Browsing by Author "Chang, Feng-Cheng"

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A digital content protection scheme using MPEG-21 REL with applications to DVB systems
(2006)
Shih, Ying-Tzu
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Chang, Feng-Cheng
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Hang, Hsueh-Ming
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電子工程學系及電子研究所
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Department of Electronics Engineering and Institute of Electronics
In a digital TV system, the Conditional Access (CA) system is essential to protect programs from unauthorized access. However, the encryption technique alone is not sufficient to protect or control the use of contents after decryption. To provide flexible and complete Digital Rights Management (DRM) protection on the Digital Video Broadcasting (DVB) programs, we propose a method that adapts the MPEG-21 REL technology and integrates it into a DVB-T system. By extending the Service Information (SI) section of a DVB stream to include an REL license, the transmitted content can be conveniently consumed and legally protected. Our design is verified by an experimental hardware system. The results show that the proposed method can provide both the conditional access functionality and the usage control of broadcasted contents.
A programming model for distributed content-based image retrieval
(2007)
Chang, Feng-Cheng
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Huang, Hsiang-Cheh
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電子工程學系及電子研究所
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Department of Electronics Engineering and Institute of Electronics
With the growth of digital contents, content-based image retrieval becomes important. The huge amount of computation can be solved by distributed computing. However, to design a distributed algorithm and program it with cross-platform capability is difficult. We present a programming model which is based on list data processing, and it can be transparently executed in a distributed environment with some auxiliary tools. This model allows us to explicitly specify the parallelism without special language support, such as new reserved keywords or new directives. Although this approach may introduce non-trivial overhead in some aspects, it can be used to write a distributed program using a conventional (and often sequential) language.
A relevance feedback image retrieval scheme using multi-instance and pseudo image concepts
(2006-05-01)
Chang, Feng-Cheng
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Hang, Hsueh-Ming
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電子工程學系及電子研究所
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Department of Electronics Engineering and Institute of Electronics
Content-based image search has long been considered a difficult task. Making correct conjectures on the user intention (perception) based on the query images is a critical step in the content-based search. One key concept in this paper is how we find the user preferred low-level image characteristics from the multiple positive samples provided by the user. The second key concept is how we generate a set of consistent "pseudo images" when the user does not provide a sufficient number of samples. The notion of image feature stability is thus introduced. The third key concept is how we use negative images as pruning criterion. In realizing the preceding concepts, an image search scheme is developed using the weighted lowlevel image features. At the end, quantitative simulation results are used to show the effectiveness of these concepts.
A study on the meta-data design for long-term digital multimedia preservation
(2008)
Chang, Feng-Cheng
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Chang, Chin-Yuan
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Hang, Hsueh-Ming
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電子工程學系及電子研究所
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Department of Electronics Engineering and Institute of Electronics
Due to the fast growth of multimedia content, the digital preservation emerges as an important technology that prolongs the life of digital objects. For audio-visual contents, we face the obsolescence problem in both supporting hardware/software and data representation formats. Migration strategy is a solution for achieving high-quality archival and easy access. In this paper, we investigate the concepts and structures in the Open Archival Information System (DAIS) and the MPEG-21 Digital Item Adaptation (DIA) specifications. By addressing the issues for a long-term audio-visual preservation system, we propose a combined meta-data scheme to record both the management and technical procedures and parameters. The detailed meta-data that keep the history of evolution versions can be used for subsequent migrations. We also implement a prototype system to realize our design. At the end of this study, we identify additional issues for future improvements.
A switchable DRM structure for embedded device
(2007)
Chang, Feng-Cheng
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Wu, Chiao-Lin
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Hang, Hsueh-Ming
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電子工程學系及電子研究所
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Department of Electronics Engineering and Institute of Electronics
Digital Rights Management (DRM) is a concept for controlling the distribution and consumption of digital media. As embedded multimedia devices are becoming popular, there are strong demands for the light-weight DRM systems that can run smoothly in a resource-limited environment. Due to the variety of embedded devices, an ideal DRM system should be platform independent and inter-operable. These requirements, however, often increase the software complexity, which is undesirable to an embedded device. In this paper, a switchable DRM system is thus proposed. It integrates the concept of downloadable tools and the OMA architecture to provide a balance between flexibility and complexity. We also implement the scheme on an embedded evaluation board to demonstrate its feasibility.
