Berk Gokberk

MEF University · Computer Engineering Department

Recovery of 3D human pose from cameras has been the subject of intensive research in the last decade. Algorithms that can estimate the 3D pose from a single image have been developed. At the same time, many camera environments have an array of cameras. In this paper, after aligning the poses obtained from single images using Procrustes Analysis, me...

Recognition of non-manual components in sign language has been a neglected topic, partly due to the absence of annotated non-manual sign datasets. We have collected a dataset of videos with non-manual signs, displaying facial expressions and head movements and prepared frame-level annotations. In this paper, we present the Turkish Sign Language (TS...

This paper proposes using the state of the art 2D facial landmark localization method, Supervised Descent Method (SDM), for facial landmark localization in 3D depth images. The proposed method was evaluated on frontal faces with no occlusion from the Bosphorus 3D Face Database. In the experiments, in which 2D features were used to train SDM, the pr...

Face is a highly utilized biometric, and 3D modality is preferred due to better handling of variations such as pose and illumination. However, occlusions covering the face alter the 3D surface and degrade the recognition performance. To improve recognition rates, the occluded parts should be detected prior to any surface comparison. In this paper,...

A basic idea of the present invention is to selectively employ one of at least two different feature extraction processes when generating a biometric template of an individual. An individual offers a physiological property, such as a fingerprint, an iris, an ear, a face, etc., from which biometric data can be derived, to a sensor of an enrollment a...

The face is one of the most natural biometrics, and as such, its acceptance by users is high. While biometrics such as fingerprint and iris can only be acquired with active cooperation of the user, the face can be acquired from a distance. This makes it an attractive modality for uncooperative scenarios. However, in such scenarios, occlusion is a c...

With advances in sensor technology, the three-dimensional (3-D) face has become an emerging biometric modality, preferred especially in high security applications. However, dealing with occlusions covering the facial surface is a great challenge, which should be handled to enable applicability to fully automatic security systems. In this paper, we...

Occlusions over facial surfaces cause performance degradation for face registration and recognition systems. In this work, we propose an occlusion-resistant three-dimensional face registration method. First, the nose area is detected on a probe face using curvedness-weighted convex shape index map. Then, probable eye and mouth patches are detected...

Facial occlusions pose significant problems for automatic face recognition systems. In this work, we propose a novel occlusion-resistant three-dimensional (3D) facial identification system. We show that, under extreme occlusions due to hair, hands, and eyeglasses, typical D face recognition systems exhibit poor performance. In order to deal with oc...

We evaluate the performance of face recognition algorithms on images at various resolutions. Then we show to what extent super-resolution (SR) methods can improve the recognition performance when comparing low-resolution (LR) to high-resolution (HR) facial images. Our experiments use both synthetic data (from the FRGC v1.0 database) and surveillanc...

Occlusions complicate the process of identifying individuals us- ing their 3D facial scans. We propose a D face recognition system that automatically removes occlusion artifacts and iden- tifies the facial image using regional classifiers. Automatic lo- calization of occluded areas is handled by using a generic face model. Restoration of missing in...

Biometric identification from three-dimensional (3-D) facial surface characteristics has become popular, especially in high security applications. In this paper, we propose a fully automatic expression insensitive 3-D face recognition system. Surface deformations due to facial expressions are a major problem in 3-D face recognition. The proposed ap...

In this work, we propose a fully automatic pose and expression invariant part-based D face recognition system. The proposed system is based on pose correction and curvature-based nose segmentation. Since the nose is the most stable part of the face, it is largely invariant under expressions. For this reason, we have concentrated on locating the nos...

Registration plays a vital role in 3D face recognition. In the registration phase, some fiducial points are needed. In this paper, a method is proposed to automatically localize landmark points. In addition, the performance of registration is affected by deformations caused by expression variations. It is asserted that regional registration and rec...

Three-dimensional human facial surface information is a powerful biometric modality that has potential to improve the identification and/or verification accuracy of face recognition systems under challenging situations. In the presence of illumination, expression and pose variations, traditional 2D image-based face recognition algorithms usually en...

