• Title/Summary/Keyword: images

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Evaluation of compression ratios using JPEG 2000 on diagnostic images in dentistry (치과병원에서 사용되는 진단영상에 대한 JPEG2000 압축률에 대한 평가)

  • Jung Gi-Hun;Han Won-Jeong;Yoo Dong-Soo;Choi Soon-Chul;Kim Eun-Kyung
    • Imaging Science in Dentistry
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    • v.35 no.3
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    • pp.157-165
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    • 2005
  • Purpose : To find out the proper compression ratios without degrading image quality and affecting lesion detectability on diagnostic images used in dentistry compressed with JPEG 2000 algorithm. Materials and Methods : Sixty Digora periapical images, sixty panoramic computed radiographic (CR) images, sixty computed tomographic (CT) images, and sixty magnetic resonance (MR) images were compressed into JPEG 2000 with ratios of 10 levels from 5:1 to 50:1. To evaluate the lesion detectability, the images were graded with 5 levels (1 : definitely absent; 2: probably absent; 3: equivocal; 4: probably present; 5: definitely present), and then receiver operating characteristic analysis was performed using the original image as a gold standard. Also to evaluate subjectively the image quality, the images were graded with 5 levels (1 definitely unacceptable; 2: probably unacceptable; 3: equivocal, 4: probably acceptable; 5· definitely acceptable), and then paired t-test was performed. Results : In Digora, CR panoramic and CT images, compressed images up to ratios of 15 : 1 showed nearly the same lesion detectability as original images, and in MR images, compressed images did up to ratios of 25 : 1. In Digora and CR panoramic Images, compressed images up to ratios of 5 : 1 showed little difference between the original and reconstructed images in subjective assessment of image quality In CT images, compressed images did up to ratios of 10: 1 and in MR images up to ratios of 15 : 1 Conclusion : We considered compression ratios up to 5 : 1 in Digora and CR panoramic images, up to 10 : 1 in CT images, up to 15 : 1 in MR images as clinically applicable compression ratios.

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Research about Image Evaluations from Jeans' Finishing -Focus on Undergraduate Students in Los Angeles of the USA- (진즈[Jeans]의 가공[Finishing]에 따른 이미지 평가 연구 -미국 L. A. 거주 대학생을 중심으로-)

  • Lee, Mi-Yeon
    • Journal of the Korean Society of Costume
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    • v.56 no.7 s.107
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    • pp.18-32
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    • 2006
  • The objectives of this research were to identify the differences of image evaluations by perceiver's gender, majors and jeans' finishing and to examine image characteristics that have an influence on attractiveness and preferences of jeans' finishing. The subjects are 96 undergraduate students in Los Angeles of the USA. Elegant and refined images had a significant effort on perceiver's gender, so men tended to highly evaluate jeans as elegant and refined images than did women. Soft images were recognized differently by perceiver's major, so non-specialists in design tended to highly evaluate jeans as soft images than did specialists in design. In finishing, shattered wash was evaluated as the most individual, attractive, energetic, and splendid images, and stone wash was evaluated as the most ordinary, unattractive, and plain images. Light images tended to have interaction effects by majors and finishing. Specialists in design did not perceive differences between light images from finishing well, but non-specialists in design perceived that stone wash finishing's image is lighter than indigo blue finishing's image. Sociable images had interaction effects by perceiver's gender, majors and jeans' finishing, and especially non-specialists in men estimated that shattered wash has the lowest sociable images in finishing. According to evaluations about finishing images of ladies' jeans, men tended to be attracted by splendid images, and women tended to be attracted by sexy images. In addition, both men and women were commonly attracted by feminine images, so the study found that feminine images is important image for developing jeans for ladies. According to evaluations about finishing images of ladies' jeans, men preferred sexy and natural images to comfortable and energetic images, and women preferred sexy and neat images. Female undergraduate students of the USA tended to be attracted by sexy images, and we found that actually they consider buying jeans with such images.

