Showing papers by "Osamu Matoba published in 2004"
TL;DR: A novel optical encryption based on polarization is proposed and applied to a holographic memory system and results are presented by demonstrating holographic recording in a bacteriorhodopsin film.
Abstract: A novel optical encryption based on polarization is proposed and applied to a holographic memory system. Original binary data are described as two orthogonal linear polarization states. These input polarization states can be modulated by use of two polarization-modulation masks located at the input and the Fourier planes. Each modulation mask can convert an input polarization state into a random polarization state. Once encrypted, the polarization state is recorded as a hologram. For the decryption, the hologram can generate a vector phase-conjugate beam. When the same polarization-modulation masks are used, the vector phase-conjugate readout can cancel the polarization modulation at each mask, and the original polarization state can be recovered. The encryption of the proposed method is evaluated numerically. We also present experimental results by demonstrating holographic recording in a bacteriorhodopsin film.
85 citations
TL;DR: An overview of three-dimensional (3D) object recognition techniques that use active sensing by interferometric imaging (digital holography) and passive sensing by integral imaging is presented.
Abstract: We present an overview of three-dimensional (3D) object recognition techniques that use active sensing by interferometric imaging (digital holography) and passive sensing by integral imaging. We describe how each technique can be used to retrieve the depth information of a 3D scene and how this information can then be used for 3D object recognition. We explore various algorithms for 3D recognition such as nonlinear correlation and target distortion tolerance. We also provide a comparison of the advantages and disadvantages of the two techniques.
58 citations
TL;DR: This is the first report on 3D polarimetric sensing imaging and 3D optical reconstruction by integral imaging of a 3D object attached to two orthogonal linear polarizers.
Abstract: A three-dimensional (3D) polarimetric image sensing and display technique based on integral imaging is proposed. Three-dimensional polarization distribution of reflected light from a 3D object can be measured as elemental image arrays by a rotating linear polarizer. After the measurement of the polarization of the 3D object, the 3D polarimetric object can be reconstructed optically by displaying the polarization-selected elemental images in spatial light modulators with two quarter-wave plates. Experimental demonstration of 3D polarimetric imaging of a 3D object attached to two orthogonal linear polarizers is presented. To the best of our knowledge, this is the first report on 3D polarimetric sensing imaging and 3D optical reconstruction by integral imaging.
48 citations
TL;DR: This work investigates the influence of quantization of the joint power spectrum in the optical correlator on the quality of the reconstructed image and proposes an optical three-dimensional display system interfaced with digital data transmission.
Abstract: An optical three-dimensional (3D) display system interfaced with digital data transmission is proposed. In this system, an original 3D object is encrypted by use of a random phase mask and then the encrypted pattern is recorded as a digital hologram. The digital hologram key is also recorded for optical decryption. Both the encrypted digital hologram and the digital hologram key are transmitted to a receiver through a conventional communication data channel. At the receiver, the 3D scene is reconstructed and displayed optically in a retrieval system based on a joint-transform correlation. Experimental results are presented. We investigate the influence of quantization of the joint power spectrum in the optical correlator on the quality of the reconstructed image.
31 citations
20 Dec 2004
TL;DR: A reflection-type holographic memory system with data security is presented and experimental results of recording and reconstruction by the correct and an incorrect phase mask are presented.
Abstract: A reflection-type holographic memory system with data security is presented. Binary data frames are recorded as encrypted volume holograms by use of random phase mask in a reference arm. Experimental results of recording and reconstruction by the correct and an incorrect phase mask are presented.
1 citations
20 Dec 2004
TL;DR: This study presents a 3D display system based on phase-shifting digital holography that can be used for real-time recording, data transmission, and reconstruction of 3D object.
Abstract: This study presents a 3D display system based on phase-shifting digital holography. This work also shows optical recording (within 30 frames/s) of a temporally changing 3D object and its numerical reconstruction. Thus, the system can be used for real-time recording, data transmission, and reconstruction of 3D object.