Latency Compensation by Horizontal Scanline Selection for Head- Mounted Displays

A fundamental task of a virtual-environment system is to present images that change appropriately as the user’s head moves. Latency produces registration error causing the scene to appear spatially unstable. To improve the spatial stability of the scene, we built a system that, immediately before scanout to a head-mounted raster display, selects a portion of each scanline from an image rendered at a wider display width. The pixel selection corrects for yaw head rotations and effectively reduces latency for yaw to the millisecond range. In informal evaluations, users consistently judged visual scenes more stable and reported no additional visual artifacts with horizontal scanline selection than the same system without. Scanline-selection hardware can be added to existing virtual-reality systems as an external device between the graphics card and the raster display.