1. QUASID: Quantifying 3D Image Perception in VR Ferdi Smit Center for Mathematics and Computer Science (CWI) Amsterdam

2. Why quantify image perception? QUASID: Quantify Interaction –Evaluate/improve 3D input-devices Hypothesis: –Improved perceived 3D images  Improved 3D interaction Challenge: –Subjective quality of 3D images/animations –How to measure/quantify?

3. Example: Crosstalk Reduction Left: Crosstalk ghost image in 3D stereo-viewing Right: Crosstalk reduction algorithm applied Which is better? How much better? [Non-uniform Crosstalk Reduction for Dynamic Scenes, IEEE-VR 2007]

4. Crosstalk Evaluation: Data Photographs of the display –Through the shutter glasses –What the user sees Compare photographs to evaluate differences Per-pixel comparison (RMSE) useless

5. Crosstalk Evaluation: VDP Need perceptual comparison –Existing software: Visible Differences Predictor [Daly90] Measure percentage of perceptually different pixels –How different is different? –Compare different pixels in perceptual color space [Three Extensions to Subtractive Crosstalk Reduction, EGVE 2007 (to appear)]

6. Example: Effects of Motion Motion can cause ‘judder’: –Visible double-image artifacts –Perceived jerky motion Extrapolate motion field –Results in smooth perceived motion –Eliminates perceptual artifacts [The Design and Implementation of a VR-Architecture for Smooth Motion, submitted to VRST 2007]

7. Example: Effects of Motion Judder reduction: –Increased feeling of system responsiveness –Lower perceived latency –Better interaction? How to measure improvement? –Only still image comparisons –Need to quantify temporal perception! How?

8. Open Questions We can now determine: – which algorithm is perceptually better … – … and by how much However: –What about animations and temporal perception? –How is interaction influenced by better images?

9. Current Status Crosstalk papers published: –Non-Uniform Crosstalk Reduction for Dynamic Scenes, IEEE-VR 2007 –Three Extensions to Subtractive Crosstalk Reduction, EGVE 2007 (to appear) Other Work: –GraphTracker: A Topology Projection Invariant Optical Tracker, EGVE 2006, and Computers and Graphics Feb. 2007 –The Design and Implementation of a VR-Architecture for Smooth Motion, Submitted to VRST 2007

10. The End Thank you for your attention. Questions / Suggestions ?