• Proceedings of the Korean Information Science Society Conference
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• 2007.10c
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• pp.50-54
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• 2007

정보기술은 통신 및 멀티미디어 기술의 발전에 힘입어 빠르게 발전되고 있으며, 이에 따른 데이타베이스의 기술이 공간데이타, XML, 비디오, 음성과 같은 다양한 멀티미디어 데이터 분야에 적용되고 있다. 비디오 데이타는 순차적인 특성을 가지며, 시간과 공간정보가 결합된 3차원 데이타로서 처리시간이 높은 작업이기 때문에 검색이나 브라우징이 대단히 비효율적이다. 본 논문에서는 비주얼리듬을 이용하여 비디오 데이타에서 대표 프레임(Key Frame)을 추출한 다음 XML을 이용한 태그 및 키워드 정보를 대표 프레임에 삽입하여 검색이나 브라우징을 할 수 있는 동영상 내용편집 도구(Authoring Tool for Video Contents)를 제안한다. 비주얼리듬은 3차원의 시공간적인 정보를 2차원으로 매핑한 정보로 IDCT(inverse Discrete Cosine Transform)과정 없이 픽셀 정보를 얻을 수 있어 처리속도가 빠르며 컷, 와이프, 디졸브 등의 편집효과를 효과적으로 구분할 수 있다. 그리고 XML 데이타에는 태그 및 정보와 함께 대표 프레임의 정보까지 저장되므로 유사 화면 검색이나 내용 기반 검색을 제공할 수 있다.

• Journal of Korea Multimedia Society
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• v.14 no.3
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• pp.403-413
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• 2011

In this paper, we proposed a digital image watermarking technique using scrambled binary phase computer generated hologram in the discrete cosine transform(DCT) domain. For the embedding process of watermark. Using simulated annealing algorithm, we would generate a binary phase computer generated hologram(BPCGH) which can reconstruct hidden image perfectly instead of hidden image and encrypt it through the scramble operation. We multiply the encrypted watermark by the weight function and embed it into the DC coefficients in the DCT domain of host image and an inverse DCT is performed. For the extracting process of watermark, we compare the DC coefficients of watermarked image and original host image in the DCT domain and dividing it by the weight function and decrypt it using descramble operation. And we recover the hidden image by inverse Fourier transforming the decrypted watermark. Finally, we compute the correlation between the original hidden image and recovered hidden image to determine if a watermark exits in the host image. The proposed watermarking technique use the hologram information of hidden image which consist of binary values and scramble encryption technique so it is very secure and robust to the various external attacks such as compression, noises and cropping. We confirmed the advantages of the proposed watermarking technique through the computer simulations.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.43 no.3 s.345
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• pp.48-58
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• 2006

This paper presents 8x8 two dimensional DCT/IDCT processor of adder-based distributed arithmetic architecture without applying ROM units in conventional memories. To reduce hardware cost in the coefficient matrix of DCT and IDCT, an odd part of the coefficient matrix was shared. The proposed architecture uses only 29 adders to compute coefficient operation in the 2-D DCT/IDCT processor, while 1-D DCT processor consists of 18 adders to compute coefficient operation. This architecture reduced 48.6% more than the number of adders in 8x8 1-D DCT NEDA architecture. Also, this paper proposed a form of new transpose network which is different from the conventional transpose memory block. The proposed transpose network block uses 64 registers with reduction of 18% more than the number of transistors in conventional memory architecture. Also, to improve throughput, eight input data receive eight pixels in every clock cycle and accordingly eight pixels are produced at the outputs.

• Journal of Korea Society of Industrial Information Systems
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• v.14 no.3
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• pp.15-21
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• 2009

In this paper, we proposed an iterative digital image watermarking technique using encrypted binary phase computer generated hologram in the discrete cosine transform(OCT) domain. For the embedding process of watermark, using simulated annealing algorithm, we would generate a binary phase computer generated hologram(BPCGH) which can reconstruct hidden image perfectly instead of hidden image and repeat the hologram and encrypt it through the XOR operation with key image that is ramdomly generated binary phase components. We multiply the encrypted watermark by the weight function and embed it into the DC coefficients in the DCT domain of host image and an inverse DCT is performed. For the extracting process of watermark, we compare the DC coefficients of watermarked image and original host image in the DCT domain and dividing it by the weight function and decrypt it using XOR operation with key image. And we recover the hidden image by inverse Fourier transforming the decrypted watermark. Finally, we compute the correlation between the original hidden image and recovered hidden image to determine if a watermark exits in the host image. The proposed watermarking technique use the hologram information of hidden image which consist of binary values and encryption technique so it is very secure and robust to the external attacks such as compression, noises and cropping. We confirmed the advantages of the proposed watermarking technique through the computer simulations.