• Title/Summary/Keyword: Image scale

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Estimating the Application Possibility of High-resolution Satellite Image for Update and Revision of Digital Map (수치지도의 수정 및 갱신을 위한 고해상도 위성영상의 적용 가능성 평가)

  • 강준묵;이철희;이형석
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.20 no.3
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    • pp.313-321
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    • 2002
  • Supplying high-resolution satellite image, we take much interest in the update and the revision of digital map and thematic map based on the satellite image. This study presented the possibility of the update and the revision to the existing digital map on a scale of l/5,000 and 1/25,000 to take advantage of the IKONOS satellite image. We performed geometric correction to make use of the ground control points of the existing digital map in IKONOS mono-image and created ortho-image by extracting digital elevation model from three dimensional contour data and altitude on the existing digital map. We revised changed features in the method of screen digitizing by overlapping orthorectified satellite image and existing digital map and flawed features of the unchanged area on the satellite images for positional accuracy analysis. As a result, rectification error is calculated at $\pm$3.35m by RMSE. There is a good possibility of update of digital map under the scale of 1/10,000. It is possible to the update of the large scale digital map over the scale of l/5,000, as if we used the method of stereo image and ground control point surveying.

Retinex-based Logarithm Transformation Method for Color Image Enhancement (컬러 이미지 화질 개선을 위한 Retinex 기반의 로그변환 기법)

  • Kim, Donghyung
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.5
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    • pp.9-16
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    • 2018
  • Images with lower illumination from the light source or with dark regions due to shadows, etc., can improve subjective image quality by using retinex-based image enhancement schemes. The retinex theory is a method that recognizes the relative lightness of a scene, rather than recognizing the brightness of the scene. The way the human visual system recognizes a scene in a specific position can be in one of several methods: single-scale retinex, multi-scale retinex, and multi-scale retinex with color restoration (MSRCR). The proposed method is based on the MSRCR method, which includes a color restoration step, which consists of three phases. In the first phase, the existing MSRCR method is applied. In the second phase, the dynamic range of the MSRCR output is adjusted according to its histogram. In the last phase, the proposed method transforms the retinex output value into the display dynamic range using a logarithm transformation function considering human visual system characteristics. Experimental results show that the proposed algorithm effectively increases the subjective image quality, not only in dark images but also in images including both bright and dark areas. Especially in a low lightness image, the proposed algorithm showed higher performance improvement than the conventional approaches.

Image Similarity Retrieval using an Scale and Rotation Invariant Region Feature (크기 및 회전 불변 영역 특징을 이용한 이미지 유사성 검색)

  • Yu, Seung-Hoon;Kim, Hyun-Soo;Lee, Seok-Lyong;Lim, Myung-Kwan;Kim, Deok-Hwan
    • Journal of KIISE:Databases
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    • v.36 no.6
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    • pp.446-454
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    • 2009
  • Among various region detector and shape feature extraction method, MSER(Maximally Stable Extremal Region) and SIFT and its variant methods are popularly used in computer vision application. However, since SIFT is sensitive to the illumination change and MSER is sensitive to the scale change, it is not easy to apply the image similarity retrieval. In this paper, we present a Scale and Rotation Invariant Region Feature(SRIRF) descriptor using scale pyramid, MSER and affine normalization. The proposed SRIRF method is robust to scale, rotation, illumination change of image since it uses the affine normalization and the scale pyramid. We have tested the SRIRF method on various images. Experimental results demonstrate that the retrieval performance of the SRIRF method is about 20%, 38%, 11%, 24% better than those of traditional SIFT, PCA-SIFT, CE-SIFT and SURF, respectively.

Muscle Activity Based on Real-time Visual Feedback Training Methods by Rehabilitative Ultrasound Image in Elderly and Relationship between Heckmatt Scale, Muscle Thickness and Tone : A Pilot Study

