@techreport{GrundhoeferBimber2008,
  author    = {Grundh{\"o}fer, Anselm and Bimber, Oliver},
  title     = {Dynamic Bluescreens},
  doi       = {10.25643/bauhaus-universitaet.1233},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20080226-13016},
  year      = {2008},
  abstract  = {Blue screens and chroma keying technology are essential for digital video composition. Professional studios apply tracking technology to record the camera path for perspective augmentations of the original video footage. Although this technology is well established, it does not offer a great deal of flexibility. For shootings at non-studio sets, physical blue screens might have to be installed, or parts have to be recorded in a studio separately. We present a simple and flexible way of projecting corrected keying colors onto arbitrary diffuse surfaces using synchronized projectors and radiometric compensation. Thereby, the reflectance of the underlying real surface is neutralized. A temporal multiplexing between projection and flash illumination allows capturing the fully lit scene, while still being able to key the foreground objects. In addition, we embed spatial codes into the projected key image to enable the tracking of the camera. Furthermore, the reconstruction of the scene geometry is implicitly supported.},
  subject      = {Association for Computing Machinery / Special Interest Group on Graphics},
  language  = {en}
}
@techreport{BimberIwai2008,
  author    = {Bimber, Oliver and Iwai, Daisuke},
  title     = {Superimposing Dynamic Range},
  doi       = {10.25643/bauhaus-universitaet.1287},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20080422-13585},
  year      = {2008},
  abstract  = {We present a simple and cost-efficient way of extending contrast, perceived tonal resolution, and the color space of static hardcopy images, beyond the capabilities of hardcopy devices or low-dynamic range displays alone. A calibrated projector-camera system is applied for automatic registration, scanning and superimposition of hardcopies. We explain how high-dynamic range content can be split for linear devices with different capabilities, how luminance quantization can be optimized with respect to the non-linear response of the human visual system as well as for the discrete nature of the applied modulation devices; and how inverse tone-mapping can be adapted in case only untreated hardcopies and softcopies (such as regular photographs) are available. We believe that our approach has the potential to complement hardcopy-based technologies, such as X-ray prints for filmless imaging, in domains that operate with high quality static image content, like radiology and other medical fields, or astronomy.},
  subject      = {Bildverarbeitung},
  language  = {en}
}
@techreport{GrosseBimber2008,
  author    = {Grosse, Max and Bimber, Oliver},
  title     = {Coded Aperture Projection},
  doi       = {10.25643/bauhaus-universitaet.1234},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20080227-13020},
  year      = {2008},
  abstract  = {In computer vision, optical defocus is often described as convolution with a filter kernel that corresponds to an image of the aperture being used by the imaging device. The degree of defocus correlates to the scale of the kernel. Convolving an image with the inverse aperture kernel will digitally sharpen the image and consequently compensate optical defocus. This is referred to as deconvolution or inverse filtering. In frequency domain, the reciprocal of the filter kernel is its inverse, and deconvolution reduces to a division. Low magnitudes in the Fourier transform of the aperture image, however, lead to intensity values in spatial domain that exceed the displayable range. Therefore, the corresponding frequencies are not considered, which then results in visible ringing artifacts in the final projection. This is the main limitation of previous approaches, since in frequency domain the Gaussian PSF of spherical apertures does contain a large fraction of low Fourier magnitudes. Applying only small kernel scales will reduce the number of low Fourier magnitudes (and consequently the ringing artifacts) -- but will also lead only to minor focus improvements. To overcome this problem, we apply a coded aperture whose Fourier transform has less low magnitudes initially. Consequently, more frequencies are retained and more image details are reconstructed.},
  subject      = {Association for Computing Machinery / Special Interest Group on Graphics},
  language  = {en}
}
@techreport{Bimber2008,
  author    = {Bimber, Oliver},
  title     = {Superimposing Dynamic Range},
  doi       = {10.25643/bauhaus-universitaet.1379},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20090303-14662},
  year      = {2008},
  abstract  = {Replacing a uniform illumination by a high-frequent illumination enhances the contrast of observed and captured images. We modulate spatially and temporally multiplexed (projected) light with reflective or transmissive matter to achieve high dynamic range visualizations of radiological images on printed paper or ePaper, and to boost the optical contrast of images viewed or imaged with light microscopes.},
  subject      = {Bildverarbeitung},
  language  = {en}
}
@techreport{KurzHaentschGrosseetal.2007,
  author    = {Kurz, Daniel and H{\"a}ntsch, Ferry and Grosse, Max and Schiewe, Alexander and Bimber, Oliver},
  title     = {Laser Pointer Tracking in Projector-Augmented Architectural Environments},
  doi       = {10.25643/bauhaus-universitaet.818},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-8183},
  year      = {2007},
  abstract  = {We present a system that applies a custom-built pan-tilt-zoom camera for laser-pointer tracking in arbitrary real environments. Once placed in a building environment, it carries out a fully automatic self-registration, registrations of projectors, and sampling of surface parameters, such as geometry and reflectivity. After these steps, it can be used for tracking a laser spot on the surface as well as an LED marker in 3D space, using inter-playing fisheye context and controllable detail cameras. The captured surface information can be used for masking out areas that are critical to laser-pointer tracking, and for guiding geometric and radiometric image correction techniques that enable a projector-based augmentation on arbitrary surfaces. We describe a distributed software framework that couples laser-pointer tracking for interaction, projector-based AR as well as video see-through AR for visualizations with the domain specific functionality of existing desktop tools for architectural planning, simulation and building surveying.},
  subject      = {Association for Computing Machinery / Special Interest Group on Graphics},
  language  = {en}
}
@techreport{GrundhoeferSeegerHaentschetal.2007,
  author    = {Grundh{\"o}fer, Anselm and Seeger, Manja and H{\"a}ntsch, Ferry and Bimber, Oliver},
  title     = {Dynamic Adaptation of Projected Imperceptible Codes},
  doi       = {10.25643/bauhaus-universitaet.816},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-8168},
  year      = {2007},
  abstract  = {In this paper we present a novel adaptive imperceptible pattern projection technique that considers parameters of human visual perception. A coded image that is invisible for human observers is temporally integrated into the projected image, but can be reconstructed by a synchronized camera. The embedded code is dynamically adjusted on the fly to guarantee its non-perceivability and to adapt it to the current camera pose. Linked with real-time flash keying, for instance, this enables in-shot optical tracking using a dynamic multi-resolution marker technique. A sample prototype is realized that demonstrates the application of our method in the context of augmentations in television studios.},
  subject      = {Association for Computing Machinery / Special Interest Group on Graphics},
  language  = {en}
}
@techreport{WetzsteinBimber2007,
  author    = {Wetzstein, Gordon and Bimber, Oliver},
  title     = {Radiometric Compensation through Inverse Light Transport},
  doi       = {10.25643/bauhaus-universitaet.812},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-8126},
  year      = {2007},
  abstract  = {Radiometric compensation techniques allow seamless projections onto complex everyday surfaces. Implemented with projector-camera systems they support the presentation of visual content in situations where projection-optimized screens are not available or not desired - as in museums, historic sites, air-plane cabins, or stage performances. We propose a novel approach that employs the full light transport between a projector and a camera to account for many illumination aspects, such as interreflections, refractions and defocus. Precomputing the inverse light transport in combination with an efficient implementation on the GPU makes the real-time compensation of captured local and global light modulations possible.},
  subject      = {Association for Computing Machinery / Special Interest Group on Graphics},
  language  = {en}
}