Abstract 3D face recognition has received a lot of attention in the last decade, leading to improved sensors and algorithms that promise to enable large-scale deployment of biometric systems that rely on this modality. This chapter discusses advances in 3D face recognition with respect to current research and technology trends, together with its op...

Three-dimensional (3D) face recognition systems have started to become popular in biometric systems recently. This is due to several factors: i) facial shape characteristics contain discriminative information, ii) availability of practical 3D acquisition devices, and iii) invariance of 3D facial information to several factors such as illumination a...

Facial expression variations and occlusions complicate the task of identifying persons from their 3D facial scans. We propose a new 3D face registration and recognition method based on local facial regions that is able to provide better accuracy in the presence of expression variations and facial occlusions. Proposed fast and flexible alignment met...

This paper presents an evaluation of several 3D face recognizers on the Bosphorus database which was gathered for studies on expression and pose invariant face analysis. We provide identification results of three 3D face recognition algorithms, namely generic face template based ICP approach, one-to-all ICP approach, and depth image-based Principal...

This paper exhibits the performance drop in 3D face recognition in the presence of expression and proposes a new 3D face registration and recognition method based on facial regions. For fast alignment, a registration method based on iterative closest point (ICP) algorithm is used which employs average regional models (ARMs). Similarity scores obtai...

In this paper, we present an extensive study of 3D face recognition algorithms and examine the benefits of various score-, rank-, and decision-level fusion rules. We investigate face recognizers from two perspectives: the data representation techniques used and the feature extraction algorithms that match best each representation type. We also cons...

A new 3D face database that includes a rich set of expressions, systematic variation of poses and different types of occlusions is presented in this paper. This database is unique from three aspects: i) the facial expressions are composed of judiciously selected subset of Action Units as well as the six basic emotions, and many actors/actresses are...

zetçe Bu bildiride, ifadenin varlığında sabit kayıtlamaya dayalı 3B yüz tanıma yöntemlerinin iyi başarım sağlamadığı gösterilmiş olup, başarım arttırımı için bölgesel kayıtlama ve tanıma yapılması önerilmiştir. Hızlı hizalama amaçlı, ortalama bölge modelleriyle yinelemeli en yakın nokta (ICP) algoritmasına dayalı kayıtlama yöntemi kullanılmıştır. B...

In this paper we apply template protection to an authentication system based on 3D face data in order to protect the privacy of its users. We use the template protection system based on the helper data system (HDS). The experimental results performed on the FRGC v2.0 database demonstrate that the performance of the protected system is of the same o...

In this paper, we design various 3D face recognizers that are based on different representation and feature extraction schemes. For each scheme, an extensive range of possible approaches are realized, and we also propose the use of novel methods such as principal curvature directions, several subspace techniques e.g., discrete Fourier/cosine transf...

We propose a novel, local feature-based face representation method based on two-stage subset selection where the first stage finds the informative regions and the second stage finds the discriminative features in those locations. The key motivation is to learn the most discriminative regions of a human face and the features in there for person iden...

In this paper, we propose the application of masks as a means to mitigate expression-distortions on 3D faces and to enhance their recognition performance. Masking becomes necessary to de-emphasize the face regions that deform un-der expression. We have conducted experiments with various masks, namely, ellipse-shaped binary masks, Gaussian, su-per-G...

In this paper, we review and compare 3D face registration and recognition algorithms, which are based solely on 3D shape information and analyze methods based on the fusion of shape features. We have analyzed two different registration algorithms, which produce a dense correspondence between faces. The first algorithm non-linearly warps faces to ob...

zet Biyometrik sistemler iki şekilde işe yarayabilirler. Günlük hayatımızda gittikçe artan sıklıkta karşılaştığımız teknolojileri daha rahat kullanılabilir hale getirebilir, ezberlemek ve sürekli değiştirmek zorunda kaldığımız onlarca şifrenin yerini alabilirler. Veya suçluların takibini kolaylaştırıp güvenliğin sıkılaştırılmasında kullanılabilirle...

D shape-based face recognition algorithms can be im- proved by using decision-level fusion algorithms. In this work, we present a comparative analysis of various fusion algorithms, and also propose novel ones. The contributions of the paper can be summarized as: i) a through analy- sis of several decision-level fusion algorithms, ii) a dynami- call...

