Vladimir I. Bobrinev

Distortion analysis in stereoscopic images

The distortions in the perceived image from a stereoscopic image pair displayed on a screen are analyzed for different conditions of photographing, projecting, and viewing for the cases of both a stereo camera and a stereo projector with a parallel configuration. The conditions used for the analysis are positions and stereo bases of viewer and the camera and magnification of the displayed image. The possible location of the image is also found for given locations of the camera and the viewer. The obtained resulted can be used to optimize stereo image display systems.

Achromatized transmission-type holographic screen for a multiview stereoscopic image system

The main drawback of the use of transmission-type holographic screens is poor color reproduction caused by their high spectral dispersion. For overcoming this drawback, a long, narrow diffusing slit is used as an object when recording the screen. The necessary size and position of the slit relative to the photoplate and to the recording and reconstruction beams are determined by the phase relations of the beams. By use of the slit, holographic screens of 30 cm x 40 cm are recorded with a diverging reference beam and are used to display a multiview full-color stereoscopic image. The images displayed on the screen show no sign of color separation except near the edges of the screen. The image brightness on the screen is high enough that it can be watched in a normally illuminated room.

Autostereoscopic imaging systems based on holographic screen

Stereoscopic imaging systems require to have a mean of creating viewing zone(s) to make viewers to perceive images with a certain depth. Holographic screen is a kind of holographic optical elements, designed for both image projection and the viewing zone creation. It has properties of a lens + a diffuser for transmission type and a diffused or simple spherical mirror for reflection type. Making full color holographic screens with a desired property requires an extra process of making chirp-type fringes in the developing stage or stacking three primary color screens for the reflection type and aligning a long narrow slit type diffuser as an object m recording process for the transmission type. The holographic screen is an analogue type screen which can create many separated viewing zones for many viewers and with a reasonable depth. The viewing zone size is proportional to projectors objective exit pupil size. Hence it can be controlled for any desired size. Making any desired size screen is also possible, however, its focal length is proportional to its size. This is why the screen is allowed to be used for only projection type stereoscopic systems. The viewing angle obtainable with the screen can be up to 70 degrees in reflection mode operation. This angle is big enough for the multiview image projection. An image combiner for Head Up Display for cars is an example of a non-stereoscopic area of application.

Methods for increasing viewing zone of a transmission-type holographic screen

The full color transmission type holographic screen for 3D image projection has a vertical direction viewing zone size of 6.5 cm. This size is too small for viewers to watch images with comfort. To increase the vertical size of the viewing zone, a vertical diffuser with an optimized scattering angle and a diffraction grating with vertical dispersion are recorded and used together with the screen. With attaching the diffuser or the grating to the screen, the vertical size of the viewing zone is increased up to 5 times with little degrading in image quality. Recording the grating and the screen on a single photo plate by exposing once is also possible. The screen performance is examined with a holographic screen with size of 60 by 80 cm2.

The Experimental Investigations of the Big Size Holographic Screen in the Autostereoscopic Displays

Results of an experimental study of possible ways to extend the capabilities of a big size transmission type holographic screen are presented. Different approaches to the problem of making a big size screen have been considered and tested experimentally. Up to 60

54.5: Holographic Screens for 3 Dimensional Image Projection

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Investigation of viewing zone parameters for full color transmission type holographic screens

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Holographic projection screen for displaying a three-dimensional color images and optical display system using the holographic screen

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Method and apparatus for direct transmission of an optical image

screens have been recorded on a single photographic plate VRP-M. By attaching a mirror behind the screen, the reflection mode of operation has been obtained. In this arrangement some additional peculiarities appear in the screen, which can be used to extend the screen capabilities. The first possibility is to increase the screen size by mosaicking the subscreens in the reflection mode of operation. Screens of 120

Method of producing a holographic projection screen for displaying a three-dimensional color images

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