Hans I. Bjelkhagen

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Image-based holographic stereogram rendering methods for holographic video have the attractive properties of moderate computational cost and correct handling of occlusions and translucent objects. These methods are also subject to the criticism that (like other stereograms) they do not present accommodation cues consistent with vergence cues and thus do not(More)
We describe a new method for imaging with visible and near visible light inside media, such as tissues, which have strong light scattering. The chrono-coherent imaging (CCI) method is demonstrated in this paper for a transmission geometry where an absorbing object is completely hidden from normal visual observation by light scattering of the media. The(More)
The 1964 publication by Emmett Leith and Juris Upatnieks [J. Opt. Soc. Am. 54, 1295 (1964)] introduced the possibility of using holograms to record three-dimensional (3D) objects. Since then, there has been an interest in creating display holograms, i.e., holograms primarily produced to show objects in 3D. More recently, full color holography has become a(More)
A new accurate method for comparing tooth positions on dental casts at different stages is described. Holograms of casts were prepared with a helium-neon gas laser. For evaluation of tooth movements, a cast and hologram representing different time points were superimposed by means of an adjustable x-y stage. Occlusal surface detail was used as a reference(More)
Silver halide sensitized gelatin (SHSG) holograms are similar to holograms recorded in dichromated gelatin (DCG), the main recording material for holographic optical elements (HOEs). The drawback of DCG is its low energetic sensitivity and limited spectral response. Silver halide materials can be processed in such away that the final hologram will have(More)
The laser reflection method of remote measurement was used to register small tooth movements of upper central incisors from a group of subjects with healthy teeth and another group with periodontally involved teeth. The mobility of the healthy maxillary incisors over a period of 24 hours was well within normal limits. Among orthodontically treated and(More)