• KIISE Transactions on Computing Practices
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• v.22 no.3
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• pp.157-162
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• 2016

The limitation of a human's visual perception is considered to be 60 frames per second, This study investigated the effects of fast update rates (above 60 fps) in terms of interaction accuracy. Initial experiments showed that the interaction accuracy increased at rates faster than 60 fps. We assumed that either or both of the following two situations would cause such an effect: the user could recognize rendering rates faster than 60 fps, or the input processing rates were significant for the high accuracy. To evaluate the significance of these events, we conducted a second and third experiment. Although the display refresh rate was also fixed at 60 fps (by disabling the vertical sync), the rendered image actually differed for 60 fps and 150 fps. This research shows that faster update rate is necessary to achieve high interaction accuracy, and its limit is far over the usually considered 60 fps.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.16 no.1
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• pp.43-53
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• 2016

In this study, under the assumption that there may be differences in colour attributes that can be perceived according to the brightness of the background and the size of the colour stimulus, a test was conducted where colour matching was done for stimulus sizes of $10^{\circ}$ and $20^{\circ}$ in terms of peripheral vision by varying the background brightness. The test results showed that depending on the background brightness and the specific combinations of the Munsell colour attributes used as the test stimulus, colours can be perceived differently even if they are the same colours. In addition, in contrast to findings from previous studies on colour perception according to the stimulus size, it was found that even if the size of the colour stimulus is relatively small, colours can be perceived more colourfully or more brightly with changes in the background brightness. Based on the findings of this study, degradation in image quality can be improved, which may occur when the size of the input image is changed at a later time, and also, contributions can be made when it comes to the reproduction of effective sold three-dimensional structures that reflect visual qualities when processing 3D holographic imagery, in addition to 2D imagery.

• Korean Journal of Heritage: History & Science
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• v.50 no.1
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• pp.58-77
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• 2017

This study applied the index called Visual Perception Intensity (VPI) which quantitatively deals with landscape values and viewpoints to designate the cultural heritage areas in the Scenic Sites. The results of the study are as follows. First, a VPI selection index was presented for designating the cultural heritage areas in the Scenic Sites. The index was applied in consideration of the distance from the viewing point to the object and its incident angle. In addition, the process of the VPI analysis was implemented with GIS and the analysis algorithm was constructed. Second, the possibility of VPI was examined by comparing the simple frequency of the cumulative visibility with the results of the VPI. The VPI was analyzed to be more influenced by the incidence angle than the distance between the viewpoint and the object within a 4.74 km area. Third, a field survey was performed to investigate the effectiveness of the VPI classification. The survey was implemented based on the results of the investigation into the VPI to examine whether human visual perception was fully reflected. It was confirmed through the field survey that an area with high VPI was also an important area. Fourth, a plan for the cultural heritage area adjustment was constructed by applying the VPI to the areas already designated as Scenic Sites. As a result of classifying the VPI into three classes, it was found that the areas with the second class or higher were needed to be designated as cultural heritage areas and the areas with the third class as the Historical and Cultural Environments Preservation Area.

• Journal of the Korea Computer Graphics Society
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• v.28 no.4
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• pp.31-40
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• 2022

This study assumed two key parameters that describe smoothness. Previously, the number of studies that defined smoothness with the concept of curvature has been limited. The parameters were the two physical characteristics of curvature: the number of waves and the amplitude of them. The purpose of the study was to observe which of the two parameters influences the perception of smoothness and to examine the relationship between the sense of aesthetic beauty and smoothness. The visual stimuli used in the study were transformed three-dimensional spheres, based on the combination of the three levels of the two parameters of nine distinct conditions. We analyzed the three responses that measured the preference of each visual stimuli, the familiarity score, and the smoothness evaluation score, each with the linear mixed model whose fixed effects were the two parameters and random effects were the participants' individual differences. Nearly the eighty percent of the variance of the smoothness evaluation score was explained by the linear model with the two key parameters and their interaction. The physical characteristics of a viewed object were far more significant than individual differences such as personality factors and the manner of art appreciation. In conclusion, the study examined the perception of smoothness based on the change of the physical characteristics of a shape. The study further recognized the relationship between smoothness and the aesthetic preference. No significant influence of the participants' individual difference such as gender, the degree in fine arts, personality factors, and the manner of art appreciation was observed. The amplitude of waves, rather than the number of them, was far more significant to the perception of smoothness.

• The Journal of the Korea Contents Association
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• v.6 no.5
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• pp.76-84
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• 2006

When a human-being gets a wrong perception about any object is a misunderstanding and what they feel through sense of sight is an optical illusion. The study about those illusions have been given out to not only the fields of fine art, design, and animation but also psychology First, this paper puts in order an op art, influenced in fine art and design, and animation using persistence of vision, relating an optical illusion. Second, it analyses the theory of art form using an optical illusion about brightness, saturation, contrast and luminosity of color. Finally, it makes an experiment of standard of perception on students. The study of art form using an optical illusion is another way to represent fine art comparisons and visual image including animation.

