Regiones salientes complejas para aplicaciones de seguimiento facial

Este trabajo presenta una metodología para detectar y realizar el seguimiento de características faciales. En el primer paso del procedimiento se detectan caras mediante Adaboost con cascadas de clasificadores débiles. El segundo paso busca las características internas de la cara mediante el CSR, detectando zonas de interés. Una vez que estas características se capturan, un proceso de tracking basado en el descriptor SIFT, que hemos llamado pseudo-SIFT, es capaz de guardar información sobre la evolución de movimiento en las regiones detectadas. Además, un conjunto de datos públicos ha sido desarrollado con el propósito de compartirlo con otras investigaciones sobre detección, clasificación y tracking. Experimentos reales muestran la robustez de este trabajo y su adaptabilidad para trabajos futuros.

Papel de la Interleucina 6 (IL-6) en la regulación de la expresión de Osteopontina (OPN) y CD44 tras axotomía del nervio facial

Investigación producida a partir de una estancia en la University of Sidney, Australia, entre octubre del 2008 y enero del 2009. Se ha desarrollado el proyecto titulado "Papel de la interleucina 6 (IL6) en la regulación de la expresión de Osteopontina (OPN) y de CD44 tras axotomía del nervio facial". Tras efectuar una transección del nervio facial, se indujo una reactividad glial en el núcleo facial (NF) localizado en el tronco cerebral, utilizando ratones transgénicos que sobrexpresan IL6 bajo promotor GFAP (tg GFAP-IL6), es decir selectivamente en astrocitos. Se han utilizado técnicas histoquímicas e inmunohistoquímicas, así como también se ha completado el estudio utilizando análisis de RPA, western blotting y citometría de flujo para la identificación de poblaciones celulares. Los resultados obtenidos indican que la OPN se expresa constitutivamente en las neuronas del NF. Tras axotomía del nervio facial, la expresión de OPN y CD44 incrementa en los ratones WT, mientras que en los tg GFAP-IL6 disminuye significativamente, sugiriendo que la IL6 podría estar involucrada en la modulación de la expresión de ambas moléculas. Sin embargo, no se ha visto diferencias en otros receptores de OPN como la integrina Alpha-5. La ctometría de flujo corroboró algunos de los resultados histológicos sobre la reactividad microglial y permitió concluir que la proporción de microglía activada (CD11b+/CD45+mid) y macrófagos (CD11b+/CD45+high) que expresan CD44 incrementa en in los tg GFAP-IL6 versus WT donde la mayor parte de microglia activada mostraba un perfil CD11b+/CD45+low.

Control de accesos mediante reconocimiento facial

En esta memoria expone el trabajo que se ha llevado a cabo para intentar crear un sistema de reconocimiento facial.

Reconeixement facial en obres d'art : avaluació del rendiment dels mètodes de l'estat de l'art actual

Aquest paper es divideix en 3 parts fonamentals, la primera relata el que pretén mostrar aquest estudi, que és aplicar els sistemes actuals de reconeixement facial en una base de dades d'obres d'art. Explica quins mètodes s'utilitzaran i perquè es interessant realitzar aquest estudi. La segona passa a mostrar el detall de les dades obtingudes en l'experiment, amb imatges i gràfics que facilitaran la comprensió. I en l'última part tenim la discussió dels resultats obtinguts en l'anàlisi i les seves posteriors conclusions.

Estudi i implementació de tècniques de reconeixement facial

Estudi i implementació de les tècniques de reconeixement facial més conegudes: eigenfaces, fisherfaces i ASM. El resultat és una aplicació implementada en Matalab que permet realitzar el reconeixement de persones en temps real.

Automatic Prediction of Facial Trait Judgments: Appearance vs. Structural Models

Evaluating other individuals with respect to personality characteristics plays a crucial role in human relations and it is the focus of attention for research in diverse fields such as psychology and interactive computer systems. In psychology, face perception has been recognized as a key component of this evaluation system. Multiple studies suggest that observers use face information to infer personality characteristics. Interactive computer systems are trying to take advantage of these findings and apply them to increase the natural aspect of interaction and to improve the performance of interactive computer systems. Here, we experimentally test whether the automatic prediction of facial trait judgments (e.g. dominance) can be made by using the full appearance information of the face and whether a reduced representation of its structure is sufficient. We evaluate two separate approaches: a holistic representation model using the facial appearance information and a structural model constructed from the relations among facial salient points. State of the art machine learning methods are applied to a) derive a facial trait judgment model from training data and b) predict a facial trait value for any face. Furthermore, we address the issue of whether there are specific structural relations among facial points that predict perception of facial traits. Experimental results over a set of labeled data (9 different trait evaluations) and classification rules (4 rules) suggest that a) prediction of perception of facial traits is learnable by both holistic and structural approaches; b) the most reliable prediction of facial trait judgments is obtained by certain type of holistic descriptions of the face appearance; and c) for some traits such as attractiveness and extroversion, there are relationships between specific structural features and social perceptions.