  • Shin, Janghoon;Lee, Wanhee
    • Physical Therapy Rehabilitation Science
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    • v.10 no.1
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    • pp.82-89
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    • 2021
  • Purpose: This study is to investigate the muscle activity based on real-time visual feedback training methods by rehabilitative ultrasound image in elderly and correlation between Heckmatt scale grade, muscle tone and thickness. Design: Cross-sectional study: Pilot study Methods: 6 elderly participated in the study with 2 conditions. Under the condition of rehabilitation ultrasound imaging equipment, all subjects performed voluntary maximal muscle contraction of the quadriceps 3 times using visual feedback based on Rehabilitative Ultrasound Imaging 1.0 (RUSI 1.0). Under the condition of only ultrasound images, all subjects performed voluntary maximal muscle contraction of the quadriceps 3 times using ultrasound image-based visual feedback. The muscle thickness and tone of the quadriceps were measured and the grades were classified by Heckmatt scale and all variables were comparative analyzed. Results: Heckmatt scale grade showed a negative correlation with muscle thickness at relaxation (p<0.05), and a negative correlation with the difference value obtained by subtracting muscle thickness at relaxation from muscle thickness at contraction in ultrasound image condition (p<0.05). The muscle tone during relaxation showed a negative correlation with the muscle thickness during relaxation (p<0.05). Conclusion: In the case of voluntary maximum muscle contraction of the quadriceps muscle in the elderly, it can be seen that the muscle thickness is getting larger when the RUSI 1.0-based visual feedback is provided than with only ultrasound image provided. And the lower Heckmatt scale grade is, the thicker the muscle is, and the lower the muscle tone is.

Enhancement of Image Contrast in Linacgram through Image Processing (전산처리를 통한 Linacgram의 화질개선)

  • Suh, Hyun-Suk;Shin, Hyun-Kyo;Lee, Re-Na
    • Radiation Oncology Journal
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    • v.18 no.4
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    • pp.345-354
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    • 2000
  • Purpose : Conventional radiation therapy Portal images gives low contrast images. The purpose of this study was to enhance image contrast of a linacgram by developing a low-cost image processing method. Materials and Methods : Chest linacgram was obtained by irradiating humanoid Phantom and scanned using Diagnostic-Pro scanner for image processing. Several types of scan method were used in scanning. These include optical density scan, histogram equalized scan, linear histogram based scan, linear histogram independent scan, linear optical density scan, logarithmic scan, and power square root scan. The histogram distribution of the scanned images were plotted and the ranges of the gray scale were compared among various scan types. The scanned images were then transformed to the gray window by pallette fitting method and the contrast of the reprocessed portal images were evaluated for image improvement. Portal images of patients were also taken at various anatomic sites and the images were processed by Gray Scale Expansion (GSE) method. The patient images were analyzed to examine the feasibility of using the GSE technique in clinic. Results :The histogram distribution showed that minimum and maximum gray scale ranges of 3192 and 21940 were obtained when the image was scanned using logarithmic method and square root method, respectively. Out of 256 gray scale, only 7 to 30$\%$ of the steps were used. After expanding the gray scale to full range, contrast of the portal images were improved. Experiment peformed with patient image showed that improved identification of organs were achieved by GSE in portal images of knee joint, head and neck, lung, and pelvis. Conclusion :Phantom study demonstrated that the GSE technique improved image contrast of a linacgram. This indicates that the decrease in image quality resulting from the dual exposure, could be improved by expanding the gray scale. As a result, the improved technique will make it possible to compare the digitally reconstructed radiographs (DRR) and simulation image for evaluating the patient positioning error.

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Factors Influencing the Smoking Behavior of Adolescents (청소년 흡연행위 영향요인)

  • Kim, Hee-Kyung;Kang, Hyun-Sook;Ko, Yun-Hwa;Moon, Sun-Soon;Park, Yoen-Suk;Shin, Yeon-Soon;Ahn, Jung-Sun;Lee, Sun-Young;Lee, Sung-Ok;Lee, Yang-Sook;Cho, Soon-Ja;Choi, Eun-Sook
    • Research in Community and Public Health Nursing
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    • v.13 no.2
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    • pp.376-386
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    • 2002
  • Objectives: The purpose of this study was to investigate factors influencing the smoking behavior of adolescents, in order to provide basic data to develop a future nursing intervention program for smoking prevention. Methods: The study subjects were 162 adolescents attending high schools, who were living in K city. The instruments included the Self Esteem Scale translated by Jeon (1974), beliefs about the social rule scale developed by the Committee for Adolescence Guidance (1988), differential peer association developed by Krohn et. al. (1982), perceived behavioral control scale developed by Hanson (1997), intention of smoking scale developed by Newman et. al.(1982), and self-efficacy scale developed by Sherer et. al. (1982). The data were analyzed using descriptive statistics, Pearson correlation coefficient, and stepwise multiple regression. Results: 1. The smoking behaviors of the subjects were significantly correlated with beliefs about social rule, perceived behavioral control. differential peer association, intention of smoking, self efficacy, grade, father's level of education, monthly pocket money, time of onset for smoking, degree of alcoholic intake, and drug abuse. 2. The multiple regression analysis revealed the most powerful predictor for smoking behavior was time of onset for smoking. A combination of beliefs about social rule, perceived behavioral control, grade, differential peer association, and intention of smoking accounted for 54.0% of the variance for smoking behavior in adolescents. Conclusion: It is recommended that these influencing factors for smoking behavior be considered when developing future nursing intervention programs for the antismoking behaviors of adolescents.

