Vol. 30, Issue 2-3, pp. 257-269

Abstract

Diffractive optically variable devices (DOVDs) are optical imaging elements such as holograms and diffraction gratings of all types. Visual applications of holograms consist in recording and reconstruction of 3D or 2D objects. Diffraction grating structures are used for visualisation of 2D images with cinematic effects. Computer generated holograms (CGHs) form 3D images of the quality which is hardly acceptable for commercial applications. The method of formation of high quality 3D images using multistereograms based on CGHs is presented. CGHs are also used to make Fourier type hidden elements. CGH based hidden elements may be combined with 2D visual features. Grating based DOVDs are used to record bright 2D images with cinematic effects. We show that diffraction gratings recorded using high-resolution equipment can be applied to true colour 3D image recording taking advantage of the stereogram concept. Similarly as in CGHs the recording of simple hidden information is possible in synthetic diffraction gratings.