Lack of support for the association between facial shape and aggression: a reappraisal based on a worldwide population genetics perspective

Antisocial and criminal behaviors are multifactorial traits whose interpretation relies on multiple disciplines. Since these interpretations may have social, moral and legal implications, a constant review of the evidence is necessary before any scientific claim is considered as truth. A recent study proposed that men with wider faces relative to facial height (fWHR) are more likely to develop unethical behaviour mediated by a psychological sense of power. This research was based on reports suggesting that sexual dimorphism and selection would be responsible for a correlation between fWHR and aggression. Here we show that 4,960 individuals from 94 modern human populations belonging to a vast array of genetic and cultural contexts do not display significant amounts of fWHR sexual dimorphism. Further analyses using populations with associated ethnographical records as well as samples of male prisoners of the Mexico City Federal Penitentiary condemned by crimes of variable level of inter-personal aggression (homicide, robbery, and minor faults) did not show significant evidence, suggesting that populations/individuals with higher levels of bellicosity, aggressive behaviour, or power-mediated behaviour display greater fWHR. Finally, a regression analysis of fWHR on individual"s fitness showed no significant correlation between this facial trait and reproductive success. Overall, our results suggest that facial attributes are poor predictors of aggressive behaviour, or at least, that sexual selection was weak enough to leave a signal on patterns of between- and within-sex and population facial variation.

The relative salience of facial features when differentiating faces based on an interference paradigm

Research on face recognition and social judgment usually addresses the manipulation of facial features (eyes, nose, mouth, etc.). Using a procedure based on a Stroop-like task, Montepare and Opeyo (J Nonverbal Behav 26(1):43-59, 2002) established a hierarchy of the relative salience of cues based on facial attributes when differentiating faces. Using the same perceptual interference task, we established a hierarchy of facial features. Twenty-three participants (13 men and 10 women) volunteered for the experiment to compare pairs of frontal faces. The participants had to judge if the eyes, nose, mouth and chin in the pair of images were the same or different. The factors manipulated were the target-distractive factor (4 face components 9 3 distractive factors), interference (absent vs. present) and correct answer (the same vs. different). The analysis of reaction times and errors showed that the eyes and mouth were processed before the chin and nose, thus highlighting the critical importance of the eyes and mouth, as shown by previous research.

Reducción del vector de características de reconocimiento facial

In this present work, we are proposing a characteristics reduction system for a facial biometric identification system, using transformed domains such as discrete cosine transformed (DCT) and discrete wavelets transformed (DWT) as parameterization; and Support Vector Machines (SVM) and Neural Network (NN) as classifiers. The size reduction has been done with Principal Component Analysis (PCA) and with Independent Component Analysis (ICA). This system presents a similar success results for both DWT-SVM system and DWT-PCA-SVM system, about 98%. The computational load is improved on training mode due to the decreasing of input’s size and less complexity of the classifier.

Lower incisor dentoalveolar compensation and symphysis dimensions among Class I and III malocclusion patients with different facial vertical skeletal patterns

Objective: To compare lower incisor dentoalveolar compensation and mandible symphysis morphology among Class I and Class III malocclusion patients with different facial vertical skeletal patterns. Materials and Methods: Lower incisor extrusion and inclination, as well as buccal (LA) and lingual (LP) cortex depth, and mandibular symphysis height (LH) were measured in 107 lateral cephalometric x-rays of adult patients without prior orthodontic treatment. In addition, malocclusion type (Class I or III) and facial vertical skeletal pattern were considered. Through a principal component analysis (PCA) related variables were reduced. Simple regression equation and multivariate analyses of variance were also used. Results: Incisor mandibular plane angle (P < .001) and extrusion (P  =  .03) values showed significant differences between the sagittal malocclusion groups. Variations in the mandibular plane have a negative correlation with LA (Class I P  =  .03 and Class III P  =  .01) and a positive correlation with LH (Class I P  =  .01 and Class III P  =  .02) in both groups. Within the Class III group, there was a negative correlation between the mandibular plane and LP (P  =  .02). PCA showed that the tendency toward a long face causes the symphysis to elongate and narrow. In Class III, alveolar narrowing is also found in normal faces. Conclusions: Vertical facial pattern is a significant factor in mandibular symphysis alveolar morphology and lower incisor positioning, both for Class I and Class III patients. Short-faced Class III patients have a widened alveolar bone. However, for long-faced and normal-faced Class III, natural compensation elongates the symphysis and influences lower incisor position.

Estudio de las técnicas de reconocimiento facial en obras de arte a través de la visión por computador

El objetivo de esta investigación es comprobar la utilidad de las técnicas actuales de reconocimiento facial a través de la visión por computador en entornos museísticos. Para alcanzar este fin, he seguido las estrategias de diseño y creación para crear una aplicación que me permita posteriormente realizar una serie de experimentos, los cuales me proporcionarán los datos necesarios con los que evaluar la funcionalidad de estas técnicas existentes en obras de arte, en mi caso concretamente, sobre cuadros.