• Title/Summary/Keyword: digital restoration

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Performance Enhancement through Row-Column Cross Scanning in Differential Histogram-based Reversible Watermarking (차이값 히스토그램 기반 가역 워터마킹의 행열 교차 스캐닝을 통한 성능 향상 기법)

  • Yeo, Dong-Gyu;Lee, Hae-Yeoun;Kim, Byeong-Man
    • The KIPS Transactions:PartB
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    • v.18B no.1
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    • pp.1-10
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    • 2011
  • Reversible watermarking inserts watermark into digital media in such a way that visual transparency is preserved, which enables the restoration of the original media from the watermarked one without any loss of media quality. It has various applications, where high capacity and high visual quality are major requirements. This paper presents a new effective multi-round embedding scheme for the differential histogram-based reversible watermarking that satisfies high capacity requirements of the application. The proposed technique exploits the row-column cross scanning to fully utilize the locality of images when multi-round embedding phase to the message inserted image. Through experiments using multiple kinds of test images, we prove that the presented algorithm provides 100% reversibility, effectiveness of multi-round embedding, and higher visual quality, while maintaining the induced-distortion low.

A Study on Modified Spatial Weighted Filter in Mixed Noise Environments (복합잡음 환경에서 변형된 공간 가중치 필터에 관한 연구)

  • Kwon, Se-Ik;Kim, Nam-Ho
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.19 no.1
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    • pp.237-243
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    • 2015
  • In recent image processing, active researches have been made along with rapid development in digital times. However, it is know that the image degradation occurs due to various external factors in the processes of image data processing, transmission and storage, and the main reason of image degradation is due to the noise. Typical methods to remove the noise are CWMF(center weighted median filter), A-TMF(alpha-trimmed mean filter) and AWMF(adaptive weighted median filter) and these methods have a little bit lacking noise reduction characteristics in mixed noise environments. Therefore, in order to remove the mixed noise, image restoration filter processing algorithm was suggested in this paper which processes by applying the median value of the mask and space weighted value after noise judgment. And for the objective judgment, it was compared with existing methods and PSNR(peak signal to noise ratio) was used as a judgment standard.

A Record and Conservation of Cultural Heritages through Web Ecomuseum : the Case of Mountain Mudeung (웹 생태박물관을 활용한 문화유산의 기록과 보존 : 무등산을 중심으로)

  • Noh, Shi-Hun
    • The Korean Journal of Archival Studies
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    • no.27
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    • pp.209-238
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    • 2011
  • Ecomuseum which appeared in France in 1968 and widely diffused over the world, is a new type of museum. The purpose of this museum is not to simply possess and exhibit the existing relics, but to discover the locational senses of a territory by in-situ conserving and interpreting its entire natural and cultural heritages, and to plan the participation of its population and the development of its local community. The significance of this museum can be found in the recovery of disappearing collective memories of a territory, the restoration of the cultural identity of its population and the revitalization of a underdeveloped area. As the majority of these museums are fragmented or open air museums, an 'web ecomuseum' which makes the remote offering of informations about whole dispersed heritages and their holistic interpretation possible by digitalizing, recording, conserving, interpreting and utilizing related heritages, is necessary. This paper considers the possibility of web ecomuseum and its constitution contents and methods through the case of Mountain Mudeung area. Especially, in relation to the latter, this paper suggests a plan which consists of selection of own local themes, construction of digital archives, design of web expositions and production of electronic cultural maps.

A Study on Modified Adaptive Weighted Filter in Mixed Noise Environments (복합잡음 환경에서 변형된 적응 가중치 필터에 관한 연구)

  • Kwon, Se-Ik;Kim, Nam-Ho
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2014.10a
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    • pp.798-801
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    • 2014
  • Nowadays, the demand for multimedia services has grown with the rapid evolution in the digital era. But due to external causes in the process of processing, transmitting and storing image data, the images are damaged. One of the major causes of such damage is known to be noise. Some of the most commonly used methods for removing noise are CWMF(center weighted median filter), A-TMF(alpha-trimmed mean filter) and AWMF(adaptive weighted median filter). However, these filters all leave a bit to be desired in removing noise in a complex noise environment. Therefore this paper suggest an image restoration filter algorithm that first judges the noise and sets a adjustment weight based on the median value and distance of the mask to remove the complex noise. For an objective analysis, the results were compared against existing methods and the PSNR(peak signal to noise ratio) was used as a reference.

