• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.31 no.1
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• pp.41-48
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• 2013

The aim of the present study is to design a memory-efficient octree for querying large 3D point cloud. The aim has been fulfilled by omitting variables for minimum bounding hexahedral (MBH) of each octree node expressed in C++ language and by passing the re-estimated MBH from parent nodes to child nodes. More efficiency has been reported by two-fold processes of generating pseudo and regular trees to declare an array for all anticipated nodes, instead of using new operator to declare each child node. Experiments were conducted by constructing tree structures and querying neighbor points out of real point cloud composed of more than 18 million points. Compared with conventional methods using MBH information defined in each node, the suggested methods have proved themselves, in spite of existing trade-off between speed and memory efficiency, to be more memory-efficient than the comparative ones and to be practical alternatives applicable to large 3D point cloud.

• Journal of Industrial Convergence
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• v.17 no.4
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• pp.15-20
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• 2019

Augmented reality is used in various fields such as culture, education, military, medical. This is a method of recognizing information of an augmented object on the camera. Exhibitions and educational contents for children are already produced in various ways. This research showed the developed contents deliver cultural property information using augmented reality. 'Galgibi AR' and 'Jang Young-sil's Invention AR' allow you to experience cultural assets up close. 'Galgibi AR' is the experience content in the form of 3D blocks. It makes to understand the structure of the zeolite, Galgibi. 'Jang Young-sil's Invention AR' make you to watch out four objects in detail by zooming in, zooming out and rotating. It can also take pictures with the inventions. Both contents implement what we want to deliver accurately through simple content. They increase the enjoyment of cultural heritage through experience contents. This research addressed to help the cultural property information spread to the public by using Augmented Reality.

• Journal of Broadcast Engineering
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• v.25 no.5
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• pp.655-664
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• 2020

Free viewpoint image synthesis technology is one of the important technologies in the MPEG-I (Immersive) standard. RVS (Reference View Synthesizer) developed by MPEG-I and in use in MPEG group is a DIBR (Depth Information-Based Rendering) program that generates an image at a virtual (intermediate) viewpoint from multiple viewpoints' inputs. RVS uses the mesh surface method based on computer graphics, and outperforms the pixel-based ones by 2.5dB or more compared to the previous pixel method. Even though its OpenGL version provides 10 times speed up over the non OpenGL based one, it still shows a non-real-time processing speed, i.e., 0.75 fps on the two 2k resolution input images. In this paper, we analyze the internal of RVS implementation and modify its structure, achieving 34 times speed up, therefore, real-time performance (22-26 fps), through the 3 key improvements: 1) the reuse of OpenGL buffers and texture objects 2) the parallelization of file I/O and OpenGL execution 3) the parallelization of GPU shader program and buffer transfer.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.49 no.3
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• pp.8-14
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• 2012

Improving the speed of image processing is in great demand according to spread of high quality visual media or massive image applications such as 3D TV or movies, AR(Augmented reality). SIMD computer attached to a host computer can accelerate various image processing and massive data operations. MAMS is a multi-access memory system which is, along with multiple processing elements(PEs), adequate for establishing a high performance pipelined SIMD machine. MAMS supports simultaneous access to pq data elements within a horizontal, a vertical, or a block subarray with a constant interval in an arbitrary position in an $M{\times}N$ array of data elements, where the number of memory modules(MMs), m, is a prime number greater than pq. MAMS-PP4 is the first realization of the MAMS architecture, which consists of four PEs in a single chip and five MMs. This paper presents implementation of image processing algorithms and performance analysis for MAMS-PP16 which consists of 16 PEs with 17 MMs in an extension or the prior work, MAMS-PP4. The newly designed MAMS-PP16 has a 64 bit instruction format and application specific instruction set. The author develops a simulator of the MAMS-PP16 system, which implemented algorithms can be executed on. Performance analysis has done with this simulator executing implemented algorithms of processing images. The result of performance analysis verifies consistent response of MAMS-PP16 through the pyramid operation in image processing algorithms comparing with a Pentium-based serial processor. Executing the pyramid operation in MAMS-PP16 results in consistent response of processing time while randomly response time in a serial processor.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.2
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• pp.188-198
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• 2021

Digital data was collected using modern three-dimensional digital technology. Current content-specific technologies were investigated through domestic and foreign cases so that three-dimensional digital technology could be applied to the utilization of various contents. First, the use of three-dimensional digital technology of architectural cultural assets has been changing from the restoration of cultural assets. Second, some of the contents produced were found to be underutilized. Third, the type of content has been changing in experience and exhibition, but the online approach was small. Fourth, digital restoration using domestic IT technology has been used as a technology to restore overseas cultural heritage. The fifth analysis of the relationship between the content types and 3D digital technologies shows the use of currently limited technologies. This study analyzed the status of digital architecture and the application of three-dimensional digital technologies to lay the foundation for the active development and utilization of content. Subsequent studies on various layers and digital technologies will be needed to revitalize digital architectural cultural assets in the future.

