The Visual Computing of Projector‐Camera Systems

Abstract

The 'Virtual Iraq' VR environment is designed to be an immersive tool foruse as an Exposure Therapy treatment tool for combat related PTSD. The application consists of a series of virtual scenarios designed to represent relevant contexts for VR exposure therapy, including city and desert road environments. In addition to the visual stimuli presented in the VR HMD, directional 3D audio, vibrotactile and olfactory stimuli of relevance can be delivered. Stimulus presentation is controlled by the clinician via a separate 'wizard of oz'; interface, with the clinician in full audio contact with the patient. The presentation at the conference will detail the results of our research and clinical treatment protocols as they stand at that time. Presently, an open clinical trial to evaluate our system's efficacy for PTSD treatment with military personnel is being conducted at the Naval Medical Center San Diego and at Ft. Lewis, Washington, and a randomized controlled trial comparing VR alone and VRcycloserine is in progress at Emory University. Ten other test sites are now on line between now and the conference addressing a variety of research questions involving assessment of PTSD, physiological markers of the disorder, impact of multiple trauma events, and an fMRI study. Thus far, eight male and female treatment completers (out of 11) at two of the treatment sites have shown clinically significant improvements at posttreatment, with these patients now no longer meeting PTSD criteria. Due to the challenges for treatment of this disorder, we are encouraged by these early results. The Visual Computing of Projector-Camera SystemsBimber,O. AbstractTheir increasing capabilities and declining cost make video projectors widespread and established presentation tools. Being able to generate images that are larger than the actual display device virtually anywhere is an interesting feature for many applications that cannot be provided by desktop screens. Several research groups discover this potential by applying projectors in unconventional ways to develop new and innovative information displays that go beyond simple screen presentations. Todays projectors are able to modulate the displayed images spatially and temporally. Synchronized camera feedback is analyzed to support a real-time image correction that enables projections on complex everyday surfaces that are not bound to projector-optimized canvases or dedicated screen configurations. In this talk I will give an overview over our projector-camera-based image correction techniques for geometric warping, radiometric compensation, reduction of global illumination (such as inter-reflections) or view-dependent effects (such as specular reflections), increasing focal depth, and embedding imperceptible codes with a single or with multiple projection units. Thereby, GPU-based real-time rendering and computer vision on graphics hardware are tightly coupled. Such techniques have proved to be useful tools for many real-world applications. Examples include ad-hoc stereoscopic VR/...

A light transport model for mitigating multipath interference in Time-of-flight sensors

“…This is a common simplification that has been exploited in prior work in light transport (see Bimber et al [5]). Intuitively, the contribution of higher order bounces rapidly diminishes due to a combination of surface absorbance, the inverse square law, and Lambert's law (see supplementary material for details).…”

Enhancing User Experiences of Mobile-Based Augmented Reality via Spatial Augmented Reality: Designs and Architectures of Projector-Camera Devices

“…(iv) Module D is often found in smart projection systems, including projector-based AR systems, where the original images for projection are transformed before actual projection. Generally this is referred to geometric [4,14,18,24,[42][43][44] and photometric (a.k.a., radiometric [5,7,24,26,[45][46][47]) compensation whose purpose is to precompensate the projected imagery so that the image when overlaid on the surface will look as similar as possible to its originally intended appearance, regardless of surface's geometry, color, texture, and so on. An example is illustrated in Figure 6 where the original project rgb1 and project ir1 are altered both geometrically and photometrically into project rgb2 and project ir2.…”

Hiding a Second Appearance in a Physical Relief Surface

“…Second, shaded image B is only visible when appropriately illuminated. While a geometrically and chromatically calibrated projector illumination system can impart a new appearance on physical surfaces (e.g., state-of-the-art report [17]), it is not sufficient to yield an arbitrary image A and image B. In particular, even with perfect calibration an arbitrary image B cannot be produced.…”