DIRECT EPIPOLAR IMAGE GENERATION FROM IKONOS STEREO IMAGERY BASED ON RPC AND PARALLEL PROJECTION MODEL

  • Oh, Jae-Hong;Kim, Kyung-Ok
    • Proceedings of the KSRS Conference
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    • v.2
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    • pp.860-863
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    • 2006
  • Epipolar images have to be generated to stereo display aerial images or satellite images. Pushbroom sensor is used to acquire high resolution satellite images. These satellite images have curvilinear epipolar lines unlike the epipolar lines of frame images, which are straight lines. The aforementioned fact makes it difficult to generate epipolar images for pushbroom satellite images. If we assume a linear transition of the sensor having constant speed and attitude during image acquisition, we can generate epipolar images based on parallel projection model (2D Affine model). Recent high resolution images are provided with RPC values so that we can exploit these values to generate epipolar images without using ground control points and tie point. This paper provides a procedure based on the parallel projection model for generating epipolar images directly from a stereo IKONOS images, and experimental results.

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Direct Epipolar Image Generation From IKONOS Stereo Imagery Based On RPC and Parallel Projection Model

  • Oh, Jae-Hong;Shin, Sung-Woong;Kim, Kyung-Ok
    • Korean Journal of Remote Sensing
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    • v.22 no.5
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    • pp.451-456
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    • 2006
  • Epipolar images have to be generated to stereo display aerial images or satellite images. Pushbroom sensor is used to acquire high resolution satellite images. These satellite images have curvilinear epipolar lines unlike the epipolar lines of frame images, which are straight lines. The aforementioned fact makes it difficult to generate epipolar images for pushbroom satellite images. If we assume a linear transition of the sensor having constant speed and attitude during image acquisition, we can generate epipolar images based on parallel projection model (20 Affine model). Recent high resolution images are provided with RPC values so that we can exploit these values to generate epipolar images without using ground control points and tie point. This paper provides a procedure based on the parallel projection model for generating epipolar images directly from a stereo IKONOS images, and experimental results.

흉부의 ANALOG-DIGITAL 영상에 대한 비교 평가

  • Jang, Yeong-Ae;Mun, Hui-Seok;Im, Han-Yeong;O, Hyeon-Ju;Kim, Seong-Su;Kim, Yeong-Il
    • Korean Journal of Digital Imaging in Medicine
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    • v.2 no.1
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    • pp.74-82
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    • 1996
  • This paper were studied the evaluation in compare with the conventional and AMBER of analog images, PACS and CR of digital images which were collected every ten sampling chest images with the J.J.Vucicuh chest evaluated chart, and were measured the chest phantom surface dose and the density of several part in chest images. The evaluated numbers were total 22 persons who were 6 persons of the M.D., 6 of the radiotechnological professors and 10 of the radiotechnologists. The obtained results summarized as following : 1. Approaching the optimum standard density of the several part in chest images drew near at the lung round region density in PACS images, the sternum region density in CR and AMBER images, the heart region density in CR AMBER images, the diaphram region density in AMBER and conventional images. 2. The evaluation measured surface dose were appeared orderly lesser dose at the AMBER images (spine 21 mR, lung 2mR, heart 12mR, apex 6mR) than the conventional images(32 mR), CR images(38mR) and PACS images(81mR). 3. The anatomical physical evaluation marks were taken the highest points at CR images(88.3), and orderly PACS images(82), AMBER images(79.2) and conventional images(65.2). 4. It is exposured with lesser surface dose at the analog images, but analog images leaves much room for image quality improvement, and digital images demand for lesser exposure surface dose, although excellent image quality.

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A Study on Clothing Preference Images of the Middle-Aged and Elderly Women (중.노년층 여성의 의복추구 이미지 연구)

  • 김유덕;김미영
    • Journal of the Korean Society of Clothing and Textiles
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    • v.28 no.6
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    • pp.746-757
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    • 2004
  • This study was intended to analyze clothing preference images according to the age groups (30's, 40's, 50's and 60's) and to clarify the differences between present clothing preference images and that of the future after 60. The data was collected through a questionnaire and a total of 482 questionnaires on the age groups ranging from 30s through 60s were used in the analysis. As for the present clothing preference images in accordance with age groups, the younger age groups in the range of 30's and 40's presented higher scores in most of these images. But the older age groups in the 50's and 60's had lower scores in most of these images. On the contrary, the older age groups had higher scores than the younger age groups with respect to similar, mature, magnificent, innocent, plump and virtuous images. As for the future clothing preference images after 60 in the elegant, luxurious, graceful, intellectual, chic, urbane, slimy and sociable images, the age groups in the 30's and 40's presented higher scores than the age groups in the 50's and 60's did. However, with respect to the youth-oriented images such as fashionable, innocent, remarkable, cute and vigorous images, the age group in the 60's had a higher score than the age group in the 30's, 40's and 50's did. There were differences between the present clothing preference images and future clothing preference images after 60. The 30's and 40's presented distinctively different clothing preference images in the present and future after 60. Thus, distinct images were pursued in the older age group. The 50s showed closest images to that of the older age group, presenting more conservative inclination in clothing preferences.

