Image-based family verification in the wild

Facial image analysis has been an important subject of study in the communities of pat- tern recognition and computer vision. Facial images contain much information about the person they belong to: identity, age, gender, ethnicity, expression and many more. For that reason, the analysis of facial images has many applications in real world problems such as face recognition, age estimation, gender classification or facial expression recognition. Visual kinship recognition is a new research topic in the scope of facial image analysis. It is essential for many real-world applications. However, nowadays there exist only a few practical vision systems capable to handle such tasks. Hence, vision technology for kinship-based problems has not matured enough to be applied to real- world problems. This leads to a concern of unsatisfactory performance when attempted on real-world datasets. Kinship verification is to determine pairwise kin relations for a pair of given images. It can be viewed as a typical binary classification problem, i.e., a face pair is either related by kinship or it is not. Prior research works have addressed kinship types for which pre-existing datasets have provided images, annotations and a verification task protocol. Namely, father-son, father-daughter, mother-son and mother-daughter. The main objective of this Master work is the study and development of feature selection and fusion for the problem of family verification from facial images. To achieve this objective, there is a main tasks that can be addressed: perform a compara- tive study on face descriptors that include classic descriptors as well as deep descriptors. The main contributions of this Thesis work are: 1. Studying the state of the art of the problem of family verification in images. 2. Implementing and comparing several criteria that correspond to different face rep- resentations (Local Binary Patterns (LBP), Histogram Oriented Gradients (HOG), deep descriptors)

Contributions on Automatic Recognition of Faces using Local Texture Features

Uno de los temas más destacados del área de visión artifical se deriva del análisis facial automático. En particular, la detección precisa de caras humanas y el análisis biométrico de las mismas son problemas que han generado especial interés debido a la gran cantidad de aplicaciones que actualmente hacen uso de estos mecnismos. En esta Tesis Doctoral se analizan por separado los problemas relacionados con detección precisa de caras basada en la localización de los ojos y el reconomcimiento facial a partir de la extracción de características locales de textura. Los algoritmos desarrollados abordan el problema de la extracción de la identidad a partir de una imagen de cara ( en vista frontal o semi-frontal), para escenarios parcialmente controlados. El objetivo es desarrollar algoritmos robustos y que puedan incorpararse fácilmente a aplicaciones reales, tales como seguridad avanzada en banca o la definición de estrategias comerciales aplicadas al sector de retail. Respecto a la extracción de texturas locales, se ha realizado un análisis exhaustivo de los descriptores más extendidos; se ha puesto especial énfasis en el estudio de los Histogramas de Grandientes Orientados (HOG features). En representaciones normalizadas de la cara, estos descriptores ofrecen información discriminativa de los elementos faciales (ojos, boca, etc.), siendo robustas a variaciones en la iluminación y pequeños desplazamientos. Se han elegido diferentes algoritmos de clasificación para realizar la detección y el reconocimiento de caras, todos basados en una estrategia de sistemas supervisados. En particular, para la localización de ojos se ha utilizado clasificadores boosting y Máquinas de Soporte Vectorial (SVM) sobre descriptores HOG. En el caso de reconocimiento de caras, se ha desarrollado un nuevo algoritmo, HOG-EBGM (HOG sobre Elastic Bunch Graph Matching). Dada la imagen de una cara, el esquema seguido por este algoritmo se puede resumir en pocos pasos: en una primera etapa se extMonzó Ferrer, D. (2012). Contributions on Automatic Recognition of Faces using Local Texture Features [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/16698Palanci

Unifying the Visible and Passive Infrared Bands: Homogeneous and Heterogeneous Multi-Spectral Face Recognition

Face biometrics leverages tools and technology in order to automate the identification of individuals. In most cases, biometric face recognition (FR) can be used for forensic purposes, but there remains the issue related to the integration of technology into the legal system of the court. The biggest challenge with the acceptance of the face as a modality used in court is the reliability of such systems under varying pose, illumination and expression, which has been an active and widely explored area of research over the last few decades (e.g. same-spectrum or homogeneous matching). The heterogeneous FR problem, which deals with matching face images from different sensors, should be examined for the benefit of military and law enforcement applications as well. In this work we are concerned primarily with visible band images (380-750 nm) and the infrared (IR) spectrum, which has become an area of growing interest.;For homogeneous FR systems, we formulate and develop an efficient, semi-automated, direct matching-based FR framework, that is designed to operate efficiently when face data is captured using either visible or passive IR sensors. Thus, it can be applied in both daytime and nighttime environments. First, input face images are geometrically normalized using our pre-processing pipeline prior to feature-extraction. Then, face-based features including wrinkles, veins, as well as edges of facial characteristics, are detected and extracted for each operational band (visible, MWIR, and LWIR). Finally, global and local face-based matching is applied, before fusion is performed at the score level. Although this proposed matcher performs well when same-spectrum FR is performed, regardless of spectrum, a challenge exists when cross-spectral FR matching is performed. The second framework is for the heterogeneous FR problem, and deals with the issue of bridging the gap across the visible and passive infrared (MWIR and LWIR) spectrums. Specifically, we investigate the benefits and limitations of using synthesized visible face images from thermal and vice versa, in cross-spectral face recognition systems when utilizing canonical correlation analysis (CCA) and locally linear embedding (LLE), a manifold learning technique for dimensionality reduction. Finally, by conducting an extensive experimental study we establish that the combination of the proposed synthesis and demographic filtering scheme increases system performance in terms of rank-1 identification rate

Gender and Ethnicity Classification Using Partial Face in Biometric Applications

As the number of biometric applications increases, the use of non-ideal information such as images which are not strictly controlled, images taken covertly, or images where the main interest is partially occluded, also increases. Face images are a specific example of this. In these non-ideal instances, other information, such as gender and ethnicity, can be determined to narrow the search space and/or improve the recognition results. Some research exists for gender classification using partial-face images, but there is little research involving ethnic classifications on such images. Few datasets have had the ethnic diversity needed and sufficient subjects for each ethnicity to perform this evaluation. Research is also lacking on how gender and ethnicity classifications on partial face are impacted by age. If the extracted gender and ethnicity information is to be integrated into a larger system, some measure of the reliability of the extracted information is needed. This study will provide an analysis of gender and ethnicity classification on large datasets captured by non-researchers under day-to-day operations using texture, color, and shape features extracted from partial-face regions. This analysis will allow for a greater understanding of the limitations of various facial regions for gender and ethnicity classifications. These limitations will guide the integration of automatically extracted partial-face gender and ethnicity information with a biometric face application in order to improve recognition under non-ideal circumstances. Overall, the results from this work showed that reliable gender and ethnic classification can be achieved from partial face images. Different regions of the face hold varying amount of gender and ethnicity information. For machine classification, the upper face regions hold more ethnicity information while the lower face regions hold more gender information. All regions were impacted by age, but the eyes were impacted the most in texture and color. The shape of the nose changed more with respect to age than any of the other regions