geologically similar regions.

## ‣ Classificação sub-pixel de séries temporais de dados MODIS para a quantificação de áreas inundadas do Pantanal.

ANTUNES, J. F. G.; ESQUERDO, J. C. D. M.
Fonte: In: SIMPÓSIO DE GEOTECNOLOGIAS NO PANTANAL, 5., 2014, Campo Grande, MS. Anais... São José dos Campos: INPE, 2014. Publicador: In: SIMPÓSIO DE GEOTECNOLOGIAS NO PANTANAL, 5., 2014, Campo Grande, MS. Anais... São José dos Campos: INPE, 2014.
Tipo: Artigo em anais de congresso (ALICE) Formato: 1 CD-ROM.; p. 325-335.
Português
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## ‣ An Autocorrelation-Based Method for Improvement of Sub-Pixel Displacement Estimation in Ultrasound Strain Imaging

Kim, Seungsoo; Aglyamov, Salavat R.; Park, Suhyun; O'Donnell, Matthew; Emelianov, Stanislav Y.
Tipo: Artigo de Revista Científica
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In ultrasound strain and elasticity imaging, an accurate and cost-effective sub-pixel displacement estimator is required because strain/elasticity imaging quality relies on the displacement SNR, which can often be higher if more computational resources are provided. In this paper, we introduce an autocorrelation-based method to cost-effectively improve sub-pixel displacement estimation quality. To quantitatively evaluate the performance of the autocorrelation method, simulated and tissue-mimicking phantom experiments were performed. The computational cost of the autocorrelation method is also discussed. The results of our study suggest the autocorrelation method can be used for a real-time elasticity imaging system.

## ‣ Sub-Pixel Response Measurement of Near-Infrared Sensors

Barron, N.; Borysow, M.; Beyerlein, K.; Brown, M.; Weaverdyck, C.; Lorenzon, W.; Schubnell, M.; Tarle, G.; Tomasch, A.
Tipo: Artigo de Revista Científica
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Wide-field survey instruments are used to efficiently observe large regions of the sky. To achieve the necessary field of view, and to provide a higher signal-to-noise ratio for faint sources, many modern instruments are undersampled. However, precision photometry with undersampled imagers requires a detailed understanding of the sensitivity variations on a scale much smaller than a pixel. To address this, a near-infrared spot projection system has been developed to precisely characterize near-infrared focal plane arrays and to study the effect of sub-pixel non uniformity on precision photometry. Measurements of large format near-infrared detectors demonstrate the power of this system for understanding sub-pixel response.; Comment: 9 pages, 13 figures, submitted to PASP

## ‣ A Sub Pixel Resolution Method

Tipo: Artigo de Revista Científica
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One of the main limitations for the resolution of optical instruments is the size of the sensor's pixels. In this paper we introduce a new sub pixel resolution algorithm to enhance the resolution of images. This method is based on the analysis of multi-images which are fast recorded during the fine relative motion of image and pixel arrays of CCDs. It is shown that by applying this method for a sample noise free image one will enhance the resolution with order of error.; Comment: World academy of science, engineering and technology (WASET), 70, 2010

## ‣ Direct measurement of sub-pixel structure of the EPIC MOS CCD on-board th e XMM/NEWTON satellite

Hiraga, J.; Tsunemi, H.; Short, A. D.; Abbey, A. F.; Bennie, P. J.; Turner, M. J. L.
Tipo: Artigo de Revista Científica
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We have used a mesh experiment in order to measure the sub-pixel structure of the EPIC MOS CCDs on-board the XMM/NEWTON satellite. The EPIC MOS CCDs have 40 $\mu$m-square pixels which have an open electrode structure in order to improve the detection efficiency for low-energy X-rays. We obtained restored pixel images for various X-ray event grades (e.g. split-pixel events, single pixel events, etc.) at various X-ray energies. We confirmed that the open electrode structure results in a distorted horizontal pixel boundary. The open electrode region generates both single pixel events and vertically split events, but no horizontally split events. Because the single pixel events usually show the best energy resolution, we discuss a method of increasing the fraction of single pixel events from the open electrode region. Furthermore, we have directly measured the thickness of the electrodes and dead-layers by comparing spectra from the open electrode region with those from the other regions: electrodes, electrode finger and channel stop. We can say that EPIC MOS CCDs are more radiation hard than front-illumination chips of ACIS on-board Chandra X-ray Observatory because of their extra absorption thickness above the charge transfer channel. We calcurated the mean pixel response and found that our estimation has a good agreement with that of the ground calibration of EPIC MOS CCD.; Comment: 20pages including 2 tables...

## ‣ A Fast Sub-Pixel Motion Estimation Algorithm for H.264/AVC Video Coding

Lin, Weiyao; Panusopone, Krit; Baylon, David M.; Sun, Ming-Ting; Chen, Zhenzhong; Li, Hongxiang
Tipo: Artigo de Revista Científica
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Motion Estimation (ME) is one of the most time-consuming parts in video coding. The use of multiple partition sizes in H.264/AVC makes it even more complicated when compared to ME in conventional video coding standards. It is important to develop fast and effective sub-pixel ME algorithms since (a) The computation overhead by sub-pixel ME has become relatively significant while the complexity of integer-pixel search has been greatly reduced by fast algorithms, and (b) Reducing sub-pixel search points can greatly save the computation for sub-pixel interpolation. In this paper, a novel fast sub-pixel ME algorithm is proposed which performs a 'rough' sub-pixel search before the partition selection, and performs a 'precise' sub-pixel search for the best partition. By reducing the searching load for the large number of non-best partitions, the computation complexity for sub-pixel search can be greatly decreased. Experimental results show that our method can reduce the sub-pixel search points by more than 50% compared to existing fast sub-pixel ME methods with negligible quality degradation.; Comment: This manuscript is the accepted version for TCSVT (IEEE Transactions on Circuits and Systems for Video Technology)

## ‣ Sub-pixel resolution with color X-ray camera SLcam(R)

Nowak, Stanisław H.; Bjeoumikhov, Aniouar; von Borany, Johannes; Buchriegler, Josef; Munnik, Frans; Petric, Marko; Radtke, Martin; Renno, Axel D.; Reinholz, Uwe; Scharf, Oliver; Wedell, Reiner
Tipo: Artigo de Revista Científica