The display is the last component in a chain of activity from image acquisition, compression, coding transmission and reproduction of 3-D images through to the display itself. There are various schemes for 3-D display taxonomy; the basic categories adopted for this paper are: holography where the image is produced by wavefront reconstruction, volumetric where the image is produced within a volume of space and multiple image displays where two or more images are seen across the viewing field. In an ideal world a stereoscopic display would produce images in real time that exhibit all the characteristics of the original scene. This would require the wavefront to be reproduced accurately, but currently this can only be achieved using holographic techniques. Volumetric displays provide both vertical and horizontal parallax so that several viewers can see 3-D images that exhibit no accommodation/convergence rivalry. Multiple image displays fall within three fundamental types: holoform in which a large number of views give smooth motion parallax and hence a hologram-like appearance, multiview where a series of discrete views are presented across viewing field and binocular where only two views are presented in regions that may occupy fixed positions or follow viewers' eye positions by employing head tracking. Holography enables 3-D scenes to be encoded into an interference pattern, however, this places constraints on the display resolution necessary to reconstruct a scene. Although holography may ultimately offer the solution for 3DTV, the problem of capturing naturally lit scenes will first have to be solved and holography is unlikely to provide a short-term solution due to limitations in current enabling technologies. Liquid crystal, digital micromirror, optically addressed liquid crystal and acoustooptic spatial light modulators (SLMs) have been employed as suitable spatial light modulation devices in holography. Liquid crystal SLMs are generally favored owing to the commercial availability of high fill factor, high resolution addressable devices. Volumetric displays provide Manuscript both vertical and horizontal parallax and several viewers are able to see a 3-D image that exhibits no accommodation/convergence rivalry. However, the principal disadvantages of these displays are: the images are generally transparent, the hardware tends to be complex and non-Lambertian intensity distribution cannot be displayed. Multiple image displays take many forms and it is likely that one or more of these will provide the solution(s) for the first generation of 3DTV displays.

We present an experimental configuration for phase retrieval from a set of intensity measurements. The key component is a spatial light modulator located in the Fourier domain of an imaging system. It performs a linear filter operation that is associated to the process of propagation in the image plane. In contrast to the state of the art, no mechanical adjustment is required during the recording process, thus reducing the measurement time considerably. The method is experimentally demonstrated by investigating a wave field scattered by a diffuser, and the results are verified by comparing them to those obtained from standard interferometry.

Accurate 3D shape measurement is of big importance for industrial inspection. Because of the robustness, accuracy and ease of use optical measurement techniques are gaining importance in industry. For fast 3D measurements on big surfaces fringe projection is commonly used: A projector projects fringes onto the object under investigation and the scattered light is recorded by a camera from a triangulation angle. Thus, it is possible reaching a depth resolution of about one by 10.000 of the measurement field size (e.g. 100 µm for a 1 m sized field).For non-or low scattering objects it is common to put scattering material like particle spray onto the object under investigation. Objects where this is not allowed are often regarded as problematic objects for full field non-coherent optical measurement techniques. The solution is to switch from fringe projection to fringe reflection.The fringe reflection technique needs a simple setup to evaluate a fringe pattern that is reflected from the surface under investigation. Like for fringe projection the evaluated absolute phase identifies the location of the originating fringe. This allows identifying the reflection angles on the object for every camera pixel. The results are high resolution local gradients on the object which can be integrated to get the 3D shape. The achievable depth resolution compared to fringe projection is much better and reaches to a depth resolution down to 1 nm for smooth surfaces.We have proven the ability, robustness and accuracy of the technique for various technical objects and also fluids. A parallel paper of this conference 'Evaluation Methods for Gradient Measurement Techniques' 1 picks up further processing of the evaluated data and explains in more detail the performed calculations. This paper mainly concentrates on the fringe reflection principle, reachable resolution and possible applications.

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A method for the remote comparison of objects with regard to their shape or response to a load is presented. The method allows interferometric sensitivity for comparing objects with different microstructure. In contrast to the well-known incoherent techniques based on inverse fringe projection this new approach uses the coherent optical wave field of the master object as a mask for the illumination of the sample object. The coherent mask is created by digital holography to allow instant access to the complete optical information of the master object at any place desired. The mask is reconstructed by a spatial light modulator (SLM). The optical reconstruction of digital holograms with SLM technology allows modification of reconstructed wavefronts with respect to improvement of image quality, the skilled introduction of additional information about the object (augmented reality), and the alignment of the master and test object.