• The Transactions of the Korea Information Processing Society
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• v.5 no.1
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• pp.236-248
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• 1998

Human observers perceive a contour where no line or edge is given, such as the border between gratings of thin lines offset by half a cycle. Illusory contours occur in a wide variety of circumstances in nature. A common factor in all such figures is the perception of a surface or contour occluding part of a background, i.e. illusory contours are always accompanied by illusory surfaces. Some examples about these kinds of figures are given by Kanizsa's triangle or square. In this paper, we proposed a neural network model for forming(extracting) the illusory surfaces, based on the mechanism of feature extraction found in a mammals' visual pathway. It will be shown that the model can extract the illusory surfaces from illusory contours successfully.

• The Research Journal of the Costume Culture
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• v.15 no.2 s.67
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• pp.214-220
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• 2007

The purpose of this study is to derive the use of the luminous source corresponding to the intention and contribute to product display by visually evaluating the relations between luminous source and colors, analyzing and reviewing the subjective perceptions depending on the luminous source, and clarifying the colors of artificial luminous source that look close to natural lights by each color. Hence, the researcher objectified the subjective evaluation for which they used sensory evaluation method with four colors of luminous sources(natural colors, 2800K, 4200K, and 6500K) and five colors of textiles(purple, blue, green, yellow, and red) by quantifying the evaluation. As a result, we could obtain the conclusion as follows. As for the temperature of textile colors under artificial luminous sources that appeared most close to the colors of textiles under natural luminous sources, 6500K was most frequent, and the temperature of the luminous sources that appeared most different was 2800K. However, as there were also 4200K colors that looked most close to the textile colors under natural light source, it was observed that the temperature differs depending on the textile colors. In addition, less glossy textiles exhibited more visual changes by luminous source colors than comparatively more glossy textiles, and it was observed that the most influenced color was purple, as purple has shown the largest difference among colors.

• ETRI Journal
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• v.31 no.1
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• pp.1-9
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• 2009

Frequency domain analysis is a fundamental procedure for understanding the characteristics of visual data. Several studies have been conducted with 2D videos, but analysis of stereoscopic 3D videos is rarely carried out. In this paper, we derive the Fourier transform of a simplified 3D video signal and analyze how a 3D video is influenced by disparity and motion in terms of temporal aliasing. It is already known that object motion affects temporal frequency characteristics of a time-varying image sequence. In our analysis, we show that a 3D video is influenced not only by motion but also by disparity. Based on this conclusion, we present a temporal anti-aliasing filter for a 3D video. Since the human process of depth perception mainly determines the quality of a reproduced 3D image, 2D image processing techniques are not directly applicable to 3D images. The analysis presented in this paper will be useful for reducing undesirable visual artifacts in 3D video as well as for assisting the development of relevant technologies.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.05a
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• pp.1009-1009
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• 2003

VIPER a new tool for the VIsual PERception of sound quality and for sound design will be presented. Requirement for the visualization of sound quality is a signal analysis modeling the information processing of the ear. The first step of the signal processing implemented in VIPER, calculates an auditory spectrogram by a filter bank adapted to the time- and frequency resolution of the human ear. The second step removes redundant information by extracting time- and frequency contours from the auditory spectrogram in analogy to contours of the visual system. In a third step contours and/or auditory spectrogram can be resynthesised confirming that only aurally relevant information were extracted. The visualization of the contours in VIPER allows intuitively to grasp the important components of a signal. Contributions of parts of a signal to the overall quality can be easily auralized by editing and resynthesising the contours or the underlying auditory spectrogram. Resynthesis of time contours alone allows e.g. to auralize impulsive components separately from the tonal components. Further processing of the contours determines tonal parts in form of tracks. Audible differences between two versions of a sound can be visually inspected in VIPER through the help of auditory distance spectrograms. Applications are shown for the sound design of several interior noises of cars.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.18 no.3
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• pp.29-34
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• 2018

The digital colour reproduced on a display can be transferred to the image through various colour spaces, and the colour transferred to the image is one of the most important factors, among both subjective and objective factors, in image quality evaluation. Therefore, the digital colour must be continuously studied objectively and quantitatively along with the display development. At the same time, the subjective evaluation should be accompanied by systematic and quantitative research as the visual characteristics must be fully reflected. In this study, we applied different lightness levels of the background in order to examine the movement phenomenon of colour properties among the digital colour properties reproduced on the display. A psychophysical experiment was conducted for the condition where various colours were presented in the background, and the size of the colour stimulus was divided into the foveal vision and peripheral vision. Based on the evaluation results of the experiment, the colour properties movement phenomenon is identified according to the lightness of the background and the size of the colour stimulus for five colours among KS basic colours selected by experimental stimulus. Furthermore, a research direction to reproduce colour on displays in the future is proposed.