Showing papers by "Nagaaki Ohyama published in 1994"
TL;DR: From experimental results, it is confirmed that the gray-level characteristic is greatly improved with the digital diffuser and high-resolution three-dimensional imagery is obtained with suppression of speckle noise.
Abstract: A digital diffuser designed for the efficient recording of Fourier holography is applied to the exposure of full-parallax holographic stereograms. From experimental results we confirm that the gray-level characteristic is greatly improved with the digital diffuser. High-resolution three-dimensional imagery is obtained with suppression of speckle noise. The limitation of the resolution is also described.
47 citations
TL;DR: In this paper, a 3D optical imaging method based on computed tomography techniques is presented, which has a higher band spherically, since 3D reconstructed images are composed only of the in-focused information of objects.
34 citations
TL;DR: An approach is proposed to estimate an object's surface topography from monocular endoscopic images by using the relative movement between the object and the endoscope for the estimation.
13 citations
TL;DR: A method to produce a hard copy of a three-dimensional (3D) image by a conventional high-resolution printer using a reflection-type holographic screen composed of a number of small elementary holograms is proposed.
Abstract: We propose a method to produce a hard copy of a three-dimensional (3-D) image by a conventional high-resolution printer. Parallax information is recorded on a transparency by the printer, and a reflection-type holographic screen composed of a number of small elementary holograms is attached on the transparency. The quality of the 3-D image is investigated, and the characteristics of the proposed method are described. 3-D image of full-parallax is experimentally produced using a laser printer.
11 citations
TL;DR: In this paper, a method for rainbow and multicolor holographic stereograms is described using the technique of multidot recording, which was originally developed for the syntheses of full-parallax holographic stereoograms.
7 citations
TL;DR: Through the experiment, it is found that the computing time required to visualize three dimensional arrays of data using the hybrid system is notably reduced and that operations like rotation, interpolation, zooming and masking the whole volume data, do not require any extra computing time.
2 citations
15 May 1994
TL;DR: A prototype IS&C (Image Save and Carry) system is under development at the National Cancer Center Hospital in Japan as a project of the Ministry of International Trade and Industry to develop a medical information filing system for personal health care using theIS&C system.
Abstract: A prototype IS&C (Image Save and Carry) system is under development at the National Cancer Center Hospital in Japan as a project of the Ministry of International Trade and Industry. The purpose of the project is to develop a medical information filing system for personal health care using the IS&C system. This paper describes the outline and present status of the project.
2 citations
15 May 1994
TL;DR: An automatic recognition method of film IDs using Synthetic Discriminant Function filters with an error check code, which greatly improves the recognition ratio, is proposed.
Abstract: By using a film digitizer it is possible to digitize X-ray film images with high quality. But from a practical point of view, conventional film digitizer systems are not satisfactory, because the identification of each film, that is indispensable for an image filing system, should be manually recorded. This procedure takes a long time and is cumbersome. In this paper we propose an automatic recognition method of film IDs using Synthetic Discriminant Function filters with an error check code, which greatly improves the recognition ratio. From experimental results it is confirmed that the proposed method is practically feasible. A full automatic film digitizer system is also described.
1 citations
15 May 1994
TL;DR: The requirements that medical information system for wide use should satisfy are discussed and the current activities of these projects are described.
Abstract: Medical information system as an infrastructure is required to be developed in Japan in order to establish, for example, a preventive medicine and better health care, that are indispensable in an aging society. For this purpose Japanese government is giving financial support to research projects, where compact media such as magneto-optical disk and IC-card are supposed to be used. This paper describes the current activities of these projects and discusses the requirements that medical information system for wide use should satisfy.© (1994) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
1 citations
29 Sep 1994
TL;DR: A large-scale holographic associative memory system of binary images is presented, with which an electronic digital computer is incorporated to realize a high performance and to combine a logical processing using external constraints.
Abstract: We present a large-scale holographic associative memory system of binary images, with which an electronic digital computer is incorporated to realize a high performance and to combine a logical processing using external constraints. In the system, associative process is performed in two steps, correlation and image synthesis steps. In the correlation step we execute a simple nonlinear operation, and in the image synthesis step we introduce an external input based on the prior knowledge about the expected output. This external input lets us control the output of the system. In the optical implementation we use spatially multiplexed Fourier transformed holograms. Experimental demonstrations are given to illustrate the performance of the system and the effectiveness of the external input.© (1994) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
1 citations
TL;DR: A new extension of IS & C (Image Save And Carry) project, which is supposed to be used in medicine, so the file protection mechanism for the security of the recorded files has also developed.
29 Sep 1994
TL;DR: A technique for the optical implementation of a color image correlation using a liquid crystal spatial light modulator (LC-SLM) to extract chromatic information from the image is presented.
Abstract: We present a technique for the optical implementation of a color image correlation using a liquid crystal spatial light modulator (LC-SLM). A color image composed of 3D vectors of RGB primaries, is mapped onto a 2D plane to extract chromatic information from the image. Then, the 2D vector image is defined as a complex function, which is displayed on the LC- SLM and employed in a complex correlation system. Results from computer simulation and an experiment are also demonstrated. Optical parallel recognition processor for color image recognition is realized by the coherent optical system of single wavelength.