Academic Appointments


  • Lecturer, Computer Science

Professional Education


  • Ph.D., Stanford University (2010)
  • M.S., Stanford University (2005)
  • B.A.Sc., University of Toronto (2003)

All Publications


  • Adaptive Distributed Source Coding IEEE TRANSACTIONS ON IMAGE PROCESSING Varodayan, D., Lin, Y., Girod, B. 2012; 21 (5): 2630-2640

    Abstract

    We consider distributed source coding in the presence of hidden variables that parameterize the statistical dependence among sources. We derive the Slepian-Wolf bound and devise coding algorithms for a block-candidate model of this problem. The encoder sends, in addition to syndrome bits, a portion of the source to the decoder uncoded as doping bits. The decoder uses the sum-product algorithm to simultaneously recover the source symbols and the hidden statistical dependence variables. We also develop novel techniques based on density evolution (DE) to analyze the coding algorithms. We experimentally confirm that our DE analysis closely approximates practical performance. This result allows us to efficiently optimize parameters of the algorithms. In particular, we show that the system performs close to the Slepian-Wolf bound when an appropriate doping rate is selected. We then apply our coding and analysis techniques to a reduced-reference video quality monitoring system and show a bit rate saving of about 75% compared with fixed-length coding.

    View details for DOI 10.1109/TIP.2011.2175936

    View details for Web of Science ID 000304160800023

    View details for PubMedID 22106146

  • Image Authentication Using Distributed Source Coding IEEE TRANSACTIONS ON IMAGE PROCESSING Lin, Y., Varodayan, D., Girod, B. 2012; 21 (1): 273-283

    Abstract

    We present a novel approach using distributed source coding for image authentication. The key idea is to provide a Slepian-Wolf encoded quantized image projection as authentication data. This version can be correctly decoded with the help of an authentic image as side information. Distributed source coding provides the desired robustness against legitimate variations while detecting illegitimate modification. The decoder incorporating expectation maximization algorithms can authenticate images which have undergone contrast, brightness, and affine warping adjustments. Our authentication system also offers tampering localization by using the sum-product algorithm.

