Hierarchical and multi-featured fusion for effective gait recognition under variable scenarios

Human identification by gait analysis has attracted a great deal of interest in the computer vision and forensics communities as an unobtrusive technique that is capable of recognizing humans at range. In recent years, significant progress has been made, and a number of approaches capable of this task have been proposed and developed. Among them, approaches based on single source features are the most popular. However the recognition rate of these methods is often unsatisfactory due to the lack of information contained in single feature sources. Consequently, in this paper, a hierarchal and multi-featured fusion approach is proposed for effective gait recognition. In practice, using more features for fusion does not necessarily mean a better recognition rate and features should in fact be carefully selected such that they are complementary to each other. Here, complementary features are extracted in three groups: Dynamic Region Area; Extension and Space features; and 2D Stick Figure Model features. To balance the proportion of features used in fusion a hierarchical feature-level fusion method is proposed. Comprehensive results of applying the proposed techniques to three well-known datasets have demonstrated that our fusion based approach can improve the overall recognition rate when compared to a benchmark algorithm

SIFT-ME: A New Feature for Human Activity Recognition

Action representation for robust human activity recognition is still a challenging problem. This thesis proposed a new feature for human activity recognition named SIFT-Motion Estimation (SIFT-ME). SIFT-ME is derived from SIFT correspondences in a sequence of video frames and adds tracking information to describe human body motion. This feature is an extension of SIFT and is used to represent both translation and rotation in plane rotation for the key features. Compare with other features, SIFT-ME is new as it uses rotation of key features to describe action and it robust to the environment changes. Because SIFT-ME is derived from SIFT correspondences, it is invariant to noise, illumination, and small view angle change. It is also invariant to horizontal motion direction due to the embedded tracking information. For action recognition, we use Gaussian Mixture Model to learn motion patterns of several human actions (e.g., walking, running, turning, etc) described by SIFT-ME features. Then, we utilize the maximum log-likelihood criterion to classify actions. As a result, an average recognition rate of 96.6% was achieved using a dataset of 261 videos comprised of six actions performed by seven subjects. Multiple comparisons with existing implementations including optical flow, 2D SIFT and 3D SIFT were performed. The SIFT-ME approach outperforms the other approaches which demonstrate that SIFT-ME is a robust method for human activity recognition

Comparing Machine Learning Classifiers and Linear/Logistic Regression to Explore the Relationship between Hand Dimensions and Demographic Characteristics

Understanding the relationship between physiological measurements from human subjects and their demographic data is important within both the biometric and forensic domains. In this paper we explore the relationship between measurements of the human hand and a range of demographic features. We assess the ability of linear regression and machine learning classifiers to predict demographics from hand features, thereby providing evidence on both the strength of relationship and the key features underpinning this relationship. Our results show that we are able to predict sex, height, weight and foot size accurately within various data-range bin sizes, with machine learning classification algorithms out-performing linear regression in most situations. In addition, we identify the features used to provide these relationships applicable across multiple applications

Avaliação de técnicas para o reconhecimento de pessoas pela forma de andar (Gait Recognition)

Resumo: A possibilidade de uso da forma de andar de seres humanos como característica biométrica para a identificação de indivíduos é o foco de estudo deste trabalho. Além de apresentar vantagens em relação a outras biometrias, como o reconhecimento por face, impressão digital ou íris, o reconhecimento de pessoas pela forma de andar possibilita a extração de características biométricas á distância de forma não invasiva, e não necessita de imagens de alta resolução. O presente trabalho apresenta um estudo das principais e atuais abordagens de reconhecimento de pessoas pela forma de andar, livres de modelos (model-free). Foram exploradas as principais bases de dados utilizadas atualmente assim como os métodos estado da arte. Cada uma das bases apresenta diferentes variações nos ambientes das ímagens (interno ou externo), tipo de superficie, tipo de calçado, ângulos de câmera e a variação de datas de gravação das sequências. Dessa forma, pode ser medido qual a influência de cada uma destas variações no processo de reconhecimento de pessoas pela forma de andar. São apresentadas em detalhes as etapas de funcionamento das abordagens de reconhecimento definidas como baseline, silhuetas médias, vetores de largura e vetores de massa. Modificações na abordagem de silhuetas médias foram propostas e os resultados obtidos são discutidos em detalhes. Após a análise de qualidade das silhuetas extraídas da USF Database, foi efetuada a classificação de uma parcela das silhuetas da base de acordo com a presença de erros de segmentação. Por meio dessa classificação são apresentadas as taxas de reconhecimento obtidas após a remoção de cada tipo de erro da base, de forma a poder avaliar a influência destes erros nos resultados dos métodos implementados

Electronic Imaging & the Visual Arts. EVA 2013 Florence

Important Information Technology topics are presented: multimedia systems, data-bases, protection of data, access to the content. Particular reference is reserved to digital images (2D, 3D) regarding Cultural Institutions (Museums, Libraries, Palace – Monuments, Archaeological Sites). The main parts of the Conference Proceedings regard: Strategic Issues, EC Projects and Related Networks & Initiatives, International Forum on “Culture & Technology”, 2D – 3D Technologies & Applications, Virtual Galleries – Museums and Related Initiatives, Access to the Culture Information. Three Workshops are related to: International Cooperation, Innovation and Enterprise, Creative Industries and Cultural Tourism

A Novel Convolutional Neural Network Pore-Based Fingerprint Recognition System

Biometrics play an important role in security measures, such as border control and online transactions, relying on traits like uniqueness and permanence. Among the different biometrics, the fingerprint stands out for their enduring nature and individual uniqueness. Fingerprint recognition systems traditionally rely on ridge patterns (Level 1) and minutiae (Level 2). However, these systems suffer from recognition accuracy with partial fingerprints. Level 3 features, such as pores, offer distinctive attributes crucial for individual identification, particularly with high-resolution acquisition devices. Moreover, the use of convolutional neural networks (CNNs) has significantly improved the accuracy in automatic feature extraction for biometric recognition. A CNN-based pore fingerprint recognition system consists of two main modules, pore detection and pore feature extraction and matching modules. The first module generates pixel intensity maps to determine the pore centroids, while the second module extracts relevant features of pores to generate pore representations for matching between query and template fingerprints. However, existing CNN architectures lack in generating deep-level discriminative feature and computational efficiency. Moreover, available knowledge on the pores has not been taken into consideration optimally for pore centroids and metrics other than Euclidean distance have not been explored for pore matching. The objective of this research is to develop a CNN-based pore fingerprint recognition scheme that is capable of providing a low-complexity and high-accuracy performance. The design of the CNN architecture of the two modules aimed at generating features at different hierarchical levels in residual frameworks and fusing them to produce comprehensive sets of discriminative features. Depthwise and depthwise separable convolution operations are judiciously used to keep the complexity of networks low. In the proposed pore centroid part, the knowledge of the variation of the pore characteristics is used. In the proposed pore matching scheme, a composite metric, encompassing the Euclidean distance, angle, and magnitudes difference between the vectors of pore representations, is proposed to measure the similarity between the pores in the query and template images. Extensive experiments are performed on fingerprint images from the benchmark PolyU High-Resolution-Fingerprint dataset to demonstrate the effectiveness of the various strategies developed and used in the proposed scheme for fingerprint recognition