An improved presentation method for relevance feedback in a content-based image retrieval system
(2008)
Chang, Feng-Cheng
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Hang, Hsueh-Ming
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電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
Content-based image retrieval (CBIR) has been adopted as a complementary technique to the keyword-based image search. Relevance feedback (RFB) is considered as an effective means to bridge the gap between the designated features and the run-time semantics on a CBIR system. Like many other interactive system, a good user interface, which in RFB is mainly the presentation of the query results, is an important factor that affects the quality of feedbacks. By incorporating the multidimensional scaling (MDS) and the outlier detection techniques, we propose a method of presenting multiple image icons in this paper. It preserves the high-dimensional distance information and shows the selected images at proper 2D locations. Viewing the matched images with distance cues, users are able to give effective and productive feedbacks. We design and implement this presentation system and show some subjective results at the end.
Applications of Reversible Data Hiding Techniques with the Quick Response Codes
(2009)
Huang, Hsiang-Cheh
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Chang, Feng-Cheng
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Fang, Wai-Chi
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交大名義發表
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National Chiao Tung University
The goal of quick response (QR) codes aims at convenience-oriented applications for mobile phone users. People can use the mobile phone cameras to capture the code with random patterns, usually displayed at the corner of web page, and then the hyperlink corresponding to the QR code can be accessed. Since QR code looks like random noise, its existence can greatly reduce the value of the original image. With the aid of reversible data hiding technique, we propose a scheme Such that when the image containing the QR code is browsed, the hyperlink corresponding to the QR code is accessed first. Then, the QR code can get vanished and the original image can be recovered to retain the information conveyed therein. Simulation results demonstrate the applicability of the proposed algorithm.
Design and implementation of an MHP video and graphics subsystem on Xilinx ML310 platform
(2006)
Chen, Min-Hong
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Chang, Feng-Cheng
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Hang, Hsueh-Ming
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電子工程學系及電子研究所
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Department of Electronics Engineering and Institute of Electronics
Multimedia Home Platform (MHP) is a standard to enable versatile applications of a DVB program. In this paper, we design and implement a simplified MHP video and graphics subsystem. The Xilinx ML310 is chosen as the hardware platform to implement our design. The execution environment consists of an embedded Linux, a frame-buffer based X server, and a Java ME Personal Basis Profile,(J2ME PBP) run-time. To implement the MHP video functionality, we incorporate the FFmpeg libraries and the JavaTV JMF Lite to provide the demultiplexing and rendering operations of an MPEG-2 video. In addition, our major efforts are put on the video and graphics integration. The J2ME PBP reference software is heavily modified to optimally compose the video objects and the AWT graphics components in an MHP-compliant way. The application examples show that our proposed system is able to provide the AWT graphics and the JMF video presentation services, including normal presentation, arbitrary clipping scaling and positioning of an MPEG-2 video.
Layered access control schemes on watermarked scalable media
(2007-12-01)
Chang, Feng-Cheng
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Hang, Hsueh-Ming
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Huang, Hsiang-Cheh
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電子工程學系及電子研究所
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Department of Electronics Engineering and Institute of Electronics
Intellectual Property (IP) protection is a critical element in multimedia transmission and delivery systems. Conventional IP protection on multimedia data can be categorized into encryption and watermarking. In this paper, a structure to perform layered access control on scalable media by combining encryption and robust watermarking is proposed, implemented, and verified. By taking advantages of the nature of both encryption and watermarking, copyrights of multimedia contents can be well protected and at the same time, multiple-grade services can be provided. In the summated examples, we assume a scalable transmission scheme over the broadcasting environment and use it to test the effectiveness of proposed method. When the embedded watermark is extracted with high confidence, the key to decrypt the next layer can be perfectly recovered. Then, the media contents are reconstructed and the copyrights are assured. The application examples also demonstrate the practicality of the proposed system.
Reversible Data Hiding with Histogram-Based Difference Expansion for QR Code Applications
(2011-05-01)
Huang, Hsiang-Cheh
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Chang, Feng-Cheng
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Fang, Wai-Chi
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電機工程學系
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Department of Electrical and Computer Engineering
In this paper, we propose a new algorithm in reversible data hiding, with the application associated with the quick response (QR) codes. QR codes are random patterns, which can be commonly observed on the corner of posters or webpages. The goal of QR codes aims at convenience-oriented applications for mobile phone users. People can use the mobile phone cameras to capture QR code at the corner of web page, and then the hyperlink corresponding to the QR code can be accessed instantly. Since QR code looks like random noise and it occupies a corner of the original image, its existence can greatly reduce the value of the original content. Thus, how to retain the value of original image, while keeping the capability for the instant access for webpages, would be the major concern of this paper. With the aid of our reversible data hiding technique, the QR codes can be hidden into the original image, and considerable increase in embedding capacity can be expected. Next, we propose a scheme such that when the image containing the QR code is browsed, the hyperlink corresponding to the QR code is accessed first. Then, the QR code could get vanished and the original image would be recovered to retain the information conveyed therein. Simulation results demonstrate the applicability of the proposed algorithm(1).