Journal ArticleDOI
Extended Depth-of-Field Projector by Fast Focal Sweep Projection
TLDR
The approximate invariance of the projector's IPSF is proved both numerically and experimentally and it is demonstrated that a structured light pattern projection technique using the proposed method can measure the shape of an object with large depth variances more accurately than normal projection techniques.Abstract:
A simple and cost-efficient method for extending a projector's depth-of-field (DOF) is proposed. By leveraging liquid lens technology, we can periodically modulate the focal length of a projector at a frequency that is higher than the critical flicker fusion (CFF) frequency. Fast periodic focal length modulation results in forward and backward sweeping of focusing distance. Fast focal sweep projection makes the point spread function (PSF) of each projected pixel integrated over a sweep period (IPSF; integrated PSF) nearly invariant to the distance from the projector to the projection surface as long as it is positioned within sweep range. This modulation is not perceivable by human observers. Once we compensate projection images for the IPSF, the projected results can be focused at any point within the range. Consequently, the proposed method requires only a single offline PSF measurement; thus, it is an open-loop process. We have proved the approximate invariance of the projector's IPSF both numerically and experimentally. Through experiments using a prototype system, we have confirmed that the image quality of the proposed method is superior to that of normal projection with fixed focal length. In addition, we demonstrate that a structured light pattern projection technique using the proposed method can measure the shape of an object with large depth variances more accurately than normal projection techniques.read more
Citations
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Journal ArticleDOI
Near-eye varifocal augmented reality display using see-through screens
TL;DR: A new optical design for see-through near-eye displays is presented that is simple, compact, varifocal, and provides a wide field of view with clear peripheral vision and large eyebox and establishes fundamental trade-offs between the quantitative parameters of resolution, field-of- view, and the form-factor of the design.
Journal ArticleDOI
Accommodation-invariant computational near-eye displays
TL;DR: This work introduces a new display technology, dubbed accommodation-invariant (AI) near-eye displays, to improve the consistency of depth cues in near- eye displays and validate the principle of operation of AI displays using a prototype display that allows for the accommodation state of users to be measured while they view visual stimuli using multiple different display modes.
Journal ArticleDOI
Recent Advances in Projection Mapping Algorithms, Hardware and Applications
Anselm Grundhöfer,Daisuke Iwai +1 more
TL;DR: The novel enhancements to simplify the 3D geometric calibration task can now be reliably carried out either interactively or automatically using self‐calibration methods, and improvements regarding radiometric calibration and compensation are summarized.
Journal ArticleDOI
Manufacturing Application-Driven Foveated Near-Eye Displays
Kaan Akşit,Praneeth Chakravarthula,Kishore Rathinavel,Youngmo Jeong,Rachel Albert,Henry Fuchs,David Luebke +6 more
TL;DR: A complete near-eye display manufacturing pipeline with a day lead time using commodity hardware is presented, and it is shown that a ski-goggles form factor, a large monocular field of view, and a resolution of 12 cycles per degree can be achieved.
Journal ArticleDOI
Fabricating Diminishable Visual Markers for Geometric Registration in Projection Mapping
TL;DR: A visual marker embedding method for the pose estimation of a projection surface to correctly map projected images onto the surface with mechanical accuracy and a radiometric compensation technique to quickly diminish the marker appearance is proposed.
References
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Journal ArticleDOI
Image quality assessment: from error visibility to structural similarity
TL;DR: In this article, a structural similarity index is proposed for image quality assessment based on the degradation of structural information, which can be applied to both subjective ratings and objective methods on a database of images compressed with JPEG and JPEG2000.
Journal ArticleDOI
Pattern codification strategies in structured light systems
TL;DR: A new and definitive classification of patterns for structured light sensors is presented, based on projecting a light pattern and viewing the illuminated scene from one or more points of view, for recovering the surface of objects.
Book
Spatial Augmented Reality: Merging Real and Virtual Worlds
Oliver Bimber,Ramesh Raskar +1 more
TL;DR: This book discusses spatial augmented reality approaches that exploit optical elements, video projectors, holograms, radio frequency tags, and tracking technology, as well as interactive rendering algorithms and calibration techniques in order to embed synthetic supplements into the real environment or into a live video of thereal environment.
Journal ArticleDOI
Flexible Depth of Field Photography
TL;DR: Flexible DOF imaging can open a new creative dimension in photography and lead to new capabilities in scientific imaging, vision, and graphics.