• Title/Summary/Keyword: Viewpoint Change

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Affine Local Descriptors for Viewpoint Invariant Face Recognition

  • Gao, Yongbin;Lee, Hyo Jong
    • Proceedings of the Korea Information Processing Society Conference
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    • 2014.04a
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    • pp.781-784
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    • 2014
  • Face recognition under controlled settings, such as limited viewpoint and illumination change, can achieve good performance nowadays. However, real world application for face recognition is still challenging. In this paper, we use Affine SIFT to detect affine invariant local descriptors for face recognition under large viewpoint change. Affine SIFT is an extension of SIFT algorithm. SIFT algorithm is scale and rotation invariant, which is powerful for small viewpoint changes in face recognition, but it fails when large viewpoint change exists. In our scheme, Affine SIFT is used for both gallery face and probe face, which generates a series of different viewpoints using affine transformation. Therefore, Affine SIFT allows viewpoint difference between gallery face and probe face. Experiment results show our framework achieves better recognition accuracy than SIFT algorithm on FERET database.

Viewpoint Unconstrained Face Recognition Based on Affine Local Descriptors and Probabilistic Similarity

  • Gao, Yongbin;Lee, Hyo Jong
    • Journal of Information Processing Systems
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    • v.11 no.4
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    • pp.643-654
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    • 2015
  • Face recognition under controlled settings, such as limited viewpoint and illumination change, can achieve good performance nowadays. However, real world application for face recognition is still challenging. In this paper, we propose using the combination of Affine Scale Invariant Feature Transform (SIFT) and Probabilistic Similarity for face recognition under a large viewpoint change. Affine SIFT is an extension of SIFT algorithm to detect affine invariant local descriptors. Affine SIFT generates a series of different viewpoints using affine transformation. In this way, it allows for a viewpoint difference between the gallery face and probe face. However, the human face is not planar as it contains significant 3D depth. Affine SIFT does not work well for significant change in pose. To complement this, we combined it with probabilistic similarity, which gets the log likelihood between the probe and gallery face based on sum of squared difference (SSD) distribution in an offline learning process. Our experiment results show that our framework achieves impressive better recognition accuracy than other algorithms compared on the FERET database.

Feature Matching Algorithm Robust To Viewpoint Change (시점 변화에 강인한 특징점 정합 기법)

  • Jung, Hyun-jo;Yoo, Ji-sang
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.40 no.12
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    • pp.2363-2371
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    • 2015
  • In this paper, we propose a new feature matching algorithm which is robust to the viewpoint change by using the FAST(Features from Accelerated Segment Test) feature detector and the SIFT(Scale Invariant Feature Transform) feature descriptor. The original FAST algorithm unnecessarily results in many feature points along the edges in the image. To solve this problem, we apply the principal curvatures for refining it. We use the SIFT descriptor to describe the extracted feature points and calculate the homography matrix through the RANSAC(RANdom SAmple Consensus) with the matching pairs obtained from the two different viewpoint images. To make feature matching robust to the viewpoint change, we classify the matching pairs by calculating the Euclidean distance between the transformed coordinates by the homography transformation with feature points in the reference image and the coordinates of the feature points in the different viewpoint image. Through the experimental results, it is shown that the proposed algorithm has better performance than the conventional feature matching algorithms even though it has much less computational load.

Comparison on the Time series of Housing Viewpoint of University Student (대학생 주거관의 시계열적 비교)

  • An, Ok-Hee;Kang, Hye-Kyung;Jo, Young-Mi
    • Proceeding of Spring/Autumn Annual Conference of KHA
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    • 2009.04a
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    • pp.243-246
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    • 2009
  • Housing distribution rate in our country has been continuously increased with economic growth, but residential plans satisfying the demands of residents are still not perfect yet. The demands of residents can be predicted by analyzing the housing viewpoint of residents. And also, the housing viewpoint can change according to various environmental changes, so it's important for us to understand the trend of change. Therefore, the housing viewpoints of university students who will be subjective residents of houses in future were analyzed by observing change due to trend of time. Target for this study is female university students in 20s. A portion of previously presented material (Korean Home Economics Association 37,1, 67-78) was used as data for 1998 and a questionnaire with 171 female university students was conducted on December 2008 for data for 2008. The following result was drawn from examination of change in the housing viewpoint due to trend of time by comparing the housing viewpoint of university students between 1998 and 2008. First, importance of was decreased and importance of was increased in functions of residence. Second, Most students thought and regardless of the time passage as their opinions on housing. And also, most students considered a living room as the most important space inside of a house regardless of the time passage and the ratio of considering a living room as the most important space was more increased.

A Study of Selecting Sequential Viewpoint and Examining the Effectiveness of Omni-directional Angle Image Information in Grasping the Characteristics of Landscape (경관 특성 파악에 있어서의 시퀀스적 시점장 선정과 전방위 화상정보의 유효성 검증에 관한 연구)

  • Kim, Heung Man;Lee, In Hee
    • KIEAE Journal
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    • v.9 no.2
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    • pp.81-90
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    • 2009
  • Relating to grasping sequential landscape characteristics in consideration of the behavioral characteristics of the subject experiencing visual perception, this study was made on the subject of main walking line section for visitors of three treasures of Buddhist temples. Especially, as a method of obtaining data for grasping sequential visual perception landscape, the researcher employed [momentum sequential viewpoint setup] according to [the interval of pointers arbitrarily] and fisheye-lens-camera photography using the obtained omni-directional angle visual perception information. As a result, in terms of viewpoint selection, factors like approach road form, change in circulation axis, change in the ground surface level, appearance of objects, etc. were verified to make effect, and among these, approach road form and circulation axis change turned out to be the greatest influences. In addition, as a result of reviewing the effectiveness via the subjects, for the sake of qualitative evaluation of landscape components using the VR picture image obtained in the process of acquiring omni-directional angle visual perception information, a positive result over certain values was earned in terms of panoramic vision, scene reproduction, three-dimensional perspective, etc. This convinces us of the possibility to activate the qualitative evaluation of omni-directional angle picture information and the study of landscape through it henceforth.

