• Title/Summary/Keyword: Perspective distortion

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Development of Photogrammetric Rectification Method Applying Bayesian Approach for High Quality 3D Contents Production (고품질의 3D 콘텐츠 제작을 위한 베이지안 접근방식의 사진측량기반 편위수정기법 개발)

  • Kim, Jae-In;Kim, Taejung
    • Journal of Broadcast Engineering
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    • v.18 no.1
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    • pp.31-42
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    • 2013
  • This paper proposes a photogrammetric rectification method based on Bayesian approach as a method that eliminates vertical parallax between stereo images to minimize visual fatigue of 3D contents. The image rectification consists of two phases; geometry estimation and epipolar transformation. For geometry estimation, coplanarity-based relative orientation algorithm was used in this paper. To ensure robustness for mismatch and localization error occurred by automation of tie point extraction, Bayesian approach was applied by introducing several prior constraints. As epipolar transformation perspective transformation was used based on condition of collinearity to minimize distortion of result images and modification for input images. Other algorithms were compared to evaluate performance. For geometry estimation, traditional relative orientation algorithm, 8-points algorithm and stereo calibration algorithm were employed. For epipolar transformation, Hartley algorithm and Bouguet algorithm were employed. The evaluation results showed that the proposed algorithm produced results with high accuracy, robustness about error sources and minimum image modification.

Privacy Disclosure and Preservation in Learning with Multi-Relational Databases

  • Guo, Hongyu;Viktor, Herna L.;Paquet, Eric
    • Journal of Computing Science and Engineering
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    • v.5 no.3
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    • pp.183-196
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    • 2011
  • There has recently been a surge of interest in relational database mining that aims to discover useful patterns across multiple interlinked database relations. It is crucial for a learning algorithm to explore the multiple inter-connected relations so that important attributes are not excluded when mining such relational repositories. However, from a data privacy perspective, it becomes difficult to identify all possible relationships between attributes from the different relations, considering a complex database schema. That is, seemingly harmless attributes may be linked to confidential information, leading to data leaks when building a model. Thus, we are at risk of disclosing unwanted knowledge when publishing the results of a data mining exercise. For instance, consider a financial database classification task to determine whether a loan is considered high risk. Suppose that we are aware that the database contains another confidential attribute, such as income level, that should not be divulged. One may thus choose to eliminate, or distort, the income level from the database to prevent potential privacy leakage. However, even after distortion, a learning model against the modified database may accurately determine the income level values. It follows that the database is still unsafe and may be compromised. This paper demonstrates this potential for privacy leakage in multi-relational classification and illustrates how such potential leaks may be detected. We propose a method to generate a ranked list of subschemas that maintains the predictive performance on the class attribute, while limiting the disclosure risk, and predictive accuracy, of confidential attributes. We illustrate and demonstrate the effectiveness of our method against a financial database and an insurance database.

3D Pose Estimation of a Circular Feature With a Coplanar Point (공면 점을 포함한 원형 특징의 3차원 자세 및 위치 추정)

  • Kim, Heon-Hui;Park, Kwang-Hyun;Ha, Yun-Su
    • Journal of the Institute of Electronics Engineers of Korea SC
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    • v.48 no.5
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    • pp.13-24
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    • 2011
  • This paper deals with a 3D-pose (orientation and position) estimation problem of a circular object in 3D-space. Circular features can be found with many objects in real world, and provide crucial cues in vision-based object recognition and location. In general, as a circular feature in 3D space is perspectively projected when imaged by a camera, it is difficult to recover fully three-dimensional orientation and position parameters from the projected curve information. This paper therefore proposes a 3D pose estimation method of a circular feature using a coplanar point. We first interpret a circular feature with a coplanar point in both the projective space and 3D space. A procedure for estimating 3D orientation/position parameters is then described. The proposed method is verified by a numerical example, and evaluated by a series of experiments for analyzing accuracy and sensitivity.

