833 resultados para distinctness of image
Resumo:
Advances in three-dimensional (313) electron microscopy (EM) and image processing are providing considerable improvements in the resolution of subcellular volumes, macromolecular assemblies and individual proteins. However, the recovery of high-frequency information from biological samples is hindered by specimen sensitivity to beam damage. Low dose electron cryo-microscopy conditions afford reduced beam damage but typically yield images with reduced contrast and low signal-to-noise ratios (SNRs). Here, we describe the properties of a new discriminative bilateral (DBL) filter that is based upon the bilateral filter implementation of Jiang et al. (Jiang, W., Baker, M.L., Wu, Q., Bajaj, C., Chin, W., 2003. Applications of a bilateral denoising filter in biological electron microscopy. J. Struc. Biol. 128, 82-97.). In contrast to the latter, the DBL filter can distinguish between object edges and high-frequency noise pixels through the use of an additional photometric exclusion function. As a result, high frequency noise pixels are smoothed, yet object edge detail is preserved. In the present study, we show that the DBL filter effectively reduces noise in low SNR single particle data as well as cellular tomograms of stained plastic sections. The properties of the DBL filter are discussed in terms of its usefulness for single particle analysis and for pre-processing cellular tomograms ahead of image segmentation. (c) 2006 Elsevier Inc. All rights reserved.
Resumo:
Este trabalho tem por objetivo analisar a forma de construção da imagem dos bispos, pastores, obreiros e obreiras da Igreja Universal do Reino de Deus (IURD), por meio da ferramenta de marketing pessoal (MP). A utilização do MP por tais agentes religiosos é uma maneira de melhorar a interação simbólica entre líderes e fiéis e atrair o público para os templos. A IURD foi escolhida para esta análise por usar de vários procedimentos que estão relacionados com as técnicas de MP, no sentido de sofisticar a aparência visual de sua liderança, a fim de representar um discurso de prosperidade disseminado pela instituição. Cremos que é dessa forma que a IURD atrai o público por meio da imagem criada dos líderes, mediante uma aparência visual sofisticada. Na pesquisa dessa Igreja, encontramos que a ferramenta de MP usada pelos seus membros hierárquicos contribui para o crescimento e a consolidação desse empreendimento no mercado religioso. A construção da imagem que estamos tratando é planejada a partir da matriz imagética do líder principal da Igreja Universal, Edir Bezerra Macedo. Por meio da imagem central do bispo Macedo é que a liderança é marcada ou estigmatizada com um perfil estético respaldado por uma noção de sucesso. Utilizamos a pesquisa bibliográfica e observação participante como método de pesquisa e ainda, pesquisamos o jornal Folha Universal e averiguamos alguns programas televisivos exibidos na TV Record, analisando o marketing pessoal da liderança em questão. Assim, verificamos que as interfaces de presentação da boa imagem produzida por meio de técnicas corporais, roupas e acessórios, favorece a representação desses líderes nos seus principais canais de comunicação, templos e televisão.(AU)
Resumo:
Este trabalho analisa sociologicamente na contemporaneidade o campo imagético na música gospel e de que forma, este influencia na mudança dos paradigmas imagético - estéticos utilizados pelas produtoras fonográficas em seu marketing religioso para a comercialização da música gospel no mercado da música evangélica brasileira, proporcionando neste modelo atual um crescimento qualitativo e quantitativo dos produtos destinados ao público evangélico. A pesquisa identifica nas produções visuais de divulgação e comercialização de CDs, DVDs, sites das produtoras fonográficas, feiras e premiações musicais, os mecanismos utilizados para a construção de um novo paradigma imagético que proporciona no campo religioso, o surgimento de um novo imaginário evangélico mimeticamente construído para alimentar um mercado gospel fomentado pela tríade social: espetáculo, consumo e entretenimento. Desta forma, a analise tem o seu recorte nas mudanças paradigmáticas que surgem a partir dos primeiros cantores e cantoras da década de 1950 até culminar na explosão da música gospel no início da década de 1990.(AU)
Resumo:
O presente estudo visa estabelecer a relação comunicação-cultura-design por meio da importância do design de comunicação no processo de comunicação gerado na reconstrução de uma imagem corporativa já consolidada para uma empresa que busca responder à cultura do consumo consciente e sustentável. Esse processo resulta no imaginário e consequentemente na imagem corporativa expressa por meio do redesign verificado em campanhas publicitárias, fachadas e internet. Para isso, será tomado por base o referencial teórico dos estudos que relacionem cultura e consumo, além de teóricos que discutem os temas da imagem e do imaginário. Será utilizada como metodologia além da pesquisa bibliográfica, a pesquisa qualitativa. Por isso, no intuito de averiguar na prática a teoria apresentada, revela-se um estudo de caso sobre a mudança na comunicação e identidade visual na rede de McDonald s no Brasil, observando-se descritivamente as alterações ocorridas na Europa como uma ousada estratégia de redesign para a rede. Parte-se da premissa de que tal ação tem o intuito de fortalecer uma imagem corporativa de ambientalmente amigável naquele país cuja cultura visa assegurar criteriosamente a proteção à saúde de seus habitantes, cada vez mais rigorosos no controle dos produtos consumidos.
