Data hidding in color images using perceptual models

One of the problems arising from the use of digital media is the ease of identical copies of digital images or audio files, allowing manipulation and unauthorized use. Copyright is an effective tool for preserving intellectual property of those documents but authors and publishers need effective techniques that prevent from copyright modification, due to the straightforward access to multimedia applications and the wider use of digital publications through the www. These techniques are generally called watermarking and allow the introduction of side information (i.e. author identification, copyrights, dates, etc.). This work concentrates on the problem embedding and optimum blind detection of data in color images through the use of spread spectrum techniques, both in space (Direct Sequence Spread Spectrum or DSSS) and frequency (Frequency Hopping). It is applied to RGB and opponent color component representations. Perceptive information is considered in both color systems. Some tests are performed in order to ensure imperceptibility and to assess detection quality of the optimum color detectors.Peer ReviewedPostprint (published version

Soy Niña

Este libro pretende contribuir al reencuentro de la educación con esas finalidades que verdaderamente importan a una niña o un niño: ser feliz, jugar, vivir juntos y (no) aprender. Para ello hemos puesto el arte, nuestras experiencias y el saber acumulado al servicio del disfrute, el cuestionamiento, el análisis crítico y la construcción común de un presente deseable. Un texto colaborativo coordinado por Ignacio Calderón Almendros y realizado por alumnado de Educación y Cambio Social en el Grado en Educación Infantil de la Universidad de Málaga

Joint physical-MAC layer design of the broadcast channel protocol in adhoc networks

Broadcast transmission mode in ad hoc networks is critical to manage multihop routing or providing medium access control (MAC)-layer fairness. In this paper, it is shown that a higher capacity to exchange information among neighbors may be obtained through a physical-MAC cross-layer design of the broadcast protocol exploiting signal separation principles. Coherent detection and separation of contending nodes is possible through training sequences which are selected at random from a reduced set. Guidelines for the design of this set are derived for a low impact on the network performance and the receiver complexity.Peer Reviewe

Joint physical-MAC layer design of the broadcast channel protocol in adhoc networks

Broadcast transmission mode in ad hoc networks is critical to manage multihop routing or providing medium access control (MAC)-layer fairness. In this paper, it is shown that a higher capacity to exchange information among neighbors may be obtained through a physical-MAC cross-layer design of the broadcast protocol exploiting signal separation principles. Coherent detection and separation of contending nodes is possible through training sequences which are selected at random from a reduced set. Guidelines for the design of this set are derived for a low impact on the network performance and the receiver complexity.Peer Reviewe

Joint physical-MAC layer design of the broadcast channel protocol in adhoc networks

Broadcast transmission mode in ad hoc networks is critical to manage multihop routing or providing medium access control (MAC)-layer fairness. In this paper, it is shown that a higher capacity to exchange information among neighbors may be obtained through a physical-MAC cross-layer design of the broadcast protocol exploiting signal separation principles. Coherent detection and separation of contending nodes is possible through training sequences which are selected at random from a reduced set. Guidelines for the design of this set are derived for a low impact on the network performance and the receiver complexity.Peer Reviewe

Data hidding in color images using perceptual models

One of the problems arising from the use of digital media is the ease of identical copies of digital images or audio files, allowing manipulation and unauthorized use. Copyright is an effective tool for preserving intellectual property of those documents but authors and publishers need effective techniques that prevent from copyright modification, due to the straightforward access to multimedia applications and the wider use of digital publications through the www. These techniques are generally called watermarking and allow the introduction of side information (i.e. author identification, copyrights, dates, etc.). This work concentrates on the problem embedding and optimum blind detection of data in color images through the use of spread spectrum techniques, both in space (Direct Sequence Spread Spectrum or DSSS) and frequency (Frequency Hopping). It is applied to RGB and opponent color component representations. Perceptive information is considered in both color systems. Some tests are performed in order to ensure imperceptibility and to assess detection quality of the optimum color detectors.Peer Reviewe