• Proceedings of the Korean Information Science Society Conference
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• 2002.10c
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• pp.592-594
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• 2002

일반적으로 디지털 영상에 대한 기존 워터마킹 기법은 기하학적인 왜곡에 허약하다. 본 논문에서는 기하학적인 왜곡에 강건한 워터마킹 기법을 제안한다. 워터마킹 기법은 워터마크의 생성단계 워터마크 삽입단계, 워터마크 추출 단계로 구성된다. 워터마크 생성단계에서는 시각적으로 구별이 가능한 그레이 영상을 워터마크로 사용하며, 워터마크 삽입 단계에서는 원 영상을 콤플렉스 웨이블릿 변환하여 위상 정보에 워터마크를 삽입한다. 그리고 워터마크 추출 단계에서는 워터마크된 영상으로부터 계층적으로 워터마크를 추출하여 자기 상관관계 비교에 의해 워터마크를 추출한다. 실험 결과를 통하여 이동, 크기 변환, 회전과 같은 기하학적인 변형에도 워터마크가 추출되는 것을 볼 수 있다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2006.05a
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• pp.565-568
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• 2006

In the luminance and chrominance signal, luminance signal creates gray images, and is capable of making each color component compatible with monochrome system. And color components of luminance and chrominance signals are useful to encode or convert the signal because they have low correlation. Each color signal has low correlation statistically, but they are not independent of one another. Therefore, this paper proposes the watermark inserting algorithm for luminance and chrominance signal in the domain of frequency founded on wavelet, considering the interdependent characteristics of color components. Therefore, it can guarantee the robustness and invisible of digital watermark.

• Journal of the Institute of Convergence Signal Processing
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• v.14 no.3
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• pp.154-161
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• 2013

In this paper, Gabor cosine and sine transform considered as human visual filter is applied to watermarking methods for digital images. Four algorithms by using singular values or principal components of SVD in the frequency domain are proposed for watermark embedding and extraction. Two dimensional image is used as an embedded watermark. To measure the similarity between the embedded watermark image and the extracted one, a normalized correlation value is computed for the comparison of the four proposed methods with various attacks. Extracted watermark images are also provided for visual inspection. The proposed GCST-SVD method which embeds a watermark image into the lowest vertical or horizontal ac frequency band can provide useful watermarking algorithm with high correlation values and visual watermark features from experimental results for various attacks.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2018.06a
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• pp.205-206
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• 2018

본 논문에서는 디지털 홀로그램 영상을 Fresnelet 변환을 하여 상관도를 확인할 수 있는 데이터로 바꾸고, 컨볼루션 오토인코더(Convolutional Autoencoder, CAE)를 이용해 압축하고 생성하는 방법을 제안한다. 컨볼루션 계층과 채널 수가 다른 2개의 네트워크로 실험한다. CAE의 인코더를 수행해 영상을 압축하고 디코더를 통해 복원한다. 원본 영상의 Fresnelet 영역과 2개의 네트워크를 진행하여 생성된 Fresnelet 영역을 다시 역 Fresnelet하여 압축률에 따른 PSNR을 비교, 분석한다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2006.05a
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• pp.163-166
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• 2006

The field of medical images has been digitalized as the development of computer and the digitalization of the medical instruments. As a result it causes a lot of problems such as an illegal copy related to medical images and property right of the medical images. Therefore, digital watermarking is used for discrimination whether the data are modified or not. It is also used to protect both the property right of medical images and the private life of many patients. The proposed theories, the Non-blind and the Blind method, have two problems. One is needed an original image and the other is using a gaussian watermarking. This paper proposes the new Blind Watermarking using binary images in order to easily recognize the results of watermark. This algorithm is described that an watermark of a binary image is wavelet-transformed, and then a transformed watermark is inserted in medium-band of frequency domains of original image by the Circular Input method. The propose method presented the good performance of over 0.97 in NC.

