@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{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{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}
}