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Visual analysis of image collections

ELER, Danilo M.; NAKAZAKI, Marcel Y.; PAULOVICH, Fernando V.; SANTOS, Davi P.; ANDERY, Gabriel F.; OLIVEIRA, Maria Cristina F.; BATISTA NETO, João do Espírito Santo; MINGHIM, Rosane
Fonte: SPRINGER Publicador: SPRINGER
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
75.54%
Multidimensional Visualization techniques are invaluable tools for analysis of structured and unstructured data with variable dimensionality. This paper introduces PEx-Image-Projection Explorer for Images-a tool aimed at supporting analysis of image collections. The tool supports a methodology that employs interactive visualizations to aid user-driven feature detection and classification tasks, thus offering improved analysis and exploration capabilities. The visual mappings employ similarity-based multidimensional projections and point placement to layout the data on a plane for visual exploration. In addition to its application to image databases, we also illustrate how the proposed approach can be successfully employed in simultaneous analysis of different data types, such as text and images, offering a common visual representation for data expressed in different modalities.

Método de análise do contorno de aglomerados de gotas de chuva artificial em imagem digital; A method for contour analysis of artificial rain drop based on both digital image and curvature processing

Koenigkan, Luciano Vieira
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 07/10/2005 PT
Relevância na Pesquisa
65.49%
Este trabalho apresenta um método para análise do contorno de gotas de chuva artificial em imagem digital, o qual se caracteriza como uma ferramenta para melhor compreensão dos processos agrícolas que envolvem o uso de chuvas artificiais, como a irrigação e a aplicação de defensivos, sendo desenvolvido com o uso de técnicas para análise de formas bidimensionais e processamento de sinais, como representação de formas por contornos paramétricos, análise de Fourier e filtragem gaussiana. Os resultados obtidos demonstram precisão na análise de imagens de aglomerados de gotas, acrescentando as características de descritor apresentadas pela curvatura, assim como a flexibilidade de calibração oferecidas pela abordagem multi-escala adotada, possibilitando a obtenção de erros de medida não maiores que 5%, para os padrões circulares testados com raios entre 10 e 200 pixels; This work presents a method for contour analysis of artificial rain drop based on both digital image and curvature processing. The method is characterized as a tool, which allows a better understanding of the raindrops in irrigation and agrochemicals spraying processes. Its development was based on parametric contours representation of shapes, Fourier analysis...

Análise estatística na interpretação de imagens: microarranjos de DNA e ressonância magnética funcional; Statistical analysis of image interpretation: DNA microarrays and functional magnetic resonance

Vencio, Ricardo Zorzetto Nicoliello
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
Publicado em 01/09/2006 PT
Relevância na Pesquisa
65.47%
O objetivo deste trabalho é apresentar os métodos originais em Bioinformática desenvolvidos para a análise estatística na interpretação dos dados de duas técnicas baseadas em imagens: a técnica de microarranjos de DNA e a técnica de ressonância magnética funcional. O interesse principal é abordar essas técnicas experimentais quando enfrenta-se uma situação clara de amostras escassas, isto é, quando existem relativamente poucas observações experimentais do fenômeno estudado, sendo a análise individual/personalizada o representante extremo desta situação, que tem que ser resolvida. Para tanto, opta-se pelo uso da Inferência Bayesiana no contexto da Teoria da Decisão sob Incerteza, implementada computacionalmente sob o arcabouço dos Sistemas de Suporte à Decisão. Ambas as tecnologias estudadas produzem dados complexos, baseados na interpretação das diferenças entre imagens obtidas da resposta do sistema a um estímulo e da resposta numa situação controle. O resultado deste trabalho é o desenvolvimento de dois sistemas de suporte à decisão, chamados HTself e Dotslashen, para a análise de dados de microarranjos e ressonância magnética funcional, respectivamente; e de seus métodos matemáticos/computacionais subjacentes. Os sistemas desenvolvidos extraem conhecimento racional de bancos-de-dados normativos...

