• Title/Summary/Keyword: Tone Mapping

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The P300 Source Localization in the Patients with Obsessive-Compulsive Disorder using the LORETA Imaging and SPM (강박장애에서 LORETA 영상을 이용한 P300 국소원의 통계적 분석)

  • Park, Sung-Kun;Choi, Jung-Seok;Yu, Soh-Young;Lee, Bo Reom;Kang, Seung-Suk;Roh, Kyu Sik;Ha, Tae-Hyun;Kwon, Jun Soo
    • Korean Journal of Biological Psychiatry
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    • v.10 no.2
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    • pp.168-176
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    • 2003
  • Objectives:We investigated the characteristics of P300 generators in obsessive-compulsive disorder(OCD) patients by using voxel-based statistical parametric mapping of current density images. Methods:P300 generators, produced by a rare target tone of 1500Hz under a frequent non-target tone of 1,000Hz, were measured in 15 right-handed OCD patients and 15 controls. Low Resolution Electromagnetic Tomography(LORETA), using a realistic head model of the boundary element method based on individual MRI, was applied to the 128-channel EEG. Statistical parametric mapping(SPM) was applied for the statistical analysis. Results:We found that both groups had the mean current density of P300 in the parietal, temporal and prefrontal lobe. There was a trend for decreased current density in the prefrontal area in OCD patients. The statistical comparison showed current density increase in the supraparietal area, a statistically significant longer P300 latency and a trend for reduced P300 amplitude in OCD patients. Conclusion:It suggests that P300 source of both groups exists in multiple brain regions at the same time. And both groups had no statistically significant differences in the current density of P300 except for increased current density in the supraparietal area in OCD patients. But, considering the statistically significant longer P300 latency, a trend for reduced P300 amplitude and relative mean current density reduction in the prefrontal area in OCD patients, this study suggests that the frontal lobe may have a reduced normal inhibitory process in OCD patients.

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Enhanced Integrated Multi-scale Retinex based on CIELAB Color Space for Improving Color Reproduction (색 재현 개선을 위한 CIELAB 색 공간 기반의 향상된 Multi -scale Retinex)

  • Kyung, Wang-Jun;Lee, Tae-Hyoung;Lee, Cheol-Hee;Ha, Yeong-Ho
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.48 no.1
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    • pp.1-7
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    • 2011
  • In this paper, we propose the digital image enhancement method including local tone reproduction and preservation of the hue. In recent studies, an integrated multi-scale retinex (IMSR) has produced great naturalness in the resulting images through enhancement of visibility in dark area in input images. However, most methods, including IMSR, work in RGB color spaces. As such, this produces hue distortion from the perspective of the human visual system, that is, hue distortion in CIELAB color space. Accordingly, this paper proposes an tone reproduction and enhancement of saturation method in a device-independent color space, CIELAB, to preserve the hue and obtain a high contrast and naturalness. First, to achieve the desired objectives, the IMSR is then applied to only the $L^*$ values in CIELAB color space, normalization, and simple mapping function, thereby preserving the balance of the color components and enhancement of visibility. Then, saturation adjustment is performed by applying the ratio of the chroma variation at the sRGB gamut boundary according to the corrected luminance. In experiments, the proposed method is shown to improve the visibility in dark shadows and bright regions in the resulting images and reduce any color distortion then preference test are performed.

Research of Quantitative Modeling that Classify Personal Color Skin Tone (퍼스널 컬러 스킨 톤 유형 분류의 정량적 평가 모델 구축에 대한 연구)

  • Kim, Yong Hyeon;Oh, Yu Seok;Lee, Jung Hoon
    • Journal of the Korean Society of Clothing and Textiles
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    • v.42 no.1
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    • pp.121-132
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    • 2018
  • Recent beauty trends focus on suitability to individual features. A personal color system is a recent aesthetic concept that influences color make up and coordination. However, a personal color concept has several weaknesses. For example, type classification is qualitative and not quantitative because its measuring system is a sensory test with no industry standard of personal color system. A quantitative personal color type classification model is the purpose of this study, which can be a solution to above problems. This model is a kind of mapping system in a 3D Cartesian coordinate system which has own axes, Value, Saturation, and Yellowness. The cheek color of the individual sample is also independent variable and personal color type is a dependent variable. In order to construct the model, this study conducted a colorimetric survey on a 993 sampling frequency of Korean women in their 20s and 30s. The significance of this study is as follows. First, through this study, personal color system is established on quantitative color space; in addition, the model has flexibility and scalability because it consisted of independent axis that allows for the inclusion of any other critical variable in the form of variable axis.