A Study on the Expression Transformation of Visual Information in 3D Architectural Models (3차원 건축모델정보의 표현변용방식에 관한 연구)

  • Park, Young-Ho
    • Korean Institute of Interior Design Journal
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    • v.22 no.1
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    • pp.105-114
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    • 2013
  • This study investigated the application and the change of various architectural models by analyzing expression viewpoint media, which were applied to the visual information of digitalized 3D contemporary architectural models. The purpose of this study was to specify how modern architects have changed 3D architectural models to conceptual, logical, and formational visual information in the process of design. This study discovered a framework of analyses by theoretically investigating a relationship between expression media and expression change in the process of visualizing architectural models. Using the framework of analyses, this study analyzed how the expression viewpoints of architectural model information have been changed and applied. The transformation media of the visual information of digitalized 3D architectural models can be classified into conceptual, analytical, and formational information: 1) Contemporary architects used author-centered subjective viewpoints to express architectural concepts, which were generated in the process of their design. They selected a perspective viewpoint and a bird's eye view in order to present their architectural concepts and to depict them with one architectural model by expanding the visual scope of conceptual information. 2) Contemporary architects adopted observer-centered objective bird's eye view expression media to effectively present their architectural information to building owners and viewers. They used transformal media, which integrate architectural information into 3D and change it to different scales, in order to express their architecture logically. 3) Contemporary architects delivered model information about the generation and change of forms by expressing the image of a project from an author-centered viewpoint, instead of objectively defining formational information. They explained the generation principle of architectural forms via transformal media which develop and rotate an architectural model.

Digital Watermarking Algorithm for Multiview Images Generated by Three-Dimensional Warping

  • Park, Scott;Kim, Bora;Kim, Dong-Wook;Seo, Youngho
    • Journal of information and communication convergence engineering
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    • v.13 no.1
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    • pp.62-68
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    • 2015
  • In this paper, we propose a watermarking method for protecting the ownership of three-dimensional (3D) content generated from depth and texture images. After selecting the target areas to preserve the watermark by depth-image-based rendering, the reference viewpoint image is moved right and left in the depth map until the maximum viewpoint change is obtained and the overlapped region is generated for marking space. The region is divided into four subparts and scanned. After applying discrete cosine transform, the watermarks are inserted. To extract the watermark, the viewpoint can be changed by referring to the viewpoint image and the corresponding depth image initially, before returning to the original viewpoint. The watermark embedding and extracting algorithm are based on quantization. The watermarked image is attacked by the methods of JPEG compression, blurring, sharpening, and salt-pepper noise.

Comparison on the Time series of Housing Viewpoint of University Student (대학생 주거관의 시계열적 비교)

The Effects of the Abduction Viewpoint on Science Teachers' Thoughts Related to Hypotheses and Laws in Ninth Grade 'Construction of Matter' and 'Rules of Matter Change' Chapters (중학교 3학년 '물질의 구성' 및 '물질 변화에서의 규칙성' 단원의 가설과 법칙에 대한 귀추적 관점이 과학 교사들의 사고에 미치는 영향)

  • Kim, Jun-Ye;Paik, Seoung-Hey
    • Journal of The Korean Association For Science Education
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    • v.29 no.1
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    • pp.10-21
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    • 2009
  • The purpose of this research was to investigate science teachers' thoughts about hypotheses and rules related to the contents of ninth grade 'Construction of Matter' and 'Rules of Matter Change' chapters. The changes of their thoughts through experience of the abduction viewpoint were also analyzed. Twenty-two science teachers in the masters course took lessons and discussions related to the abduction viewpoint in the course of three weeks. The changes in thought of four teachers selected among them were investigated through individual interviews and their reports. From the investigation, it was found that the two teachers who had not recognized the problems of textbook content order could distinguish rules and hypotheses after the lessons and discussions. The two teachers who had recognized the problems before the lessons gained the abduction viewpoint through the lessons. They also recognized new opinions related to teaching styles for students and the meaning of the abduction viewpoint on education.

Analysis on the Effects of the Induced Noise Voltage with the Impedance Changes of Telecommunication Line in the Power Inducting Situation (전력 유도 장애 발생 시 통신 선로의 접지체 임피던스 크기가 유도 잡음 전압에 미치는 영향 분석)

  • Choi, Mun-Hwan;Lee, Sang-Mu;Cho, Pyoung-Dong
    • 한국정보통신설비학회:학술대회논문집
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    • 2007.08a
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    • pp.227-230
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    • 2007
  • In this paper, we have analyzed the change characteristics of induced noise due to the impedance change of the ground in both ends of telecommunication line. As what affects the induced noise, there are power influence or longitudinal transverse voltages and its weighted filtered voltage. In the result of measurement, we can see the noise level change due to the change of the ground impedance, that is, as the ground impedance at either end of the telecommunication line become grower, the noise level is increased, and as the ground impedance at either end of the telecommunication line become smaller, the noise level is decreased. However, we can't define the relation between ground impedance size and PIF in these measurement results, so we will have to carry out the measurement more deeply and more practically with various conditions in environmental viewpoint and/or experimental viewpoint to establish the definition between ground impedance size and PIF.

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