As we know, the discrete cosine transform (DCT) is widely used in H.261, H.263, MPEG and JPEG. In the high bit-rate environment, it has successful performance, while in low bit-rate, the performace drops greatly due to the :"blocking effect". The discrete wavelet transform (DWT), however, is free from the blocking artifacts due to the nature of its global decomposition. The wavelet representation provides a multiresolution/multiscale expression of a signal with localization in both time and frequency. Therefore, compared with the DCT, the wavelet representation is more flexible and can be easily adapted to the nature of human visual system.
 

This work has been accepted by SPIE Visual Communication and Image Processing, 2004.

•  F. Zhai and T. N. Pappas, "Motion-compensated wavelet video coding using adaptive mode selection," SPIE Visual Communication and Image Processing (VCIP'04), San Jose, CA, Jan. 2004. [pdf]

This project is mainly focus on the application-layer error control components (error resillience, forward error protection, and error concealment) for scalable video transmission over the Internet.
 
• This work has been accepted by ICME'03.
• F. Zhai, R. Berry, T. N. Pappas, and A. K. Katsaggelos, "A rate-distortion optimized error control scheme for scalable video streaming over the Internet," Proc. IEEE International Conference on Multimedia and Expo (ICME'03), Baltimore, MD, July 6-9, 2003, [pdf]

Continuous Media (CM) Internet applications, such as streaming video and videoconferencing, are gaining increased popularity. One of the major difficulties in the deployment of these applications is the lack of quality of service (QoS) guarantees in today's Internet. For this reason, there have been several proposals for supporting QoS in the Internet. In our research, we study the interaction of video source coding and network layer QoS. Our goal is to obtain an optimal balance between received video quality and overall cost.
 
• This work has been accepted by IEEE Trans on Multimedia abd ICIP'03.
•  F. Zhai, C. E. Luna, Y. Eisenberg, T. N. Pappas, R. Berry, and A. K. Katsaggelos, "A novel cost-distortion optimization framework for video streaming over differentiated services networks," Proc. IEEE International Conf. Image Processing (ICIP'03), Barcelona, Spain, Sept. 2003. [pdf]
•  F. Zhai, C. E. Luna, Y. Eisenberg, T. N. Pappas, R. Berry, and A. K. Katsaggelos, "Joint source coding and packet classification for video streaming over differentiated services networks," IEEE Trans. Multimedia, 2004, To appear [pdf]

Real-time video applications, such as on-demand video streaming, videophone and videoconferencing, have gained increased popularity. However, it is well known that the best effort design of the current Internet makes it difficult to provide the QoS needed by these applications. A direct approach for dealing with the lack of QoS is to use error control. In this paper, we consider a combination of common error control approaches. Specifically, we consider error resilient source coding and error correction at the sender side, and error concealment at the receiver. We present an integrated joint source channel coding (IJSCC) framework for jointly optimizing these application-layer error control components to achieve the best video quality.

We study hybrid error control for real-time video transmission. The study is carried out using the proposed IJSCC framework, which jointly considers error resilient source coding, channel coding, and error concealment, in order to achieve the best video quality. We focus on the performance comparison of several error correction scenarios, such as FEC, retransmission, and the combination of both. Simulation results show that either FEC or retransmission can be optimal depending on the packet loss rates and network round trip time. The proposed hybrid FEC/retransmission scheme outperforms both.

• The study of packetization schemes for forward error correction (FEC) in Internet video streaming has been accepted by 41st Allerton Conf.
• F. Zhai, Y. Eisenberg, C. E. Luna, T. N. Pappas, R. Berry, and A. K. Katsaggelos, "Packetization schemes for forward error correction in Internet video streaming," Proc. 41st Allerton Conf. Communication, Control, and Computing, Oct. 2003. [pdf]
• The work of hybrid FEC/retransmission has been submitted to ICC'04 for publication.
• F. Zhai, Y. Eisenberg, T. N. Pappas, R. Berry, and A. K. Katsaggelos, "Rate-distortion optimized hybrid error control for real-time packetized video transmission," International Conf. Communications (ICC'04), 2004, accepted. [pdf]
• The study of Integrated joint source-channel coding framework has been submitted to ICIP'04 and IEEE Trans. Image Processing.
• F. Zhai, Y. Eisenberg, T. N. Pappas, R. Berry, and A. K. Katsaggelos, "An integrated joint source-channel coding framework for video transmissions over packet lossy networks," IEEE ICIP'04. [pdf]
• F. Zhai, Y. Eisenberg, T. N. Pappas, R. Berry, and A. K. Katsaggelos, "Rate-distortion optimized hybrid error control for real-time packetized video transmission," IEEE Trans. Image Processing, submitted, Jan. 2004. [pdf]

We consider a cross-layer resource allocation problem for energy-efficient wireless video communications. In order to efficiently utilize network resources, we present a framework of joint source-channel coding and power allocation, where error resilient source coding, channel coding, and transmission power allocation are jointly designed to compensate for channel errors. The focus of this work is on the channel coding and transmission power adaptation. Specifically, at the transport layer, Reed-Solomon coding is used to provide inter-packet protection. In addition, RCPC coding is used at the link layer to provide unequal intra-packet protection. The above two measures are jointly considered with power adaptation to achieve the best video quality. An efficient algorithm based on Lagrangian relaxation and dynamic programming is proposed to solve the optimization problem with two constraints. Simulation results illustrate the advantage of the proposed framework.

• The work of product code FEC for video streaming over IP-based wireless networks has been accepted by ICASSP'04 for publication.
• F. Zhai, Y. Eisenberg, T. N. Pappas, R. Berry, and A. K. Katsaggelos, "Rate-distortion optimized product code forward error correction for video transmission over IP-based wireless networks," International Conf. Acoustics, Speech, and Signal Processing (ICASSP'04), May 2004, accepted. [pdf]
• The work of joint source-channel coding and power allocation (JSCCPA) for energy efficient video wireless communications has been accepted by 41st Allerton Conf.
• F. Zhai, Y. Eisenberg, T. N. Pappas, R. Berry, and A. K. Katsaggelos, "Joint source-channel coding and power allocation for energy efficient wireless video communications," Proc. 41st Allerton Conf. Communication, Control, and Computing, Oct. 2003. [pdf]
• The work of Energy efficient wireless transmission of MPEG-4 Fine Granular Scalable video has been submitted to ICC'04 for publication.
•  C. Costa, Y. Eisenberg, F. Zhai, and A. K. Katsaggelos, "Energy efficient wireless transmission of MPEG-4 Fine Granular Scalable video," International Conf. Communications (ICC'04), 2004, accepted.