Several factors impact the light irradiance and relative illumination produced by a lens system at its image plane. In addition to the cosine-fourth-power radiometric law, image and pupil aberrations, and light vignetting also count. In this paper, we use an irradiance transport equation to derive a closed form solution that provides insight into how individual aberration terms affect the light irradiance and relative illumination. The theoretical results are in agreement with real ray tracing.

<p>Optical microscopy plays a crucial role in the biological sciences for its ability to enable visualization of biological samples at sub-cellular levels. Many imaging subdivisions exist under this umbrella of general microscopy, and each are tailored towards specific design, contrast, and visualization constraints. Standard examples that have found widespread use include dark-field, phase-contrast, holographic, and fluorescent microscopies. However, a critical factor that physically limits the optical resolution of general microscopy is diffraction. Unfortunately, this “diffraction-limit” can prevent visualization of significant biologically relevant structures, which in turn can limit biological insights. In response to such a limit, several works have advanced the field of sub-diffraction resolution imaging, which consist of optical imaging techniques that seek to achieve imaging resolutions beyond that which is allowed by the diffraction-limit. This set of techniques can largely be divided into two classes. The first class of sub-diffraction techniques is targeted towards cases where the sample is coherently illuminated and diffracts into the imaging system’s aperture. For such cases, synthetic aperture (SA) is a popular choice and operates by using oblique illuminations to spatiotemporally synthesize a wider frequency support into the image than allowed by the diffraction limit. The second class of sub-diffraction techniques, often referred to as "super-resolution" techniques, typically utilize specialized fluorophores with either photoswitching or depletion capabilities. Photoactivated localization microscopy (PALM) is a super-resolution example that localizes photoswitchable fluorophores to sub-diffraction resolutions per acquisition, before combining into a final super-resolved image. Stimulated emission depletion (STED) is another super-resolution example that spatially modulates its excitation to narrow its optical point-spread-function. Unfortunately, SA and fluorescent super-resolution techniques are generally incompatible for sub-diffraction resolution fluorescent and coherent imaging, respectively – thus, a multimodal sub-diffraction imaging solution compatible with both coherent and fluorescent imaging has remained elusive. </p><p> In this dissertation, we demonstrate that structured illumination (SI) is a sub-diffraction technique compatible with both diffractive and fluorescent imaging. We first develop the theoretical framework that extends SI to coherent imaging and experimentally demonstrate SI’s capabilities for 2D sub-diffraction resolution imaging of coherently diffractive samples. Sub-diffraction resolution imaging based on scattering intensity and transmission-based quantitative-phase (QP) are shown. In addition, we show extend SI to 3D coherent imaging, and show applications of this towards 3D QP and refractive-index (RI) tomography. Finally, we show multimodal applications of SI that allow sub-diffraction resolution fluorescent and coherent imaging, which has great potential utility for the biological sciences.</p> / Dissertation

Several factors impact the light irradiance and relative illumination produced by a lens system at its image plane. In addition to cosine-fourth-power radiometric law, image and pupil aberrations and light vignetting also count. We use an irradiance transport equation to derive a closed form solution that provides insight into how individual aberration terms affect the light irradiance and relative illumination. The theoretical results are in agreement with real ray tracing. (C) 2016 Society of Photo-Optical Instrumentation Engineers (SPIE)

We present an optical surface in closed form that can be used to design lenses for controlling relative illumination on a target surface. The optical surface is constructed by rotation of the pedal curve to the ellipse about its minor axis. Three renditions of the surface are provided, namely as an expansion of a base surface, and as combinations of several base surfaces. Examples of the performance of the surfaces are presented for the case of a point light source. (C) 2016 Society of Photo-Optical Instrumentation Engineers (SPIE)