Uma abordagem baseada em técnicas de visualização de informações para avaliação de características de imagens e aplicações; Approach based on information visualization techniques for evaluation of image features and applications

Cruz, Laura Elizabeth Florian
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 24/09/2012 PT
Relevância na Pesquisa
65.48%
Na maioria dos processos de análise de imagens há a necessidade de um pré-processamento, no qual são extraídos e calculados vetores de características que representem as imagens são utilizados no cálculo de similaridade. Uma dificuldade nessas tarefas é o grande número de características que definem um espaço de alta dimensionalidade, afetando fortemente o desempenho das tarefas que seguem, que podem envolver uma análise visual, um agrupamento ou uma classificação de dados, por exemplo. Lidar com esse problema normalmente exige técnicas de redução de dimensionalidade ou seleção de características. O presente trabalho dá sequência a trabalhos que utilizam técnicas de visualização como suporte para avaliar espaços de características gerados a partir de coleções de imagens. Nele, objetiva-se aprimorar um método baseado na análise visual de conjuntos de imagens empregando a árvore de similaridade Neighbor-Joining que apoia o usuário a selecionar um subespaço de características que mantenha ou melhore os resultados das visualizações do conjunto de imagens. A partir da metodologia proposta, a avaliação e a seleção de características representativas é realizada usando a visualização NJ. A maior parte dos experimentos responde positivamente para diferentes conjuntos de imagens representados por vários extratores...

Morphometric study by image analysis of Ag-stained nucleoli in thyroids bearing proliferating lesions

Abdo-Banhos, C. R.; Cordeiro, J. A.; Rosa, C. S.; Bicudo, H. E M C
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 37-43
ENG
Relevância na Pesquisa
65.54%
The Ag-NOR staining technique and image analysis were used to evaluate morphological parameters (area, perimeter and axis ratio) in nucleoli from normal thyroids and from thyroids bearing proliferating lesions (carcinomas, adenomas and hyperplasias). Regions with normal appearance located close to adenomatous and carcinomatous regions, in the thyroid of every patient, were also analyzed for comparison with the respective pathological regions and with normal thyroids. Statistical analysis of data for the nucleolar area and perimeter allowed the separation of adenomas and carcinomas from hyperplasias and normal tissue but not the two components in each of these two groups. However, if we look at the numbers, a sequence of increasing nucleolar mean areas in the order: normal, hyperplasia, adenoma and carcinoma may be observed, indicating the sequence of increasing rRNA requirements in these different kinds of cells. The axis ratio that denotes the nucleolar shape (round or oblong) did not show significant differences among tissues, suggesting that shape is not important in the characterization of these pathologies. Differences in nucleolar areas and perimeter between normal and affected regions from each patient were statistically significant for adenomas and carcinomas. When these normal regions were compared with the normal thyroids...

Automated analysis of investigational near-infrared fluorescence lymphatic imaging in humans

Zhang, Jingdan; Zhou, Shaohua Kevin; Xiang, Xiaoyan; Bautista, Merrick L.; Niccum, Blake A.; Dickinson, Gabriel S.; Tan, I-Chih; Chan, Wenyaw; Sevick-Muraca, Eva M.; Rasmussen, John C.
Fonte: Optical Society of America Publicador: Optical Society of America
Tipo: Artigo de Revista Científica
Publicado em 22/06/2012 EN
Relevância na Pesquisa
65.36%
ALFIA (Automated Lymphatic Function Imaging Analysis), an algorithm providing quantitative analysis of investigational near-infrared fluorescence lymphatic images, is described. Images from nine human subjects were analyzed for apparent lymphatic propagation velocities and propulsion periods using manual analysis and ALFIA. While lymphatic propulsion was more easily detected using ALFIA than with manual analysis, statistical analyses indicate no significant difference in the apparent lymphatic velocities although ALFIA tended to calculate longer propulsion periods. With the base ALFIA algorithms validated, further automation can now proceed to provide a clinically relevant analytic tool for quantitatively assessing lymphatic function in humans.

Application of artificial neural networks for quantitative analysis of image data in chest radiographs for detection of interstitial lung disease

Ishida, Takayuki; Katsuragawa, Shigehiko; Ashizawa, Kazuto; MacMahon, Heber; Doi, Kunio
Fonte: Springer-Verlag Publicador: Springer-Verlag
Tipo: Artigo de Revista Científica
Publicado em /11/1998 EN
Relevância na Pesquisa
65.5%
The authors have developed an automated computeraided diagnostic (CAD) scheme by using artificial neural networks (ANNs) on quantitative analysis of image data. Three separate ANNs were applied for detection of interstitial disease on digitized chest images. The first ANN was trained with horizontal profiles in regions of interest (ROIs) selected from normal and abnormal chest radiographs for distinguishing between normal and abnormal patterns. For training and testing of the second ANN, the vertical output patterns obtained from the 1st ANN were used for each ROI. The output value of the second ANN was used to distinguish between normal and abnormal ROIs with interstitial infiltrates. If the ratio of the number of abnormal ROIs to the total number of all ROIs in a chest image was greater than a specified threshold level, the image was classified as abnormal. In addition, the third ANN was applied to distinguish between normal and abnormal chest images. The combination of the rule-based method and the third ANN also was applied to the classification between normal and abnormal chest images. The performance of the ANNs was evaluated by means of receiver operating characteristic (ROC) analysis. The average Az value (area under the ROC curve) for distinguishing between normal and abnormal cases was 0.976±0.012 for 100 chest radiographs that were not used in training of ANNs. The results indicate that the ANN trained with image data can learn some statistical properties associated with interstitial infiltrates in chest radiographs.

