• Journal of the Korean Institute of Telematics and Electronics
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• v.26 no.2
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• pp.140-146
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• 1989

An efficient quantization and encoding of BTC (Block Truncation Coding) parameters {($Y_{\alpha},\;Y_{\beta}),\;P_{{\beta}/{\beta}}$} are investigated, In our algorithm 4${\times}$4 blocks are classified into flat or edge block. While edge block is represented by two approximation level $Y_{\alpha},\;Y_{\beta}$ with label plane $P_{{\beta}/{\beta}}$, flat block is represented by single approximation level Y. The approximation levels Y, $Y_{\alpha}$ and $Y_{\beta}$ are encoded by predictive quatization specially designed, and the label plane $P_{{\beta}/{\beta}}$ is tried to be encoded using stored 32 reference plantes. The performance of the proposed scheme has appeared comparable to much more complex transform coding in terms of SNR, although it requires more study on the representation of small slope in background.

• Journal of Broadcast Engineering
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• v.15 no.1
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• pp.133-143
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• 2010

This paper proposes a quadtree image compression method which encodes images efficiently and also makes unartificial compressed images. The proposed compression method uses edge-based quadtree decomposition to preserve the significant edge-lines, and it utilizes the predictive coding scheme to exploit the high correlation of the leaf node blocks. The simulation results with $256\times256$ grayscale images verify that the proposed method yields better coding efficiency than the JPEG by about 25 percents. The proposed method can provide more natural compressed images as it is free from the ringing effect in the compressed images which used to be in the images compressed by the fixed block based encoders such as the JPEG.

• The KIPS Transactions:PartB
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• v.12B no.3 s.99
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• pp.223-232
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• 2005

In this paper, we propose a novel post-filtering algorithm with low computational complexity that improves the visual quality of decoded images using block boundary classification and simple adaptive filter (SAF). At first, each block boundary is classified into smooth or complex sub-region. And for smooth-smooth sub-regions, the existence of blocking artifacts is determined using blocky strength. And simple adaptive filtering is processed in each block boundary area. The proposed method processes adaptively, that is, a nonlinear 1-D 8-tap filter is applied to smooth-smooth sub-regions with blocking artifacts, and for smooth-complex or complex-smooth sub-regions, a nonlinear 1-D variant filter is applied to block boundary pixels so as to reduce the blocking and ringing artifacts. And for complex-complex sub-regions, a nonlinear 1-D 2-tap filter is only applied to adjust two block boundary pixels so as to preserve the image details. Experimental results show that the proposed algorithm produced better results than those of conventional algorithms both subjective and objective viewpoints.

• Journal of Korea Multimedia Society
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• v.5 no.4
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• pp.458-467
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• 2002

There has been proposed many simplification algorithms for effectively decreasing large-volumed polygonal surface data. These algorithms apply their own cost function for collapse to one of fundamental simplification unit, such as vertex, edge and triangle, and minimize the simplification error occurred in each simplification steps. Most of cost functions adopted in existing works use the error estimation method based on distance optimization. Unfortunately, it is hard to define the local characteristics of surface data using distance factor alone, which is basically scalar component. Therefore, the algorithms cannot preserve the characteristic features in surface areas with high curvature and, consequently, loss the detailed shape of original mesh in high simplification ratio. In this paper, we consider the vector component, such as surface orientation, as one of factors for cost function. The surface orientation is independent upon scalar component, distance value. This means that we can reconsider whether or not to preserve them as the amount of vector component, although they are elements with low scalar values. In addition, we develop a simplification algorithm based on half-edge collapse manner, which use the proposed cost function as the criterion for removing elements. In half-edge collapse, using one of endpoints in the edge represents a new vertex after collapse operation. The approach is memory efficient and effectively applicable to the rendering system requiring real-time transmission of large-volumed surface data.

