• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.19 no.12
• /
• pp.2313-2327
• /
• 1994

As the communication environment evolves, there is an increasing need for multiresolution image coding. To meet this need, the entrophy constratined vector quantizer(ECVQ) for coding of image pyramids by spline wavelet transform is introduced in this paper. This paper proposes a new scheme for image compression taking into account psychovisual feature both in the space and frequency domains : this proposed method involves two steps. First we use spline wavelet transform in order to obtain a set of biorthogonal subclasses of images ; the original image is decomposed at different scale using a pyramidal algorithm architecture. The decomposition is along the vertical and horizontal directions and maintains constant the number of pixels required the image. Second, according to Shannon's rate distortion theory, the wavelet coefficients are vectored quantized using a multi-resolution ECVQ(entropy-constrained vector quantizer) codebook. The simulation results showed that the proposed method could achieve higher quality LENA image improved by about 2.0 dB than that of the ECVQ using other wavelet at 0.5 bpp and, by about 0.5 dB at 1.0 bpp, and reduce the block effect and the edge degradation.

• KIPS Transactions on Software and Data Engineering
• /
• v.5 no.9
• /
• pp.401-410
• /
• 2016

3D registration is a computer vision technique of aligning multi-view range images with respect to a reference coordinate system. Various 3D registration algorithms have been introduced in the past few decades. Iterative Closest Point (ICP) is one of the widely used 3D registration algorithms, where various modifications are available nowadays. In the ICP-based algorithms, the closest points are considered as the corresponding points. However, this assumption fails to find matching points accurately when the initial pose between point clouds is not sufficiently close. In this paper, we propose a new method to solve this problem using the 6D distance (3D color space and 3D Euclidean distances). Moreover, a color segmentation-based adaptive sampling technique is used to reduce the computational time and improve the registration accuracy. Several experiments are performed to evaluate the proposed method. Experimental results show that the proposed method yields better performance compared to the conventional methods.

• Journal of the Korean Society of Costume
• /
• v.65 no.5
• /
• pp.126-141
• /
• 2015

The purpose of this study is to examine the works of choreographer Philippe $Decoufl{\acute{e}}$ and the performance costumes designer Philippe Guillotel, and identify the intrinsic values shown in the formative characteristics in their works. And it proposes a vision and a direction for the development and performance of modern fashion phenomenon of media convergence performing arts complex. The results were as follows. First, the performance characteristics shown in Philippe $Decoufl{\acute{e}}$'s art pattern applies dynamic improvisation, decategorization reflected in the media interactivity, time and space of a variable scalability, complex artistic genres and transcends cultural boundaries. Second, the characteristics of the performance costume can be described as a co-existence between dynamics of aesthetic layers, 'Media body' represented by the interaction of the compounds with the technology, and integrated variable expandability. And aesthetic values inherent in the performance costumes are summarized as abstraction, playfulness, reproducibility, and theatricality. Modern fashion performance and limited production of the center 'costumes' in the fashion images can be used in diverse ways, and innovative marketing has gone through a change in image production. Metaphysical text of the advanced performance genre can be presented in a new perspective to fashion derivatives 'Media body'. And the aesthetics of popular culture kitsch, the grotesque, and surrealism in theater will produce creative stage direction.

• Journal of the Korea Society of Computer and Information
• /
• v.19 no.2
• /
• pp.49-56
• /
• 2014

This thesis proposes CBIRS/TB method that uses a tablet's color distribution information and form distinctive in content-based search. CBIRS/TB can avoid misuses and improper tablet uses by conducting content-based search in commonly prescribed tablets. The existing FE-CBIRS system is limited to recognizing only the image of color and shape of the tablet, that leads to applying insufficient form-specific information. While CBIRS/TB utilizes average, standard deviation, hue and saturation of each tablets in color, brightness, and contrast, FE-CBIRS has partial-sphere application problem; only applying the typical color of the tablet. Also, in case of the shape-specific-information, Invariant Moment is mainly used for the extracted partial-spheres. This causes delayed processing time and accuracy problems. Therefore, to improve this setback, this thesis indexed color-specific-information of the extracted images into categorized classification for improved search speed and accuracy.

• Korean Journal of Optics and Photonics
• /
• v.24 no.5
• /
• pp.237-244
• /
• 2013

Supermultiview and electro-holographic displays are promising displays for the future because they provide continuous parallaxes as their depth cue. But they are still in the early development stage due to the lack of supporting technologies. Achieving the continuous parallax in the supermultiview relies more on the number and size of pixels in the pixel cell/elemental image rather than the number of different view images. For the electro-holographic display, it also relies on the number and size of pixels in the panel. So these two methods share the same requirements for achieving the parallax. But the image displayed on the holographic display provides more impressive visual appeal than that on the supermultiview because the image can be floated on the front space of the display.

• Journal of Digital Contents Society
• /
• v.8 no.4
• /
• pp.441-449
• /
• 2007

In video coding, motion estimation is a process to estimate the pixel of the current frame from the reference frame, which affects directly the predictive quality and the encoding time. This paper is related to AHHS(Adaptive Hierarchical Hexagon Search) using spatio-temporal motion activity for fast motion estimation. The proposed method defines the spatio-temporal motion activity of the current macroblock using the motion vectors of its spatio-temporally adjacent macroblocks, and then conventional AHS(Adaptive Hexagon Search) is performed if the spatio-temporal motion activity is lower, otherwise, hierarchical hexagon search is performed on a multi-layered hierarchical space constructed by multiple sub-images with low frequency in wavelet transform. In the paper, based on computer simulation results for multiple video sequences with different motion characteristics, the performance of the proposed method was analysed and assessed in terms of the predictive quality and the computational time. Experimental results indicate that the proposed method is both suitable for (quasi-) stationary and large motion searches. The proposed method could keep the merit of the adaptive hexagon search capable of fast estimating motion vectors and also adaptively reduce the local minima occurred in the video sequences with higher spatio-temporal motion activity.