Perceptually-based Comparison of Image Similarity Metrics

Russell, Richard; Sinha, Pawan
Fonte: MIT - Massachusetts Institute of Technology Publicador: MIT - Massachusetts Institute of Technology
Formato: 13 p.; 9714300 bytes; 2612761 bytes; application/postscript; application/pdf
EN_US
Relevância na Pesquisa
65.47%
The image comparison operation ??sessing how well one image matches another ??rms a critical component of many image analysis systems and models of human visual processing. Two norms used commonly for this purpose are L1 and L2, which are specific instances of the Minkowski metric. However, there is often not a principled reason for selecting one norm over the other. One way to address this problem is by examining whether one metric better captures the perceptual notion of image similarity than the other. With this goal, we examined perceptual preferences for images retrieved on the basis of the L1 versus the L2 norm. These images were either small fragments without recognizable content, or larger patterns with recognizable content created via vector quantization. In both conditions the subjects showed a consistent preference for images matched using the L1 metric. These results suggest that, in the domain of natural images of the kind we have used, the L1 metric may better capture human notions of image similarity.

Design and analysis of a scanning beam interference lithography system for patterning gratings with nanometer-level distortions

Konkola, Paul Thomas, 1973-
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 364 p.; 9844945 bytes; 9844637 bytes; application/pdf; application/pdf
ENG
Relevância na Pesquisa
65.46%
This thesis describes the design and analysis of a system for patterning large-area gratings with nanometer level phase distortions. The novel patterning method, termed scanning beam interference lithography (SBIL), uses the interference fringes between two coherent laser beams to define highly coherent gratings in photo resist. The substrate is step and scanned under the interference pattern to expose large gratings. Our experimental system, the "Nanoruler", employs interference lithography optics, an X-Y air bearing stage, column referencing displacement interferometry, refractometry, a grating length-scale reference, a beam alignment system, and acousto-optic fringe locking. Supporting systems also include an environmental enclosure, a beam steering system, and vibration isolation with feedforward. The system can pattern 300 mm diameter substrates. The errors are categorized and analyzed. The image-to-substrate motion during writing is comprised of "servo error", which is calculated from interferometric measurements, and unobservable error. The Nanoruler contains a built-in metrology capability where it can measure directly the image-to-substrate motions, which includes the unobservable error. In this special metrology mode, measurements can be performed at all substrate locations and on the fly - a capability possessed by no other patterning machine. This feature is used to assess the image-to-substrate motions. On-the-fly writing and metrology is further noted to be important because periodic errors in the interferometry can be eliminated. I control the fringe placement with a novel system of stage control and acousto-optic fringe locking. The experimentally verified system performance allows control of the servo error to the limits of quantization and latency.; (cont.) The impacts of stage controller performance and vibration isolation feedforward performance on unobservable errors are modeled and verified. Extremely high resonant frequency metrology frames were designed that provided unusual insensitivity to disturbances. The vibration errors are estimated to be sub angstrom (0 to 100 Hz). Based on my results and modeling...

Projective minimal analysis of camera geometry; Projective nonlinear minimal analysis of camera geometry

Romano, Raquel Andrea
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 120 p.; 4705947 bytes; 4705755 bytes; application/pdf; application/pdf
ENG
Relevância na Pesquisa
65.48%
This thesis addresses the general problem of how to find globally consistent and accurate estimates of multiple-view camera geometry from uncalibrated imagery of an extended scene. After decades of study, the classic problem of recovering camera motion from image correspondences remains an active area of research. This is due to the practical difficulties of estimating many interacting camera parameters under a variety of unknown imaging conditions. Projective geometry offers a useful framework for analyzing uncalibrated imagery. However, the associated multilinear models-the fundamental matrix and trifocal tensorare redundant in that they allow a camera configuration to vary along many more degrees of freedom than are geometrically admissible. This thesis presents a novel, minimal projective model of uncalibrated view triplets in terms of the dependent epipolar geometries among view pairs. By explicitly modeling the trifocal constraints among projective bifocal parameters-the epipoles and epipolar collineations-this model guarantees a solution that lies in the valid space of projective camera configurations. We present a nonlinear incremental algorithm for fitting the trifocally constrained epipolar geometries to observed image point matches. The minimal trifocal model is a practical alternative to the trifocal tensor for commonly found image sequences in which the availability of matched point pairs varies widely among different view pairs. Experimental results on synthetic and real image sequences with typical asymmetries in view overlap demonstrate the improved accuracy of the new trifocally constrained model.; (cont.) We provide an analysis of the objective function surface in the projective parameter space and examine cases in which the projective parameterization is sensitive to the Euclidean camera configuration. Finally...

