Comparing of radial and tangencial geometric for cylindric panorama

Cameras generally have a field of view only large enough to capture a portion of their surroundings. The goal of immersion is to replace many of your senses with virtual ones, so that the virtual environment will feel as real as possible. Panoramic cameras are used to capture the entire 360°view, also known as panoramic images.Virtual reality makes use of these panoramic images to provide a more immersive experience compared to seeing images on a 2D screen. This thesis, which is in the field of Computer vision, focuses on establishing a multi-camera geometry to generate a cylindrical panorama image and successfully implementing it with the cheapest cameras possible. The specific goal of this project is to propose the cameras geometry which will decrease artifact problems related to parallax in the panorama image. We present a new approach of cylindrical panoramic images from multiple cameras which its setup has cameras placed evenly around a circle. Instead of looking outward, which is the traditional ”radial” configuration, we propose to make the optical axes tangent to the camera circle, a ”tangential” configuration. Beside an analysis and comparison of radial and tangential geometries, we provide an experimental setup with real panoramas obtained in realistic conditionsLes caméras ont généralement un champ de vision à peine assez grand pour capturer partie de leur environnement. L’objectif de l’immersion est de remplacer virtuellement un grand nombre de sens, de sorte que l’environnement virtuel soit perçu comme le plus réel possible. Une caméra panoramique est utilisée pour capturer l’ensemble d’une vue 360°, également connue sous le nom d’image panoramique. La réalité virtuelle fait usage de ces images panoramiques pour fournir une expérience plus immersive par rapport aux images sur un écran 2D. Cette thèse, qui est dans le domaine de la vision par ordinateur, s’intéresse à la création d’une géométrie multi-caméras pour générer une image cylindrique panoramique et vise une mise en œuvre avec les caméras moins chères possibles. L’objectif spécifique de ce projet est de proposer une géométrie de caméra qui va diminuer au maximum les problèmes d’artefacts liés au parallaxe présent dans l’image panoramique. Nous présentons une nouvelle approche de capture des images panoramiques cylindriques à partir de plusieurs caméras disposées uniformément autour d’un cercle. Au lieu de regarder vers l’extérieur, ce qui est la configuration traditionnelle ”radiale”, nous proposons de rendre les axes optiques tangents au cercle des caméras, une configuration ”tangentielle”. Outre une analyse et la comparaison des géométries radiales et tangentielles, nous fournissons un montage expérimental avec de vrais panoramas obtenus dans des conditions réaliste

A comparative study of algorithms for realtime panoramic video blending

Unlike image blending algorithms, video blending algorithms have been little studied. In this paper, we investigate 6 popular blending algorithms—feather blending, multi-band blending, modified Poisson blending, mean value coordinate blending, multi-spline blending and convolution pyramid blending. We consider their application to blending realtime panoramic videos, a key problem in various virtual reality tasks. To evaluate the performances and suitabilities of the 6 algorithms for this problem, we have created a video benchmark with several videos captured under various conditions. We analyze the time and memory needed by the above 6 algorithms, for both CPU and GPU implementations (where readily parallelizable). The visual quality provided by these algorithms is also evaluated both objectively and subjectively. The video benchmark and algorithm implementations are publicly available1

Learning from THEODORE: A Synthetic Omnidirectional Top-View Indoor Dataset for Deep Transfer Learning

Recent work about synthetic indoor datasets from perspective views has shown significant improvements of object detection results with Convolutional Neural Networks(CNNs). In this paper, we introduce THEODORE: a novel, large-scale indoor dataset containing 100,000 high-resolution diversified fisheye images with 14 classes. To this end, we create 3D virtual environments of living rooms, different human characters and interior textures. Beside capturing fisheye images from virtual environments we create annotations for semantic segmentation, instance masks and bounding boxes for object detection tasks. We compare our synthetic dataset to state of the art real-world datasets for omnidirectional images. Based on MS COCO weights, we show that our dataset is well suited for fine-tuning CNNs for object detection. Through a high generalization of our models by means of image synthesis and domain randomization, we reach an AP up to 0.84 for class person on High-Definition Analytics dataset.Comment: Paper accepted in WACV 202

Science related information in European television: a study of prime-time news

According to the few studies carried out on this subject, in spite of its importance and interest for the audience, science has been a marginal topic in television news, and has presented several problems of quality. This article presents the main results of a comparative research on science in European television, focusing on the main prime-time news programs of the leading public and the leading commercial channel, in the five largest countries. A sample of two weeks (2676 stories) was analyzed, with an outcome of 218 science related stories, which were coded (topic, length, explicit news values, contextual information and scientific explanation). Results indicate that the number and airtime of science related stories have increased, compared to a decade ago, but still do not seem to match the interest that citizens declare to have in science. The quality of the information broadcast seems relatively acceptable, although it still needs to be improved in some aspects, for which new formats of news programs would be helpful