An algorithm for the multi-view image improvement with the restricted number of images in texture extraction (텍스쳐 추출시 제한된 수의 참여 영상을 이용한 multi-view 영상 개선 알고리즘)

  • 김도현;양영일
    • Proceedings of the IEEK Conference
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    • 1998.06a
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    • pp.773-776
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    • 1998
  • In this paper, we propose an efficient multi-view images coding algorithm which finds the optimal texture from the restricted number of multi-view images. The X-Y plane of the normalized object space is divided into triangular patches. The depth value of the node is determined by applying the block based disparity compensation method and then the texture of the each patch is extracted by applying the affine transformation patch is extracted by applying the affine transformation based disparity compensation method to the multi-view images. We restricted the number of images contributed to determining the texture comapred to traditional methods which use all the multi-view images in the texture extraction. Experimental results show that the SNR of images encoded by the proposed algorithm is better than that of imaes encoded by the traditional method by the amount about 0.2dB for the test sets of multi-view images called dragon, kid, city and santa. The recovered images from the encoded data by the proposed method show the better visual images than the recovered images from the encoded data by the traditional methods.

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Korean Character Recognition with Tree Structure Using Representative Images (대표영상을 이용한 나무구조의 한글문자 인식)

  • 김정우;정수길;조웅호;김성용;김수중
    • Journal of the Korean Institute of Telematics and Electronics B
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    • v.31B no.4
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    • pp.18-29
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    • 1994
  • For the efficient recognition of Korean Alphabets, we proposed the tree structure algorithm which was based on K-tuple NRF-SDF using representative images as training images. Representative images consisted of ECP-SDF images of several consonants or vowels. To reduce the effect of sidelobe in the output correlation plane, we used the representative images as training images and obtained the elements of a vector inner product matrix using the peak value of AMPOF correlation of training images with one another. The proposed algorithm consisted of three main-step containing several substeps. In filter synthesis of each step, representative images were used as training images in the first and the second main-step and each consonant or vowel was used as training images in the third main-step. The performance of this algorithm is demonstrated by computer simulation and optical experiment.

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The Linguistic Analysis of Visual Images in Elementary Science Textbooks by 2007 Curriculum Revision: Focused on the Changes of the Weather (2007개정 교육과정 초등 과학 교과서의 시각 이미지에 대한 언어학적 분석: 날씨의 변화 단원을 중심으로)

  • Lee, Jeong-A
    • Journal of Korean Elementary Science Education
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    • v.30 no.4
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    • pp.482-489
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    • 2011
  • This study analyzed the visual images covering 'the changes of weather' in elementary science textbooks by 2007 curriculum revision from a perspective of linguistics. The findings showed that there were inclined to increasing in terms of ideational and textual metafunctions. It meant that the informative images were increased and the form of images became more abstractive. It also showed an increase in terms of interpersonal metafunctions. It was interpreted as decreasing the ratios of images inducing epistemological detachments and increasing images help familiarity and involvement between images and readers. These results showed that the visual images of 'the changes of weather' in 2007 revised elementary science textbook were professionally, technical, and abstractive in terms of the contents and formality. And these trends of images were complemented by the involvement and familiarity of images in the aspect of interpersonal metafunctions.

Role-Balance Based Multi-Secret Images Sharing using Boolean Operations

  • Chan, Chi-Shiang;Chou, Yung-Chen;Chen, Yi-Hui;Tsai, Yuan-Yu
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.8 no.5
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    • pp.1785-1800
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    • 2014
  • In 2011, Chen and Wu proposed their method of sharing n secret images to n+1 shadow images through the concept of a Boolean-based Visual Secret Sharing (VSS) method. However, the shadow images produced by this method are not equally important. If the participant who owns an important shadow image does not want to cooperate with other participants, most secret images can not be reconstructed. In the proposed method, the relationship between the shadows images and secret images are designed in a circular way mostly. Each shadow image only relates to two secret images. This means that if one participant refuses to cooperate with other participants, there are only two secret images which can not be reconstructed. Moreover, our proposed method only needs to produce n shadow images and n secret images can be shared to them.