• Korean Journal of Remote Sensing
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• v.19 no.3
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• pp.247-253
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• 2003

The mainly used technique to correct satellite images with geometric distortion is to develop a mathematical relationship between pixels on the image and corresponding points on the ground. Polynomial models with various transformations have been designed for defining the relationship between two coordinate systems. GCP based geometric correction has peformed overall plane to plane mapping. In the overall plane mapping, overall structure of a scene is considered, but local variation is discarded. The Region with highly variant height is rectified with distortion on overall plane mapping. To consider locally variable region in satellite image, TIN-based rectification on a satellite image is proposed in this paper. This paper describes the relationship between GCP distribution and rectification model through experimental result and analysis about each rectification model. We can choose a geometric correction model as the structural characteristic of a satellite image and the acquired GCP distribution.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.35S no.10
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• pp.118-125
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• 1998

We introduce an adaptive finite state vector quantization using a new side match distortion function. The conventional side match distortion function can make the gray level transition between the block bounddaries as smooth as possible and proper state codebooks in the flat areas where the spatial correlations are high. But it can't make proper codebooks in the edge areas where the spatial correlations are not high. The proposed distortion function adds the variances which represent the image characteristics to the conventional side match distortion function as weighted values. Then it can select better state codebooks than the conventional side match distortion function. Also if it predicts a wrong state, the proposed quantizer can correct the state. As a result, we can obtain the satisfiable image quality.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.3
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• pp.587-599
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• 1996

In general fractal imge compression, each range block is approximated by a contractive transform of the matching domain block under the mean squared error criterion. In this paper, a distortion measure reflecting the properties of human visual system is defined and applied to a fractal image compression. the perceptual distortion measure is obtained by multiplying the mean square error and the noise sensitivity modeled by using the background brightness and spatial masking. In order to compare the performance of the mean squared error and perceptual distortion measure, a simulation is carried out by using the 512*512 Lena and papper gray image. Compared to the results, 6%-10% compression ratio improvements under improvements under the same image quality are achieved in the perceptual distortion measure.

• Journal of architectural history
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• v.14 no.2 s.42
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• pp.71-88
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• 2005

This study aims at clarifying the spatial generative process of Borromini's architecture. The close examination of his sketches and the analysis of his major four works such as San Carlo alle Quattro Fontane (1634-1667), Sant'Ivo della Sapienza (1642-1660), Santa Maria dei Sette Dolori, Chapel (1643-1646), Collegio di Propaganda Fide, Chapel (1652-1667) show common features in the generation of space as follow. 1) The spatial generative process of Borromini's architecture is dominated by the plan of main space which is formulated from simple geometric elements into complexly folded space by mean of union, addition, copy and warping. 2) Borromini made various kinds of annexed space around the main space to create long and continuous circulation. 3) Borromini's architecture has a tendency to divide interior elevation into two parts, wall part and roof part by thick entablature. Moreover the entablature play important role to copy the figure of the plan of main space three-dimensionally. 4) Borromini tried to create the sense of depth through perspectival distortion and multi-focal space through the ceiling pattern.

• ETRI Journal
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• v.32 no.4
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• pp.577-587
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• 2010

The layered coding structure of scalable video coding (SVC) with adaptive inter-layer prediction causes noticeable computational complexity increments when compared to existing video coding standards. To lighten the computational complexity of SVC, we present a fast algorithm to speed up the inter-mode decision process. The proposed algorithm terminates inter-mode decision early in the enhancement layers by estimating the rate-distortion (RD) cost from the macroblocks of the base layer and the enhancement layer in temporal, spatial, and inter-layer directions. Moreover, a search range decision algorithm is also proposed in this paper to further increase the motion estimation speed by using the motion vector information from temporal, spatial, or inter-layer domains. Simulation results show that the proposed algorithm can determine the best mode and provide more efficient total coding time saving with very slight RD performance degradation for spatial and quality scalabilities.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.34 no.4
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• pp.413-423
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• 2016

Worldview-3 satellite sensor provides panchromatic image with high-spatial resolution and 8-band multispectral images. Therefore, an image-sharpening technique, which sharpens the spatial resolution of multispectral images by using high-spatial resolution panchromatic images, is essential for various applications of Worldview-3 images based on image interpretation and processing. The existing pansharpening algorithms tend to tradeoff between spectral distortion and spatial enhancement. In this study, we applied six pansharpening algorithms to Worldview-3 satellite imagery and assessed the quality of pansharpened images qualitatively and quantitatively. We also analyzed the effects of time lag for each multispectral band during the pansharpening process. Quantitative assessment of pansharpened images was performed by comparing ERGAS (Erreur Relative Globale Adimensionnelle de Synthèse), SAM (Spectral Angle Mapper), Q-index and sCC (spatial Correlation Coefficient) based on real data set. In experiment, quantitative results obtained by MRA (Multi-Resolution Analysis)-based algorithm were better than those by the CS (Component Substitution)-based algorithm. Nevertheless, qualitative quality of spectral information was similar to each other. In addition, images obtained by the CS-based algorithm and by division of two multispectral sensors were shaper in terms of spatial quality than those obtained by the other pansharpening algorithm. Therefore, there is a need to determine a pansharpening method for Worldview-3 images for application to remote sensing data, such as spectral and spatial information-based applications.

• Korean Journal of Cognitive Science
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• v.14 no.3
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• pp.51-59
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• 2003

Various perceptual distortions in spatial vision occur during eye movements. Most of the studies on perceptual distortion have focused on the conjunctive eye movements. Recently, Li, Kham, Kim & Yoon (2002) reported that subjects experienced perceptual distortion of 3D slant of an object defined by the spatiotemproal pattern of occlusion. The present research examined whether the subjects experienced the same perceptual distortion in the target object whose luminance is different from that of background. It also examined the effect of the reference on the perceptual distortion of 3D slant of an object.

• Journal of Korean Association for Spatial Structures
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• v.2 no.1 s.3
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• pp.67-73
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• 2002

Measurement of fluctuating pressure by tube system is carefully designed due to the organ-pipe resonance. It is necessary to correct the pressure before analysis. The three method for correction the distortion fluctuation pressure short tube length and the frequency response functions and insert a restrictor in the tube to increase the damping. The first method is useful when the tube length is short. In second method, the distorted signal through the tubing transformed into the frequency domain, dividing by transfer function and inverse fourier transforming back into the time domain gives the required pressure signal. In this paper three types of tubing which have different length of 100cm, 150cm, 200cm were experimented the distorted signal and correct the distortion signal

• Korean Journal of Optics and Photonics
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• v.8 no.5
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• pp.357-361
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• 1997

We report the operation of a self-starting phase conjugate laser(PCL) oscillator which compensates intracavity phase distortion. The self-starting PCL in the population inverted Nd:YAG gain media produced an output energy of 200 mJ in a 20 ns single-longitudinal-mode pulse at 10Hz. And it showed well-defined Gaussian spatial profile.

• Journal of Korea Multimedia Society
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• v.3 no.2
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• pp.164-173
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• 2000

This paper presents an efficient bandwidth allocation method for multiple source in the two-layer video coding of different spatial resolution. We first investigate the model of bitrate distortion in the MPEG-2 spacial scalable coding,. By using approximated model parameters, than we propose an efficient bitrate control method in order to keep the same distortion level among coders and the constant quality ratio between layers. Simulation results show that the proposed method can satify the user requirement in comparison to the conventional method.