• Journal of The Korean Society of Grassland and Forage Science
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• v.36 no.4
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• pp.365-369
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• 2016

Red sorrel (Rumex acetosella L.), as one of exotic weeds in Korea, was dominated in grassland and reduced the quality of forage. Improving current pasture productivity by precision management requires practical tools to collect site-specific pasture weed data. Recent development in unmanned aerial vehicle (UAV) technology has offered cost effective and real time applications for site-specific data collection. To map red sorrel on a hill pasture, we tested the potential use of an UAV system with digital cameras (visible and near-infrared (NIR) camera). Field measurements were conducted on grazing hill pasture at Hanwoo Improvement Office, Seosan City, Chungcheongnam-do Province, Korea on May 17, 2014. Plant samples were obtained at 20 sites. An UAV system was used to obtain aerial photos from a height of approximately 50 m (approximately 30 cm spatial resolution). Normalized digital number values of Red, Green, Blue, and NIR channels were extracted from aerial photos. Multiple linear regression analysis results showed that the correlation coefficient between Rumex content and 4 bands of UAV image was 0.96 with root mean square error of 9.3. Therefore, UAV monitoring system can be a quick and cost effective tool to obtain spatial distribution of red sorrel data for precision management of hilly grazing pasture.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.10
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• pp.1773-1779
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• 2008

Images play the most important role in human perception. In order to send the image information by the digital type, the compression is essential. Recently, a lot of studies on encoding algorithms for image by wavelet transform are going on. In this paper, a quadtree-based method of image compression applied to the images decomposed by wavelet transform by using the correlations between pixels and '0' data grouping is proposed. For the proposed method, the experimental gray image with $256{\times}256$ size and 8[bit], is used. And, the performance of proposed method is evaluated to compare with DCT compression method.

• Journal of the Korea Society of Computer and Information
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• v.8 no.3
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• pp.94-99
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• 2003

In this paper, a rotation invariant fingerprint identification system is implemented using the circular harmonic filter and phase only correlator. We extracted the phase component from input fingerprint image and correlate it with the circular harmonic filter of the reference fingerprint image by POC. The input image is obtained using a prism operating in the internal full reflection mode. Then the input image is transformed to two dimensional Fourier spectrum in optical way and the phase component is extracted using a digital system from the spectrum. Because composed of the optical system and digital algorithm, the proposed system has the advantages of the two technologies such as realtime parallel processing property of the optics and the flexibility of the digital system.

• Journal of Digital Contents Society
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• v.5 no.4
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• pp.311-315
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• 2004

In this paper, we proposed a robust watermarking algorithm based on fuzzy inference and human visual system. In the first, discrete wavelet transform(DWT) is involved to calculate additive energy strength, then we devised fuzzy inference, which was established by computing contrast and texture degree in gray-level image. Watermark is embeded into the coefficients of 3-level DWT so as to consider a spatial effects. Visual recognizable patterns such as binary image were used as a watermark Consequently, experimental results showed that proposed algorithm is robust in JPEC compression.

• Journal of Korea Multimedia Society
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• v.16 no.12
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• pp.1475-1481
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• 2013

A subject always follows desire caused by primal lack which exceeds its desire on survival. At this time, the immediacy provided by vision and the excellence of information become important means in mediating the object of the desire. The subject who is attracted to the vision and image toward desire cannot get out of the trap of the image. When the film raised unconsciousness to pleasure while reproducing the desire of 'mirror image', the digital image presents a virtual experience on the desire of subject by dominating audience with its perfect image regardless of the existence of the object. This study attempted to prove that unconsciousness of subject has close relation with digital image, which takes other's desire as its own by wrongly identifying other's desire as its own desire and captivates subject by the experience of desiring. According to the result of study, digital image escalates the imaginary desire of subject through the virtuality of image close to reality and captivates subject by giving pleasure to the unconsciousness of subject as a path in going along with the desire of other.