• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.4C
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• pp.458-471
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• 2006

Digital watermarking of multimedia data is a very active research area that has enjoyed a considerable amount of attention in recent years. In this paper, we propose an algorithm for embedding/detecting a fragile watermark in MPEG-4 compressed video domain (Simple and Advance Simple Profiles). The watermark bits are put directly into Huffman VLC-codespace of quantized DCT domain. The advantage of watermark embedding into the compressed domain is the significant savings for a real-time implementation as it does not require a full decoding operation. The watermark embedding does not change the video file size. The algorithm demonstrates high watermarking capacity, thereby providing reliable foolproof authentication. The results of experimental testing demonstrate that watermark embedding preserves the video quality. Watermark detection is performed without using the original video.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.45 no.4
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• pp.1-9
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• 2008

This paper presents a rapid watermarking algorithm based on DC image, which provides a resilience to geometric distortion. Our proposed scheme is based on $8{\times}8$ block DCT that is widely used in image/video compression techniques (e.g., JPEG and MPEG). In particular, a DC image is analyzed by DWT to embed a watermark. To overcome a quality degradation caused by a watermark insertion into DC components, we discern carefully the intensity and amount of watermark along the different subbands of DWT. Note that the proposed technique supports a high throughput for a real-time watermark insertion and extraction by relying on a partial decoding (i.e., DC components) on $8{\times}8$ block DCT domain. Experimental result shows that the proposed watermarking scheme significantly reduces computation time of 82% compared with existing DC component based algorithm and yet provides invariant properties against various attacks such as geometric distortion and JPEG compression, etc.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.5C
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• pp.406-414
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• 2005

The necessity for a technique to protect intellectual property of a digital content has been increasing, especially for the image/video contents which are the most favorite because of their high information-intensive property. According to this demand, this paper proposed a digital watermarking algorithm, which is recognized as the most promising technique. This algorithm targets MPEG compression system and the watermarking process is to be performed during the compression process. It inserts watermark only in Y components of I-frames. Experimental results showed that the proposed method satisfied both imperceptibility and robustness against various attacks. The PSNR difference between the compressed images(the average compression ratio was about 27:1 with Y:Cb:Cr=4:2:0 color format for TM5-based compression) with and without watermarking was only 1.8dB ($4.2\%$). In each case that the resulting image after an attack was reusable the normalized correlation between the extracted watermark and the original one was above 0.8.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.7 no.4
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• pp.656-664
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• 2006

In this paper, we introduce a new LUT based watermarking method for a halftone image. Watermark bits are hidden at pseudo-random locations of halftone image in the proposed method. The pixel values of the halftone image are determined from the LUT entry indexed by both the neighborhood halftone pixels and current grayscale value. The LUT is trained by a set of grayscale images and corresponding halftone images. Advantage of the LUT method is that it can be executed very fast compared with other watermarking methods for a halftone image. Therefore, the algorithm can be embedded in a printer. Experiments for real scanned images showed that the method is a feasible method to hide the large amount of data within a halftone image without noticeable distortion and comparing to the DHED method, is almost same in quality but significantly shorten in processing time.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.3C
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• pp.287-296
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• 2007

3D keyframe animation is used widely in 3D graphics for real-time animation. This is a method that registers the animated key values in the important several frames among the entire frames and generates the rest frame by interpolator using the registered key values. This paper proposed the watermarking for 3D keyframe animation using PositionInterpolator. The proposed algorithm selects randomly the embedding meshes, which are transform nodes among the entire hierarchical structure. Then the watermark is embedded into keyValues of PositionInterpolator in selected transform node. Experimental results verified that the proposed algorithm has the robustness against geometrical attacks and timeline attacks.

• Proceedings of the IEEK Conference
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• 2001.09a
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• pp.719-722
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• 2001

