• Korean Journal of Optics and Photonics
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• v.16 no.3
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• pp.225-234
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• 2005

In the integral imaging system for 3D display, the elemental image size is closely related to the several variables, such as the size of elemental lens, the distance between elemental lens and elemental image, etc., on the pick up system. We have analyzed the geometric relation between the variables. In addition, we have investigated the integrated image variation for the individual and whole conversion of the size of the elemental images, different from in pick up process, and presented experimental results.

• Korean Journal of Optics and Photonics
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• v.18 no.1
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• pp.24-30
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• 2007

We have studied depth conversion of a reconstructed image by means of recombination of the elemental images in the integral imaging system for 3D display. With the recombination, depth conversion to the pseudoscopic, the orthoscopic, the real or the virtual as well as to arbitrary depth without any distortion is possible under proper conditions. The conditions on the recombinations for the depth conversion are theoretically derived. The reconstructed images using the converted elemental images are presented.

• ETRI Journal
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• v.27 no.6
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• pp.708-712
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• 2005

We propose a computational reconstruction technique in large-depth integral imaging where the elemental images have information of three-dimensional objects through real and virtual image fields. In the proposed technique, we reconstruct full volume information from the elemental images through both real and virtual image fields. Here, we use uniform mappings of elemental images with the size of the lenslet regardless of the distance between the lenslet array and reconstruction image plane. To show the feasibility of the proposed reconstruction technique, we perform preliminary experiments and present experimental results.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.10
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• pp.1944-1949
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• 2007

In this paper, a new plane-based computational reconstruction technique for three-dimensional (3D) objects in 3D internal imaging based on a lens model is proposed. For the proposed technique, computational experiments have been carried out for various test images. Resolution of the reconstructed images is analyzed and compared with that obtained by the conventional technique. From experiments, it is shown that the resolution of a 3-D reconstructed image was improved by using the proposed technique.

• Current Optics and Photonics
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• v.5 no.1
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• pp.40-44
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• 2021

In this paper, LED arrays with segmented mirrors and a mask are presented as a new dark-field illuminator for reflective Fourier ptychographic microscopy (FPM). The illuminator can overcome the limitations of the size and the position of samples that the dark-field illuminator using a parabolic mirror has had. The new concept was demonstrated by measuring a USAF 1951 target, and it resolved a pattern in group 10 element 6 (274 nm) in the USAF target. The new design of the dark-field illuminator can enhance competitiveness of the reflective FPM as a versatile measurement method in industry.

• Journal of Yeungnam Medical Science
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• v.4 no.1
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• pp.1-15
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• 1987

Magnetic Resonance (M.R.) is rapidly emerging technique that provides high quality images and potentially provides much more diagnostic information than do conventional imaging modalities. M.R.I. is conceptually quite different from currently used imaging methods. The complex nature of M.R.I. allows a great deal of flexibility in image product ion and available information, and key points are as follows. 1. M.R.I. offers a non-invasive technique with which to gene rate in vivo human images without ionizing radiation and with no known adverse biological effects. 2. Imaging mechanism of M.R.I. is quite different from conventional imaging modality and for more accurate diagnostic application, It is necessary for physician to understand imaging mechanism of M.R.I. 3. M.R. makes available basic chemical parameters that may provide to be useful for diagnostic medical imaging and more specific pathophysiologic information which are not available by alternate techniques. 4. M.R. can be produced by number of different methods. This flexibility allows the imaging technique to be applicated for particular clinical purpose. Multiplanar and three dimensional imaging may extend the imaging process beyond the single section available with current CT. 5. Future directions include efforts to; a. Further development of hard ware b. More fasternning scan time c. Respiratory and cardiac gated imaging d. Imaging of additional nuclei except hydrogen e. Further development of contrast media f. M.R. in vivo spectroscopy g. Real time M.R. imaging.

