In this tutorial paper, we discuss the ITU-T H.263+ (or H.263 Version 2) low-bit-rate video coding standard. We first describe, briefly, the H.263 standard including its optional modes. We then address the 12 new negotiable modes of H.263+. Next, we present experimental results for these modes, based on our public-domain implementation (see our Web site at http://spmg.ece.ubc.ca). Tradeoffs among compression performance, complexity, and memory requirements for the H.263+ optional modes are discussed. Finally, results for mode combinations are presented.Index Terms-H.263, H.263+, video compression standards, video compression and coding, video conferencing, video telephony.
The design and implementation of a portable meeting recorder is presented. Composed of an omni-directional video camera with four-channel audio capture, the system saves a view of all the activity in a meeting and the directions from which people spoke. Subsequent analysis computes metadata that includes video activity analysis of the compressed data stream and audio processing that helps locate events that occurred during the meeting. Automatic calculation of the room in which the meeting occurred allows for efficient navigation of a collection of recorded meetings. A user interface is populated from the metadata description to allow for simple browsing and location of significant events.
A new method for augmenting paper documents with electronic information is described that does not modify the format of the paper document in any way. Applicable to both commercially printed documents as well as documents that are output from PC's, the technique we call Paper-Based Augmented Reality substantially improves the utility of paper. We describe the recognition technology that makes this possible as well as several applications. An implementation on a camera phone is discussed that lets users retrieve data and access links from paper documents to electronic data. Recognition is performed at 4 frames per second on a Treo 700w and support is provided for several user applications, including "clickable paper" -printed web pages whose appearance is unchanged but that can be navigated with a camera phone.
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