• Publications of The Korean Astronomical Society
• /
• v.30 no.2
• /
• pp.133-137
• /
• 2015

The Galactic center uniquely provides opportunities to resolve how star clusters form in neutral gas overdensities engulfed in a large-scale accretion flow. We have performed sensitive Green Bank 100m Telescope (GBT), Karl G. Jansky Very Large Array (JVLA), and Submillimeter Array (SMA) mapping observations of molecular gas and thermal dust emission surrounding the Galaxy's supermassive black hole (SMBH) Sgr $A^{\ast}$. We resolved several molecular gas streams orbiting the center on ${\gtrsim}10$ pc scales. Some of these gas streams appear connected to the well-known 2-4 pc scale molecular circumnuclear disk (CND). The CND may be the tidally trapped inner part of the large-scale accretion flow, which incorporates inflow via exterior gas filaments/arms, and ultimately feeds gas toward Sgr $A^{\ast}$. Our high resolution GBT+JVLA $NH_3$ images and SMA+JCMT 0.86 mm dust continuum image consistently reveal abundant dense molecular clumps in this region. These gas clumps are characterized by ${\gtrsim}100$ times higher virial masses than the derived molecular gas masses based on 0.86 mm dust continuum emission. In addition, Class I $CH_3OH$ masers and some $H_2O$ masers are observed to be well associated with the dense clumps. We propose that the resolved gas clumps may be pressurized gas reservoirs for feeding the formation of 1-10 solar-mass stars. These sources may be the most promising candidates for ALMA to probe the process of high-mass star-formation in the Galactic center.

• Publications of The Korean Astronomical Society
• /
• v.30 no.2
• /
• pp.439-442
• /
• 2015

We observed multiple CO transition lines and the HCN(1-0) line at ~ 1" (~ 34 pc) or higher resolution toward the Seyfert 2 nucleus of M51 using the IRAM Plateau de Bure Interferometer (PdBI) and the Submillimeter Array (SMA). All the images show very similar overall molecular gas distribution; there are two discrete clouds at the eastern and western sides of the nucleus, and the western cloud exhibits an elongated distribution and velocity gradient along the radio jet. In addition, high HCN(1-0)/CO(1-0) brightness temperature ratios of about unity have been observed, especially along the radio jet, similar to those observed in shocked molecular gas in our Galaxy. This strongly indicates that the molecular gas along the jet is shocked, that the radio jet and the molecular gas are interacting, and the jet is entraining both diffuse (CO) and dense (HCN) molecular gas outwards from the circumnuclear region. This is the first clear imaging of the outflowing molecular gas entrained by the AGN jet, and showing the detailed physical status of outflowing molecular gas. Since a relatively high HCN(1-0)/CO(1-0) ratio has been observed in the high velocity wing of ultraluminous infrared galaxies, it can also be explained by a similar mechanism to those we describe here.

• The Bulletin of The Korean Astronomical Society
• /
• v.37 no.2
• /
• pp.107.1-107.1
• /
• 2012

We present the results of far-ultraviolet (FUV) observations of comet C/2001 Q4 (NEAT) obtained with Far-ultraviolet Imaging Spectrograph (FIMS) on board the Korean microsatellite STSAT-1, which operated at an altitude of 700 km in a sun-synchronous orbit. FIMS is a dual-channel imaging spectrograph (S channel 900-1150 ${\AA}$, L channel 1350-1750 ${\AA}$, ${\lambda}/{\Delta}{\lambda}$ ~ 550) with large image fields of view (S: $4^{\circ}.0{\times}4^{\prime}.6$, L: $7^{\circ}.5{\times}4^{\prime}.3$, angular resolution 5'-10') optimized for the observation of diffuse emission of astrophysical radiation. Comet C/2001 Q4 (NEAT) was observed with a scanning survey mode when it was located around the perihelion between 8 and 15 May 2004. Several important emission lines were detected including S I (1425, 1474 ${\AA}$), C I (1561, 1657 ${\AA}$) and several emission lines of CO $A^1{\Pi}-X^1{\Sigma}^+$ system in the L channel. Production rates of the notable molecules, such as C I, S I and CO, were estimated from the photon fluxes of these spectral lines and compared with previous observations. We compare the flux and the production rates in the radius of $3{\times}10^5$ km with $20{\times}10^5$ km from the central coma. We obtained L-channel image which have map size $5^{\circ}{\times}5^{\circ}$ The image was constructed for the wavelength band of L-channel (1350 - 1710 ${\AA}$. We also present the radial profiles of S I, C I, CO obtained from the spectral images of the central coma. The radial profiles of $2{\times}10^6$ km region are compared with the Haser model.

• Journal of Cadastre & Land InformatiX
• /
• v.50 no.1
• /
• pp.25-45
• /
• 2020

The primary purpose of this study is to compare and analyze the performance of local spatial autocorrelation techniques in identifying spatial distribution patterns of green spaces. To achieve the objective, this researcher uses satellite image analysis and spatial autocorrelation techniques. The result of the study shows that the LISA cluster map with the spatial outlier cluster is superior to other analytical methods in identifying the spatial distribution pattern of urban green space. This study can contribute to the related fields in that it uses several different research methods than the existing ones. Despite this differentiation and usefulness, this study has limitations in using low-resolution satellite imagery and NDVI among vegetation indices in identifying spatial distribution patterns of green areas. These limitations may be overcome in future studies by using UAV images or by simultaneously using several vegetation indices.