研究者詳細 - 馬場口　登

論文 - 馬場口　登

分割表示 251 件中 101 - 120 件目／全件表示 >>

Anonymous Communication System Based on Multiple Loopbacks 査読

K. Kono, S. Nakano, Y. Ito, N. Babaguchi

Journal of Information Assurance and Security 6 ( 2 ) 124 - 131 2011年2月

Example-based video remixing 査読

Naoko Nitta, Noboru Babaguchi

MULTIMEDIA TOOLS AND APPLICATIONS 51 ( 2 ) 649 - 673 2011年1月

A video remix is generally created by arranging selected video clips and combining them with other media streams such as audio clips and video transition effects. This paper proposes a system for semi-automatically creating video remixes of good expressive quality. Given multiple original video clips, audio clips, and transition effects as the input, the proposed system generates a video remix by five processes: I) video clip sequence generation, II) audio clip selection, III) audio boundary extraction, IV) video segment extraction, and V) transition effect selection, based on the spatial and temporal structural patterns automatically learned from professionally created video remix examples. Experiments using movie trailers of action genre as video remix examples not only demonstrate that video remixing by professionals can be imitated based on examples but also reveal that the video clip sequence generation and audio clip selection are the most important processes to improve the perceived expressive quality of video remixes.

【フェロー記念講演】セマンティックギャップに架ける橋招待

馬場口登

電子情報通信学会技術研究報告 PRMU2010-184 2011年1月

Automatic generation of privacy-protected videos using background estimation 査読

Yuta Nakashima, Noboru Babaguchi, Jianping Fan

Proceedings - IEEE International Conference on Multimedia and Expo 2011年

Recently, video sharing services such as YouTube and Daily-motion have become popular and many videos taken with mobile video cameras are uploaded to such a video sharing service. However, such videos can infringe on the privacy right of people in the videos because they may contain privacy sensitive information (PSI) of the people, i.e., their appearances. This strongly motivates us to develop a technique to generate privacy-protected videos. In this paper, we propose a novel system for automatic generation of privacy-protected videos based on background estimation. In most conventional techniques, objects that contain PSI are detected and obscured by, e.g., blurring. Conversely, in our system, background pixels are estimated and then substituted with intended human objects that are essential for the camera person's capture intention. We quantitatively evaluate our system to demonstrate its potential applicability. © 2011 IEEE.

Content-preserving zoom-in view generation for surveillance videos 査読

Kenji Watanabe, Naoko Nitta, Noboru Babaguchi

COMPUTATIONAL IMAGING IX 7873 2011年

There are several zoom-in video display methods including full-zoom and fisheye view that magnify the regions of interest (ROIs). However, those methods usually discard or deform the remaining regions without considering their content. In this paper, we propose a method for generating a content-preserving zoom-in view which magnifies ROIs and at the same time preserves the content of the remaining regions. Targeting on surveillance videos, our method firstly extracts moving objects from every input frame as ROIs. Then, the importance score is calculated for each pixel in the input frame based on its content to determine where the deformation, which may cause the destruction of the content, should be avoided. Finally, a mapping problem from the input frame to the zoom-in view with respect to the importance score is formulated to deform less important regions more than the important ones. Experiments are conducted to study the effectiveness of considering the content importance. We also compare the results of our method with those of other methods, fisheye view and a method of using uniform scaling and seam carving.

Image Retrieval Considering People Co-occurrence Relations Using Relevance Feedback 査読

Kazuya Shimizu, Naoko Nitta, Noboru Babaguchi

MULTIMEDIA ON MOBILE DEVICES 2011 AND MULTIMEDIA CONTENT ACCESS: ALGORITHMS AND SYSTEMS V 7881 2011年

The recent popularity of digital cameras allows us to take a large number of images. There is an increasing need for efficiently and accurately retrieving images containing a specific person from such image collections. While only the visual features of the specific person are used in many query-by-example retrieval methods, we focus on the fact that some people such as family or friends are more likely to appear in the same images than others and use visual features of not only the queried person but also people who have strong co-occurrence relations with the queried person to improve the retrieval performance. The relevance feedback is used to learn who co-occur with the queried person in the same images, their faces, and the strength of their co-occurrence relations. For 116 images collected from 6 persons, after five feedback iterations, the recall rate of 53% was obtained by considering the co-occurrence relations among people, as against 34% when using only features of the queried person.

Extracting intentionally captured regions using point trajectories 査読

Yuta Nakashima, Noboru Babaguchi

MM'11 - Proceedings of the 2011 ACM Multimedia Conference and Co-Located Workshops 1417 - 1420 2011年

When camera persons take videos with mobile video cameras, they usually have capture intentions, i.e., what they want to express in their videos, and there are intentionally captured regions (ICRs) in the video frames that are essential for the capture intentions. Extracting ICRs is thus beneficial for wide range of applications such as video summarization and video adaptation for small displays. In this paper, we present a novel method for automatically extracting ICRs. A camera person usually moves his/her camera so that ICRs can be arranged in appropriate positions in video frames
therefore, ICRs can yield specific motion. This observation indicates that such specific motion is a vital cue for extracting ICRs. The proposed method represents motion by point trajectories, which are long-term trajectories of spatially dense points in video frames, and extracts ICRs using an ICR model based on the point trajectories. We experimentally evaluate the proposed method to demonstrate its potential applicability. Copyright 2011 ACM.