Analysis of pulsed thermographic sequences based on radon transform

González Fernández, Daniel Aquilino; Ibarra Castanedo, Clemente; Madruga Saavedra, Francisco Javier; Maldague, Xavier P. V.
Fonte: SPIE Society of Photo-Optical Instrumentation Engineers Publicador: SPIE Society of Photo-Optical Instrumentation Engineers
Tipo: info:eu-repo/semantics/conferenceObject; publishedVersion
ENG
Relevância na Pesquisa
65.5%
The automatic detection of subsurface defects has become a desired goal in the application of Non Destructive Techniques. In this paper, a new algorithm based on the Radon Transform is proposed to reduce human intervention to a minimum in the field of Thermography for defect detection and/or characterization. The analysis of a thermographic sequence for the detection of subsurface defects can be reduced to the identification of the -0.5 slope in the surface temperature decay for each pixel within the image. Employing techniques commonly used in computer vision, an algorithm can be developed in order to look for the -0.5 slope in the temporal temperature decay profiles of each pixel. In our case, the Radon transform can be used to detect those -0.5 slope lines in the temporal temperature decay profiles. The final result provided by this algorithm is an image showing the different defects avoiding the necessity of evaluating parameters as relevant in other algorithms as the delayed time of the first image or any subjective point of view in the analysis. All the information is contained in only one image and leads to a quantitative estimation of the defect depths. The principal limitation is that the specimens under inspection should be semi-infinite homogeneous samples because this algorithm is supported on a 1-D Fourier diffusion equation approximation. Experimental works using a PlexiglasTM specimen were performed showing a good agreement with other semi-automated techniques.

Visual Grading Analysis of image quality in pediatric abdominal images acquired by Direct Digital Radiography and Computer Radiography Systems

Oliveira, Anais; Martins, Alexandra; Avelãs, Rita; Santos, Mónica; Martins, Paula; De Francesco, Silvia; Sá-Couto, Pedro; Ferreira, Carlos
Fonte: European Society of Radiology Publicador: European Society of Radiology
Tipo: Conferência ou Objeto de Conferência
ENG
Relevância na Pesquisa
65.47%
The advent of digital technology allowed for great improvements in radiology and lead the way for digital radiology, leaving behind conventional x-ray techniques, [1]. Digital post-processing of image is the main advantage of digital image systems (e.g., computed radiology and direct digital radiology) over the conventional systems. Image quality can indeed be improved avoiding the increase of patient dose and the number of unnecessary exposures [1-3]. Image quality is directly linked to the dose of radiation applied to the patient. The literature points out the need for appropriate image evaluation in order to reduce the patient dose. Optimization and practice justification are of great relevance in diagnostic radiology. In pediatric patients a good practice justification is even more important as radiation exposure on the first 10 years of life increases the possibility of negative effects on the patient's health compared to an exposure between the ages of 30 to 40 years old [4, 5]. In the past, the main concern of radiology technicians was image quality, leaving radiation dose to a second plan. Nowadays, dose reduction and the cost/benefit ratio represent the main concerns in radiology. The radiographer is responsible for applying the ALARA (As Low As Reasonable Acceptable) concept in every study involving the use of ionizing radiation [4...

