Techniques for Ocular Biometric Recognition Under Non-ideal Conditions

The use of the ocular region as a biometric cue has gained considerable traction due to recent advances in automated iris recognition. However, a multitude of factors can negatively impact ocular recognition performance under unconstrained conditions (e.g., non-uniform illumination, occlusions, motion blur, image resolution, etc.). This dissertation develops techniques to perform iris and ocular recognition under challenging conditions. The first contribution is an image-level fusion scheme to improve iris recognition performance in low-resolution videos. Information fusion is facilitated by the use of Principal Components Transform (PCT), thereby requiring modest computational efforts. The proposed approach provides improved recognition accuracy when low-resolution iris images are compared against high-resolution iris images. The second contribution is a study demonstrating the effectiveness of the ocular region in improving face recognition under plastic surgery. A score-level fusion approach that combines information from the face and ocular regions is proposed. The proposed approach, unlike other previous methods in this application, is not learning-based, and has modest computational requirements while resulting in better recognition performance. The third contribution is a study on matching ocular regions extracted from RGB face images against that of near-infrared iris images. Face and iris images are typically acquired using sensors operating in visible and near-infrared wavelengths of light, respectively. To this end, a sparse representation approach which generates a joint dictionary from corresponding pairs of face and iris images is designed. The proposed joint dictionary approach is observed to outperform classical ocular recognition techniques. In summary, the techniques presented in this dissertation can be used to improve iris and ocular recognition in practical, unconstrained environments

Beauty3DFaceNet:Deep geometry and texture fusion for 3D facial attractiveness prediction

We present Beauty3DFaceNet, the first deep convolutional neural network to predict attractiveness on 3D faces with both geometry and texture information. The proposed network can learn discriminative and complementary 2D and 3D facial features, allowing accurate attractiveness prediction for 3D faces. The main component of our network is a fusion module that fuses geometric features and texture features. We further employ a novel sampling strategy for our network based on a prior of facial landmarks, which improves the performance of learning aesthetic features from a face point cloud. Comparing to previous work, our approach takes full advantage of 3D geometry and 2D texture and does not rely on handcrafted features based on highly accurate facial characteristics such as feature points. To facilitate 3D facial attractiveness research, we also construct the first 3D face dataset ShadowFace3D, which contains 6,000 high-quality 3D faces with attractiveness labeled by human annotators. Extensive quantitative and qualitative evaluations show that Beauty3DFaceNet achieves a significant correlation with the average human ratings. This validates that a deep learning network can effectively learn and predict 3D facial attractiveness.</p

Aging effects in automated face recognition

The main objective of this work was to analyze the effects of aging on the automated face recognition process. A dataset was used to perform experiments and obtain indicators to measure the impact of aging. To compare the effects of aging the dataset was segmented based on the age difference between the subjects’ face images. The image quality metrics were also part of the analysis performed in this study. The results of the experiments shown that the higher the gap between the images, the higher the error rates. These were the expected results and it is consistent with other experiments performed in the past. The False Rejection Rate (FRR) was measured at 1%, 0.1%, and 0.01% False Acceptance Rate (FAR) obtaining the similar output as the gap between the images increased

Computer analysis of face beauty: a survey

The human face conveys to other human beings, and potentially to computer systems, information such as identity, intentions, emotional and health states, attractiveness, age, gender and ethnicity. In most cases analyzing this information involves the computer science as well as the human and medical sciences. The most studied multidisciplinary problems are analyzing emotions, estimating age and modeling aging effects. An emerging area is the analysis of human attractiveness. The purpose of this paper is to survey recent research on the computer analysis of human beauty. First we present results in human sciences and medicine pointing to a largely shared and data-driven perception of attractiveness, which is a rationale of computer beauty analysis. After discussing practical application areas, we survey current studies on the automatic analysis of facial attractiveness aimed at: i) relating attractiveness to particular facial features; ii) assessing attractiveness automatically; iii) improving the attractiveness of 2D or 3D face images. Finally we discuss open problems and possible lines of research

Advanced Techniques for Face Recognition under Challenging Environments

Automatically recognizing faces captured under uncontrolled environments has always been a challenging topic in the past decades. In this work, we investigate cohort score normalization that has been widely used in biometric verification as means to improve the robustness of face recognition under challenging environments. In particular, we introduce cohort score normalization into undersampled face recognition problem. Further, we develop an effective cohort normalization method specifically for the unconstrained face pair matching problem. Extensive experiments conducted on several well known face databases demonstrate the effectiveness of cohort normalization on these challenging scenarios. In addition, to give a proper understanding of cohort behavior, we study the impact of the number and quality of cohort samples on the normalization performance. The experimental results show that bigger cohort set size gives more stable and often better results to a point before the performance saturates. And cohort samples with different quality indeed produce different cohort normalization performance. Recognizing faces gone after alterations is another challenging problem for current face recognition algorithms. Face image alterations can be roughly classified into two categories: unintentional (e.g., geometrics transformations introduced by the acquisition devide) and intentional alterations (e.g., plastic surgery). We study the impact of these alterations on face recognition accuracy. Our results show that state-of-the-art algorithms are able to overcome limited digital alterations but are sensitive to more relevant modifications. Further, we develop two useful descriptors for detecting those alterations which can significantly affect the recognition performance. In the end, we propose to use the Structural Similarity (SSIM) quality map to detect and model variations due to plastic surgeries. Extensive experiments conducted on a plastic surgery face database demonstrate the potential of SSIM map for matching face images after surgeries