Analysis of Color Visualization in High Dynamic Range Image (높은 동적 범위 영상에서 색상 시각화 분석)

  • Lee, Yong-Hwan;Kim, Heung-Jun;Kim, Bong-Gi
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2015.10a
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    • pp.705-708
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    • 2015
  • High dynamic range (HDR) imaging is a techniques used in imaging to reproduce a greater dynamic range of luminosity than is possible with standard digital imaging. Tone mapping of HDR images for realistic display is commonly studied. However, scientific visualization of HDR image for analysis of scene luminance has much less attention. In this paper, we present and implement a simple approach for the reproduction and visualization of color information in HDR images. We attempt several simple color visualizing functions, and estimate their effectiveness through the evaluation factors with common HDR images.

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FH DFT-Spreading OFDM System for the Effective Channel Estimation and PAPR Reduction in Jamming Channel (재밍 채널에서 효과적 채널 추정과 PAPR 저감을 위한 주파수 도약 DFT-Spreading OFDM 시스템)

  • Kim, Jang-Su;Ryu, Heung-Gyoon;Lee, Seung-Jun;Ko, Dong-Kuk
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.21 no.7
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    • pp.796-804
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    • 2010
  • It is important to use the comb type pilot allocation for the continuous channel and efficient processing. And DFT-spreading OFDM is used a lot to solve high PAPR problem of OFDM system. However, PAPR is increased again when comb type pilot is used to estimate channel characteristics. So, in this paper, we employ a new SLM method to DFT-spreading OFDM system to reduce increased high PAPR. And we suggest an effective method to transmit side information without additional bandwidth. Pilot and side information must be preserved from jamming or intentional interferences since those are very important in DFT spread OFDM system using SLM. So, in this paper, we like to analyze and simulate the performance of DFT spread OFDM system based on SLM against jamming signal. To remedy the vulnerable shortcomings of DFT spread OFDM about jamming or intentional interferences, we employ FH(Frequency Hopping) method and analyze system performance under the several jamming conditions such as MTJ(Multi Tone Jamming) and PBJ(Partial Band Jamming).

Improved characterization method for mobile phone camera and LCD display (모바일 폰 카메라와 LCD의 향상된 특성화 방법)

  • Jang, In-Su;Son, Chang-Hwan;Lee, Cheol-Hee;Song, Kun-Woen;Ha, Yeong-Ho
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.45 no.2
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    • pp.65-73
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    • 2008
  • The characterization process for the accurate color reproduction in mobile phone with camera and LCD is popular. The camera and LCD characterization, gamut mapping process is necessary to map the camera's input color stimulus, CIEXYZ value, into the LCD's output color stimulus. Each characterization is the process estimating the relation between input and output signals. In case of LCD, because of output device, the output color stimulus for the arbitrary input signal can be measured by spectro-radiometer However, in the camera, as the input device, the characterization is an inaccurate and needs the manual works in the process obtaining the output signal because the input signal can not be generated. Moreover, after gamut mapping process, the noise is increased because the optimized gamma tone curve of camera for the noise is distorted by the characterization. Thus, this paper proposed the system of obtaining the output signal of camera and the method of gamma correction for the noise. The camera's output signal is obtained by RGB values of patches from captured the color chart image. However, besides the illumination, the error for the location of the chart in the viewfinder is generated when many camera modules are captured the chart. The method of correcting the position to correct the error from manual works. The position of camera is estimated by captured image. This process and moving of camera is accomplished repeatedly, and the optimized position can be obtained. Moreover, the lightness curve of camera output is corrected partly to reduce the noise from the characterization process.

Image Enhancement based on Piece-wise Linear Enhancement Curves for Improved Visibility under Sunlight (햇빛 아래에서 향상된 시인성을 위한 Piece-wise Linear Enhancement Curves 기반 영상 개선)

  • Lee, Junmin;Song, Byung Cheol
    • Journal of Broadcast Engineering
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    • v.27 no.5
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    • pp.812-815
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    • 2022
  • Images displayed on a digital devices under the sunlight are generally perceived to be darker than the original images, which leads to a decrease in visibility. For better visibility, global luminance compensation or tone mapping adaptive to ambient lighting is required. However, the existing methods have limitations in chrominance compensation and are difficult to use in real world due to their heavy computational cost. To solve these problems, this paper propose a piece-wise linear curves (PLECs)-based image enhancement method to improve both luminance and chrominance. At this time, PLECs are regressed through deep learning and implemented in the form of a lookup table to real-time operation. Experimental results show that the proposed method has better visibility compared to the original image with low computational cost.

