Selected Recent Talks:

[slide] [project web site]

Overview of our new project aiming at blind detection of digital tampering of photographs, without using any watermark or digital signature. Our approach combines statistical modeling of natural image signals, camera filters and transfer functions, and 3D scene-lighting-reflectance modeling. We have developed algorithms and software for detecting block-level splicing and computer graphics generated images. We have also constructed benchmark data sets that can be used by researchers for evaluating performance.

keynote speech at International Conference on Image Analysis and Processing (ICIAP), Mantova, Italy, Sept. 2003. [slide]

In this talk, I use the ubiquitous media access scenarios to advocate exploration of content analysis techniques for new applications such as adaptive video presentation, streaming, and transcoding. I presented the need and some solutions for real-time event detection and unsupervised pattern discovery in new domains. I also described our recent results in real-time content-based utility function prediction for automatically selecting the optimal MPEG-4 transcoding options.

This talk includes an overview of our research in video indexing, structure discovery, skimming, and their applications. Specific topics include
    1. detecting structures using rule-based models and HMM models
    2. content-adaptive real-time streaming based on detected structures
    3. Video skimming using a rigorous utility model
    4. Application of video indexing in medical domains

I presented the utility-based optimization framework to model the relationships between different types of resources, utilities, and adaptation operations. The framework is analogous to the conventional rate-distortion model, in which rate (resource), distortion (utility), and coding parameters (adaptation operators) are considered. I described how the framework can be used to help derive optimal solutions for video skimming and transcoding operator selection.

(abstract and bio)