• ETRI Journal
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• v.24 no.5
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• pp.401-404
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• 2002

In this paper, we propose a non-blind watermarking method that embeds a pseudo-random sequence (watermarks) into wavelet DC components. The DC area is not suitable for embedding because of severe visual degradation. We overcome the degradation problem by embedding watermarks into visually insensitive locations. We compare our experimental results with respect to JPEG compression with Cox’s popular correlation-based method. We also compare the robustness of our technique with other methods registered in CheckMark. This study reveals that the proposed method simultaneously provides good fidelity in quality as well as robustness against external attacks.

• Proceedings of the IEEK Conference
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• 1999.11a
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• pp.605-608
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• 1999

In this paper, we proposed several scene analysis algorithms. These algorithms using image difference and histogram operate on the sequence of DC coefficient which is extracted from Motion JPEG or MPEG without full-frame decompression. Since DC sequence has the most information of full frame while it has reduced data. Experimental results show less than 1/64 of full frame analysing complexity and exactly analyze scene changes and extract key frames.

• Proceedings of the Korean Information Science Society Conference
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• 1998.10c
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• pp.577-579
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• 1998

본 논문에서는 디지털 영상 데이터에 워터마크를 삽입하는 알고리즘을 제시한다. 디지털 데이터를 주파수 공간으로 변환시켜 인간이 잘 감지 못하는 주파수 영역과 중요한 주파수를 선택하여 대역확산통신(Spread Spectrum Communication)에서 사용되는 유사한 방법으로 워터마크를 삽입하였다. Fourier 스펙트럼 공간에서 JPEG 압축의 다양한 양자화 단계를 거쳐도 변화가 덜 민감한 Phase에서 워터마크를 삽입할 주파수 영역을 찾았다. 원본과 워터마크가 삽입된 데이터를 가지고 워터마크는 자기상관관계 특성으로 추출하였다. 그리고 다양한 신호처리(손실 압축, 필터링, 양자화)에도 워터마크를 추출하였다.

• Proceedings of the IEEK Conference
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• 2002.06d
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• pp.219-222
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• 2002

In this paper, we propose a new blind image watermarking method in wavelet domain. It is necessary to find out watermark insertion location in blind watermark. We use horizontal and vertical difference of LL components to select watermark insertion location, because increment or decrement of successive components is rarely changed in LL band. A pseudo-random sequence is used as a watermark. Experimental results show that the proposed method is robust to various kinds of attacks such as JPEG lossy compression, averaging, median filtering, resizing, histogram equalization, and additive Gaussian noise.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.687-688
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• 2006

This paper presents implementation of the lifting based DWT processor interface which the process of JPEG2000. The proposed architecture uses Excalibur device produced Altera. This study describes CIS(CMOS Image Sensor), DMA(Direct Memory Access) and DWT control logic

• Proceedings of the IEEK Conference
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• 2007.07a
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• pp.239-240
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• 2007

We suggest an image watermarking algorithm. We perform the modified Log-Polar Mapping (LPM) and the DFT/DCT on the original image and embed the watermark. Binary images are used for watermarks. Watermarking strength is adaptively adjusted depend on the mapped data Experimental results show that this method is robust to JPEG and rotation distortions.

• Proceedings of the IEEK Conference
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• 2007.07a
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• pp.203-204
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• 2007

In this work, we propose a compression algorithm for depth images, which are obtained from multi-view sequences. The proposed algorithm represents a depth image using a 3-D regular triangular mesh and predictively encodes the mesh vertices using a linear prediction scheme. The prediction errors are encoded with a arithmetic coder. Simulation results demonstrate that the proposed algorithm provides better performances than the JPEG2000 lossless coder.

• Proceedings of the KIEE Conference
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• 1996.07b
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• pp.1362-1364
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• 1996

In this paper a Dear lossless compression of medical images with vector quantizer is proposed. In order to apply the vector quantizer to medical images, the peak error in the reconstructed image is reduced down to 1. Simulation results show that the proposed coding scheme provides better performance with a PSNR improvement compared to the conventional JPEG standard.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2003.11a
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• pp.181-183
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• 2003

We propose a new watermarking scheme that can be used to embed multiple bits and also resilient to JPEG compression and geometrical transforms such as scaling, rotation, and cropping, based on off-axis holographic watermark that allows multiple watermark recovery without original content(cover image). The holographic watermark is that Fourier transformed digital hologram is embedded into cover image in the spatial domain. The proposed method has not only increased robustness with a stronger embedding but also imperceptibility of the watermark in the evaluation process.

• 한국정보통신설비학회:학술대회논문집
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• 2008.08a
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• pp.201-204
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• 2008

In this paper a new steganographic method is presented with minimum distortion. This paper focused on DCT rounding error and optimized that in a very easy way, resulting stego image has less distortion than other existing methods. The proposed method compared with F5 steganography algorithm, and the proposed method achieved better performance. This paper considered the DCT rounding error for lower distortion with possibly higher embedding capacity.