Group Member

Howard Wing Ho Leung
PhD.

Personal Homepage: http://www.cs.cityu.edu.hk/~howard/
Email: wingho@alumni.carnegiemellon.edu

Office: Porter Hall B43
Lab: Porter Hall B6
Phone: 412-268-7100
Fax: 412-268-1679

Mailing Address:
Porter Hall B6, Department of ECE,
Carnegie Mellon University,
5000 Forbes Avenue, Pittsburgh,
PA 15213-3890, USA

[Research Interests] [Project] [Publications] [Joint Collaboration between CMU and IBM]

Research Interests

Sketch Retrieval
- Using a pen-based device as input provides the user a more natural way of interaction compared with other input devices such as the keyboard. As a result, this motivation opens up a new field of research for improving pen-computing technologies in order to justify the use of these pen-based devices. For example, in the classroom, the lecture notes written by the teacher on the whiteboard can be captured electronically by a collaboration device such as "mimio". Later students can retrieve relevant lecture materials from the hand-drawn sketch database by sketching a query drawing. Each sketch (hand-drawing) in the database consists of strokes that are sequences of coordinates of the points sampled by the pen-based device. Retrieval in the hand-drawn sketch database is equivalent to finding a stroke or multiple strokes from the database that are a good match to the query stroke(s).
Image-Based Rendering (IBR)
- For Image-Based Rendering applications, different views of a scene can be reconstructed by processing the images acquired at some fixed views of that scene. Often the number of captured images is very large, we have to store these images efficiently. In other words, can we compress these images in such a way that we obtain the most efficient representation of these IBR images ?
3D Virtual Conferencing Environment
- In a virtual 3D conferencing environment, users can communicate with each other freely by using animated human-like characters known as avatars to represent themselves. We can apply various audio-visual communication technologies such as real-time spatialized audio or face and eye tracking to provide consistent spatial relationship among users, both visually and acoustically, and to preserve the eye contact and the sense of immersion. Moreover, we can use texture mapping or image-based rendering to provide a more realistic look of an object or the environment in this virtual space.

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Project

NetICE
Networked Intelligent Collaborative Environment

When multiple participants are involved in video conferencing, current software places different participants in different windows. This arrangement makes it difficult for the participants to tell who is talking to whom, and there is no sense of immersion. By enhancing the capabilities of the network and adding intelligence to the end terminal, the quality of the audio-visual communication can be improved. In this project, we would like to provide a system that will reproduce an actual conference setting, so that people can communicate from anywhere at any time and still feel that they are in the same environment without realizing the limitation of the physical network.

For more details on the project please see the NetICE project page.

Hand-Drawn Sketch Retrieval

In this system, the user is able to draw a query and the system will search through similar sketches from a collection of free-form hand-drawings. For example, in the classroom, the lecture notes written by the teacher on the whiteboard can be captured electronically by a collaboration device such as "mimio". Later students can retrieve relevant lecture materials from the hand-drawn sketch database by sketching a query drawing.

For more details on the project please see the Hand-Drawn Sketch Retrieval project page.

Trademark Retrieval

In traditional trademark retrieval systems, the trademarks are first annotated with keywords that are then used for retrieval. However, this process requires a lot of manual labor in order to assign keywords. Also, the annotation for the same trademark may not be consistent with different users. As a result, it is more desirable to allow the user to input a query by providing a rough sketch and then the system is smart enough to automatically extract features from this query sketch and use them for comparison in order to search for similar trademarks in the database.

For more details on the project please see the Trademark Retrieval project page.

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Publications

Journal:

Wing Ho Leung and Tsuhan Chen, "A Multi-User 3-D Virtual Environment with Interactive Collaboration and Shared Whiteboard Technologies", Journal of Multimedia Tools and Applications, Special Issue on Distributed Multimedia Systems for Virtual Society, Vol. 19, No. 3, April 2003.
Wing Ho Leung and Tsuhan Chen, "Creating a Multiuser 3-D Virtual Environment", IEEE Signal Processing Magazine, Vol. 18, pp.9-16, May 2001.

Conference:

Wing Ho Leung and Tsuhan Chen, "Hierarchical Matching for Retrieval of Hand-Drawn Sketches", IEEE Intl. Conf. on Multimedia and Expo. (ICME 2003), Vol 2, pp.29-32, Baltimore, MD, July 2003.
Wing Ho Leung and Tsuhan Chen, "Retrieval of Hand-Drawn Sketches With Partial Matching", IEEE Intl. Conf. on Acoustics Speech and Signal Processing (ICASSP 2003), Vol. 3, pp.5-8, Hong Kong, China, April 2003.
Wing Ho Leung and Tsuhan Chen, "eMeeting: A Multimedia Application for Interactive Meeting and Seminar", IEEE Global Telecommunications Conference (Globecom 2002), Vol. 3, pp.2994-2998, Taipei, Taiwan, R.O.C., November 2002.
Wing Ho Leung and Tsuhan Chen, "Retrieval of Sketches Based on Spatial Relation Between Strokes", IEEE Intl. Conf. on Image Processing (ICIP 2002), Vol. 1, pp. 908-911, New York, September 2002.
Wing Ho Leung and Tsuhan Chen, "Trademark Retrieval Using Contour-Skeleton Stroke Classification", IEEE Intl. Conf. on Multimedia and Expo. (ICME 2002), Lausanne, Switzerland, August 2002.
Wing Ho Leung and Tsuhan Chen, "User-Independent Retrieval of Free-Form Hand-Drawn Sketches", IEEE Intl. Conf. on Acoustics Speech and Signal Processing (ICASSP 2002), Vol. 2, pp.2029-2032, Orlando, Florida, May 2002.
Belle Tseng, Zon-Yin Shae, Wing Ho Leung and Tsuhan Chen, "Immersive Whiteboards in a Networked Collaborative Environment", IEEE Intl. Conf. on Multimedia and Expo. (ICME 2001), Tokyo, August 2001.
Wing Ho Leung and Tsuhan Chen, "Compression with Mosaic Prediction for Image-Based Rendering Applications", IEEE Intl. Conf. on Multimedia and Expo. (ICME 2000), Vol. 3., pp.1649-1652, New York, July 2000.
Wing Ho Leung, Khalid goudeaux, Sooksan Panichpapiboon, Sy-Bor Wang and Tsuhan Chen, "Networked Intelligent Collaborative Environment (NetICE)", IEEE Intl. Conf. on Multimedia and Expo. (ICME 2000), Vol. 3., pp.1645-1648, New York, July 2000.
Wing Ho Leung, Belle L. Tseng and Tsuhan Chen, "Realistic Video Avatar", IEEE Intl. Conf. on Multimedia and Expo. (ICME 2000), Vol. 2, pp.631-634, New York, July 2000.
Wing Ho Leung and Tsuhan Chen, "Networked Collaborative Environment with animated 3D avatar", IEEE Workshop on Multimedia Signal Processing, Los Angeles, California, Dec 1998.

Technical Report and White Paper:

Wing Ho Leung and Tsuhan Chen, "CMU Trademark Retrieval System", White Paper, October 2002.
Wing Ho Leung and Tsuhan Chen, "Line-Space Representation and Compression for Image-Based Rendering", Carnegie Mellon Technical Report: AMP01-02

Thesis:

Howard Wing Ho Leung, "Representations, Feature Extraction, Matching and Relevance Feedback for Sketch Retrieval", Carnegie Mellon University, June 2003.

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