Jindan Zhou

A content-based system for human identification based on bitewing dental X-ray images

This paper presents a system for assisting in human identification using dental radiographs. The goal of the system is to archive antemortem (AM) dental images and enable content-based retrieval of AM images that have similar teeth shapes to a given postmortem (PM) dental image. During archiving, the system classifies the dental images to bitewing, periapical, and panoramic views. It then segments the teeth and the bones in the bitewing images, separates each tooth into the crown and the root, and stores the contours of the teeth in the database. During retrieval, the proposed system retrieves from the AM database the images with the most similar teeth to the PM image based on Hausdorff distance measure between the teeth contours. Experiments on a small database show that our method is effective for dental image classification and teeth segmentation, provides good results for separating each tooth into crown and root, and provides a good tool for human identification.

Human ear recognition from face profile images

In this paper, we present a novel system for ear identification from profile images of the face. The system has two steps. In the first step, the ear is automatically detected from the profile image of the face. In the second step, the ear image is transformed to a force field, then feature points are extracted and the best match is found from a database. We propose a method based on differential geometry to extract ear feature points. We use a transformation of the ear image to make it suitable for extracting the feature points using differential geometry. During recognition, the feature points obtained from a query image are aligned and compared with those in the database using Hausdorff distance. The experimental results show that our method is effective.

Towards an Automated Dental Identification System (ADIS)

This paper addresses the problem of developing an automated system for postmortem identification using dental records. The Automated Dental Identification System (ADIS) can be used by law enforcement agencies to locate missing persons using databases of dental x-rays. Currently, this search and identification process is carried out manually, which makes it very time-consuming and unreliable. In this paper, we propose architecture for ADIS, we define the functionality of its components, and we briefly describe some of the techniques used in realizing these components.

Histograms of Categorized Shapes for 3D ear detection

We introduce a novel shape-based feature set, termed the Histograms of Categorized Shapes (HCS), for robust Three-Dimensional (3D) object recognition. By adopting the sliding window approach and a linear Support Vector Machine (SVM) classifier, the efficacy of the HCS feature is assessed on a 3D ear detection task. Experimental results demonstrate that the approach achieves a perfect detection rate, i.e., a 100% detection rate with a 0% false positive rate, on a validation set consisting of 142 range profile images from the University of Notre Dame (UND) 3D ear biometrics database. It is to the best of our knowledge that the detection rate achieved here outperforms those reported in the literature for the given dataset. The proposed detector is also extremely efficient in both training and detection due to the simplicity of the feature extraction and speed of the classification process, suggesting that the method is suitable for practical use in 3D ear biométrie applications.

Toward an automated dental identification system

Forensic odontology has long been carried out by forensic experts of law enforcement agencies for postmortem identification. We address the problem of developing an automated system for postmortem identification using dental records (dental radiographs). This automated dental identification system (ADIS) can be used by law enforcement agencies as well as military agencies throughout the United States to locate missing persons using databases of dental x rays of human remains and dental scans of missing or wanted persons. Currently, this search and identification process is carried out manually, which makes it very time-consuming in mass disasters. We propose a novel architecture for ADIS, define the functionality of its components, and describe the techniques used in realizing these components. We also present the performance of each of these components using a database of dental images.

An Efficient 3-D Ear Recognition System Employing Local and Holistic Features

We present a complete three-dimensional (3-D) ear recognition system combining local and holistic features in a computationally efficient manner. The system is comprised of four primary components, namely: 1) ear image segmentation; 2) local feature extraction and matching; 3) holistic feature extraction and matching; and 4) a fusion framework combining local and holistic features at the match score level. For the segmentation component, we introduce a novel shape-based feature set, termed the Histograms of Indexed Shapes (HIS), to localize a rectangular region containing the ear. For the local feature extraction and representation component, we extend the HIS feature descriptor to an object-centered 3-D shape descriptor, the Surface Patch Histogram of Indexed Shapes (SPHIS), for local ear surface representation and matching. For the holistic matching component, we introduce a voxelization scheme for holistic ear representation from which an efficient, voxel-wise comparison of gallery-probe model pairs can be made. The match scores obtained from both the local and holistic matching components are fused to generate the final match scores. Experimental results conducted on the University of Notre Dame (UND) collection G dataset, containing range images of 415 subjects yielded a rank-one recognition rate of 98.3% and an equal error rate of 1.7%. These results demonstrate that the proposed approach outperforms state-of-the-art 3-D ear biometric systems. Additionally, the method is considerably more efficient compared to the state-of-the-art because it employs a sparse set of features rather than using the dense model.

Automatic human identification based on dental X-ray images

This paper presents an automated system for human identification using dental radiographs. The goal of the system is to automatically archive dental images and enable identification based on shapes of the teeth in bitewing images. During archiving, the system builds the antemortem (AM) database, where it segments the teeth and the bones, separates each tooth into crown and root, and stores the contours of the teeth in the database. During retrieval, given a dental image of a postmortem (PM), the proposed system identifies the person from the AM database by automatically matching extracted teeth contours from the PM image to the teeth contours in the AM database. Experiments on a small database show that our method is effective for teeth segmentation, separation of teeth into crowns and roots, and matching.

A computationally efficient approach to 3D ear recognition employing local and holistic features

We present a complete, Three-Dimensional (3D) object recognition system combining local and holistic features in a computationally efficient manner. An evaluation of the proposed system is conducted on a 3D ear recognition task. The ear provides a challenging case study because of its high degree of inter-subject similarity. In this work, we focus primarily on the local and holistic feature extraction and matching components, as well as the fusion framework used to combine these features at the match score level. Experimental results conducted on the University of Notre Dame (UND) collection G dataset, containing range images of 415 subjects, yielded a rank-one recognition rate of 98.6% and an equal error rate of 1.6%. These results demonstrate that the proposed system outperforms state-of-the-art 3D ear biometric systems.

Exploiting color SIFT features for 2D ear recognition

In this paper, we present a robust method for 2D ear recognition using color SIFT features. Firstly, we extend the Scale Invariant Feature Transform (SIFT) algorithm originally performed on the intensity channel [1] to the RGB color channels to maximize the robustness of the SIFT feature descriptor. Secondly, a feature matching algorithm for ear recognition is proposed by fusion of the features extracted from the different color channels. Experiments conducted on the University of Notre Dame (UND) and the West Virginia University (WVU) ear biometric datasets indicate that our method can achieve better recognition rates than the state-of-the-art methods applied on the same datasets.

Gender classification using automatically detected and aligned 3D ear range data

Gender classification received attention due to its use in many applications. In this paper, the potential of using the 3D shape of the ear for gender recognition is established. We demonstrate the first attempt for gender classification from 3D ear data and evaluate different algorithms using automatically detected and aligned ears. Experiments were conducted on the University of Notre Dame (UND) database collections F and J2 which contain images with large occlusion and pose variations. It is observed that the use of Histogram of Indexed Shapes (HIS) feature along with Support Vector Machine (SVM) yields an average classification accuracy of 92.94%, which is superior to the state-of-the-art for gender classification from 2D ear images, and shows that the 3D shape of the ear comprises rich gender information.