In D face recognition systems, 3D facial shape information plays an important role. 3D face recognizers usually depend on point cloud representation of faces where faces are represented as a set of 3D point coordinates. In many of the previous studies, faces are represented holistically and the discriminative contribution of local regions are as- s...

In 3D face recognition systems, 3D facial shape information plays an important role. Various shape representations have been proposed in the literature. The most popular techniques are based on point clouds, surface normals, facial profiles, and statistical analysis of depth images. The contribution of the presented work can be divided into two par...

Face recognition (FR) is the preferred mode of identity recognition by humans: It is natural, robust and unintrusive. However, auto-matic FR techniques have failed to match up to expectations: Vari-ations in pose, illumination and expression limit the performance of 2D FR techniques. In recent years, 3D FR has shown promise to overcome these challa...

We address the use of three-dimensional facial shape information for human face identification. We propose a new method to represent faces as 3D registered point clouds. Fine registration of facial surfaces is done by first automatically finding important facial landmarks and then, establishing a dense correspondence between points on the facial su...

We use three dimensional facial shape information for human face identification. We propose a new method to represent faces as 3D registered point clouds. Fine registration of facial surfaces is done by first automatically finding important facial landmarks and, then, establishing a dense correspondence between points on the facial surface with the...

Many security systems depend upon face recognizers to identify a person. Many of these systems are passive and are deployed at places such as airline terminals. However, face recognizers are sensitive to deception attacks. Previ-ous studies suggest that hair regions are very crucial in face recognition and the success of a recognizer depends on the...

In local feature-based face recognition systems, the topographical locations of feature extractors directly affect the discriminative power of a recognizer. Better recognition accuracy can be achieved by the determination of the positions of salient image locations. Most of the facial feature selection algorithms in the literature work with two ass...

In this paper, a two-level supervised feature selection algorithm for local feature-based face recognition is presented. In the first part, a genetic algorithm is used to determine the useful locations of the face region for recognition. 2D Gabor wavelet-based feature extractors are used for local image descriptors at these locations. In the second...

One of the major difficulties in face recognition systems is the in-depth pose variation problem. Most face recognition approaches assume that the pose of the face is known. In this work, we have designed a feature based pose estimation and face recognition system using 2D Gabor wavelets as local feature information. The difference of our system fr...

One of the major difficulties in face recognition systems is the in-depth pose variation problem. Most face recognition approaches assume that the pose of the face is known. In this work, we have designed a feature based pose estimation and face recognition system using 2D Gabor wavelets as local feature information. The difference of our system fr...

One of the major difficulties in face recognition systems is the in-depth pose variation problem. Most face recognition approaches assume that the pose of the face is known. In this work, we use a variation of Gabor wavelet transform for the representation of human face images to efficiently solve the pose estimation problem. Parameters of the Gabo...

In this paper, a two–level supervised feature selection algorithm for local feature–based face recognition is presented. In the first part, a genetic algorithm is used to determine the useful locations of the face region for recognition. 2D Gabor wavelet–based feature extractors are used for local image descriptors at these locations. In the second...

zetçe Yerel öznitelik tabanlı yüz tanıma sistemlerinde, öznitelik çıkarıcılarının topoğrafik yerleri, tanıyıcının ayırdetme gücünü doğrudan etkiler. Tanıma başarımının yükseltilmesi için, imgedeki belirgin noktaların bulunması gereklidir. Çoğu yüz öznitelik çıkarımı algoritması şu iki varsayıma dayanır: 1. Her özniteliğin önemi, diğerlerinden bağım...

zetçe Bu bildiride, farklı betimleme ve öznitelik çıkarma yöntemlerine dayalı çok sayıda üç boyutlu (3B) yüz tanıma yöntemi geliştirilmiş ve karşılaştırmalı analizi yapılmıştır. 1 Betimleme yöntemleri olarak nokta bulutları, derinlik imgeleri, yüzey kıvrım bilgisi, 3B vokseller, ve doku bilgisi kullanılmış olup, betimleme yöntemlerinin seçimine gör...