Casual 3D photography

We present an algorithm that enables casual 3D photography. Given a set of input photos captured with a hand-held cell phone or DSLR camera, our algorithm reconstructs a 3D photo, a central panoramic, textured, normal mapped, multi-layered geometric mesh representation. 3D photos can be stored compactly and are optimized for being rendered from viewpoints that are near the capture viewpoints. They can be rendered using a standard rasterization pipeline to produce perspective views with motion parallax. When viewed in VR, 3D photos provide geometrically consistent views for both eyes. Our geometric representation also allows interacting with the scene using 3D geometry-aware effects, such as adding new objects to the scene and artistic lighting effects. Our 3D photo reconstruction algorithm starts with a standard structure from motion and multi-view stereo reconstruction of the scene. The dense stereo reconstruction is made robust to the imperfect capture conditions using a novel near envelope cost volume prior that discards erroneous near depth hypotheses. We propose a novel parallax-tolerant stitching algorithm that warps the depth maps into the central panorama and stitches two color-and-depth panoramas for the front and back scene surfaces. The two panoramas are fused into a single non-redundant, well-connected geometric mesh. We provide videos demonstrating users interactively viewing and manipulating our 3D photos

Design and application of an automated system for camera photogrammetric calibration

This work presents the development of a novel Automatic Photogrammetric Camera Calibration System (APCCS) that is capable of calibrating cameras, regardless of their Field of View (FOV), resolution and sensitivity spectrum. Such calibrated cameras can, despite lens distortion, accurately determine vectors in a desired reference frame for any image coordinate, and map points in the reference frame to their corresponding image coordinates. The proposed system is based on a robotic arm which presents an interchangeable light source to the camera in a sequence of known discrete poses. A computer captures the camera's image for each robot pose and locates the light source centre in the image for each point in the sequence. Careful selection of the robot poses allows cost functions dependant on the captured poses and light source centres to be formulated for each of the desired calibration parameters. These parameters are the Brown model parameters to convert from the distorted to the undistorted image (and vice versa), the focal length, and the camera's pose. The pose is split into the camera pose relative to its mount and the mount's pose relative to the reference frame to aid subsequent camera replacement. The parameters that minimise each cost function are deter- mined via a combination of coarse global and fine local optimisation techniques: genetic algorithms and the Leapfrog algorithm, respectively. The real world applicability of the APCCS is assessed by photogrammetrically stitching cameras of differing resolutions, FOVs and spectra into a single multi- spectral panorama. The quality of these panoramas are deemed acceptable after both subjective and quantitative analyses. The quantitative analysis compares the stitched position of matched image feature pairs found with the Shape Invariant Feature Tracker (SIFT) and Speeded Up Robust Features (SURF) algorithms and shows the stitching to be accurate to within 0.3°. The noise sensitivity of the APCCS is assessed via the generation of synthetic light source centres and robot poses. The data is realistically created for a hy- pothetical camera pair via the corruption of ideal data using seven noise sources emulating the robot movement, camera mounting and image processing errors. The calibration and resulting stitching accuracies are shown to be largely independent of the noise magnitudes in the operational ranges tested. The APCCS is thus found to be robust to noise. The APCCS is shown to meet all its requirements by determining a novel combination of calibration parameters for cameras regardless of their properties in a noise resilient manner

Science related information in European television: a study of prime-time news

According to the few studies carried out on this subject, in spite of its importance and interest for the audience, science has been a marginal topic in television news, and has presented several problems of quality. This article presents the main results of a comparative research on science in European television, focusing on the main prime-time news programs of the leading public and the leading commercial channel, in the five largest countries. A sample of two weeks (2676 stories) was analyzed, with an outcome of 218 science related stories, which were coded (topic, length, explicit news values, contextual information and scientific explanation). Results indicate that the number and airtime of science related stories have increased, compared to a decade ago, but still do not seem to match the interest that citizens declare to have in science. The quality of the information broadcast seems relatively acceptable, although it still needs to be improved in some aspects, for which new formats of news programs would be helpful

Biochemical and structural features of the catalytic domain of cellulase CelE2 and its relation with the Calx-beta accessory domain

