• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2002.11a
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• pp.169-172
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• 2002

Embedding information into video data is a topic that recently gained increasing attention. This paper proposes a new approach for digital watermarking and secure copyright protection of video, the principal aim being to discourage illicit copying and distribution of copyrighted material. The method presented here is based on the three dimensional discrete cosine transform of video scene, in contrast with previous works on video watermarking where each video frame was marked separately, or where only intra-frame or motion compensation parameters were marked in MPEG compressed videos. The watermark sequence used is encrypted, pseudo-noise signal to the video. The performance of the presented technique is evaluated experimentally

• ETRI Journal
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• v.34 no.3
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• pp.410-420
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• 2012

A series of reversible watermarking technologies have been proposed to increase embedding capacity and the quality of the watermarked image simultaneously. The major skills include difference expansion, histogram shifting, and optimizing embedding order. In this paper, an accurate predictor is proposed to enhance the difference expansion. An efficient sorter is also suggested to find a more desirable embedding order. The payload is differently distributed into two sub-images, split like a chessboard pattern, for better watermarked image quality. Simulation results of the accurate prediction and sorter based on the payload balancing method yield generally better performance over previous methods. The gap is wide, in particular, in low payload for natural images. The peak signal-to-noise ratio improvement is around 2 dB in low payload ranges.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 2006.07a
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• pp.450-450
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• 2006

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2015.11a
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• pp.176-179
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• 2015

본 논문에서는 3D 디지털 영상 컨텐츠의 저작권 보호를 위해 DWT(Discrete Wavelet Transform)를 이용하여 강인성(robustness), 비가시성(invisibility), 보안성(security)을 만족하는 블라인드(Blind) 워터마킹 방법을 제안한다. 이 방법은 깊이 영상 기반 랜더링(DIBR, Depth Image Based Rendering)에 효과적으로 대처하기위해 고안된 알고리즘으로, 랜더링시 발생하는 왜곡에 영향이 적은 1-Level DWT LH 부대역에 워터마크를 삽입하는 방법이다. 이 방법에서 저작권에 대한 판단은 추출한 워터마크 정보를 통합 판단하는 방법을 사용한다. 이 방법은 저작권 보호를 위해 원본 영상을 보관할 필요가 없으며, 깊이 영상 기반 랜더링 baseline distance 5% 공격에 좌,우시점 영상 모두 효율적으로 적은 에러율을 보이며 워터마크로서 충분한 강인성을 보여준다.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.54 no.12
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• pp.716-722
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• 2005

In this paper, we propose the audio watermarking algorithm based on the critical band of HAS(human auditory system) without audibly affecting the quality of the watermarked audio and implement the detecting algorithm on the BSS(broadcast synchronizing system) for testing the proposed algorithm. According to the audio quality test, the SNR(signal to noise ratio) of the watermarked audio objectively is 66dB above. In the robustness test, the proposed algorithm can detect the watermark more than $90\%$ from various compression(MP3, AAC), A/D and D/A conversions, sampling rate conversions and especially asynchronizing attacks. The BSS automatically switches the programs between the key station and the local station in broadcasting system. The result of reliability test of implemented system by using the real broadcasting audio has no false positive error during 30 days. Because of detecting once processing per 0.5 second, we can judge that the false positive error does not occur.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2016.06a
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• pp.280-283
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• 2016

