Imager Lab Meetings

The Imager meetings are held at 12:30-2:00pm every other Wednesday in MCML building room 256 (across from CICSR building) and are comprised of a supposedly short discussion of lab operations and then a technical presentation. The technical presentations are presented first on a need and then a rotational basis. Everyone in the lab is expected to take their turn presenting.

Duties of Chair

  • Post meeting reminder and abstract of technical presentation to ubc.cs.imager a day or two before the meeting.
  • Stop faculty from rambling aimlessly.
  • Take and post minutes.

Technical Presentations

A technical presentation is a talk about anything related to computer graphics, HCI, or visualization. This talk can be as short and informal as you like. Please note that "I have nothing to present" is not a valid excuse for not giving a presentation. There is no need to stress out over your talk; just have fun with it! Some tried and true technical presentation topics include:

  • a course project that involves graphics, HCI, or visualization
  • a review of a paper or papers
  • a half-baked idea that needs roasting
  • paper presentation dry run
  • M.Sc . presentation
  • Ph.D. proposal dry run
  • Ph.D. defense dry run

Technical presentations are about 20 minutes long with a 10 minute question and answer session afterwards. Really technical presentations should start with a 5-10 minute introduction that everyone in the lab should be able to understand.

When Attending a Technical Presentation

When attending a technical presentation, it is important to be as supportive to the speaker as you can. Don't forget, many of our lab members are relatively inexperienced public speakers; it does not do them any good to be overly critical on minor points.

When Do I Give a Technical Presentation?

See the schedule below. But if you want to give a presentation before your turn comes, just email ( and I'll schedule your talk. Except for dates marked with asterisks, the following schedule is somewhat flexible and is based on a longest-time-since-last-presentation rotation. After giving a talk, you drop to the bottom of the list.

Schedule of Chairs and Technical Presentations



General Information

September 15

Vladislav Kraevoy

Technical Presentation:

Robert Bridson presented a new sci-fi horror movie made by his animation class students.

Agenda items:

1.      Discussed the issue of Imager meeting conflict with Michiel's grad animation course. Unanimously decided that Michiel is not important.

2.      Lavana brought up Siggraph reimbursements.

September 29

Fred Kimberley

Technical Presentation:

Presenter: Fred Kimberley

Title: Low Dimensional Search for Efficient Texture Synthesis

Abstract: Most current pixel-based texture synthesis algorithms select the value of the pixel to be synthesized by using a high dimensional (typically 100-300 dimensions) approximate nearest neighbour (ANN) search.Nearest neighbour search in high dimensions is sucky.It is very computationally expensive and has questionable usefulness.We present an algorithm that selects a small subset of the dimensions and performs an ANN search in this lower dimensional space.This results in a faster search with more meaningful results.In addition we perform most of the distance calculation as a preprocess so that very little computation has to be done at runtime.

Agenda items:

October 13

Andrew Chan

Technical Presentation:

Presenter: Andrew Chan

Abstract: Collaboration is taking place increasingly between individuals living in different cities, countries, or continents. Instead of relying on time-consuming, expensive, and exhausting business travel, companies are turning to web conferencing systems, Internet-based systems that support distributed meetings, training, and collaboration. These systems support /view-sharing/, where an individual can share an application with his or her collaborators, allowing them to view and interact with the application in real-time. While flexible, these systems only permit one user to control the application at a time, necessitating a turn-taking protocol. Current web conferencing systems depend heavily on visual elements like dialog boxes or tool-tips to deliver messages such as requests for control. However, the collaborative tasks being performed are typically highly visual in nature themselves, meaning that messages can either intrude or be missed. Another shortcoming of current systems is that they fail to support flexibility in requesting control, something we take for granted in face-to-face collaboration.

In this thesis, we introduce a novel urgency-based turn-taking protocol, where users can request control with two levels of urgency or immediately take control. Haptic icons, touch-sense stimuli that have been assigned a meaning, are used in this protocol to periodically inform a user of the current turn-taking state. Our research was conducted in three phases. First, we designed the protocol and selected a set of haptic icons. Next, we evaluated the ability of subjects to learn the haptic icons and identify them under different amounts of cognitive workload. Finally, we recruited groups of subjects to use the protocol in a collaborative environment and evaluated their performance.

Our results show that haptic feedback is a viable channel for communicating turn-taking information. The haptic icons can be learned in a reasonable amount of time and recalled with high accuracy. As well, users in control are more responsive to requests for control and control is shared ore equally among group members when haptic feedback is present. The urgency-based protocol also shows promise when used with haptic feedback.

Agenda items:

October 27

Vladislav Kraevoy

Technical Presentation:

Presenter: Dan Archambault

Title: Hierarchical Graph Layout by Topological Features

Agenda items: TBA

November 10



November 24



December 01