• Journal of the Korea Society of Computer and Information
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• v.16 no.1
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• pp.61-69
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• 2011

This paper proposes a new algorithm that improve color component of compensated image using Retinex method for back-light image. A back-light image has two regions, one of the region is too bright and the other one is too dark. If an back-light image is improved contrast using Retinex method, it loses color information in the part of brightness of the image. In order to make up loss information, proposed algorithm adds color components from original image. The histogram can be divided three parts that brightness, darkness, midway using K-mean (k=3) algorithm. For the brightness, it is used color information of the original image. For the darkness, it is converted using by Retinex method. The midway region is mixed between original image and Retinex result image in the ratio of histogram. The ratio is determined by distance from dark area. The proposed algorithm was tested on nature back-light images to evaluate performance, and the experimental result shows that proposed algorithm is more robust than original Retinex algorithm.

• Science of Emotion and Sensibility
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• v.12 no.1
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• pp.65-76
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• 2009

This study aims to characterize the sensibility image and interaction effect of striped necktie according to same-tone coordination and 1:2:3 area-ratio variation on the gender. The experimental materials developed for this study are a set of stimuli and response scales. The stimuli consist of 56 color pictures manipulated with every combination of 4 different colors, 2 different tones and 7 different area-ratio. The 7-point scale designed for visual evaluation of sensibility image included 26 bipolar adjectives. The subjects were 1344 undergraduate students in Gyeongnam, Seoul, Busan, and Daegu areas. The results of this study were as follows. The analyses of sensibility images in terms of same-tone coordination and 1:2:3 area-ratio variation of stripe necktie reveal that the concerned factors are of five characteristic dimensions of attractiveness, youth-activity, appeal, ability, and warmness. In the 5 factors of sensibility image, color combination and tone showed independent effect. In addition, significant interaction effects of area-ratio and tone on appeal and ability were found. Interaction effects of gender and area-ratio on youth-activity were found. Interaction effects of gender and tone on warmness were found. Interaction effects of color combination and tone on appeal and warmness were found. The study results are highly expected to be used as useful sources in developing men's coordination.

• Journal of the Korean Association of Geographic Information Studies
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• v.11 no.1
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• pp.116-124
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• 2008

This study presents the application of multi-temporal and multi-scale panchromatic aerial photos for change detection in a small urban area. For aerial photos of the scale of 1:20,000 taken in 1987 and 1996 and the scale of 1:37,500 taken in 2000. Pre-processing that make the same conditions to all of the aerial photos was carried out through geometric correction, registration, contrasting, resamplimg, and mosaicking and then change detection were carried out respectively by image differencing and image ratio techniques. As a result, the change of urban features and landcover were able to be detected from panchromatic aerial photos that is single-band images and then the detected change results were compared between both techniques.

• The Korean Journal of Community Living Science
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• v.24 no.4
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• pp.447-456
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• 2013

This study was conducted to find out the weight control experiences, body image perception and eating disorder status of high school students in Yantai City, Shandong Province, China. The subjects of the study were 457 high school students in Yantai City. The results were as follows. The ratio of underweight and overweight and obesity of the subjects were 20.0% and 12.6% respectively. And 35% of the subjects had weight control experiences. There were significant differences according to the students' gender, location and BMI. In body image perception, the subjects who were normal and underweight overestimated their body figure, and the subjects who were overweight and obese underestimated their body figure. The girls wanted to have extremely skinny figure than standard figure and the degree of dissatisfactions with their figure was high. In the case of overweight and obese students, it showed a high degree of dissatisfaction of their body image. The ratio of the eating disorder group and eating disorder risk group were 7% and 19.3%, Compared to the students in rural areas, downtown students had significantly higher ratio of eating disorder. In conclusion, the education of healthy body weight and body image is necessary to the students in Yantai City, China. Especially the female students who live in downtown are considered to be the most important subjects of nutrition education.

• Journal of the Korean Society of Radiology
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• v.13 no.4
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• pp.509-516
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• 2019

In the linear transformation method, the original image is divided into a plurality of range blocks, and a partial transform system for finding an optimal domain block existing in the image for each range block is used to adjust the performance of the compression ratio and the picture quality, The nonlinear transformation method uses only the rotation transformation among eight shuffle transforms. Since the search is performed only in the limited domain block, the coding time is faster than the linear transformation method of searching the domain block for any block in the image, Since the optimal domain block for the range block can not be selected in the image, the performance may be lower than other methods. Therefore, the nonlinear transformation method improves the performance by increasing the approximation degree of the brightness coefficient conversion instead of selecting the optimal domain block, The smaller the size of the block, the higher the PSNR value, The higher the compression ratio is increased groups were quadtree block divided to encode the image at best.