The Swag Look in Modern Fashion (현대패션에 나타난 스웨그(swag)룩)

  • Lee, Jung-Ho;Lee, Jin-Min
    • Journal of the Korean Society of Costume
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    • v.66 no.4
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    • pp.94-110
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    • 2016
  • The purpose of this study is to delve into the identity of the swag style which has diversified into various forms by exploring the phenomenon, formative characteristics and the internal values of the swag style in modern fashioin. This study discusses the concept and the socio-cultural meanings of swag from the perspective of Jean Baudrillard's hyper-reality, and a form of existence. The classifies the swag fashion styles into parody, hip hop and collage-type mix-and-match. Expressive characteristics of the swag look in modern fashion are as follows. First, the swag look utilizes the parody technique. In the mid-2000s, the look parodied brand logos as a form of self-mocking and active self-derision toward cheap imitations. Second, the swag look borrows from the expressive factors of the hip-hop style. Born as a sub-culture based on music, hip-hop has become a way of life, as its nature became multi-cultural and trans-cultural while its fashion style gained popularity globally after the 1980s. Third, the swag look barrows from the pop-type collage form as it mixes-and-matches costume items based on the expressive characteristics of hip hop, and this can be seen through items being used in new, non-formative and free styles. Comic aesthetics is revealed in parodied expression, hip-hop factors and collage-style mix-and-match. Swag as a hyper-reality manifests itself in various natures: humorous nature, negative nature and deconstructive nature through reflection and re-enactment of reality, transmutation and distortion of reality, and absence of reality respectively. However, it does not have a binding nature, which is the norm for subcultures. This characteristic, in combination with it having internal lightness, strong meaning of communication, and a sharing of self-contentment, distinguishes itself from the general meanings of existing parody fashion, hip-hop fashion and collage fashion.

The Present and the Future Issues in Korean Feminist Theatre (한국의 페미니즘 연극, 그 현황과 과제)

  • 최영주
    • Lingua Humanitatis
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    • v.6
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    • pp.359-380
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    • 2004
  • Considering Korean feminist theatre is not successful at all these days, it is needed to find the reasons of its crisis. As two Korean feminist theatre Scholars argued, the crisis owed to the structural problem from the start. That is the Korean feminist theatre started and developed depending on the imported popular feminist plays without social and cultural self-consciousness. Once the imported feminist theatres were flourished, some theatre companies pursued the commercial success blurring the feminist issues. It was resulted into the intentional ignorance in and out of the theatre society. While, some feminist plays were too inclined to the agit-prop without artistic sophistication. This essay tries to examine how the feminist theatres have been developing and what kinds of feminist performances have been made until now. And it intends to emphasize that the play text should be based on the Korean women's past, present, and future reality. Besides, they have to delve into the problem by which the Korean women were trapped in historical, social, and cultural environment. To make the women's matter the social issue at present and fur the future, the Korean feminist theatre should re-find its place as the socio-cultural forum. First, Korean theatre should cooperate with the other women's group crossing the different disciplines of the society, the culture, the politics etc . Secondly, we need to observe and watch where and how the distortion happens in women's matter, and react to correct it. Thirdly, we need to discover, to support, and to protect the women centered perspective of some playwrights as well as the performers. Co-writing or co-performing is also very positive to diversify the women's subjects. Lastly, to protect the feminist theatre against the consumerism, they need to have the financial support from the government or some civil society.

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Assessment of Interoperability Between Touchless and Legacy Rolled Fingerprints (비접촉식 지문의 날인 지문과의 호환성 평가 연구)

  • Choi, Hee-Seung;Kim, Jai-Hie
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.48 no.1
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    • pp.149-156
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    • 2011
  • The purpose of this paper is the brief introduction of touchless fingerprint recognition and the assessment of interoperability between touchless and legacy rolled fingerprints for the wide use of touchless fingerprint recognition system. In order to assess the interoperability, the contrast and resolution of the touchless images are optimized firstly. And we perform the matching by using conventional minutiae-based matcher. Experimental results are promising that our touchless fingerprints have enough matching performance with equal error rate 7.9%. We can expect that our paper will make a significant contribution to the wide use of touchless fingerprint recognition and the increment of interoperability in the system integration between touchless-based and touch-based fingerprint systems.

