Projection distortion analysis for flattened image mosaicing from straight uniform generalized cylinders

This paper presents a new approach for reconstructing images mapped or painted on straight uniform generalized cylinders (SUGC). A set of monocular images is taken from different viewpoints in order to be mosaiced and to represent the entire scene in detail. The expressions of the SUGC's projection axis are derived from two cross-sections projected onto the image plane. Based on these axes we derive the SUGC localization in the camera coordinate system. We explain how we can find a virtual image representation when the intersection of the two axes is matched to the image center. We analyze the perspective distortions when flattening a scene which is mapped on a SUGC. We evaluate the lower and the upper bounds of the necessary number of views in order to represent the entire scene from a SUGC, by considering the distortions produced by perspective projection. A region matching based mosaicing method is proposed to be applied on the flattened images in order to obtain the complete scene. The mosaiced scene is visualized on a new synthetic surface by a mapping procedure. The proposed algorithm is used for the representation of mural paintings located on SUGCs with closed cross-sections (circles for columns), or opened cross-sections (ellipses or parabolas for vaults). (C) 2001 Pattern Recognition Society. Published by Elsevier Science Ltd. All rights reserved

Binary image decomposition applied to a submarine sweeping pattern problem

This paper describes geometrical methods of binary image decompositton . These images are characterized by a complex architecture and the proposcd method uses a graph environnent to connect elementary structures . The application concerns the elaboration of the trajectory of a mining system for the industrial recovery of nodules . Différent sweeping patterns are proposed in illustrations .Méthodes géométriques de décomposition d'images binaires d'architecture complexe. La décomposition est effectuée à l'aide de structures dans un environnement de graphe d'interprétatio

Effects of vacuum packaging on the physical quality of minimally processed potatoes

In recent years, consumers have become more health conscious in their food choices but they also have less time to prepare healthy meals. As a result, minimally processed (MP) products have become an important sector of the food industry because of their ‘fresh-like’ qualities, convenience and speed of meal preparation. In this study, the physical qualities of MP potatoes (‘Désirée’ variety) stored for 7 days in vacuum packaging were evaluated. The shelf life of MP potatoes was effectively extended to nearly 1 week under refrigerated storage by using vacuum packaging systems. The main quality parameters were constant during storage

Digital image watermarking: its formal model, fundamental properties and possible attacks

While formal definitions and security proofs are well established in some fields like cryptography and steganography, they are not as evident in digital watermarking research. A systematic development of watermarking schemes is desirable, but at present their development is usually informal, ad hoc, and omits the complete realization of application scenarios. This practice not only hinders the choice and use of a suitable scheme for a watermarking application, but also leads to debate about the state-of-the-art for different watermarking applications. With a view to the systematic development of watermarking schemes, we present a formal generic model for digital image watermarking. Considering possible inputs, outputs, and component functions, the initial construction of a basic watermarking model is developed further to incorporate the use of keys. On the basis of our proposed model, fundamental watermarking properties are defined and their importance exemplified for different image applications. We also define a set of possible attacks using our model showing different winning scenarios depending on the adversary capabilities. It is envisaged that with a proper consideration of watermarking properties and adversary actions in different image applications, use of the proposed model would allow a unified treatment of all practically meaningful variants of watermarking schemes

Architecture of discrete binary images geometrical tools

This paper deals with the presentation of geometric methods used to manipulate discrete binary images, in the aim to perform image understanding . This discussion is based on the use of two methods for representation of an image : by contour and by region . We shah discuss about filtering and methods related to the analysis of the global shape : decomposition and partitionning . We shah notice that shape analysis currently used decomposition processes into simpler entities, completed by a relational graph between the resulting primitives . We will present such a method based on the medial axis transform . This study is justified by a problem of treatment of submarine maps. To solve it, several of the presented methods have been used.On traite les 2 modes de représentation utilisés pour une image, à savoir la représentation par contour et la représentation par région. Procédé de filtrage, de description ou de décomposition de formes en vue d'une interprétation locale ou globale des objets représenté

Design of an industrial catalytic membrane reactor prototype for tritiated gaseous effluent treatment

International audienceIn the framework of gloveboxes tritiated gaseous effluent treatment, efficiency of packed bed membrane reactors has been successfully demonstrated under lab scale. In such an intensified process, tritium from tritiated water can be recovered under the valuable Q2 form (Q = H, D or T) thanks to isotope exchange reactions on catalyst surface. In the meanwhile, the use of permselective Pd-based membrane allows extraction of reactions products all along the reactor, and thus limits reverse reaction rate to the benefit of the direct one (shift effect). In such a process, it is possible to obtain a conversion rate of tritiated water up to nearly 90-95percent and recover tritium under pure mixture of hydrogen isotopes. Based on former experimental studies, a phenomenological model was built to predict the efficiency of a fixed catalytic membrane reactor (CMR) design but this model does not allow optimizing the design of a CMR to reach fixed performance. However, the phenomenological model has given sufficient precise knowledge on the phenomena occurring in the CMR to allow the implementation of a CMR calculation module in the Prosimplus process simulation software environment. This paper describes the transfer step from phenomenological model to chemical process simulation tool and presents the methodology to be used to optimize the design of an industrial CMR under the Prosimplus software environment. The application of the proposed methodology for the design of a CMR for the Tokamak Exhaust Processing system of DEMO is given as an example

Ondigital plane preimage structure

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