• Korean Journal of Heritage: History & Science
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• v.57 no.1
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• pp.82-108
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• 2024

With the transition of archaeological recording method's transition from analog to digital, the 3D scanning technology has been actively adopted within the field. Research on the digital archaeological digital data gathered from 3D scanning and photogrammetry is continuously being conducted. However, due to cost and manpower issues, most buried cultural heritage organizations are hesitating to adopt such digital technology. This paper aims to present a digital recording method of relics utilizing open-source software and photogrammetry technology, which is believed to be the most efficient method among 3D scanning methods. The digital recording process of relics consists of three stages: acquiring a 3D model, creating a joining map with the edited 3D model, and creating an digital drawing. In order to enhance the accessibility, this method only utilizes open-source software throughout the entire process. The results of this study confirms that in terms of quantitative evaluation, the deviation of numerical measurement between the actual artifact and the 3D model was minimal. In addition, the results of quantitative quality analysis from the open-source software and the commercial software showed high similarity. However, the data processing time was overwhelmingly fast for commercial software, which is believed to be a result of high computational speed from the improved algorithm. In qualitative evaluation, some differences in mesh and texture quality occurred. In the 3D model generated by opensource software, following problems occurred: noise on the mesh surface, harsh surface of the mesh, and difficulty in confirming the production marks of relics and the expression of patterns. However, some of the open source software did generate the quality comparable to that of commercial software in quantitative and qualitative evaluations. Open-source software for editing 3D models was able to not only post-process, match, and merge the 3D model, but also scale adjustment, join surface production, and render image necessary for the actual measurement of relics. The final completed drawing was tracked by the CAD program, which is also an open-source software. In archaeological research, photogrammetry is very applicable to various processes, including excavation, writing reports, and research on numerical data from 3D models. With the breakthrough development of computer vision, the types of open-source software have been diversified and the performance has significantly improved. With the high accessibility to such digital technology, the acquisition of 3D model data in archaeology will be used as basic data for preservation and active research of cultural heritage.

• Proceedings of the Acoustical Society of Korea Conference
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• 1998.06e
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• pp.15-18
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• 1998

지금까지의 입체음향 재생 연구에서는 Dummy head 나 Head and Torso Simulator(HATS)를 사용한 측정 HRTF(Head-Related Transfer Function)를 사용하여 입체음향 재생 시스템을 설계해왔다. 하지만 이러한 시스템은 구현의 단순함에도 불구하고 계산량 증가로 인한 실시간 구현의 어려움과, 신호처리로 인한 음색의 변화 및 음질의 저하, 정면 정위의 어려움 등 많은 문제점을 내포하고 있었다. 본 연구팀이 제안하는 Relative HRTF는 인체의 가하학적 모델링을 통한 구조적 접근 방법으로 이러한 단점을 극복할 수 있는 새로운 HRTF 모델링 기법이다. 이는 신호처리 과정의 단순화를 통하여 실시간 구현과 음색의 변화를 극소화시키고 스피커 구동 방식에서도 적절히 사용될 수 있다. 또한 본 연구를 위하여 기존의 HRTF 측정 방법의 문제점을 개선한 HATS를 이용한 Blocked Ear Canal HRTF 측정 방법에 대해서도 소개한다.

• Cartoon and Animation Studies
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• s.44
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• pp.33-56
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• 2016

As the rapid extension of the game and film industry, studies on developing natural movements on a 3D characters are increasing. Rigging a character with joints is essential to create realistic movements on a 3D character. The rapid development of the CG industry, rigging technologies and workflow is becoming more sophisticated. Despite the progress and the growth of rigging operations, has shown the limitations of such repetitive tasks. For this study, analyzes the issues and inefficiency of the old method of skin weights and propose a better approach. First, need to understand the general process of an animation pipeline and learn the technology term of skin weights. Second, comparing the traditional ways of skinning a character and applying other deformers to work properly. Third, testing out new ways of weighting a character by applying deformers such as lattice and finally converting lattice weights back to skin weights. Forth, verifying effectiveness of the new method of skin weights by comparing with the traditional skin weighting process. The study shows that the new method of skin weights, reduced working hours and a better final weighting outcome. Expecting this study to enhance the method of skin weights and able to utilize this new skinning technology.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.12 no.5
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• pp.475-481
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• 2019

A splint is one of assisting devices for the disabled with hemiplegia or contracture and is manually made by an experienced expert. Heated thermoplastic materials are continuously fitted to the affected part. This traditional method has a possible risk of low-temperature burn, quality variance of the splint due to the proficiency of maker. etc. While various approaches has been made using 3D printing technology in order to redeem those disadvantages, they still carry high cost issues with 3D scanners or accuracy issues with manual measurement. This research begins with symmetrical characteristics of human body and focuses on the preliminary study for the possibility of splint manufacturing with 3D printing technology based on geometric characteristics of unaffected arm. 3D right and left forearm models of healthy male adults were created by photogrammetry software and a series of digital images in order to measure the circumference and cross-sectional area of the forearm models at every 20mm from the elbow. The circumference and cross-sectional area showed tolerable levels of differences between both sides within subjects; The circumference and cross-sectional area showed very strong correlations between both sides within subjects. From these findings, the possibility of splint manufacturing with 3D printing technology could be confirmed based on the geometric characteristics of unaffected side.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.36 no.3
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• pp.227-231
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• 2010

Among various make-up products, foundations are widely used to express clear and flawless skin. Foundations can be classified by its formula to 3 types, liquid foundation, powder foundation, and oil dispersion foundation. Powder foundations are easy to carry and use, so it is commonly possessed. In the R&D point of view, the developing method of powder foundations can be classified again to 3 types. Dry-process, baked-process, and the wet slurry-process. The fact that the wet slurry-process goes through either the back injection method or the front injection method is previously known. The front injection process is used as the main method in this study. We observed the quality dependence on the kind of solvent and the powder coating system. In brief, when water was used as the main solvent, the hardness increased than when volatile silicones or hydrocarbons were used. And the sensory results were shown to prefer volatile solvents (silicones or hydrocarbons) over water. Similarly, when the amino acid-coating system was applied, the hardness was shown to increase, when silicone-coating system shown no specific change. By these results, tailor-made powder foundations targeting specific customer grades can be easily produced.