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The two books presented by Walter of Milemete to Edward III in 1326-7 are treated together. Two campaigns of decoration are suggested for the Milemete Treatise: an original campaign c1326-7 and one largely executed by a single artist before Queen Isabella's fall from power c1330. Three campaigns of decoration are suggested for the companion volume the Holkham Secretum. An original campaign, perhaps earlier than that on the Milemete Treatise, but still c1326-7, a second campaign c1327-30 and later work added when the book was repaired c1340-50. The iconography of the Milemete Treatise is related to court models and the 'Flores Historiarum'. The iconography of the Holkham Secretum is seen as having been created in three campaigns related to the different artists who worked on the book. From an analysis of the documentary evidence concerning illuminators in England in the Middle Ages, a model is applied which suggests the existence of three major centres of illumination in England, Oxford, Cambridge and London, as well as minor regional towns which also supported illuminators. The localisation of liturgical manuscripts, the patronage evidence from both secular and liturgical manuscripts as well as iconographical and codicological comparisons, are all used to suggest that the first group of illuminators of the Holkham Secretum were based at oxford. The main group of the Milemete Treatise itself can be associated with these artists, but also with more metropolitan trends and London. The later work on the Holkham Secretum is associated with an 'Ely group' of manuscripts c1340-50, produced by artists who may have been based at Cambridge. 3 it is suggested that some artists may have been trained in one 'centre' or 'workshop', but could be itinerant. other artists appear to be more closely related to Court painting in London through their style and the iconography of their miniatures. At least two of the artists who worked on the Milemete Treatise and Holkham Secretum1 after the initial campaign, but before c1330, fall into the latter category.

Orientador: João Roberto Gomes de Faria / Banca: Paulo Sérgio Sacarazzato / Banca: Luiz Gonzaga Campos Porto / Resumo: O conforto visual no ambiente de trabalho também é alvo de estudo da ergonomia, e com o auxílio da análise de imagens digitais - HDR (High Dynamic Range) é possível ter um estudo mais rápido e barato contribuindo assim para o bem estar dos trabalhadores, já que uma boa iluminação tornará o ambiente de trabalho mais produtivo e prazeroso. Tem-se por objetivo especificamente, estudar formas de caracterizar o ambiente em relação à possibilidade da ocorrência de ofuscamento a partir de imagens HDR e viabilizar o uso de câmeras fotográficas digitais de uso amador, com lentes padrão, no desenvolvimento de uma sistemática e da correspondente instrumentação para avaliar índices de ofuscamento empregando imagens HDR compostas a partir de fotos obtidas com tais câmeras / Abstract: The visual comfort in the work environment also is white of study of the ergonomics, and with the aid of the analysis of digital images - HDR (High Dynamic Range) is possible to have a cheap study faster e thus constributing it welfare of the workers, science a good illumination will became the environment of more productive and pleasant work. It is had specifically for objective, to study forms to characterize the environment in relation a possibility da ofuscamento occurrence to leave of images HDR and to make possible the use of digital cameras of amoteur use, with leses standard, no development of a systematics and da corresponding instrumentation to evaluate ofuscamento indices being used composed images HDR to leave of photos gotten with such cameras / Mestre

The limitations of foreground segmentation in difficult environments using standard color space features often result in poor performance during autonomous tracking. This work presents a new approach for classification of foreground and background pixels in image sequences by employing an ensemble of classifiers, each operating on a different feature type such as the three RGB features, gradient magnitude and orientation features, and eight Haar features. These thirteen features are used in an ensemble classifier where each classifier operates on a single image feature. Each classifier implements a Mixture of Gaussians-based unsupervised background classification algorithm. The non-thresholded, classification decision score of each classifier are fused together by taking the average of their outputs and creating one single hypothesis. The results of using the ensemble classifier on three separate and distinct data sets are compared to using only RGB features through ROC graphs. The extended feature vector outperforms the RGB features on all three data sets, and shows a large scale improvement on two of the three data sets. The two data sets with the greatest improvements are both outdoor data sets with global illumination changes and the other has many local illumination changes. When using the entire feature set, to operate at a 90% true positive rate, the per pixel, false alarm rate is reduced five times in one data set and six times in the other data set.

<p>Ultrasound (US) volume data is noisy, so traditional methods for direct volume rendering (DVR) are less appropriate. Improved methods or new techniques are required. There are furthermore a high performance requirement and limited pre-processing to be considered in order for it to be used interactively, since the volume data might be time-varying.</p><p>There exist numerous techniques for improving visual perception of volume rendering, and while some perform well and produce a visually enhanced result, many are designed and compared for use with medical data that has a high signal-to-noise ratio. This master thesis describe and compare recent methods for DVR illumination, in the form of ambient occlusion or direct/indirect lighting from an external light source. New designs and modifications are introduced for efficiently and effectively enhancing the visual quality of DVR with US data. Furthermore, this thesis addresses the issue of how clipping is performed during rendering and for the different illumination techniques, which is commonly used in ultrasound visualization.</p><p>This diploma work was conducted at Siemens Corporate Research in Princeton, NJ where the partially open source framework XIP is developed. The framework was extended further to include modern methods for DVR illumination that are described in detail within this thesis. Finally, presented results show that several methods can be used to visually enhance the visualization within highly interactive frame-rates.</p>