Orientadores: Fabio Marcio Squina, Thabata Maria AlvarezDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de BiologiaResumo: As glicosil hidrolases (GHs) compõem uma classe de enzimas amplamente utilizadas nos processos enzimáticos por atuarem na hidrólise das ligações glicosídicas de polissacarídeos. Além do domínio catalítico, diversas GHs apresentam domínios acessórios que podem influenciar diversos aspectos bioquímicos e estruturais das enzimas. A celulase CelE2 de origem metagenômica, caracterizada recentemente, apresenta em sua estrutura um domínio catalítico N-terminal característico da família GH5 e um domínio C-terminal com identidade para o domínio Calx-beta, previamente identificado em outras GHs mas sem função claramente definida nestes casos. Com o intuito de investigar as características bioquímicas e estruturais dos domínios de CelE2 separadamente, foram construídas derivações truncadas referentes ao domínio catalítico e ao domínio acessório Calx-beta. Como resultados, observou-se que a excisão do domínio acessório Calx-beta (CelE2382-477) não provocou alterações nas características bioquímicas de CelE2, visto que o domínio catalítico (CelE21-381) apresentou valores semelhantes de atividade enzimática em beta-glucano, carboximetilcelulose e liquenana, valores de pH e temperatura ótimos próximos de 5,3 e 45 ºC, respectivamente, estabilidade térmica a 40 ºC e 50 ºC por 360 minutos e aumento de atividade enzimática na presença de CaCl2. O perfil de degradação e as evidências de transglicosilação também foram mantidas após a excisão do domínio acessório Calx-beta. No entanto, o domínio catalítico apresentou um aumento de cerca de 4 vezes da atividade enzimática na hidrólise de Avicel, comparado à CelE2. As análises por dicroísmo circular (CD) de CelE21-381 indicaram um perfil predominante de alfa-hélice, diminuição de 4,6 ºC da temperatura de desnaturação e um aumento destes valores na presença de CaCl2, tanto para a construção completa, quanto para CelE21-381. Assim como para CelE2, as análises por espalhamento de raio-X de baixo ângulo (SAXS) mostraram que a adição de CaCl2 resultou na diminuição da tendência de agregação proteica para CelE21-381. Os ensaios de avaliação da ligação a polissacarídeos solúveis e insolúveis indicaram que CelE2382-477 não apresentou capacidade de ligação para os substratos testados. A estrutura tridimensional do domínio catalítico CelE21-381 foi determinada a uma resolução de 2,1 Å que permitiu a identificar um enovelamento do tipo barril (alfa/beta)8. Os resultados obtidos mostraram que a presença do domínio acessório Calx-beta não é fundamental para atividade enzimática de CelE2, de modo que a alteração mais significativa diz respeito ao aumento da atividade enzimática do domínio catalítico em Avicel em comparação à construção completa. Estes resultados contribuirão para estudos futuros acerca deste domínio pouco estudado entre as celulases e informações para a família 5 das GHsAbstract: Glycoside hydrolases (GHs) comprise a class of enzymes widely used in the enzymatic processes, acting in the hydrolysis of the polysaccharides glycosidic bonds. In addition to the catalytic domain, several GHs present accessory domains, which may influence the biochemical and structural aspects of the enzymes. The CelE2, a metagenomic-derived cellulase, recently characterized, harbors in its structure an N-terminal catalytic domain characteristic of the GH5 family, and a C-terminal domain with identity for the Calx-betadomain, previously identified in other glycoside hydrolases but without clearly defined function in these cases. In order to investigate the biochemical and structural characteristics of the CelE2 domains separately, truncated derivations were constructed regarding the catalytic domain and the accessory domain Calx-beta. The results showed that the deletion of Calx-beta domain (CelE2382-477) did not cause alterations in the biochemical characteristics of CelE2, since the catalytic domain (CelE21-381) presented similar values of enzymatic activity in beta-glucan, carboxymethylcellulose and lichenan, optimal pH and temperature values near 5,3 and 45 ºC, respectively, thermal stability at 40 ºC and 50 ºC up to 360 minutes, and increase of enzymatic activity in the presence of CaCl2. The cleavage pattern and evidence of transglycosylation were also maintained after Calx-beta deletion from CelE2. However, the catalytic domain showed a 4-fold increase in the enzymatic activity of Avicel hydrolysis, compared to CelE2. Circular dichroism (CD) analysis of CelE21-381 indicated a predominant alpha-helix profile, decrease in the denaturation temperature around 4.6 ºC and an increase of these values in the presence of CaCl2, both for the complete construct and for CelE21-381. As well as CelE2, small angle X-ray scattering (SAXS) analyzes showed that the addition of CaCl2 resulted in a decrease in the protein aggregation tendency for CelE21-381. The binding assays for soluble and insoluble polysaccharides indicated that CelE2382-477 did not show the binding ability for the substrates tested. The three-dimensional structure of the catalytic domain CelE21-381 was determined at a resolution of 2.1 Å which allowed to identify an (alpha/beta)8 barrel fold. The results showed that the presence of the accessory domain Calx-beta is not fundamental for the enzymatic activity of CelE2, so that the most significant change concerns the increase of the enzymatic activity of the catalytic domain in Avicel, comparing to the whole construct. These results may contribute to future studies about this understudied domain among cellulases and information for the family 5 of glycoside hydrolasesMestradoBioquimicaMestra em Biologia Funcional e Molecular132372/2016-92016/01926-2FAPESPCNP