Example-based video remixing support system 査読

Naoko Nitta, Noboru Babaguchi

MM'11 - Proceedings of the 2011 ACM Multimedia Conference and Co-Located Workshops 563 - 572 2011年

Video remixes are generally created by sequentially arranging selected video clips and mixing them with other media streams such as audio clips and transition effects. Especially, mixing music clips often effectively improves the expressive quality of video clips. This paper proposes an example-based system for supporting average users in the 3 steps in video remixing: I)video shot sequence creation, II)music clip selection, and III)audio volume adjustment. The proposed system creates a template for a video remix and gives suggestions to users on an interface such as which video clips should be selected to create a video shot sequence and which music clips should be mixed to the created video shot sequence based on professionally created video remix examples. Then, the audio volume of each video shot is automatically adjusted based on its audio content so that the sounds in the video shots and the music clips would not interfere with each other. Experiments have verified that our system was able to create a video shot sequence whose quality was improved equally as the professionally created one by mixing the selected music clips, doubling the subjective scores from 1.7 to 3.7 on a scale of 1-5. Automatic audio volume adjustment improved the subjective scores by approximately 0.5 points on average. Further, the suggestions provided on the interface was evaluated useful by 5 subjects when creating a video remix by selecting 32 video clips and 4 music clips from 265 video clips and 180 music clips. © 2011 ACM.

Example-based video remixing for home videos

Naoko Nitta, Noboru Babaguchi

Proceedings - IEEE International Conference on Multimedia and Expo 2011年

Video remixes are generally created by sequentially arranging selected video clips and combining them with other media streams such as audio clips. In this paper, an example-based approach is adopted for semi-automatically creating video remixes of good expressive quality from home videos. Given multiple home video clips and audio clips, the proposed system generates a video remix by four processes: I)video clip sequence generation, II)audio clip selection, III)audio boundary extraction, and IV)video segment extraction based on professionally created video remix examples. A user interface which presents video clips according to their suitability to the examples and their perceived quality is developed so that users can efficiently and effectively select and arrange suitable video clips in video clip sequence generation. By using movie trailers of action genre as video remix examples, a 43-second video remix was created from 45-minute home videos and was subjectively evaluated better than the one created considering only the perceived quality of video clips. © 2011 IEEE.

Learning people co-occurrence relations by using relevance feedback for retrieving group photos

Kazuya Shimizu, Naoko Nitta, Noboru Babaguchi

Proceedings of the 1st ACM International Conference on Multimedia Retrieval, ICMR'11 2011年

This paper proposes an image retrieval method which retrieves images of a specific person from group photos. Many query-by-example methods have focused only on the visual features of the queried person. However, since socially related people such as family and friends are often taken photos together, their co-occurrence relations can be useful information. Thus, we propose an image retrieval method which uses the visual features of not only the queried person but also those who co-occur with the queried person in the same images. Relevance feedback is used to learn who co-occur with the queried person, their faces, and how strong their co-occurrence relations are. When retrieving the images of 19 persons in total from 158 images, after five feedback iterations, the recall rate of 50% was obtained by considering the people co-occurrence relations, as against 33% when considering only the queried person. With human errors in giving relevance feedback, the recall rate still improved to 40%. © 2011 ACM.

Three-Level Privacy Control for Sensing-Based Real-World Content Digital Diorama（共著）

T. Takehara, N. Nitta, N. Babaguchi

Proc. of Third International Conference on Internet Multimedia Computing and Service (ICIMCS2011) 17 - 20 2011年

不均衡データからのランダムフォレストを利用した高速高次特徴抽出査読

河合吉彦, 住吉英樹, 藤井真人, 柴田正啓, 馬場口登

映像情報メディア学会誌 64 ( 12 ) 1951 - 1955 2010年12月

[Invited Speech] Visual Processing for Privacy-Sensitive Information 招待

Noboru Babaguchi

2010年10月

A new spatio-temporal method for event detection and personalized retrieval of sports video 査読

