@unpublished{WetzsteinBimber2006,
  author    = {Wetzstein, Gordon and Bimber, Oliver},
  title     = {A Generalized Approach to Radiometric},
  doi       = {10.25643/bauhaus-universitaet.762},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-7625},
  year      = {2006},
  abstract  = {We propose a novel method that applies the light transport matrix for performing an image-based radiometric compensation which accounts for all possible types of light modulation. For practical application the matrix is decomposed into clusters of mutually influencing projector and camera pixels. The compensation is modeled as a linear system that can be solved with respect to the projector patterns. Precomputing the inverse light transport in combination with an efficient implementation on the GPU makes interactive compensation rates possible. Our generalized method unifies existing approaches that address individual problems. Based on examples, we show that it is possible to project corrected images onto complex surfaces such as an inter-reflecting statuette, glossy wallpaper, or through highly-refractive glass. Furthermore, we illustrate that a side-effect of our approach is an increase in the overall sharpness of defocused projections.},
  subject      = {Association for Computing Machinery / Special Interest Group on Graphics},
  language  = {en}
}
@misc{Wetzstein2006,
  type      = {Master Thesis},
  author    = {Wetzstein, Gordon},
  title     = {Radiometric Compensation of Global Illumination Effects with Projector-Camera Systems},
  doi       = {10.25643/bauhaus-universitaet.810},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-8106},
  school      = {Bauhaus-Universit{\"a}t Weimar},
  year      = {2006},
  abstract  = {Projector-based displays have been evolving tremendously in the last decade. Reduced costs and increasing capabilities have let to a widespread use for home entertainment and scientific visualization. The rapid development is continuing - techniques that allow seamless projection onto complex everyday environments such as textured walls, window curtains or bookshelfs have recently been proposed. Although cameras enable a completely automatic calibration of the systems, all previously described techniques rely on a precise mapping between projector and camera pixels. Global illumination effects such as reflections, refractions, scattering, dispersion etc. are completely ignored since only direct illumination is taken into account. We propose a novel method that applies the light transport matrix for performing an image-based radiometric compensation which accounts for all possible lighting effects. For practical application the matrix is decomposed into clusters of mutually influencing projector and camera pixels. The compensation is modeled as a linear equation system that can be solved separately for each cluster. For interactive compensation rates this model is adapted to enable an efficient implementation on programmable graphics hardware. Applying the light transport matrix's pseudo-inverse allows to separate the compensation into a computational expensive preprocessing step (computing the pseudo-inverse) and an on-line matrix-vector multiplication. The generalized mathematical foundation for radiometric compensation with projector-camera systems is validated with several experiments. We show that it is possible to project corrected imagery onto complex surfaces such as an inter-reflecting statuette and glass. The overall sharpness of defocused projections is increased as well. Using the proposed optimization for GPUs, real-time framerates are achieved.},
  subject      = {Association for Computing Machinery / Special Interest Group on Graphics},
  language  = {en}
}
@unpublished{GrundhoeferBimber2006,
  author    = {Grundh{\"o}fer, Anselm and Bimber, Oliver},
  title     = {Real-Time Adaptive Radiometric Compensation},
  doi       = {10.25643/bauhaus-universitaet.784},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-7848},
  year      = {2006},
  abstract  = {Recent radiometric compensation techniques make it possible to project images onto colored and textured surfaces. This is realized with projector-camera systems by scanning the projection surface on a per-pixel basis. With the captured information, a compensation image is calculated that neutralizes geometric distortions and color blending caused by the underlying surface. As a result, the brightness and the contrast of the input image is reduced compared to a conventional projection onto a white canvas. If the input image is not manipulated in its intensities, the compensation image can contain values that are outside the dynamic range of the projector. They will lead to clipping errors and to visible artifacts on the surface. In this article, we present a novel algorithm that dynamically adjusts the content of the input images before radiometric compensation is carried out. This reduces the perceived visual artifacts while simultaneously preserving a maximum of luminance and contrast. The algorithm is implemented entirely on the GPU and is the first of its kind to run in real-time.},
  subject      = {Maschinelles Sehen},
  language  = {en}
}
@incollection{Bimber2006,
  author    = {Bimber, Oliver},
  title     = {Projector-Based Augmentation},
  series = {Emerging Technologies of Augmented Reality: Interfaces \& Design},
  booktitle = {Emerging Technologies of Augmented Reality: Interfaces \& Design},
  doi       = {10.25643/bauhaus-universitaet.735},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-7353},
  year      = {2006},
  abstract  = {Projector-based augmentation approaches hold the potential of combining the advantages of well-establishes spatial virtual reality and spatial augmented reality. Immersive, semi-immersive and augmented visualizations can be realized in everyday environments - without the need for special projection screens and dedicated display configurations. Limitations of mobile devices, such as low resolution and small field of view, focus constrains, and ergonomic issues can be overcome in many cases by the utilization of projection technology. Thus, applications that do not require mobility can benefit from efficient spatial augmentations. Examples range from edutainment in museums (such as storytelling projections onto natural stone walls in historical buildings) to architectural visualizations (such as augmentations of complex illumination simulations or modified surface materials in real building structures). This chapter describes projector-camera methods and multi-projector techniques that aim at correcting geometric aberrations, compensating local and global radiometric effects, and improving focus properties of images projected onto everyday surfaces.},
  subject      = {Erweiterte Realit{\"a}t <Informatik>},
  language  = {en}
}