Browsing by Author "Zhou, C. H."

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    Binary Mask Programmable Hologram
    Tsang, Peter Wai Ming; Poon, Ting-Chung; Zhou, C. H.; Cheung, K. W. K. (Optical Society of America, 2012-11-01)
    We report, for the first time, the concept and generation of a novel Fresnel hologram called the digital binary mask programmable hologram (BMPH). A BMPH is comprised of a static, high resolution binary grating that is overlaid with a lower resolution binary mask. The reconstructed image of the BMPH can be programmed to approximate a target image (including both intensity and depth information) by configuring the pattern of the binary mask with a simple genetic algorithm (SGA). As the low resolution binary mask can be realized with less stringent display technology, our method enables the development of simple and economical holographic video display. (C) 2012 Optical Society of America
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    Multiple-image encryption by compressive holography
    Di, Hong; Zheng, Kangfeng; Zhang, Xin; Lam, Edmund Y.; Kim, Taegeun; Kim, You Seok; Poon, Ting-Chung; Zhou, C. H. (Optical Society of America, 2012-03-01)
    We present multiple-image encryption (MIE) based on compressive holography. In the encryption, a holographic technique is employed to record multiple images simultaneously to form a hologram. The two-dimensional Fourier data of the hologram are then compressed by nonuniform sampling, which gives rise to compressive encryption. Decryption of individual images is cast into a minimization problem. The minimization retains the sparsity of recovered images in the wavelet basis. Meanwhile, total variation regularization is used to preserve edges in the reconstruction. Experiments have been conducted using holograms acquired by optical scanning holography as an example. Computer simulations of multiple images are subsequently demonstrated to illustrate the feasibility of the MIE scheme. (C) 2012 Optical Society of America