    View details for DOI 10.1109/TIP.2011.2157515

    View details for Web of Science ID 000298325500023

    View details for PubMedID 21609882

  • Optimal Electric Energy Storage Operation General Meeting of the IEEE-Power-and-Energy-Society Qin, J., Sevlian, R., Varodayan, D., Rajagopal, R. IEEE. 2012
  • Error-resilient live video multicast using low-rate visual quality feedback ACM Multimedia Systems Varodayan, D., Tan, W. 2011
  • SMART METER PRIVACY USING A RECHARGEABLE BATTERY: MINIMIZING THE RATE OF INFORMATION LEAKAGE Varodayan, D., Khisti, A., IEEE IEEE. 2011: 1932–35
  • SIDE-INFORMATION-ADAPTIVE DISTRIBUTED SOURCE CODING IEEE International Conference on Image Processing Varodayan, D., Girod, B. IEEE. 2010: 3729–3732
  • Redundant Metering for Integrity with Information-Theoretic Confidentiality Varodayan, D. P., Gao, G., IEEE IEEE. 2010: 345–49
  • Authenticating cropped and resized images using distributed source coding and expectation maximization IS&T/SPIE Electronic Image, Media Forensics and Security XI Lin, Y., Varodayan, D., Girod, B. 2009
  • Video quality monitoring for mobile multicast peers using distributed source coding International Mobile Multimedia Communications Conference Lin, Y., Varodayan, D., Girod, B. 2009
  • DISTRIBUTED SOURCE CODING AUTHENTICATION OF IMAGES WITH CONTRAST AND BRIGHTNESS ADJUSTMENT AND AFFINE WARPING Picture Coding Symposium 2009 Lin, Y., Varodayan, D., Girod, B. IEEE. 2009: 317–320
  • DISTRIBUTED SOURCE CODING AUTHENTICATION OF IMAGES WITH AFFINE WARPING IEEE International Conference on Acoustics, Speech and Signal Processing Lin, Y., Varodayan, D., Girod, B. IEEE. 2009: 1481–1484
  • Wyner-Ziv coding of video with unsupervised motion vector learning SIGNAL PROCESSING-IMAGE COMMUNICATION Varodayan, D., Chen, D., Flierl, M., Girod, B. 2008; 23 (5): 369-378
  • WYNER-ZIV CODING OF MULTIVIEW IMAGES WITH UNSUPERVISED LEARNING OF TWO DISPARITIES IEEE International Conference on Multimedia and Expo (ICME 2008) Chen, D., Varodayan, D., Flierl, M., Girod, B. IEEE. 2008: 629–632
  • Collusion-aware traitor tracing in multimedia fingerprinting using sparse signal approximation Varodayan, D., Pepin, C., IEEE IEEE. 2008: 1645-+
  • AUTHENTICATING CONTRAST AND BRIGHTNESS ADJUSTED IMAGES USING DISTRIBUTED SOURCE CODING AND EXPECTATION MAXIMIZATION IEEE International Conference on Multimedia and Expo (ICME 2008) Lin, Y., Varodayan, D., Fink, T., Bellers, E., Girod, B. IEEE. 2008: 613–616
  • LOCALIZATION OF TAMPERING IN CONTRAST AND BRIGHTNESS ADJUSTED IMAGES USING DISTRIBUTED SOURCE CODING AND EXPECTATION MAXIMIZATION 15th IEEE International Conference on Image Processing (ICIP 2008) Lin, Y., Varodayan, D., Fink, T., Bellers, E., Girod, B. IEEE. 2008: 2204–2207
  • Distortion-Aware Retransmission and Concealment of Video Packets Using A Wyner-Ziv-Coded Thumbnail 10th IEEE Workshop on Multimedia Signal Processing Li, Z., Lin, Y., Varodayan, D., Baccichet, P., Girod, B. IEEE. 2008: 428–432
  • Network Image Coding for Multicast 10th IEEE Workshop on Multimedia Signal Processing Varodayan, D., Chen, D., Girod, B. IEEE. 2008: 369–374
  • WYNER-ZIV CODING OF MULTIVIEW IMAGES WITH UNSUPERVISED LEARNING OF DISPARITY AND GRAY CODE 15th IEEE International Conference on Image Processing (ICIP 2008) Chen, D., Varodayan, D., Flierl, M., Girod, B. IEEE. 2008: 1112–1115
  • Distributed stereo image coding with improved disparity and noise estimation 33rd IEEE International Conference on Acoustics, Speech and Signal Processing Chen, D., Varodayan, D., Flierl, M., Girod, B. IEEE. 2008: 1137–1140
  • Audio authentication based on distributed source coding 33rd IEEE International Conference on Acoustics, Speech and Signal Processing Varodayan, D., Lin, Y., Girod, B. IEEE. 2008: 225–228
  • REDUCED-REFERENCE IMAGE QUALITY ASSESSMENT USING DISTRIBUTED SOURCE CODING IEEE International Conference on Multimedia and Expo (ICME 2008) Chono, K., Lin, Y., Varodayan, D., Miyamoto, Y., Girod, B. IEEE. 2008: 609–612
  • Optimal slice size for streaming regions of high resolution video with virtual pan/tilt/zoom functionality European Signal Processing Conference Mavlankar, A., Baccichet, P., Varodayan, D., Girod, B. 2007
  • Image authentication based on distributed source coding IEEE International Conference on Image Processing (ICIP 2007) Lin, L., Varodayan, D., Girod, B. IEEE. 2007: 1133–1136
  • Image authentication and tampering localization using distributed source coding 9th IEEE Workshop on Multimedia Signal Processing Lin, Y., Varodayan, D., Girod, B. IEEE. 2007: 393–396
  • Distributed grayscale stereo image coding with unsupervised learning of disparity 17th Data Compression Conference Varodayan, D., Mavlankar, A., Flierl, M., Girod, B. IEEE COMPUTER SOC. 2007: 143–152
  • Region-of-interest prediction for interactively streaming regions of high resolution video IEEE International Packet Video Workshop Mavlankar, A., Varodayan, D., Girod, B. 2007
  • Wyner-Ziv coding of stereo images with unsupervised learning of disparity Picture Coding Symposium Varodayan, D., Lin, Y., Mavlankar, A., Flierl, M., Girod, B. 2007
  • Spatial models for localization of image tampering using distributed source codes Picture Coding Symposium Lin, Y., Varodayan, D., Girod, B. 2007
  • Wyner-Ziv residual coding of video Picture Coding Symposium Aaron, A., Varodayan, D., Girod, B. 2006
  • Distributed coding of random dot stereograms with unsupervised learning of disparity 8th IEEE Workshop on Multimedia Signal Processing Varodayan, D., Mavlankar, A., Flierl, M., Girod, B. IEEE. 2006: 5–8
  • Exploiting spatial correlation in pixel-domain distributed image compression Picture Coding Symposium Varodayan, D., Aaron, A., Girod, B. 2006
  • Rate-adaptive codes for distributed source coding Signal Processing Journal, Special Section on Distributed Source Coding Varodayan, D., Aaron, A., Girod, B. 2006; 86 (11): 3123-3130
  • Trellis and convolutional precoding for transmitter-based interference presubtraction IEEE TRANSACTIONS ON COMMUNICATIONS Yu, W., Varodayan, D. P., Cioffi, J. M. 2005; 53 (7): 1220-1230
  • Rate-adaptive distributed source coding using Low-Density Parity-Check codes 39th Asilomar Conference on Signals, Systems and Computers Varodayan, D., Aaron, A., Girod, B. IEEE. 2005: 1203–1207