Biometrics

Age Group Classification via Structured Fusion of Uncertainty-driven Shape Features and Selected Surface Features

Author: Kuan-Hsien Liu, Shuicheng Yan, and C.-C. Jay Kuo

Facial image processing has attracted a lot of attention in the computer vision community over the last two decades. The human face can reveal important perceptual characteristics such as the identification, gender, race, emotion, pose, age, etc. Among these characteristics, the age information has its particular importance. The aging progress is complicated, nonreversible and uncontrollable. It is affected by various factors, including the living environment, climate, health, life style, and biological reasons. Age-related facial image processing is being extensively studied, and facial age group classification is one of major research topics in this area.

Examples include age-based facial image retrieval, internet access control, security control and surveillance, biometrics, age-based human-computer interaction (HCI), age prediction for finding missing children, and age estimation based on the result of age groups classification. Age estimation can be done more accurately if it is worked on groups containing a narrower age range. Hence, the age group classification problem is an interesting one that demands further efforts.

We presented a structured fusion method for facial age group classification as shown in Figure 1. To utilize the structured fusion of shape features and surface features, we introduced the region of certainty (ROC) to not only control the classification accuracy for shape feature based system but also reduce the classification needs on surface feature based system. In the first stage, we design two shape features, which can be used to classify frontal faces with high accuracies. In the second stage, a surface feature is adopted and then selected by a statistical method. The statistical selected surface features combined with a SVM classifier can offer high classification rates. With properly adjusting the ROC by a single non-sensitive [...]

By |November 21st, 2013|Biometrics|Comments Off on Age Group Classification via Structured Fusion of Uncertainty-driven Shape Features and Selected Surface Features|

Advanced techniques for text detection in compound images

Author: Harshad Kadu, Jian Li, and C.-C. Jay Kuo

Detecting text regions in natural images is an important task for many computer vision applications like compound video compression, optical character recognition, reading text for visually impaired subjects, robotic navigation etc. We are trying to solve this text localization problem, also known as the compound image segmentation problem. Contrary to the scanned documents, text in natural images may have different sizes, fonts, orientations, colors and foreground or background illumination. The cluttered background in natural images may also pose a serious threat to the accuracy of the text localization algorithms. So the compound image segmentation is inherently a difficult problem to solve.

In our research, we propose a novel text localization scheme based on the fusion of diverse local operators such as, the morphological detector, maximally stable extremal regions (MSER) blob analyzer [3, 4], distance transform and stroke-width transform [2]. These operators investigate different peculiar characteristics of text to discover regions with possible textual content. An ensemble of trained SVM classifiers categorizes these regions into text or non-text using the local feature information. Finally a fragment grouping mechanism merges these text candidates together and carves out individual words. Refer to the figure below.

Our proposed fusion technique uses a novel three-tier framework to systematically separate out the individual words in the images. The text regions have some peculiar properties which distinguish them from the non-text regions. To gain insights, we explore these properties using our novel morphological text detector. Apart from the aforementioned operator we also use some existing detectors such as, the MSER [3, 4] and stroke width transform [2] to improve the detection accuracy. We hope to get a significantly enhanced performance using this fusion framework.

The future [...]

By |November 21st, 2013|Biometrics|Comments Off on Advanced techniques for text detection in compound images|

Facial Recognition in Heterogeneous Environment

Author: Chun-Ting Huang and C.-C. Jay Kuo

“Facial Recognition” has become an important technique to handle the tremendous growing need for identification and verification since last century. The replacement of traditional transaction by electronic transaction successfully gathered attention for facial recognition from research and business communities, because facial recognition requires no physical interaction on behalf of users. The research on facial recognition can be traced back to early 1990s, from the Eigenface proposed by Turk and Pentland in 1991 [1], which has over 11409 citations on Google Scholar. The follow-up development can be concluded into general directions discussed in Face Recognition Vendor Test – FRVT 2002 [2], and different face databases are developed in order to solve various conditions, such as poses, expressions, and environment. A new database called Long Distance Heterogeneous Face Database (LDHF-DB) [3] is focused on face images under various distances and near-infrared camera, which provides an new challenge within this field.

Since under the long distance, the near-infrared camera can only capture blurred and vague face images, as shown in Fig. 1, causing the template feature’s low performance on LDHF-DB. Therefore, our research only adopts geometric and shape-based features, locally and globally, to determine the input of structured-fusion method. Based on the different characteristics of features we collected from database, we aim to develop an robust classification algorithm with machine learning to distinguish faces under various quality.

The major difference between our work and other research is the feature selection and structured fusion model. I have explained the reason why template method only has a fair performance under the influence of heterogeneous environment. Our proposed model can boost up the recognition rate by adopting different feature’s strength and discarding the outliers for particular [...]

By |November 21st, 2013|Biometrics|Comments Off on Facial Recognition in Heterogeneous Environment|