Mohammad H. Mahoor, Ph.D.

Assistant Professor

University of Denver

Department of Electrical and Computer Engineering

2390 S. York Street, CMK 306

Denver, CO 80208

Email: mmahoor [at] du [dot] edu

Phone:  (303)-871-3745

Fax:      (303)-871-4450

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Research Projects:

 

  •  Computer Vision and Pattern Recognition

  •      Spontaneous Facial Emotion Recognition

  •      Automated Gaze Estimation

  •      Facial Feature Extraction

  •     Vision-Based UAV navigation and control

  •     Multimodal Biometrics (FACE, EAR,...)

  •     Image Blending/Mosaicing

  •     Human Activity Recognition  

  • Tele Health and Monitoring

  •    Telemonintoring System for Patients with Congestive Heart Failure

  •    Telemonintoring System for Patients with Total Knee Replacement

 Computer Vision and Pattern Recognition Research Projects

Spontaneous Facial Emotion Recognition: In this research project, our focus is on developing automated computer vision techniques for measuring/recognizing spontaneous facial expressions and FACS action units and map onto expert human coding. We apply developed automated techniques to analyze emotion expressions of children with autism. Autism is a severe early childhood developmental disorder that is characterized by deficits in cognitive performance as well as progressive qualitative impairments in social interactions. In the absence of a reliable biological marker, diagnosis of this devastating disorder is still based on its clinical manifestations. One of the clinical features of autism is difficulties in appropriately creating facial expressions that reflect child’s emotions.

 

Automatic Gaze Detection in Facial Images: The focus of this research is to develop a novel holistic-based framework to estimate gaze direction. The gaze direction of an infant in a face-to-face interaction is classified as either 1) looking at the parent’s face or 2) looking away from the parent’s face. In our approach, we track facial images in captured videos using an Active Appearance Model (AAM). We obtain an eye patch by cropping the facial image utilizing AAM mesh nodes that surround the eye region as a boundary. We make use of the appearance component of the eye patch as our representation for estimating gaze direction. Despite the huge dimensionality of the visual data, events such as gaze shifting have low dimensions embedded in a large dimensional space. We adopt the spectral regression technique to learn projection functions that map AAM   representations into a subspace termed the gaze direction sub-space. Reduced feature points presented in the sub-space are employed to estimate gaze direction based on a Support Vector Machine (SVM) classifier. 

Facial Features Extraction: Facial feature extraction is an important step in face recognition and is defined as the process of locating specific regions, points, landmarks, or curves/contours in a given 2-D image or a 3-D range image. Active Shape Model (ASM) is a statistical approach for shape modeling and 2-D feature extraction using a parameterized statistical shape model obtained from a training set of manually labeled features. In my research work, I improved the ASM method for extraction of facial features. The core of the enhancement relies on incorporating color information to present the local structure of the feature points. In addition, I developed an algorithm for labeling facial features (i.e., the two corners of the eyes and the tip of the nose), in 3-D range images. 

Mutli-Modal Face Recognition: Most of the approaches that have been developed for 3-D face recognition are based on 3-D surface matching. I presented an approach for 3-D face recognition based on Ridge lines extracted from range facial images. Only the points around the important facial regions on the face (i.e., the eyes, the nose, and the mouth) were used, and the surface patches on the face were ignored during the matching process. I showed by experiments on the Face Recognition Grand Challenge (FRGC) database, the largest available 3-D face database, that the ridge lines carry the most important information on the face surface for face recognition.

Multi-Modal Ear and Face Recognition: For more than three decades, researchers have worked in the area of face recognition. Despite these efforts, face recognition is not ready yet for real world applications. Ear biometric is a relatively new area of research. There have been few studies conducted using 2-D data (image intensity) and 3-D shape data. Because of the lack of robustness of a single biometric, multimodal biometric have caught the attention of researcher in the area of computer vision. There are several motivations for a multi-modal ear and face biometric. First, the ear and face data can be captured using regular cameras. Second, the data collection for face and ear is nonintrusive. Third, the ear and face are physically close to each other and most of the time acquiring data for ear (face) encounters face (ear) too. Most of the time, these two bio-markers exist in an image or video captured from humans’ head and both are available to a biometric system. Thus, a multi-modal face and ear recognition system is more feasible than a multi-modal face and fingerprint recognition system. Based on the above discussion, we present a multi-modal ear and face biometric system.  

Graph Cut Optimization and Its Application in Image Blending: In the area of computer vision, optimization is an important issue. One of the new developed techniques that caught my attention recently is “Graph-Cut”. I worked on using this new optimization technique in applications such as image blending or image segmentation. I presented a novel approach for combining a set of registered images into a composite mosaic with no visible seams and minimal texture distortion. Pair-wise image blending was performed by means of watershed segmentation and Graph-Cut optimization. This approach is fast because searching the optimal intersection between the images was restricted over a small set of watershed segments, instead of optimizing over the entire set of pixels in the intersection zone. The solution is found efficiently via Graph-Cut, using a given photometric criterion.

Human Activity Recognition: Most video surveillance systems can only provide simple event alarms such as Virtual Perimeter Breach, in which a person crosses an imaginary line (Below), or Abandoned Object Detection.  Our goal is to detect more complex multi-persons’ actions such as two people interacting (e.g., shaking hands) or a person interacting with an object (e.g., gun-shooting). This is useful for online surveillance or video database indexing.

 

 

 

 

 

 

Tele Health and Monitoring Research Projects

Telemonintoring System for Patients with Congestive Heart Failure: Remote chronic illness management is a growing need in Colorado as the general population ages.  Through the Urban Health Initiative, a team of researchers at the University of Denver and the Denver Health Medical Center are launching a pilot study focused on Congestive Heart Failure which is the second largest chronic illness in the U.S. The goal of this investigation is to reduce hospitalization by 25% through the use of a home monitoring system. In order to pursue the goal of decreasing the percentage of hospitalization for CHF disease, we started our pilot study on 65 patients.  Each patient has to make a weight measurement everyday with the scale which sends the weight value to the RTX3370 device through a Bluetooth connection. The RTX3370 is connected to the analog phone line, therefore the data will be sent to the University of Denver Server. Patient data is aggregated in a database. Every night data from the last midnight-midnight period is exported to a single file. That file is being sent to the Denver Health, where the evaluation of data is done by assigned nurses.

 

TeleMonitoring System for Patients with Total Knee Replacement: The subject of this project is to design and implement a home monitoring system for patients with knee rehabilitation recovering after surgery. Usually they go to hospital for exercising and they are monitored by physicians to assure that their knee performs enough degree of flexion (i.e., they can bend their knee and improve it over the exercise course). However, this costs the patients and the hospital a lot of money. Thus, developing a system to monitor patients’ knee angle while they are exercising at home without going to the hospital will be vital. We have developed a system that comprises of a brace, a magnetic angle encoder, and a microcontroller that can measure the knee angle during the exercise session and send it to the hospital. The patients wear on a brace during the exercise and the microcontroller measures the current knee angle and send it to a smart phone via Bluetooth port. The transmitted angle is stored in the smart phone and the maximum and minimum knee angles during an exercise session are calculated and sent to a server housed at the University of Denver. The maximum and minimum angles are the two important signatures that show patient’s improvement (knee flexion) after a knee surgery.

| Copyright © M.H. Mahoor | Updated August 2009|