Resumo:
We describe a method of recognizing handwritten digits by fitting generative models that are built from deformable B-splines with Gaussian ``ink generators'' spaced along the length of the spline. The splines are adjusted using a novel elastic matching procedure based on the Expectation Maximization (EM) algorithm that maximizes the likelihood of the model generating the data. This approach has many advantages. (1) After identifying the model most likely to have generated the data, the system not only produces a classification of the digit but also a rich description of the instantiation parameters which can yield information such as the writing style. (2) During the process of explaining the image, generative models can perform recognition driven segmentation. (3) The method involves a relatively small number of parameters and hence training is relatively easy and fast. (4) Unlike many other recognition schemes it does not rely on some form of pre-normalization of input images, but can handle arbitrary scalings, translations and a limited degree of image rotation. We have demonstrated our method of fitting models to images does not get trapped in poor local minima. The main disadvantage of the method is it requires much more computation than more standard OCR techniques.
Resumo:
This paper addresses the security of a specific class of common watermarking methods based on Dither modulation-quantisation index modulation (DM-QIM) and focusing on watermark-only attacks (WOA). The vulnerabilities of and probable attacks on lattice structure based watermark embedding methods have been presented in the literature. DM-QIM is one of the best known lattice structure based watermarking techniques. In this paper, the authors discuss a watermark-only attack scenario (the attacker has access to a single watermarked content only). In the literature it is an assumption that DM-QIM methods are secure to WOA. However, the authors show that the DM-QIM based embedding method is vulnerable against a guided key guessing attack by exploiting subtle statistical regularities in the feature space embeddings for time series and images. Using a distribution-free algorithm, this paper presents an analysis of the attack and numerical results for multiple examples of image and time series data.
Resumo:
This paper addresses the security of a specific class of common watermarking methods based on Dither modulation-quantisation index modulation (DM-QIM) and focusing on watermark-only attacks (WOA). The vulnerabilities of and probable attacks on lattice structure based watermark embedding methods have been presented in the literature. DM-QIM is one of the best known lattice structure based watermarking techniques. In this paper, the authors discuss a watermark-only attack scenario (the attacker has access to a single watermarked content only). In the literature it is an assumption that DM-QIM methods are secure to WOA. However, the authors show that the DM-QIM based embedding method is vulnerable against a guided key guessing attack by exploiting subtle statistical regularities in the feature space embeddings for time series and images. Using a distribution-free algorithm, this paper presents an analysis of the attack and numerical results for multiple examples of image and time series data.
Resumo:
Purpose - To generate a reflectance model of the fundus that allows an accurate non-invasive quantification of blood and pigments. Methods - A Monte Carlo simulation was used to produce a mathematical model of light interaction with the fundus at different wavelengths. The model predictions were compared with fundus images from normal volunteers in several spectral bands (peaks at 507, 525, 552, 585, 596 and 611nm). Th e model was then used to calculate the concentration and distribution of the known absorbing components of the fundus. Results - The shape of the statistical distribution of the image data generally corresponded to that of the model data; the model however appears to overestimate the reflectance of the fundus in the longer wavelength region.As the absorption by xanthophyll has no significant eff ect on light transport above 534nm, its distribution in the fundus was quantified: the wavelengths where both shape and distribution of image and model data matched (<553nm) were used to train a neural network which was then applied to every point in the image data. The xanthophyll distribution thus found was in agreement with published literature data in normal subjects. Conclusion - We have developed a method for optimising multi-spectral imaging of the fundus and a computer image analysis capable of estimating information about the structure and properties of the fundus. Th e technique successfully calculates the distribution of xanthophyll in the fundus of healthy volunteers. Further improvement of the model is required to allow the deduction of other parameters from images; investigations in known pathology models are also necessary to establish if this method is of clinical use in detecting early chroido-retinopathies, hence providing a useful screening and diagnostic tool.