• Journal of Korean Neurosurgical Society
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• v.51 no.2
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• pp.120-123
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• 2012

Objective : Percutaneous vertebroplasty (PVP) is usually carried out under three-dimensional (2D) fluoroscopic guidance. However, operative complications or bone cement distribution might be difficult to assess on the basis of only 2D radiographic projection images. We evaluated the feasibility of performing an intraoperative and postoperative examination in patients undergoing PVP by using three-dimensional (3D) reconstructive C-arm. Methods : Standard PVP procedures were performed on 14 consecutive patients by using a Siremobil Iso-$C^{3D}$ and a multidetector computed tomography machine. Post-processing of acquired volumetric datasets included multiplanar reconstruction (MPR) and surface shaded display (SSD). We analyzed intraoperative and immediate postoperative evaluation of the needle trajectory and bone cement distribution. Results : The male : female ratio was 2 : 12; mean age of patients, 70 (range, 77-54) years; and mean T score, -3.4. The mean operation time was 52.14 min, but the time required to perform and post-process the rotational acquisitions was 7.76 min. The detection of bone cement distribution and leakage after PVP by using MPR and SSD was possible in all patients. However, detection of the safe trajectory for needle insertion was not possible. Conclusion : 3D rotational image acquisition can enable intra- or post-procedural assessment of vertebroplasty procedures for the detection of bone cement distribution and leakage. However, it is difficult to assess the safe trajectory for needle insertion.

• 한국지구물리탐사학회:학술대회논문집
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• 2003.11a
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• pp.21-26
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• 2003

The visualization of three dimensional geophysical data is forcing a revolution in the way of working, and allowing the discovery and production of hydrocarbons at much lower costs than previously thought possible. There are many aspects of this revolution that are behind the scenes, such as the database structure, the storage and retrieval of data, and the exchange of data among programs. Also the user had changes where the interpreter (or manager, or processor) actually looks at and somehow interacts with the data. The use of opacity in volume rendering, and how its judicious application can assist in imaging geologic features in three dimensional seismic data. This revolutionary development of new technology is based on the philosophy of synergy of inter-disciplines of the oil industry. Group interaction fostered by large room visualization environments enables the integration of disciplines we strive for, by putting the petrophysicist, geologist, geophysicist, and reservoir engineer in one place, looking at one image together, without jargon or geography separating them. All these tools developed in the oil industry can be applied into the civil engineering industry also such as the prior geological and geophysical survey of the constructions. Many examples will show how three dimensional geophysical technology might make a revolution in the oil business industry now and in future. This change can be considered as a fusion process at data, information, and knowledge levels.

• Archives of Plastic Surgery
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• v.48 no.4
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• pp.427-432
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• 2021

The conventional approach of looking down a microscope to perform microsurgical procedures is associated with occupational injuries, anti-ergonomic postures, and increased tremor and fatigue, all of which predispose microsurgeons to early retirement. Recently, three-dimensional (3D) visualization of real-time microscope magnification has been developed as an alternative. Despite its commercial availability, no supermicrosurgical procedures have been reported using this technology to date. Lymphovenous anastomoses (LVAs) often require suturing vessels with diameters of 0.2-0.8 mm, thus representing the ultimate microsurgical challenge. After performing the first documented LVA procedure using 3D-augmented visualization in our unit and gaining experience with this technique, we conducted an anonymized in-house survey among microsurgeons who had used this approach. The participants considered that 3D visualization for supermicrosurgery was equivalent in terms of handling, optical detail, depth resolution, and safety to conventional binocular magnification. This survey revealed that team communication, resident education, and ergonomics were superior using 3D digital hybrid visualization. Postoperative muscle fatigue, tremor, and pain were also reduced. The major drawbacks of the 3D visualization microscopic systems are the associated costs, required space, and difficulty of visualizing the lymphatic contrast used.

• The Journal of the Korea Contents Association
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• v.6 no.12
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• pp.261-268
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• 2006

A hologram is a three-dimensional image reproduced from a pattern of interference produced by a split coherent beam of radiation. Therefore not only can it express the three dimensional properties of the object, but because of it ability to show the depth and spatial properties of the object holograms may be a more effective tool in advertising for its visual appeal. This study presents 'hologram'a three dimensional stereo imaging, as the expression technique in advertising of the next generation, and with proper understanding of 'hologram' and of all its potential applications discusses opportunities for advertisements that are distinct from the multi media advertisements of today. The basic concept of Holograms and their application methods were presented in the thesis, and by using Sales Promotion advertisement as example, discussed what elements are required in order to produce an effective advertisement using holograms.