• Journal of Broadcast Engineering
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• v.16 no.5
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• pp.801-810
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• 2011

This paper proposes a new lossless data embedding algorithm on spatial domain of digital images. A single key parameter is required to embed and extract data in the algorithm instead of embedding any additional information such as the location map. A $3{\times}3$ window slides over the cover image by one pixel unit, and one bit can be embedded at each position of the window. So, the ideal embedding capacity equals to the number of pixels in an image. For further increase of embedding capacity, new weight parameters for the estimation of embedding target pixels have been used. As a result, significant increase in embedding capacity and better quality of the message-embedded image in high capacity embedding have been achieved. This algorithm is verified with simulations.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.39 no.6
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• pp.602-611
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• 2002

Recent advances in technology have resulted in rapid growth in mobile communication. With this explosive growth, reliable transmission and error resilient technique become increasingly necessary to offer high quality multimedia service. The success of error resilient techniques at decoder sensitively depends on error detection performance. Therefore, this paper proposes a computationally very simple and efficient error detection technique using fragile watermark for real-time video communication. To balance between image quality degradation and error detection efficiency, fragile watermark is embedded only in least significant bits of selected transform coefficients. The proposed method is workable without additional bit in video bitstream and can be implemented very efficiently. This method will be useful in video communication in error prone environment such as wireless channel.

• Journal of Convergence for Information Technology
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• v.9 no.1
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• pp.92-98
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• 2019

Due to the development of hologram display technology, various studies are being conducted to provide realistic contents for augmented reality. In the case of the HMD for hologram, since augmented reality objects must be rendered by a small processor, it is necessary to use a low-capacity content. To solve this problem, there is a need for a technique of rendering resources by providing resources through a network. In the case of the existing augmented reality system, there is no problem of contents modulation because the resources are loaded and rendered in the internal storage space. However, when providing resources through the network, security problems such as content tampering and malicious code insertion should be considered. Therefore, in this paper, we propose a network rendering technique applying security techniques to provide augmented reality contents in a holographic HMD device.

• The KIPS Transactions:PartB
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• v.16B no.1
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• pp.25-34
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• 2009

DVR(Digital Video Recorder) system stores video inputs in compressed digital formats and retrieve them. DVR system has several advantages over traditional analog tape recorder system which are (1) improved real-time monitoring, recording and searching capability, and (2) other capabilities such as watermarking and remote monitoring through network. AVI format is the most popular format used for DVR systems. However, AVI format has drawbacks in recording and searching due to structural problem. Some vendors develop and use their own format, do not open the format to the public. In this paper, ESP format is proposed. ESP format solves the drawbacks of AVI format, and the advantages of AVI format apply to ESP format. Moreover, ESP format provides multistream recording/replay and event-recording. In result, ESP format enchances functionality of recording and searching in DVR system.

• The KIPS Transactions:PartD
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• v.15D no.5
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• pp.713-720
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• 2008

Fingerprinting scheme uses digital watermarks to trace originator of unauthorized or pirated copies, however, multiple users may collude and escape identification by creating an average or median of their individually watermarked copies. Previous research works are based on ACC (anti-collusion code) for identifying each user, however, ACC are shown to be resilient to average and median attacks, but not to LCCA and cannot support large number of users. In this paper, we propose a practical SACC (scalable anti-collusion code) scheme and its angular decoding strategy to support a large number of users from basic ACC (anti-collusion code) with LCCA (linear combination collusion attack) robustness. To make a scalable ACC, we designed a scalable extension of ACC codebook using a Gaussian distributed random variable, and embedded the resulting fingerprint using human visual system based watermarking scheme. We experimented with standard test images for colluder identification performance, and our scheme shows good performance over average and median attacks. Our angular decoding strategy shows performance gain over previous decoding scheme on LCCA colluder set identification among large population.