Resumo:
Error and uncertainty in remotely sensed data come from several sources, and can be increased or mitigated by the processing to which that data is subjected (e.g. resampling, atmospheric correction). Historically the effects of such uncertainty have only been considered overall and evaluated in a confusion matrix which becomes high-level meta-data, and so is commonly ignored. However, some of the sources of uncertainty can be explicity identified and modelled, and their effects (which often vary across space and time) visualized. Others can be considered overall, but their spatial effects can still be visualized. This process of visualization is of particular value for users who need to assess the importance of data uncertainty for their own practical applications. This paper describes a Java-based toolkit, which uses interactive and linked views to enable visualization of data uncertainty by a variety of means. This allows users to consider error and uncertainty as integral elements of image data, to be viewed and explored, rather than as labels or indices attached to the data. © 2002 Elsevier Science Ltd. All rights reserved.
Resumo:
This paper presents an up to date review of digital watermarking (WM) from a VLSI designer point of view. The reader is introduced to basic principles and terms in the field of image watermarking. It goes through a brief survey on WM theory, laying out common classification criterions and discussing important design considerations and trade-offs. Elementary WM properties such as robustness, computational complexity and their influence on image quality are discussed. Common attacks and testing benchmarks are also briefly mentioned. It is shown that WM design must take the intended application into account. The difference between software and hardware implementations is explained through the introduction of a general scheme of a WM system and two examples from previous works. A versatile methodology to aid in a reliable and modular design process is suggested. Relating to mixed-signal VLSI design and testing, the proposed methodology allows an efficient development of a CMOS image sensor with WM capabilities.
Resumo:
A new distance function to compare arbitrary partitions is proposed. Clustering of image collections and image segmentation give objects to be matched. Offered metric intends for combination of visual features and metadata analysis to solve a semantic gap between low-level visual features and high-level human concept.
Resumo:
The process of automatic handwriting investigation in forensic science is described. The general scheme of a computer-based handwriting analysis system is used to point out at the basic problems of image enhancement and segmentation, feature extraction and decision-making. Factors that may compromise the accuracy of expert’s conclusion are underlined and directions for future investigations are marked.
Resumo:
ACM Computing Classification System (1998): J.2.
Resumo:
Many Object recognition techniques perform some flavour of point pattern matching between a model and a scene. Such points are usually selected through a feature detection algorithm that is robust to a class of image transformations and a suitable descriptor is computed over them in order to get a reliable matching. Moreover, some approaches take an additional step by casting the correspondence problem into a matching between graphs defined over feature points. The motivation is that the relational model would add more discriminative power, however the overall effectiveness strongly depends on the ability to build a graph that is stable with respect to both changes in the object appearance and spatial distribution of interest points. In fact, widely used graph-based representations, have shown to suffer some limitations, especially with respect to changes in the Euclidean organization of the feature points. In this paper we introduce a technique to build relational structures over corner points that does not depend on the spatial distribution of the features. © 2012 ICPR Org Committee.
Resumo:
Given the importance of color processing in computer vision and computer graphics, estimating and rendering illumination spectral reflectance of image scenes is important to advance the capability of a large class of applications such as scene reconstruction, rendering, surface segmentation, object recognition, and reflectance estimation. Consequently, this dissertation proposes effective methods for reflection components separation and rendering in single scene images. Based on the dichromatic reflectance model, a novel decomposition technique, named the Mean-Shift Decomposition (MSD) method, is introduced to separate the specular from diffuse reflectance components. This technique provides a direct access to surface shape information through diffuse shading pixel isolation. More importantly, this process does not require any local color segmentation process, which differs from the traditional methods that operate by aggregating color information along each image plane. ^ Exploiting the merits of the MSD method, a scene illumination rendering technique is designed to estimate the relative contributing specular reflectance attributes of a scene image. The image feature subset targeted provides a direct access to the surface illumination information, while a newly introduced efficient rendering method reshapes the dynamic range distribution of the specular reflectance components over each image color channel. This image enhancement technique renders the scene illumination reflection effectively without altering the scene’s surface diffuse attributes contributing to realistic rendering effects. ^ As an ancillary contribution, an effective color constancy algorithm based on the dichromatic reflectance model was also developed. This algorithm selects image highlights in order to extract the prominent surface reflectance that reproduces the exact illumination chromaticity. This evaluation is presented using a novel voting scheme technique based on histogram analysis. ^ In each of the three main contributions, empirical evaluations were performed on synthetic and real-world image scenes taken from three different color image datasets. The experimental results show over 90% accuracy in illumination estimation contributing to near real world illumination rendering effects. ^