• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.1224-1227
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• 2009

When evaluating the quality of images and displays, it is important to combine the characteristics as perceived by the human visual system and measured by equipment using subjective and objective methods, respectively. In the case of objective methods, the quality of a display is measured using colorimetric or radiometric devices according to existing standards covering the color temperature, gamut size, gamma characteristic, and device characterization. Meanwhile, subjective methods assess the quality of an image using the human visual system based on a comparison with a reference or counterpart using such metrics as the sharpness, noise, contrast, saturation, and color accuracy. Objective and subjective methods are usually used together in comparison, as ultimately it is observers watching images on a display. In addition to existing objective methods, a new image quality metric is also introduced as regards the JPEG compression ratio that is reflected in the relationship between the gamut size and the color fidelity in CIELAB color space.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.1
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• pp.452-472
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• 2019

Most existing wavelet-based multiplicative watermarking methods are affected by geometric attacks to a certain extent. A serious limitation of wavelet-based multiplicative watermarking is its sensitivity to rotation, scaling, and translation. In this study, we propose an image watermarking method by using dual-tree complex wavelet transform with a multi-objective optimization approach. We embed the watermark information into an image region with a high entropy value via a multiplicative strategy. The major contribution of this work is that the trade-off between imperceptibility and robustness is simply solved by using the multi-objective optimization approach, which applies the watermark error probability and an image quality metric to establish a multi-objective optimization function. In this manner, the optimal embedding factor obtained by solving the multi-objective function effectively controls watermark strength. For watermark decoding, we adopt a maximum likelihood decision criterion. Finally, we evaluate the performance of the proposed method by conducting simulations on benchmark test images. Experiment results demonstrate the imperceptibility of the proposed method and its robustness against various attacks, including additive white Gaussian noise, JPEG compression, scaling, rotation, and combined attacks.

• Journal of the Ergonomics Society of Korea
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• v.30 no.1
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• pp.195-202
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• 2011

Objective: The aim of this study is to investigate and review the previous researches about objective measuring fatigue caused by visual stimuli. Also, we analyze possibility of alternative visual fatigue measurement methods using facial expression recognition and gesture recognition. Background: In most previous researches, visual fatigue is commonly measured by survey or interview based subjective method. However, the subjective evaluation methods can be affected by individual feeling's variation or other kinds of stimuli. To solve these problems, signal and image processing based visual fatigue measurement methods have been widely researched. Method: To analyze the signal and image processing based methods, we categorized previous works into three groups such as bio-signal, brainwave, and eye image based methods. Also, the possibility of adopting facial expression or gesture recognition to measure visual fatigue is analyzed. Results: Bio-signal and brainwave based methods have problems because they can be degraded by not only visual stimuli but also the other kinds of external stimuli caused by other sense organs. In eye image based methods, using only single feature such as blink frequency or pupil size also has problem because the single feature can be easily degraded by other kinds of emotions. Conclusion: Multi-modal measurement method is required by fusing several features which are extracted from the bio-signal and image. Also, alternative method using facial expression or gesture recognition can be considered. Application: The objective visual fatigue measurement method can be applied into the fields of quantitative and comparative measurement of visual fatigue of next generation display devices in terms of human factor.

• Journal of Fashion Business
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• v.16 no.4
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• pp.64-74
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• 2012

The purpose of this study would be to find out the relationship of social as a sign of fashion image and the followership. This study is classified into theoretical and experimental research. Following are the summary of the results revealed through the experimental study. First, The relationship of oneself pursuit of fashion image types and leader's favourite fashion image types for regression analysis result indicated significant difference. Second, The factor analysis of followership are used, developed by Colangeol is asking. The results of factor analysis are four types classification as to Active Participation, Convergence objective, Team Spirit, Critical Thinking. Third, The relationship of types of fashion images and factor variance of followership indicated a difference in Active Participation factors. But The relationship of types of leader's fashion images and factor variance of followership indicated a difference in Convergence objective factors. Analysis of the fashion image based on the conceptual properties of followership is to understand the characteristics of followers, and the leader's image based on research for building materials will be provided.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.49 no.2
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• pp.61-68
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• 2012

This paper describes a normalized numeric image descriptor used to assess the luminance and contrast of the image. The proposed image descriptor used the each pixel data as weighted value of the probability density function (PDF) and defined by normalization in order to objective represent. The proposed image numeric descriptor can be used to the adaptive gamma process because it suggests the objective basis of the gamma value selection.