• Journal of Biomedical Engineering Research
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• v.17 no.4
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• pp.443-448
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• 1996

Sequential brain SPECT imaging has been used to assess the cerebral perfusion reserve(CPR) in cerebrovascular diseases(UD). We have realized parametric images of CPR using deadtime correction of gamma camera and normalized difference ratio. For the anatomical localization of CPR, the parametric images were registered to the contours of the cerebral regions using optimal threshold method, which showed to reflect the CPR more reliably and distinctively than the simple subtraction. We conclude that the quantitative estimation of CPR using normalized difference ratio image could be useflll for the diagnosis and prognostic assessment of CVD.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.22 no.2
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• pp.325-333
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• 1997

In fractral decoding procedure, the reconstructed image is obtained by iteratively applying the contractive transform to an arbitrary initial image. But this method is not suitable for the fast decoding because convergence speed depends on the selection of initial image. Therefore, the initial image to achieve fast decoding should be selected. In this paper, we propose an initial image estimation that can be applied to various decoding methods. The initial image similar to the original image is estimated by using only the compressed data so that the proposed method does not affect the compression ratio. From the simulation, the PSNR of the proposed initial image is 6dB higher han that of ones iterated output image of conventional decoding with Babaraimage. Computations in addition and multiplication are reduced about 96%. On the other hands, if we apply the proposed initial image to other decoding algorithms, the faster convergence speed is expected.

• ETRI Journal
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• v.29 no.5
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• pp.703-705
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• 2007

An image fidelity assessment using the edge histogram descriptor (EHD) of MPEG-7 is presented. Neither additional data nor fragile watermarking is needed, and there is no need to access the original image as a reference. Only the EHDs of the original image and the received image are required. The peak signal-to-noise ratio (PSNR) obtained by comparing the EHD extracted from the received image and that of the original image is used to assess the noise level of the received image. Experimental results show that the PSNRs calculated from the conventional pixel-to-pixel gray level and from the proposed bin-to-bin EHD maintain a proportional relationship. This implies that the EHD can be used instead of image data for the image fidelity assessments.

• Journal of the Semiconductor & Display Technology
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• v.21 no.3
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• pp.87-91
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• 2022

Bokeh effect is a stylistic technique that can produce blurring the background of photos. This paper implements to produce a bokeh effect with a single image by post processing. Generating depth map is a key process of bokeh effect, and depth map is an image that contains information relating to the distance of the surfaces of scene objects from a viewpoint. First, this work presents algorithms to determine the depth map from a single input image. Then, we obtain a sparse defocus map with gradient ratio from input image and blurred image. Defocus map is obtained by propagating threshold values from edges using matting Laplacian. Finally, we obtain the blurred image on foreground and background segmentation with bokeh effect achieved. With the experimental results, an efficient image processing method with bokeh effect applied using a single image is presented.

• The Journal of the Korea Contents Association
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• v.13 no.8
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• pp.275-283
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• 2013

The patient radiation dose is different depending on selection of Ion chamber when taking Chest PA which using AEC. In this paper, we studied acquiring the best diagnostic images according to selection of Ion chamber on AEC mode as well as minimizing patient radiation dose. Experimental methods were selection of Ion chamber and change of sensitivity under the same conditions as Chest PA projection. At AEC mode, two upper ion chambers sensors and one lower ion chamber sensor were divided into 7 cases according to selection of on/off. after measuring five times respectively, we obtained average value and calculated exposure dose. Image assessment was done with measured Modulation Transfer Function, Peak Signal to Noise Ratio, Root Mean Square, Signal to Noise Ratio, Contrast to Noise Ratio, Mean to Standard deviation Ratio respectively. In exposure assessment results, selection of two upper chambers was the lowest. In resolution assessment results, image of two upper chambers had the second high spatial frequency at sensitivity at 625(High) was 1.343 lp/mm. RMS value of image selecting two upper chambers was low secondly. SNR, CNR, MSR were the high value secondly. As the sensitivity was increased, radiation dose was decreased but better image could be obtained on image quality. In order to obtain the best medical images while minimizing the dose, usage of two upper ion chambers is considered to be clinically useful at sensitivity 625(High).