• Conservation Science in Museum
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• v.14
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• pp.13-22
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• 2013

The Nectar Ritual Painting(Jeung7551) in National Museum of Korea is estimated to have been produced in the 16th century. Ezimagodo who is the head priest of Ruganji in Kyoto, Japan donated this painting in 2010. Overall, damages were serious, such as missing, staining, folding, insects of the face and mounting silk, therefore, it need to conservation treatment. The treatment of conservation in painting was removing surface stains and repairing missing area. It was mounted by following the original form. The analysis result of textile in mounting and support fiber used silk and hemp in microscope. Pigments in paint were divided into six color types. This painting was used that vermilion(cinnabar) and red lead for red color, litharge(massicot) and gold for yellow color, lead white for white color, malachite for green color, azurite for blue color, and carbon black(chinese ink) for black color.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.05a
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• pp.666-668
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• 2016

Salt and pepper noise generally occurs due to errors in the transmission channel or sensors and it lowers the resolution of the image and causes visual errors. To remove this salt and pepper noise, SMF(standard median filter), which represents simple algorithm and excellent noise removal performance, is widely used. However preservation characteristics in the pitch areas of the image is rather lacking. Therefore to effectively restore images damaged by salt and pepper noise, the study suggested a multiple filter that applies filters differently according to size by applying noise density threshold value of local mask on noise signal, while preserving non-noise signal.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.41 no.5
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• pp.51-58
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• 2004

In this paper, a mesh simplification algorithm is proposed which considers the conservation of the volume of a 3D model. In General, most of mesh simplification algorithm use a distance metric. The distance metric is very efficient to measure geometric error, but it causes volume changes between the original model and the simplified model. In this paper a mesh simplification algorithm which conserves the volume of the original model is suggested. A new vertex resulting from an edge contraction, takes a position which conserves the volume of the 3D model using the proposed algorithm. Although the new algorithm needs more time than the QEM algorithm, it is shown that it conserves the original volumn of the 3D model during the simplification.

• Journal of the Korea Society of Computer and Information
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• v.25 no.4
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• pp.165-172
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• 2020

In this paper we propose an uses on-device-based edge computing technology and big data analysis methods through the use of on-device-based edge computing technology and analysis of big data, which are distributed computing paradigms that introduce computations and storage devices where necessary to solve problems such as transmission delays that occur when data is transmitted to central centers and processed in current general smart factories. However, even if edge computing-based technology is applied in practice, the increase in devices on the network edge will result in large amounts of data being transferred to the data center, resulting in the network band reaching its limits, which, despite the improvement of network technology, does not guarantee acceptable transfer speeds and response times, which are critical requirements for many applications. It provides the basis for developing into an AI-based facility prediction conservation analysis tool that can apply deep learning suitable for big data in the future by supporting intelligent facility management that can support productivity growth through research that can be applied to the field of facility preservation and smart factory industry with integrated hardware technology that can accommodate these requirements and factory management and control technology.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.12
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• pp.2271-2282
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• 2006

This paper is concerned with simulation issues arising in the PDE-based image restoration such as the total variation minimization(TVM) and its generalizations. In particular, we study the issues of staircasing and excessive dissipation of TVM-like smoothing operators. A strategy of scaling the algebraic system and a non-convex minimization are considered respectively for anti-staircasing and anti-diffusion. Furthermore, we introduce a variable constraint parameter to better preserve image edges. The resulting algorithm has been numerically verified to be efficient and reliable in denoising. Various numerical results are shown to confirm the claim.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2014.11a
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• pp.134-137
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• 2014

화질의 개선을 위해 잡음을 제거하는 기술이 많이 개발되고 있으며 그 기술들 중에 효과적으로 사용되고 있는 것 하나가 양방향 필터이다. 양방향 필터는 거리에 대한 가중치와 화소 값에 대한 가중치를 모두 고려하기 때문에 경계 부분을 보존하면서 잡음을 제거하는 것이 가능하다. 필터를 적용함으로 잡음이 제거되지만 본 논문에서는 그보다 나은 결과를 위해서 경계 부분을 캐니 에지 검출기로 검출하고 강조함으로써 양방향 필터의 장점을 전보다 부각시켜 이전보다 효과적인 화질개선 방법을 제시하고자 하였다.