Gilberto Arantes Carrijo

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Wireless mesh network are very vulnerable to attacks by malicious users due to, mainly, the cooperation among their nodes. The methods for detection of attacks are grouped into two categories: analysis of anomalies and signatures. The former detects possible new attacks, which have not been previously discovered and the latter depends on prior knowledge to(More)
This work aims to evaluate how does the performance of the iris localization algorithms is influenced by severe compression of eye images used in an automatic iris recognition system. The correct localization of the iris region is essential to guarantee the credibility of the biometric recognition. As it is the first processing stage of the system, it is(More)
This paper describes a new single-image super-resolution algorithm based on sparse representations with image structure constraints. A structure tensor based regularization is introduced in the sparse approximation in order to improve the sharpness of edges. The new formulation allows reducing the ringing artefacts which can be observed around edges(More)
The visualization of a computerized tomographic (TC) exam in 3D increases the quality of the medical diagnosis and, consequently, the success probability in the treatment. To obtain a high quality image it is necessary to obtain slices which are close to one another. Motivated towards the goal of reaching an improved balance between quantity of slices and(More)
A very common problem in forestry is the realization of the forest inventory. The forest inventory is very important because it allows the trading of medium- and long-term timber to be extracted. On completion , the inventory is necessary to measure different diameters and total height to calculate their volumes. However, due to the high number of trees and(More)