The Camera Calibration Parameters Estimation using The Projection Variations of Line Widths (선폭들의 투영변화율을 이용한 카메라 교정 파라메터 추정)

  • Jeong, Jun-Ik;Moon, Sung-Young;Rho, Do-Hwan
    • Proceedings of the KIEE Conference
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    • 2003.07d
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    • pp.2372-2374
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    • 2003
  • With 3-D vision measuring, camera calibration is necessary to calculate parameters accurately. Camera calibration was developed widely in two categories. The first establishes reference points in space, and the second uses a grid type frame and statistical method. But, the former has difficulty to setup reference points and the latter has low accuracy. In this paper we present an algorithm for camera calibration using perspective ratio of the grid type frame with different line widths. It can easily estimate camera calibration parameters such as focal length, scale factor, pose, orientations, and distance. But, radial lens distortion is not modeled. The advantage of this algorithm is that it can estimate the distance of the object. Also, the proposed camera calibration method is possible estimate distance in dynamic environment such as autonomous navigation. To validate proposed method, we set up the experiments with a frame on rotator at a distance of 1,2,3,4[m] from camera and rotate the frame from -60 to 60 degrees. Both computer simulation and real data have been used to test the proposed method and very good results have been obtained. We have investigated the distance error affected by scale factor or different line widths and experimentally found an average scale factor that includes the least distance error with each image. It advances camera calibration one more step from static environments to real world such as autonomous land vehicle use.

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CNN-based Building Recognition Method Robust to Image Noises (이미지 잡음에 강인한 CNN 기반 건물 인식 방법)

  • Lee, Hyo-Chan;Park, In-hag;Im, Tae-ho;Moon, Dai-Tchul
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.24 no.3
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    • pp.341-348
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    • 2020
  • The ability to extract useful information from an image, such as the human eye, is an interface technology essential for AI computer implementation. The building recognition technology has a lower recognition rate than other image recognition technologies due to the various building shapes, the ambient noise images according to the season, and the distortion by angle and distance. The computer vision based building recognition algorithms presented so far has limitations in discernment and expandability due to manual definition of building characteristics. This paper introduces the deep learning CNN (Convolutional Neural Network) model, and proposes new method to improve the recognition rate even by changes of building images caused by season, illumination, angle and perspective. This paper introduces the partial images that characterize the building, such as windows or wall images, and executes the training with whole building images. Experimental results show that the building recognition rate is improved by about 14% compared to the general CNN model.

A Study on Reinterpretation and Categorization of Normative Meaning of Tradition (전통의 규범적 의미에 대한 재해석과 범주화)

  • Yoon, Young-don;Sim, Seungwoo;Chi, Chun-Ho;Han, Sung Gu
    • The Journal of Korean Philosophical History
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    • no.50
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    • pp.333-361
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    • 2016
  • The purpose of this study is to delve into reinterpretation and categorization of normative meaning of tradition. The normative meaning of tradition which plays a key role of the action-guiding power is the main source of morality. According to ecological cultural approach to diachronic transition of traditional value, traditional value leads its dynamic life: its origin, acculturation, transformation, distortion of traditional value depending upon periodic social change. It is necessary for traditional value to be reinterpreted and categorized, with a view to contributing to attribute & competency of democratic citizen in future society. The normative meaning of traditional value applicable for Korea's future society can be reinterpreted from its origin revealed in the classic. The order of discussion in this paper runs as follows. Firstly, we will investigate into dynamic change of the traditional value on the basis of the ecological cultural perspective and seek the possibility of modern reinterpretation of loyalty & filial piety as representative traditional value. Finally, we will treat the categorization and its significance of traditional value in the frame of Korean value including both western value and Korean traditional value.

Transformer Network for Container's BIC-code Recognition (컨테이너 BIC-code 인식을 위한 Transformer Network)

  • Kwon, HeeJoo;Kang, HyunSoo
    • Journal of Korea Society of Industrial Information Systems
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    • v.27 no.1
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    • pp.19-26
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    • 2022
  • This paper presents a pre-processing method to facilitate the container's BIC-code recognition. We propose a network that can find ROI(Region Of Interests) containing a BIC-code region and estimate a homography matrix for warping. Taking the structure of STN(Spatial Transformer Networks), the proposed network consists of next 3 steps, ROI detection, homography matrix estimation, and warping using the homography estimated in the previous step. It contributes to improving the accuracy of BIC-code recognition by estimating ROI and matrix using the proposed network and correcting perspective distortion of ROI using the estimated matrix. For performance evaluation, five evaluators evaluated the output image as a perfect score of 5 and received an average of 4.25 points, and when visually checked, 224 out of 312 photos are accurately and perfectly corrected, containing ROI.