Interpolating Vertical Parallax for an Autostereoscopic 3 D Projector Array

We present a technique for achieving tracked vertical parallax for multiple users using a variety of autostereoscopic projector array setups, including frontand rearprojection, and curved display surfaces. This hybrid parallax approach allows for immediate horizontal parallax as viewers move left and right and tracked parallax as they move up and down, allowing cues such as 3D perspective and eye contact to be conveyed faithfully. We use a lowcost RGB-depth sensor to simultaneously track multiple viewer head positions in 3D space, and we interactively update the imagery sent to the array so that imagery directed to each viewer appears from a consistent and correct vertical perspective. Unlike previous work, we do not assume that the imagery sent to each projector in the array is rendered from a single vertical perspective This lets us apply hybrid parallax to displays where a single projector forms parts of multiple viewers’ imagery. Thus, each individual projected image is rendered with multiple centers of projection, and might show an object from above on the left and from below on the right. We demonstrate this technique using a dense horizontal array of pico-projectors aimed into an anisotropic vertical diffusion screen, yielding 1.5◦ angular resolution over 110◦ field of view. To create a seamless viewing experience for multiple viewers, we smoothly interpolate the set of viewer heights and distances on a per-vertex basis across the array’s field of view, reducing image distortion, crosstalk, and artifacts from tracking errors.