Research Trend of Joint Mobilization Type on Shoulder : A scoping review (어깨관절 질환에 대한 관절가동술 유형의 연구 동향 : 주제범위 문헌고찰)

  • Jeong-Woo Lee;Nam-Gi Lee
    • Journal of The Korean Society of Integrative Medicine
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    • v.11 no.3
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    • pp.171-183
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    • 2023
  • Purpose : This study sought to investigate research trends regarding joint mobilization type among patients with shoulder joint diseases. Methods : A scoping review was conducted according to the five steps outlined by Arskey and O'Malley and PRISMA-ScR. We searched six domestic databases (ScienceOn, DBpia, Riss, Kmbase, Kiss, KCI) and three international databases (CINAHL, Pubmed, Cochrane central) between 2013 and June 2023. The keyword terms used were 'joint mobilization', 'Kaltenborn', 'Maitland', 'Mulligan', and 'shoulder joint'. Results : There were a total of 44 studies that investigated the topic, and these were divided into quantitative analysis and topic analysis. In terms of publication year, the number of studies within the last five years has increased more than compared to the previous five years, with most of them being randomized clinical trials. In shoulder joint diseases, it was found that the majority of joint movement studies focused on adhesive joint cystitis and shoulder collision syndrome. The Mulligan concept was the most commonly studied type of joint motion. The dependent variables used included pain, joint function (disability), and muscle function. The visual analog scale was the most commonly used for the pain variable, followed by the numeric rating scale. For joint function and disability variables, range of motion was the most commonly used, followed by shoulder pain and disability index, and disabilities of the arm, shoulder, and hand. For muscle function, variables such as muscle tone, strength, and activity were used. Conclusion : We believe that findings of this scoping review can serve as valuable mapping data for joint mobilization research on shoulder joint diseases. Further studies including systematic reviews and meta-analyses based on these results are recommended.

Estimation of Differently Exposed Low Dynamic Range Images from a Single Bayer Image (단일 Bayer 영상으로 부터 다양한 노출을 가지는 Low Dynamic Range 영상들의 추정)

  • Lee, Tae-Hyoung;Ha, Ho-Gun;Ha, Yeong-Ho
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.48 no.2
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    • pp.74-79
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    • 2011
  • HDR(high dynamic range) imaging techniques supports wider dynamic range than normal images captured from general still camera. These usually need several shots to obtain LDR(low dynamic range) images, causing ghosting artifacts. Accordingly, this paper suggests a method to generate new LDR images from a single Bayer image using Exposure LUT(look-up table) by considering channel dependency. We prior construct exposure LUT for each RGB channel, showing the relationship between input and average output luminance values. In the process, by applying the average luminance of input image and current exposure to LUT, new exposures which are determined by user choice are first estimated. Next, LDR images which are corresponded to new exposures are generated based on each LUT. Saturated areas are improved by considering channel dependency in the last procedure. In the experimental comparison, high PSNR values are obtained between estimated and captured images. Also, we have similar appearance on displayed images.

Selective Skin Tone Reproduction using Preferred Skin Colors (선호 피부색을 사용한 선택적인 피부색 재현 기법)

  • Kim, Dae-Chul;Kyung, Wang-Jun;Ha, Yeong-Ho
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.49 no.4
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    • pp.10-15
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    • 2012
  • In a color image, people and especially facial patterns are important and interesting visual objects. Thus, effective skin color reproduction is essential, as skin color is a key memory color in color application systems. Previous studies suggested skin color reproduction by mapping only to the center value of preferred skin region. However, it is not suitable to determine one preference color because preference color from the observer's preference test is not dominant. In this paper, skin color reproduction using multiple preferred skin colors for each race is proposed. The proposed method first defines multiple preferred skin colors for each race according to their luminance level. After that, skin region is detected in an image. The race is then selected by calculating distance between average chromaticity of detected region and that of each racial skin from a database to assign preferred skin color for each race. Next, each corresponding preferred skin color is determined for each selected race. Finally, input skin color is proportionally mapped toward preferred skin color according to the difference between the input skin color and the preferred skin color for a smoothly reproduced skin color. In the experimental results, the proposed method gives better color correction on the objective and subjective evaluation than the previous methods.