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A Study on Image Scale of the Hand and Sensibility of Silk Woven Fabrics (견직물의 태와 감성 차원의 이미지 스케일에 관한 연구;넥타이용 직물을 중심으로)

  • 김춘정;나영주
    • Journal of the Korean Society of Clothing and Textiles
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    • v.23 no.6
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    • pp.898-908
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    • 1999
  • This paper was aimed to identify the hand and sensibility of silk woven fabrics for neckties to find their relationships to the hand and purchasing preferences and to make their image scale. 56 male and female students evaluated 20 specimens with semantic differential scale of 21 hand and 25 sensibility adjectives. Data were analyzed through factor analysis pearson correlational coefficient t-test using PC SAS package. the hand adjectives were grouped as 4 surface property thermal property flexibility and dryness. The sensibility adjectives were modern classic character and natural,. The flat fabrics with warm hand displayed 'modern' sensibility but those with col hand show 'classic' The rough fabrics with warm hand showed 'natural' but those with cool hand showed 'character' The fabrics rated as high hand preference and purchasing preference showed soft and flat hand occuring 'modern' and 'classic' sensibility.

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An Edge Detection Method for Gray Scale Images Based on their Fuzzy System Representation

  • Moon, Byung-Soo;Lee, Hyun-Chul;Kim, Jang-Yeol
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 2001.12a
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    • pp.283-286
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    • 2001
  • Based on a fuzzy system representation of gray scale images, we derive an edge detection algorithm whose convolution kernel is different from the known kernels such as those of Roberts', Prewitt's or Sobel's gradient. Our fuzzy system representation is an exact representation of the bicubic spline function which represents the gray scale image approximately. Hence the fuzzy system is a continuous function and it provides a natural way to define the gradient and the Laplacian operator. We show that the gradient at grid points can be evaluated by taking the convolution of the image with a 3 3 kernel. We also show that our gradient coupled with the approximate value of the continuous function generates an edge detection method which creates edge images clearer than those by other methods. A few examples of applying our methods are included.

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Rotation and scale-invariant pattern recognition using WCHF-fSDF filter (WCHF-fSDF 필터를 이용한 회전과 크기불변 패턴 인식)

  • 이승희;김철수;이하운;도양회;박세준;김수중
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.22 no.2
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    • pp.392-400
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    • 1997
  • In this paper we porposed WCHF-fSDF filter to obtain a roration and scale-invariant correlation output. WCHF-fSDF filter is synthesized by each single CHF exttracted from scale-changed and wavelet tranformed imagesfor a refereence image as tranining images. The wavelet transform is defined as the correlation of an input image with a wavelet function. Therefore two 4f optical correlation systems are needed for pattern recognition using wavelet transform. We here include the wavelet function for the input image in the process of the proposed filter design and substitute the two 4f optical correlation system with a single 4f optical correlation system. The Performances of the proposed filter are compared with conventional CHF-SDF, POCHF-SDF filters through the computer simulation. The results of computer simulation show that the proposed filter has the rotation and scale-invariant correlation output and it has better performances than thoseof the conventioanl filters.

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Low Resolution Rate Face Recognition Based on Multi-scale CNN

  • Wang, Ji-Yuan;Lee, Eung-Joo
    • Journal of Korea Multimedia Society
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    • v.21 no.12
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    • pp.1467-1472
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    • 2018
  • For the problem that the face image of surveillance video cannot be accurately identified due to the low resolution, this paper proposes a low resolution face recognition solution based on convolutional neural network model. Convolutional Neural Networks (CNN) model for multi-scale input The CNN model for multi-scale input is an improvement over the existing "two-step method" in which low-resolution images are up-sampled using a simple bi-cubic interpolation method. Then, the up sampled image and the high-resolution image are mixed as a model training sample. The CNN model learns the common feature space of the high- and low-resolution images, and then measures the feature similarity through the cosine distance. Finally, the recognition result is given. The experiments on the CMU PIE and Extended Yale B datasets show that the accuracy of the model is better than other comparison methods. Compared with the CMDA_BGE algorithm with the highest recognition rate, the accuracy rate is 2.5%~9.9%.