Image Authentication Using Distributed Source Coding
2006~Present, with IVMS Group Stanford University and NXP Semiconductors
Image authentication is important in content delivery via untrusted intermediaries, such as peer-to-peer(P2P) file sharing. Many differently encoded versions of the original image might exist. On the other hand, intermediaries might tamper with the contents. Distinguishing the legitimate diversity of encodings from malicious manipulation is the challenge addressed in this research.
We develop a novel approach based on distributed source coding for the problem of backward-compatible image authentication. The key idea is to provide a Slepian-Wolf encoded quantized image projection as authentication data. This version can be correctly decoded only with the help of an authentic image as side information. Distributed source coding provides the desired robustness against legitimate encoding variations, while detecting illegitimate modification. We demonstrate false acceptance rates close to zero for authentication data sizes that are only a few percent of the compressed image size.
Low Power Compression for Mobile Video Recording Using a Combination of H.264 and Wyner-Ziv Coding
2005~2006, with IVMS Group Stanford University and Philips Semiconductors
We proposed a spatial-temporal scalable video coding scheme in which low resolution base layer is coded conventionally while high resolution enhancement layer is coded in Wyner-Ziv approach with side information extracted from base layer and motion compensated interpolation. The video can be coded into two resolution layers with low complexity. For mobile device, a low resolution video can be decoded with low complexity; for powered device, a high resolution video can be decoded with hight complexity. The proposed scheme takes benefites from Philips Software Natural Motion as well as Philips TriMedia Platform.
MPEG-21 Test Bed
2001~2002, with CommLab, National Chiao Tung University
It is a challenging problem to stream real-time video over heterogeneous networks with time-vary channel conditions and devices with different capabilites. We present an FGS-based unicast video streaming test bed, which is now being considered by the MPEG-4/21 committee as a reference test bed. The proposed system supports resource adaptation delivery of MPEG-21 DIA scheme which leads to a more strict evaluation methodology according to the MPEG commitee specified common test conditions for scalable video coding. It provides easy control media delivery with duplicable network conditions. To provide the best quality of service for each client, we propose relevant rate control, error protection, and transmission approaches in the content server, netowrk interface, and clients. respectively.
C.-N. Wang, C.-Y. Tsai, Y.-C. Lin, H.-C. Lin, H.-C. Chuang, J.-H. Chen, K. L. Tong, F.-C. Chang, C.-J. Tsai, T. Chiang, S.-Y. Lee, and H.-M. Hang, “FGS-based video streaming test bed for MPEG-21 universal multimedia access with digital item adaptation,” in Proceeding of IEEE International Symposium on Circuits and Systems (ISCAS-2003), Bangkok, Thailand, May 2003.
Efficient FGS-to-Single Layer Transcoder
2001~2002, with CommLab, National Chiao Tung University and Mitsubishi Electric Research Lab
A novel architecture for the transcoding of FGS coded video to a single-layer format is proposed. Results indicate that the proposed architecture has almost the same performance as the cascaded transcoding method, but with much lower complexity.
Y.-C. Lin, C.-N. Wang, T. Chiang, A. Vetro, and H. Sun, “Efficient FGS-to-single Layer Transcoding,” in Proceeding of IEEE International Conference on Consumer Electronics (ICCE-2002), Los Angeles, CA, June 2002.
Y.-C. Lin, C.-N. Wang, T. Chiang, A. Vetro, and H. Sun, “Video Transcoding of Scalable Multi-Layer Videos to Single Layer Video,” US Patent 2003,0,202,579 (A1) Oct. 2003.