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

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?

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]

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

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)]

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]

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?

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?

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 –The Design and Implementation of a VR-Architecture for Smooth Motion, Submitted to VRST 2007

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