Minh-Son Dao, Noboru Babaguchi

MULTIMEDIA TOOLS AND APPLICATIONS 50 ( 1 ) 227 - 248 2010年10月

In this paper, a new spatio-temporal method for adaptively detecting events based on Allen temporal algebra and external information support is presented. The temporal information is captured by presenting events as the temporal sequences using a lexicon of non-ambiguous temporal patterns. These sequences are then exploited to mine undiscovered sequences with external text information supports by using class associate rules mining technique. By modeling each pattern with linguistic part and perceptual part those work independently and connect together via transformer, it is easy to deploy this method to any new domain (e.g baseball, basketball, tennis, etc.) with a few changes in perceptual part and transformer. Thus the proposed method not only can work well in unwell structured environments but also can be able to adapt itself to new domains without the need (or with a few modification) for external re-programming, re-configuring and re-adjusting. Results of automatic event detection progress are tailored to personalized retrieval via click-and-see style using either conceptual or conceptual-visual query scheme. Experimental results carried on more than 30 hours of soccer video corpus captured at different broadcasters and conditions as well as compared with well-known related methods, demonstrated the efficiency, effectiveness, and robustness of the proposed method in both offline and online processes.

Constructing Distributed Hippocratic Video Databases for Privacy-Preserving Online Patient Training and Counseling 査読

Jinye Peng, Noboru Babaguchi, Hangzai Luo, Yuli Gao, Jianping Fan

IEEE TRANSACTIONS ON INFORMATION TECHNOLOGY IN BIOMEDICINE 14 ( 4 ) 1014 - 1026 2010年7月

Digital video now plays an important role in supporting more profitable online patient training and counseling, and integration of patient training videos from multiple competitive organizations in the health care network will result in better offerings for patients. However, privacy concerns often prevent multiple competitive organizations from sharing and integrating their patient training videos. In addition, patients with infectious or chronic diseases may not want the online patient training organizations to identify who they are or even which video clips they are interested in. Thus, there is an urgent need to develop more effective techniques to protect both video content privacy and access privacy. In this paper, we have developed a new approach to construct a distributed Hippocratic video database system for supporting more profitable online patient training and counseling. First, a new database modeling approach is developed to support concept-oriented video database organization and assign a degree of privacy of the video content for each database level automatically. Second, a new algorithm is developed to protect the video content privacy at the level of individual video clip by filtering out the privacy-sensitive human objects automatically. In order to integrate the patient training videos from multiple competitive organizations for constructing a centralized video database indexing structure, a privacy-preserving video sharing scheme is developed to support privacy-preserving distributed classifier training and prevent the statistical inferences from the videos that are shared for cross-validation of video classifiers. Our experiments on large-scale video databases have also provided very convincing results.

Theoretical Analysis of the Performance of Anonymous Communication System 3-Mode Net 査読

Kazuhiro Kono, Shinnosuke Nakano, Yoshimichi Ito, Noboru Babaguchi

IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES E93A ( 7 ) 1338 - 1345 2010年7月

This paper aims at analyzing the performance of an anonymous communication system 3-Mode Net with respect to the number of relay nodes required for communication and sender anonymity. As for the number of relay nodes, we give explicit formulas of the probability distribution, the expectation, and the variance. Considering sender anonymity, we quantify the degree of sender anonymity under a situation where some relay nodes collude with each other. The above analyses use random walk theory, a probability generating function, and their properties. From obtained formulas, we show several conditions for avoiding a situation where the number of relay nodes becomes large, and for providing high sender anonymity. Furthermore, we investigate the relationship between the number of relay nodes and sender anonymity, and give a condition for providing a better performance of 3MN.

［解説］視覚的なプライバシー・センシティブ情報とその処理

馬場口登

「監視社会におけるプライバシー保護のあり方特集号」, システム/制御/情報 54 ( 6 ) 242 - 247 2010年6月

［招待講演］センサ情報に基づく実世界コンテンツ招待

馬場口登

2010年3月

A Consideration on the Numbers of Relay Nodes and Encryption Required for Anonymous Communication System 3-Mode Net 査読

K. Kono, S. Nakano, Y. Ito, N. Babaguchi

Journal of Information Assurance and Security 5 ( 3 ) 276 - 283 2010年1月

Recoverable Privacy Protection for Video Content Distribution 査読

Guangzhen Li, Yoshimichi Ito, Xiaoyi Yu, Naoko Nitta, Noboru Babaguchi

EURASIP Journal on Information Security 2009 Article No. 293031 - 11 pages 2010年1月

This paper presents a method which attains recoverable privacy protection for video content distribution. The method is based on discrete wavelet transform (DWT), which generates scaling coefficients and wavelet coefficients. In our method, scaling coefficients, which can be regarded as a low-resolution image of an original image, are used for producing privacy-protected image. On the other hand, wavelet coefficients, which can be regarded as privacy information, are embedded into the privacy-protected image via information hiding technique. Therefore, privacy protected image can be recovered by authorized viewers if necessary. The proposed method is fully analyzed through experiments from the viewpoints of the amount of the embedded privacy information, the deterioration due to the embedding, and the computational time. © 2009 Guangzhen Li et al.

　前のページ - 次のページ　

<馬場口 登>

論文 - 馬場口 登

<馬場口　登>

論文 - 馬場口　登