최근 정지영상, 동영상, 음성 등의 멀티미디어 컨텐트가 디지털화 되고 네트워크가 발달함에 따라 영상을 포함한 멀티미디어 데이터의 접근이 용이해 졌다. 이러한 데이터의 불법적 사용과 인위적인 조작으로부터 소유권과 저작권을 효율적으로 보호하기 위한 워터마킹 기술이 많이 연구되고 있다. 일반적으로 정지 영상 및 음성에 대한 워터마킹 기술은 많이 연구가 되었지만 이러한 방법을 동영상에 그대로 적용하기에는 실시간 처리에 적용하기가 힘들다는 큰 문제점이 있다. 따라서 본 논문에서는 비디오 신호에서의 빠른 처리과정과 실시간으로 워터마크를 삽입하고, 원 영상 없이 워터마크를 추출 할 수 있는 새로운 방법(Blind Watermarking)을 제안하고자 한다. 제안한 방법은 대역확산을 근거로 하여 워터마크 은닉 과정에서 치환(Permutation) 과정과 LSB 부호화 방법을 이용하여 비디오 시퀀스의 모든 I-프레임에 은닉한다. 복원과정은 모든 I-프레임에서 LSB 복호화와 역 치환 과정을 거쳐 본래의 저작권 정보를 추출한다. 제안한 방법을 여러 가지 동영상 비디오에 적용해 본 결과 기존의 워터마킹 방법보다 효율적이고 시각적 손상이 없었으며 빠른 실시간 처리가 가능함을 볼 수 있었다.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.42 no.6
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• pp.149-158
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• 2005

This paper proposed a blind watermarking method for video contents which satisfies both the invisibility and the robustness to attacks to prohibit counterfeiting, modification, illegal usage and illegal re-production of video contents. This watermarking algorithm targets MPEG compression system and was designed to control the amount of watermarking to be inserted according to the adaptive quantization scale code to follow the adaptive quantization of the compression system. The inserting positions of the watermark were chosen by considering the frequency property of an image and horizontal, vertical and diagonal property of a $8{\times}8$ image block. Also the amount of watermarking for each watermark bit was decided by considering the quantization step. This algorithm was implemented by C++ and experimented for invisibility and robustness with MPEG-2 system. The experiment results showed that the method satisfied enough the invisibility of the inserted watermark and robustness against attacks. For the general attacks, the error rate of the extracted watermark was less than $10\%$, which is enough in robustness against the attacks. Therefore, this algorithm is expected to be used effectively as a part in many MPEG systems for real-time watermarking, especially in the sensitive applications to the network environments.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.8C
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• pp.1113-1124
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• 2004

In this paper, we proposed a hardware(H/W) structure which can compress and recontruct the input image in real time operation and implemented it into a FPGA platform using VHDL(VHSIC Hardware Description Language). All the image processing element to process both compression and reconstruction in a FPGA were considered each of them was mapped into H/W with the efficient structure for FPGA. We used the DWT(discrete wavelet transform) which transforms the data from spatial domain to the frequency domain, because use considered the motion JPEG2000 as the application. The implemented H/W is separated to both the data path part and the control part. The data path part consisted of the image processing blocks and the data processing blocks. The image processing blocks consisted of the DWT Kernel fur the filtering by DWT, Quantizer/Huffman Encoder, Inverse Adder/Buffer for adding the low frequency coefficient to the high frequency one in the inverse DWT operation, and Huffman Decoder. Also there existed the interface blocks for communicating with the external application environments and the timing blocks for buffering between the internal blocks The global operations of the designed H/W are the image compression and the reconstruction, and it is operated by the unit of a field synchronized with the A/D converter. The implemented H/W used the 69%(16980) LAB(Logic Array Block) and 9%(28352) ESB(Embedded System Block) in the APEX20KC EP20K600CB652-7 FPGA chip of ALTERA, and stably operated in the 70MHz clock frequency. So we verified the real time operation of 60 fields/sec(30 frames/sec).

• Proceedings of the IEEK Conference
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• 2001.09a
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• pp.217-220
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• 2001

본 논문에서는 MPEG 비트스트림 기반의 동영상 저작권 보호를 위한 간단하면서도 효율적인 실시간 워터마킹 알고리즘을 제안한다. 제안된 알고리즘에서는 MPEG 부호화된 동영상에 대해 DCT 계수 영역으로 부분 복호화한 후 양자화 기법을 사용하여 DC 계수에 비가시성을 가지도록 워터마크를 삽입한다. 실험결과 제안된 알고리즘은 기존의 비트스트림 기반 워터마킹 기법보다 계산 복잡도 및 강인성 면에서 향상된 성능을 보여주고 있다.

• Proceedings of the Korea Information Processing Society Conference
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• 2010.04a
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• pp.518-519
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• 2010

워터마킹 기술은 디지털 데이터에 대한 소유권을 보호하기 위한 기술로 다양한 방법이 제시되어 왔다. 본 논문에서는 웹상에서 실시간 워터마킹을 통해 디지털 데이터를 열람하고 있는 사용자의 정보를 열람하고 있는 이미지에 기록하여 무단 복제, 불법 배포 등의 일이 발생하였을 경우 출처를 찾아낼 수 있도록 하는 방법을 제시하였다.