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Image Restoration Filter for Preserving High Frequency Components in Impulse Noise Environments (임펄스 잡음 환경에서 고주파 성분을 보존하기 위한 영상 복원 필터)

  • Cheon, Bong-Won;Kim, Nam-Ho
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.23 no.4
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    • pp.394-400
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    • 2019
  • Noise removal is one of the required step in processing digital video and there are many researches to develop algorithm that fits with its purpose and environment. However, present impulse noise removal methods are lacking in its function in terms of removing noise in edge and high frequency factors. Therefore, this research has Extended range of masks depending on density to determine noise so that high frequency factors can be preserved. The range of resolution is set based on median and standard deviation of inside resolution after removing impulse noise. afterwards, those resolution within the range are calculated by adding weight to have the final output value. The suggested algorithm has an enhanced function in removing noise in various areas with many edge and high frequency factors than present methods and their functions are compared through simulation.

In vivo wear determination of novel CAD/CAM ceramic crowns by using 3D alignment

  • Aladag, Akin;Oguz, Didem;Comlekoglu, Muharrem Erhan;Akan, Ender
    • The Journal of Advanced Prosthodontics
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    • v.11 no.2
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    • pp.120-127
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    • 2019
  • PURPOSE. To determine wear amount of single molar crowns, made from four different restoratives, and opposing natural teeth through computerized fabrication techniques using 3D image alignment. MATERIALS AND METHODS. A total of 24 single crowns (N = 24 patients, age range: 18 - 50) were made from lithium disilicate (IPS E-max CAD), lithium silicate and zirconia based (Vita Suprinity CAD), resin matrix ceramic material (Cerasmart, GC), and dual matrix (Vita Enamic CAD) blocks. After digital impressions (Cerec 3D Bluecam, DentsplySirona), the crowns were designed and manufactured (Cerec 3, DentsplySirona). A dualcuring resin cement was used for cementation (Variolink Esthetic DC, Ivoclar). Then, measurement and recording of crowns and the opposing enamel surfaces with the intraoral scanner were made as well as at the third and sixth month follow-ups. All measurements were superimposed with a software (David-Laserscanner, V3.10.4). Volume loss due to wear was calculated from baseline to follow-up periods with Siemens Unigraphics NX 10 software. Statistical analysis was accomplished by Repeated Measures for ANOVA (SPSS 21) at = .05 significance level. RESULTS. After 6 months, insignificant differences of the glass matrix and resin matrix materials for restoration/enamel wear were observed (P>.05). While there were no significant differences between the glass matrix groups (P>.05), significant differences between the resin matrix group materials (P<.05) were obtained. Although Cerasmart and Enamic were both resin matrix based, they exhibited different wear characteristics. CONCLUSION. Glass matrix materials showed less wear both on their own and opposing enamel surfaces than resin matrix ceramic materials.

Developing Experiential Exhibitions Based on Conservation Science Content of Bronze Mirror