본 논문에서는 DIBR 3 차원 영상을 위한 블라인드 워터마크 방법을 제안한다. DIBR 을 이용한 3 차원 영상은 낮은 Bitrate 와 시점조정 가능성으로 인해 주목받고 있지만, DIBR 과정 중 워터마크 손상이 발생해 워터마크에 어려움이 있다. 이를 극복하기 위해 DIBR 의 특성을 이용한 깊이영상 기반으로 워터마크 삽입 영역을 탐색하는 방법을 사용하며, 이를 통해 시점이동에 민감하지 않은 영역에 워터마크를 삽입하는 것이 효과적임을 실험적으로 증명하였다. 또한 시점이동 후 사라질 가능성이 큰 불필요한 워터마크 삽입을 최소화하여 워터마크 삽입 후 영상의 화질저하를 줄였다. 이에 본 논문에서는 깊이영상을 이용해 변화가 적은 영역을 탐색하기 위한 연구를 진행하였다. 이는 후에 가상 시점 영상에 추가적인 공격이 가해지더라도 더 강인성을 가질 수 있는 기초가 되었다. 또한 블라인드 워터마크 방법을 적용하기 위해 기존 워터마크 데이터와 유사도를 측정하는 방식으로 워터마크 삽입 위치를 파악하였다.

• Journal of Broadcast Engineering
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• v.26 no.3
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• pp.296-307
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• 2021

A digital hologram (DH) is an ultra-high value-added video content that includes 3D information in 2D data. Therefore, its intellectual property rights must be protected for its distribution. For this, this paper proposes a watermarking method of DH using a deep neural network. This method is a watermark (WM) invisibility, attack robustness, and blind watermarking method that does not use host information in WM extraction. The proposed network consists of four sub-networks: pre-processing for each of the host and WM, WM embedding watermark, and WM extracting watermark. This network expand the WM data to the host instead of shrinking host data to WM and concatenate it to the host to insert the WM by considering the characteristics of a DH having a strong high frequency component. In addition, in the training of this network, the difference in performance according to the data distribution property of DH is identified, and a method of selecting a training data set with the best performance in all types of DH is presented. The proposed method is tested for various types and strengths of attacks to show its performance. It also shows that this method has high practicality as it operates independently of the resolution of the host DH and WM data.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.17 no.6
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• pp.131-142
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• 2007

In this paper, semi-fragile watermarking algorithm was proposed for the application to RP(Rapid Prototyping) system. In the case of the perceptual change or distortion of the original one, the prototype product will be affected from the process because the RP system requires the high precision measure. Therefore, the geometrical transformations like translation, rotation and scaling, the mesh order change and the file format change are used in the RP system because they do not change the basic shapes of the 3D models, but, the decimation and the smoothing are not used because they change the models. The proposed algorithm which is called semi-fragile watermarking is robust against to these kinds of manipulations which preserve the original shapes because it considers the limitations of the RP system, but fragile against to the other manipulations which change the original shapes. This algorithm does not change the model shapes after embedding the watermark information, that is, there is no shape difference between the original model and the watermarked model. so, it will be useful to authenticate the data integrity and hide the information in the field of mechanical engineering which requires the high precision measure.

• Journal of the Korea Computer Graphics Society
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• v.9 no.2
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• pp.1-9
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• 2003

Information assurance(IA) refers to methodologies to protect engineering information by ensuring its availability, confidentiality, integrity, non-repudiation, authentication, access control, etc. In collaborative design, IA techniques are needed to protect intellectual property, establish security privileges and create "need to know" protections on critical features. Aside from 3D watermarking, research on how to provide IA to distributed collaborative engineering teams is largely non-existent. This paper provides a framework for information assurance within collaborative design, based on a technique we call role-based viewing. Such role-based viewing is achieved through integration of multi-resolution geometry and security models. 3D models are geometrically partitioned, and the partitioning is used to create multi-resolution mesh hierarchies. Extracting an appropriately simplified model suitable for access rights for individual designers within a collaborative design environment is driven by an elaborate access control mechanism.

• Proceedings of the Korea Information Processing Society Conference
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• 2009.11a
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• pp.355-356
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• 2009

점자 체계와 CMYK 모델을 이용하여 시각 장애인과 일반인이 읽을 수 있는 책을 만들기 위한 방법론을 제시한다. CMYK의 K를 이용해 8개의 점으로 구성된 셀 문자를 텍스트에 삽입하여, 텍스트 스캔 시 빠르고 정확한 문자 인식이 가능하게 한다.