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A set of active partially pixelated masks is designed to pick up appropriate images from a large number serial pictures or a three-dimensional computer numerical model for the natural three-dimensional display with smooth motion parallax. To realize the smooth three-dimensional display without view zone jumping, each subpixel at the boundary in the pixelated mask is subdivided into partial pixels. Each active partially pixelated mask can periodically shift according to the design requirement. With active partially pixelated masks in the liquid crystal panel combining with a precision lenticular lens array, the three-dimensional display with 500 views from captured serial pictures and 1200 views from a computer numerical model is demonstrated in 56° viewing angle, which is functionally equivalent to the holographic stereogram. The displayed depth is more than 40cm. The light intensity ripple with 18 active partially pixelated masks is decreased to 0.9% in the viewing zone. The screen size is 50.7cm×28.5cm. [ABSTRACT FROM AUTHOR]

Abstract: In recent years, a number of methods have been proposed in the literature for the encryption of two-dimensional information by using the fractional Fourier transform, but most of their encryptions are complex values and need digital hologram technique to record information, which is inconvenient for digital transmission. In this paper, we propose a new approach for image encryption based on the real-valuedness and decorrelation property of the reality-preserving multiple-parameter fractional Fourier transform in order to meet the requirements of the secure image transmission. In the proposed scheme, the original and encrypted images are respectively in the spatial domain and the reality-preserving multiple-parameter fractional Fourier transformed domain determined by the encryption keys. Numerical simulations are performed to demonstrate that the proposed method is reliable and more robust to blind decryption than several existing methods. [Copyright &y& Elsevier]

Abstract: A new double-image encryption method on the joint transform correlator using two-step-only quadrature phase-shifting digital holography, based on the calculated intensity of reference beam is proposed. The technique realizes the double-image encryption using one random phase encoding on the joint transform correlator; and only records two quadrature-phase holograms on CCD camera without recording reference-wave intensity or object-wave intensity. With the acquired reference-wave intensity from 2-D correlation coefficient and the keys known, the clear retrieved image can be obtained at high speed by certain algorithm. Its feasibility and validity were verified by a series of computer simulations. [Copyright &y& Elsevier]

Abstract: A wavefront reconstruction method by two-step generalized phase-shifting interferometry (GPSI) with blind phase shift extraction algorithm is verified by both the computer simulations and optical experiments. This method can retrieve complex object wave field by using two interferograms, the recorded object and reference wave intensities, and an unknown phase shift without additional processing. The simulations with irregular wavefronts have shown the effectiveness and high accuracy of this method for blind phase-shift extraction and wavefront reconstruction over a wide range of phase-shifts, while the optical experiments for both the direct and indirect objects have yielded satisfactory results with a higher resolution of reconstructed image than those reported recently. [Copyright &y& Elsevier]