"The Image of PLAZA" : an analysis of an academic community web space using Kevin Lynch's approach for "The image of the city"

Kim, Jaecheol, 1971-
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 113 p.; 6866274 bytes; 6866082 bytes; application/pdf; application/pdf
ENG
Relevância na Pesquisa
65.51%
This thesis is a case study of how the design issues of a community web space can be approached from the viewpoint of urban design not in terms of appearance but in terms of its functionality. An urban public place like a plaza and a community web space both serve their residents' social lives whether real or virtual. There have been many efforts to replicate public spaces into the virtual world. However, considering the completely different materials that compose both spaces, it may be not proper to duplicate just the visual appearance of a city in the virtual world. Therefore, in this thesis, using not the literal adoption of but the functional analogy of urban design, I analyze the legibility of a community web space, 'PLAZA'. This analogy can be divided into two parts. The first part utilizes Kevin Lynch's methodology for the analysis of "the Image of City". I examine the design of PLAZA using the public's mental image of PLAZA, as he used the citizens' image of cities to analyze city spaces. The second part uses physical urban space to interpret the relation between users' mental image of PLAZA and its design. Spatial concepts that are familiar in designing physical spaces are used for this analysis; Graphic, Location, Vitality of a place...

Shape analysis of different populations of clams in relation to their geographical structure

Costa, Corrado; Aguzzi, Jacopo; Menesatti, Paolo; Antonucci, Francesca; Rimatori, Valentina; Mattoccia, M.
Fonte: Zoological Society of London Publicador: Zoological Society of London
Tipo: Artículo Formato: 22195 bytes; application/pdf
ENG
Relevância na Pesquisa
65.44%
10 pages, 6 figures, 5 tables.; Bivalves are excellent candidates for geographically based studies of the morphological variation in individuals of different populations based on the analysis of their shape profiles. In this study, we quantified the overall shell shape differences in individuals of different populations of Ruditapes decussatus and Ruditapes philippinarum in relation to their geographical and genetic distances. A total of 395 and 124 individuals of R. decussatus (nine populations) and R. philippinarum (four populations), respectively, were sampled in different Mediterranean and Atlantic coastal locations. Pictures of the left valve were taken from all individuals. Their profiles were analysed using elliptic Fourier analysis. Mean outlines were computed. In order to classify different individuals for species, the coefficients of harmonic equations were analysed by partial least square discriminant analysis and soft independent modelling of class analogy. The results showed a high percentage of correct classification (99%) between the two species in the independent test. We found that the morphological distance between R. philippinarum and R. decussatus is higher than the morphological distance among populations of the same species. The absence of correspondence between the geographical location and the pattern of morphological and genetic variation indicates the occurrence of a reaction norm in the morphological adaptation of shell shapes to different local environmental conditions.; We would like to thank Davide Cascione for his help during the process of image acquisition. Jacopo Aguzzi is a Fellow of the ‘Juan de la Cierva’ Postdoctoral Program (MECSpain).; Peer reviewed

Quantitative analysis of image factors in a cultural heritage tourist destination

Bové-Sans, Miquel-Àngel; Laguado Ramírez, Raquel Irene
Fonte: Xarxa de Referència en Economia Aplicada (XREAP) Publicador: Xarxa de Referència en Economia Aplicada (XREAP)
Tipo: Trabalho em Andamento Formato: application/pdf
Publicado em //2012 CAT
Relevância na Pesquisa
65.51%
The tourism consumer’s purchase decision process is, to a great extent, conditioned by the image the tourist has of the different destinations that make up his or her choice set. In a highly competitive international tourist market, those responsible for destinations’ promotion and development policies seek differentiation strategies so that they may position the destinations in the most suitable market segments for their product in order to improve their attractiveness to visitors and increase or consolidate the economic benefits that tourism activity generates in their territory. To this end, the main objective we set ourselves in this paper is the empirical analysis of the factors that determine the image formation of Tarragona city as a cultural heritage destination. Without a doubt, UNESCO’s declaration of Tarragona’s artistic and monumental legacies as World Heritage site in the year 2000 meant important international recognition of the quality of the cultural and patrimonial elements offered by the city to the visitors who choose it as a tourist destination. It also represents a strategic opportunity to boost the city’s promotion of tourism and its consolidation as a unique destination given its cultural and patrimonial characteristics. Our work is based on the use of structured and unstructured techniques to identify the factors that determine Tarragona’s tourist destination image and that have a decisive influence on visitors’ process of choice of destination. In addition to being able to ascertain Tarragona’s global tourist image...

Analysis of image noise in multispectral color acquisition

Burns, Peter
Fonte: Rochester Instituto de Tecnologia Publicador: Rochester Instituto de Tecnologia
Tipo: Dissertação
EN_US
Relevância na Pesquisa
65.56%
The design of a system for multispectral image capture will be influenced by the imaging application, such as image archiving, vision research, illuminant modification or improved (trichromatic) color reproduction. A key aspect of the system performance is the effect of noise, or error, when acquiring multiple color image records and processing of the data. This research provides an analysis that allows the prediction of the image-noise characteristics of systems for the capture of multispectral images. The effects of both detector noise and image processing quantization on the color information are considered, as is the correlation between the errors in the component signals. The above multivariate error-propagation analysis is then applied to an actual prototype system. Sources of image noise in both digital camera and image processing are related to colorimetric errors. Recommendations for detector characteristics and image processing for future systems are then discussed.

