Below is a general description of the research projects on-going at DISCOVER Lab.  Some of them are projects we are planning for the coming academic year.  As the year progresses, we may add more details regarding each topic.
 


  Research and development of our video conferencing algorithm, CU30, has been the central focus of DISCOVER Lab.  Traditionally, development of our video conferencing software has been on the MS Windows platform, under the name of CU30.  In 1999, initiated by Aron Rosenberg, Andy Dodd and Ben Luk, the CU30 code was successfully ported to the Linux platform.  Then with the creation of a project on Sourceforge.net (no longer maintained), our CU30 project also became a part of the open source software community.  Being one of the very few video conferencing applications that support the commonly used USB netcams (or webcams), CU30 quickly became quite popular among Linux users. 

 Screen capture of our Linux video conferencing application's main control window.

 Screen capture of our MS Windows video conferencing application's main control window.

  Currently, we have on-going projects that enhance CU30 in these areas:

Open loop rate Control

  As opposed to closed loop systems, we would like to investigate on using an open loop to adaptively adjust the frame rate based on the network´s status.
 

Enhancements to audio support and compression

  We are looking into ways to improve our voice codec in order to enhance the audio functionalities of qVIX.
 

Enhancements to the quantizer

  The quantizer is an important part of the CU30 algorithm, as it greatly determines the quality of the transmitted video signals.  More work can be done in this area, especially on aspects related to foreground (eg. the speaker´s face - intense movements) and background (static to no movement) pixel quantizing.
 

Browser plugin support for qVIX

  A new area in our development, but as qVIX users proliferate a web browser based plugin is naturally called for. 
 

Feedback in data stream and two-way control messaging

  A more network related study on the effects of providing feedback of the channel´s status and the use of more complicated two-way control messaging mechanism.
 

Encryption in the data stream

  This involves investigating possible security loop-holes in the current CU30/qVIX architecture and formulating solutions, like data encryption, to combat them.
 

High frame rate qVIX

  With the advent of broadband networking, high data rate connections are becoming readily available.  The constraint for providing low latency 30-frame video stream at a very low-bit rate that the CU30 algorithm was originally developed for does not apply to most workstations anymore.  Work should be done on investigating how CU30 should be modified to leverage higher data rates.
 

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  Initiated by Aron Rosenberg, DISCOVER Lab is very happy to receive Applied Data Systems´ support and donation for a joint development of a Linux-based 802.11b enabled handheld device that runs CU30.

  ADS is a embedded computer system manufacturer in Maryland that specializes in ARM-based single board computers (SBC).  As part of the joint program, ADS has loaned us one Graphics Master, a development system on their SBC line, and will be donating us two Bitsy device, smaller battery-opearated SBC clients.

 Graphics Master (Photo from ADS´ website)

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 A Symbol AP4121 HR Access Point

  In 2000, as IEEE 802.11b was becoming the industry standard for wireless computer networks, DISCOVER Lab started a few research projects on investigating video conferencing with CU30 over 802.11b networks.  Among those research projects, we also looked into scenarios with using handheld devices in a classroom environment using 802.11b WLANs and issues related to WLAN security. 

  Our research was greatly benefited with Symbol Technologies´ donation of WLAN equipment, as their equipment gives us a testbed for our software and also allows us to verify and compare results generated through simulations with actual experiments.

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  Our speech recognition group was established in 1998. Since then, the group has been involved in various interesting areas, with contribution from Ph.D. student research, M.Eng. projects and undergraduate projects. The two major projects are:

(1) Speaker verification:

  Speaker verification is one of the techniques in biometrics. As "voiceprint", speech can be used to verify a person's claimed identity by the use of a machine automatically. Speaker verification can be classified into text-independent and text-dependent verification. Both systems have been developed in our group based on Hidden Markov Model (HMM) and Gaussian Mixture Model (GMM). This technique can be used in many access-control applications, such as bank security, telephone transaction, and computer login, etc.

(2) Keyword spotting:

  Keyword spotting is trying to detect the words that we are interested in from spontaneous conversational speech. It is much more computationally efficient than a large vocabulary speech recognition system. The corresponding response can be made based on the decision. A demo system was developed for this technique. Keyword spotting can be used for automatic information retrieval from large amount of recorded audio data.

  Our work also includes some other projects, such as voice conversion and speech synthesis. Some joint work has been done with the researchers in IBM T.J. Watson research center. Multiple papers have been published in ICASSP and ICSLP during recent years.

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  BREW, or Binary Runtime Environment for Wireless, is a development platform for 3G cellular networks released by Qualcomm Inc.  With BREW, developers can create applications for any Qualcomm CDMA2000 handsets without requring the developer to have the chip system´s source code or relationship for a manufacturer.  This means once an application is developed, there is no need to redevelop for or port to a specific platform.

  We are currently working on such an applet call BREW Video which is a video conferencing application designed for 3G mobile networks.  Our bandwidth efficient video encoding and compression algorithms should be very advantageous for mobile phone operations.

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