  • Jo, Young Hoon;Kim, Jikio;Yun, Yong Hyun;Cho, Nam Chul;Lee, Chan Hee
    • Journal of Conservation Science
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    • v.37 no.4
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    • pp.362-369
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    • 2021
  • In museums, exhibition content focuses mostly on cultural heritage's historical values and functions, but doing so tends to limit visitors' interest and immersion. To counter this limitation, the study developed an experiential media art exhibition fusing bronze mirrors' traditional production technology and modern conservation science. First, for the exhibition system, scientific cultural heritage contents were projected on the three-dimensional (3D) printed bronze mirror through interactions between motion recognition digital information display (DID) and the projector. Then, a scenario of 17 missions in four stages (production process, corrosion mechanism, scientific analysis and diagnosis, and conservation treatment and restoration) was prepared according to the temporal spectrum. Additionally, various media art effects and interaction technologies were developed, so visitors could understand and become immersed in bronze mirrors' scientific content. A user test was evaluated through the living lab, reflecting generally high levels of satisfaction (90.2 points). Qualitative evaluation was generally positive, with comments such as "easy to understand and useful as the esoteric science exhibition was combined with media art" (16.7%), "wonderful and interesting" (11.7%), and "firsthand experience was good" (9.2%). By combining an esoteric science exhibition centered on principles and theories with visual media art and by developing an immersive directing method to provide high-level exhibition technology, the exhibition induced visitors' active participation. This exhibition's content can become an important platform for expanding universal museum exhibitions on archaeology, history, and art into conservation science.

Image Restoration Algorithm using Weighted Switching Filter for Remove Random-Valued Impulse Noise (랜덤 임펄스 잡음을 제거하기 위한 가중치 스위칭 필터를 이용한 영상 복원 알고리즘)

  • Cheon, Bong-Won;Kim, Nam-Ho
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.24 no.5
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    • pp.609-615
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    • 2020
  • In the modern society, the use of digital equipment is increasing along with the 4th industrial revolution, and the importance of image and signal processing is increasing. At the same time, research on noise reduction is being actively conducted. In this paper, we propose a switching filter algorithm for random-valued impulse noise cancellation. The proposed algorithm obtains the threshold value by determining the noise level present in the image, and threshold value is compared with the difference between the input pixel value and the reference value, and is used in the weight switching process of the filter. The final output of the filter is estimated by applying a pixel weight and a modified weight median filter according to the switching, and obtains a final output by comparing the estimated value with the input pixel value. To evaluate the performance of the proposed algorithm, we compared it with the existing methods using simulation and PSNR.

Image Restoration Algorithm based on Segmented Mask and Standard Deviation in Impulse Noise Environment (임펄스 잡음 환경에서 분할 마스크와 표준편차에 기반한 영상 복원 알고리즘)

  • Cheon, Bong-Won;Kim, Woo-Young;Sagong, Byung-Il;Kim, Nam-Ho
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.25 no.8
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    • pp.1039-1045
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    • 2021
  • In modern society, due to the influence of the 4th industrial revolution, camera sensors and image-based automation systems are being used in various fields, and interest in image and signal processing is increasing. In this paper, we propose a digital filter algorithm for image reconstruction in an impulse noise environment. The proposed algorithm divides the image into eight masks in vertical, horizontal, and diagonal directions based on the local mask set in the image, and compares the standard deviation of each segmentation mask to obtain a reference value. The final output is calculated by applying the weight according to the spatial distance and the weight using the reference value to the local mask. To evaluate the performance of the proposed algorithm, it was simulated with the existing algorithm, and the performance was compared using enlarged images and PSNR.

An Effective Control Method for Improving Integrity of Mobile Phone Forensics (모바일 포렌식의 무결성 보장을 위한 효과적인 통제방법)

  • Kim, Dong-Guk;Jang, Seong-Yong;Lee, Won-Young;Kim, Yong-Ho;Park, Chang-Hyun
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.19 no.5
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    • pp.151-166
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    • 2009
  • To prove the integrity of digital evidence on the investigation procedure, the data which is using the MD 5(Message Digest 5) hash-function algorithm has to be discarded, if the integrity was damaged on the investigation. Even though a proof restoration of the deleted area is essential for securing the proof regarding a main phase of a case, it was difficult to secure the decisive evidence because of the damaged evidence data due to the difference between the overall hash value and the first value. From this viewpoint, this paper proposes the novel model for the mobile forensic procedure, named as "E-Finder(Evidence Finder)", to ,solve the existing problem. The E-Finder has 5 main phases and 15 procedures. We compared E-Finder with NIST(National Institute of Standards and Technology) and Tata Elxsi Security Group. This paper thus achieved the development and standardization of the investigation methodology for the mobile forensics.