Adaptive multilevel median filtering of image sequences

Jackson, Shawn; Savakis, Andreas
Fonte: Institute of Electrical and Electronics Engineers (IEEE) Publicador: Institute of Electrical and Electronics Engineers (IEEE)
Tipo: Artigo de Revista Científica
EN_US
Relevância na Pesquisa
65.48%
This paper presents a new method for adaptive multilevel median (AML3D) filtering of image sequences that can be used for impulse noise suppression in movies that have been converted from film to digital format. The proposed AML3D filter operates on three consecutive frames using an adaptive window and is designed to provide good image quality at modest computational cost. In addition, we present a benchmark comparison of methods used for median filtering of image sequences. Testing includes both grayscale and color images that are synthetically degraded by various levels of impulse noise. Results obtained for timing performance and image quality illustrate that the AML3D filter provides the highest PSNR improvement, while maintaining a reasonable throughput.; "Adaptive multilevel median filtering of image sequences," The International Conference on Image Processing, vol. 3. The Institute of Electrical and Electronics Engineers. Held in Geona, Italy: 11-14 September 2005. ©2005 Institute of Electrical and Electronics Engineers (IEEE). Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists...

The objective evaluation of image quality produced with physical development

Smith, Bruce; Snyder, Keith
Fonte: Rochester Instituto de Tecnologia Publicador: Rochester Instituto de Tecnologia
Tipo: Tese de Doutorado
EN_US
Relevância na Pesquisa
65.51%
This experiment was an analysis of the difference in objective measures of image quality between chemical and physical development methods, including prefixation and postfixation processes. Of particular interest was the process outlined by Matejec1 for postfixation physical development. An investigation of resolving power and MTF for two fine grain films was carried out for four different development processes all possessing approximately the same speed capability. Both the effect of combined chemical and optical spread functions and the chemical spread alone were investigated through edge analysis using Fourier methods. A significant increase in image quality was found with the finest grain film (Eastman 5302) for prefixation while a significant decrease was found with the highly active Matejec's physical developer on the same film. A dye inhibition reaction on the dye sensitized emulsion, Panatomic-x, prevented analysis of image quality for postfixation processes for that film.

Analysis of Remotely Sensed Data: The Formative Decades and the Future

Richards, John
Fonte: Institute of Electrical and Electronics Engineers (IEEE Inc) Publicador: Institute of Electrical and Electronics Engineers (IEEE Inc)
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
65.51%
Developments in the field of image understanding in remote sensing over the past four decades are reviewed, with an emphasis, initially, on the contributions of David Landgrebe and his colleagues at the Laboratory for Applications of Remote Sensing, Purdue University. The differences in approach required for multispectral, hyperspectral and radar image data are emphasised, culminating with a commentary on methods commonly adopted for multisource image analysis. The treatment concludes by examining the requirements of an operational multisource thematic mapping process, in which it is suggested that the most practical approach is to analyze each data type separately, by techniques optimized to that data's characteristics, and then to fuse at the label level.

New method for the analysis of images: the square wave method

Skliar,Osvaldo; Oviedo,Guillermo; Monge,Ricardo E.; Medina,Víctor; Gapper,Sherry
Fonte: Revista de Matemática Teoría y Aplicaciones Publicador: Revista de Matemática Teoría y Aplicaciones
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2013 EN
Relevância na Pesquisa
65.55%
The Square Wave Method (SWM) - previously applied to the analysis of signals - has been generalized here, quite naturally and directly, for the analysis of images. Each image to be analyzed is subjected to a process of digitization so that it can be considered to be made up of pixels. A numeric value or “level” ranging from 0 to 255 (on a gray scale going from black to white) corresponds to each pixel. The analysis process described causes each image analyzed to be “decomposed” into a set of “components”. Each component consists of a certain train of square waves. The SWM makes it possible to determine these trains of square waves unambiguously. Each row and each column of the image analyzed can be obtained once again by adding all the trains of square waves corresponding to a particular row or to a particular column. In this article the entities analyzed were actually sub-images of a certain digitized image. Given that any sub-image of any image is also an image, it was feasible to apply the SWM for the analysis of all the sub-images.