• Journal of the Korean Society of Costume
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• v.59 no.5
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• pp.152-166
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• 2009

The purpose of this study was to propose a brand image profile by analyzing how the consumer perceived the rival brands having relative structure between corporate image, store image, and. product image. Fifty-two questions were prepared for the respondents, and 262 questionnaires were selected for analyzing. The data were analyzed by a frequency, a mean, a reliability, and a paired t-test of the SPSS 12.0. The results were as follows : 1. As influence rank of the brand image, a product image had greatest influence followed by a store image and a corporate image. 2. The factors, which were regarded as important from consumer, and satisfaction of those factors were evaluated. As a result of the analysis, the degree of satisfaction of the factors was relatively low than that of the importance. It was proved that the important factors of the brand's image and the degree of satisfaction of the factors were not the same from this study.

• Current Optics and Photonics
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• v.4 no.3
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• pp.200-209
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• 2020

We describe an approach that uses a bilateral filter to reduce the ringing artifact in motion-blurred restoration image. It takes into account the specific physical structure of the ringing artifact combined with the properties of the human visual system. To properly reduce the ringing artifact, each of the adjacent pixels is limited in a straight line which has a given direction. To protect the edges and the texture regions of an image, our algorithm divides the image into texture regions and flat regions, and the artifact reduction algorithm is only applied to the flat region. Finally, we use 8 typical images and 5 objective quality evaluation indices to evaluate our algorithm. Experimental results show that our algorithm can obtain better results in subjective visual effect and in objective image quality evaluation.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.22 no.1
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• pp.67-75
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• 1992

Transcranial radiograph is widely used in the diagnosis of craniomandibular disorder because it can be used by the dentist with relative ease in spite of image distortion. But correct information can be obtained only when one know the image change by projection angulation. The author compared the condyle position in the 3 groups of transcranial radiographs (horizontal angulation - 0°, 5°, individualized) with that in the individualized corrected lateral tomogram by objective and subjective evaluation methods. The results were as follows: 1. Among 3 transcranial groups, the condyle position in individualized group showed the highest concordance rate with that in the tomogram group in objective and subjective evaluation methods. 2. Correlation coefficient between individualized transcranial group and tomogram group in objective evaluation method was highest (P≤0.01). 3. Image clarity in individualized transcranial group was worse than that of the other two transcranial groups.

• 한국가시화정보학회:학술대회논문집
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• 2001.12a
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• pp.123-137
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• 2001

PIV (particle image velocimetry) systems use a camera to take snapshots of particles carried by a fluid at some precise instants. Signal processing methods are then used to compute the flow velocity field. In this paper, the design of the camera objective (optics) is addressed. The optimization is done in order to maximize the signal-to-noise ratio of in-focus particles. Four different kinds of noise are considered: photon shot noise, thermal and read noise, background glow shot noise, and noise made by the other particles. A semi-empirical model for the lens aberrations of a two-doublet objective is first addressed, since further, it is shown that lens aberrations (low f-value $f_{\#}$) should be used instead of the Fraunhofer diffraction (high f-value) for the fitting of the particle image size with the pixel size. Other important conclusions of the paper include the expression of optimum values for the magnification M, for the exposure period $\tau$ and for the pixel size $\xi$.

• Fibers and Polymers
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• v.6 no.1
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• pp.79-81
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• 2005

Fuzz on the fabrics, which is the fibers protruded from the fabric surface, is very important in view of appearance quality, since it causes unpleasant appearance on the fabrics and also leads to pilling which makes fabric appearance and soft­ness worse. However, fuzz on fabric surface is measured mostly by subjective methods (human vision) rather than objective methods. Thus, in this study, objective method using image analysis techniques has been developed for the measurement of fuzz on fabric surface. Fuzz on the fabric has also been ranked and rated by experts in order to see the reliability of the results obtained from the fuzz measurement. It was observed that correlation coefficient (r) between rating value and objective mea­surement value was 0.9 and this correlation coefficient value confirmed the reliability of this method.