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One common drawback of virtually all current data embedding methods is the fact that the original image is inevitably distorted due to data embedding itself. This distortion typically cannot be removed completely due to quantization, bit-replacement, or truncation at the grayscales 0 and 255. Although the distortion is often quite small and perceptual models are used to minimize its visibility, the distortion may not be acceptable for medical imagery (for legal reasons) or for military images inspected under nonstandard viewing conditions (after enhancement or extreme zoom). In this paper, we introduce a new paradigm for data embedding in images (lossless data embedding) that has the property that the distortion due to embedding can be completely removed from the watermarked image after the embedded data has been extracted. We present lossless embedding methods for the uncompressed formats (BMP, TIFF) and for the JPEG format. We also show how the concept of lossless data embedding can be used as a powerful tool to achieve a variety of nontrivial tasks, including lossless authentication using fragile watermarks, steganalysis of LSB embedding, and distortion-free robust watermarking.

La motivation derrière la stéganographie, quand tout est dit, est de rendre la communication privée avec l'objectif final de dissimuler le contenu du message à un intrus. La stéganographie contraste énormément avec la cryptographie de divers points de vue et ses applications vont loin. Dans cet article, la stéganographie est utilisée pour dissimuler des images mystérieuses en utilisant une méthode d'insertion. Ce système peut être utilisé pour des images de toute taille et de tout type, tels que jpeg, tiff, bmp, etc. L’utilisation de la stéganographie dans cet article est extrêmement sécurisée, le but ultime étant que tout étranger ou intrus ne puisse pas penser au contenu des images mystérieuses envoyées. Un autre plan de cryptage et de décodage est utilisé ici. Le calcul pour coder et décoder l’image profite d’une structure de Feistel et prend des contributions à une organisation double, à savoir 1 ou 0. Les résultats de différents exemples fournissent une sécurité élevée et la substance dissimulée ne peut pas être suivie efficacement. The motivation behind steganography when all is said in done is to make acommunication private with the end goal to conceal the message content from a gatecrasher. Steganography by and large contrasts from cryptography from various perspectives and its applications are far reaching. In this paper, steganography is utilized to conceal the mystery picture utilizing an inserting method. This system can be utilized for pictures of any size and types, e.g., jpeg, tiff, bmp and so on. The utilization of steganography in this paper given greatest security with the end goal that any outsider or gatecrasher can't think about what mystery picture content was sent. An alternate encryption and decoding plans are utilized here. The calculation utilized for encoding and decoding the picture utilizes a Feistel structure and it takes contributions to twofold organization i.e., 1 or 0. The results of different examples furnish security with high proficiency and the concealed substance isn't effectively traceable.

En este artículo se muestra el desarrollo de un modelo conceptual del tipo new economics geography de dos ciudades; este modelo ayuda a analizar cómo la importancia relativa (peso) que los individuos asignan a las economías y las deseconomías de aglomeración afectan los lugares en los que se celebran actividades económicas. Se muestra que el peso asignado a las externalidades puede cambiar drásticamente la localización poblacional. Se ilustra la importancia de cuantificar la magnitud de estas externalidades, y cómo su incorporación simultánea en los análisis de sistemas urbanos puede evitar conclusiones engañosas. I develop a New Economics Geography model of two-cities, to analyse how the relative importance (weight) that individuals assign to agglomeration economies and diseconomies affects the places where economic activities take place. It is shown that the weight assigned to externalities can drastically change the population location. We illustrate the importance of quantifying the magnitude of these externalities, and how urban systems analysis that simultaneously incorporates agglomeration effects can avoid misleading conclusions.

Purpose The aim of this study was to assess the body weight-tailored contrast material injection protocol for 64-detector computed tomography (CT) to maintain optimal coronary CT attenuation. Materials and methods A total of 60 patients who underwent CT coronary angiography were assigned to one of three groups: protocol A, total of 0.7 ml kg −1 with 300 mg I/ml iodine concentration; protocol B, total of 0.6 ml kg −1 with 350 mg I/ml; protocol C, total of 0.7 ml kg −1 with 350 mg I/ml. The injection duration was 10 s in all patients. The proportion of intracoronary attenuation values >325 HU was compared on a pervessel and per-patient basis. Results The attenuation value was significantly more likely to exceed 325 HU with protocol C (95% for reader 1 and 90% for reader 2) than with protocol A or B on the per-vessel analysis ( P < 0.05). The attenuation value also signifi cantly exceeded 325 HU with protocol C (95% and 90%, respectively) more often than with protocol A or B on the per-patient analysis ( P < 0.05). Conclusion A total of at least 0.7 ml kg −1 contrast material with 350 mg/ml iodine concentration is required to achieve optimal coronary CT attenuation (>325 HU) with 64-detector CT when using an injection duration of 10 s.

A cladistic analysis of the saprophytic genus Voyria Aubl. (Gentianaceae) was performed to evaluate infrageneric classification, character evolution, and biogeography. A matrix of 19 species of Voyria and 39 morphological characters yielded three most-parsiomonious trees, one of which was identical to their strict consensus. The major division within Voyria based on character support is also the rooting point suggested by a larger cladistic analysis of gentians. We have chosen to treat these distinct clades as two new subgenera, Voyria subgen. Voyria Aubl. and Voyria subgen. Leiphaimos (Schltdl. & Cham.) V. A. Albert & L. Struwe, stat. nov. Concerning character evolution, Voyria subgen. Voyria (5 spp.) is the most similar to other Gentianaceae. The saprophytic condition is more advanced in Voyria subgen. Leiphaimos (14 spp.), in which stomates and a continuous vascular cylinder are lacking. Within subgen. Leiphaimos, trends toward extreme vascular rediction and wind-mediated seed dispersal are evident. The extensive character evolution observed within Voyria as a whole may correlate with relaxation of autotrophic structural constraints. Optimization of an area of distribution character on the cladograms obtained suggests that Guayana (and therefore northern South America) may represent the most ancestral area for extant Voyria.