• Journal of the Korean Institute of Telematics and Electronics C
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• v.34C no.11
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• pp.20-28
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• 1997

In this paper, quantization and inverse quantizatio unit, a sa component of MPEG-2 moving picture compression system, ar edesigned. In the processing of quantization, this design adopted newly designed arithmetic units in which quantization matrices and scale code was expressed with SD(signed-digit) code. In the arithmetic unit of inverse quantization, quantization scale code, which has 5-bits length, is splited into two pieces; 2-bits for control code, 3-bits for quantization data, and the method to devise quantization step size is proposed. The design was coded with VHDL and synthesis results in that it consumed about 6,110 gates, and operating speed is 52MHz.

• Proceedings of the Korea Contents Association Conference
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• 2010.05a
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• pp.437-440
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• 2010

동영상, 음악, 카메라영상, 음성 등 다양한 객체를 결합하는 강의 제작기는 강의 콘텐츠 제작에 유용하다. 본 프로그램은 다양한 객체를 결합하여 무 손실 압축 처리한 강의 콘텐츠를 제작한다. 결과물로서 음성/영상/인덱스의 3가지 종류의 파일이 생성된다. 인덱스파일은 영상 정보, 영상 파일 구성정보, 음성정보, 음성파일 구성정보를 가지며 음성파일은 각 객체의 음성만을 interpolation 처리 후 하나의 데이터로서 혼합한 결과물이다. 영상 파일은 영상 정보만을 결합한 뒤 wavelet, motion estimation, 사전코드 방식과 huffmancode 방식을 혼합한 방식을 응용한 무 손실 압축 영상데이터 이다.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.31B no.10
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• pp.130-139
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• 1994

Video compression algorithms are based on removing spatial and/or temproal redundancy inherent in image sequences by predictive(DPCM) encoding, transform encoding, or a combination of predictive and transform encoding. In this paper, each 8$\times$8 DCT coefficient of DFD(displaced frame difference) is adaptively quantized by one of the four quantizers depending on total distortion level, which is determined by characteristics of HVS(human visual system) and buffer status. Therefore, the number of possible quantizer selection vectors(patterns) is 4$^{64}$. If this vectors are coded, toomany bits are required. Thus, the quantizer selection vectors are limited to 2048 for Y and 512 for each U, V by the proposed method using SWAD(sum of weighted absolute difference) for discriminating vectors. The computer simulation results, using the codebook vectors which are made by the proposed method, show that the subjective and objective image quality (PSNR) are goor with the limited bit allocation. (17Mbps)

• Proceedings of the KIEE Conference
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• 2007.04a
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• pp.38-40
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• 2007

In this paper, we propose a novel architecture, which is based on DCT (Discrete Cosine Transform), for ME (Motion Estimation) and MC (Motion Compensation). The traditional algorithms of ME and MC based on DCT did not suffer the advantage of the coarseness of the 2-dimensional DCT (2-D DCT) coefficients to reduce the operational time. Therefore, we derive a recursion equation for transform-domain ME and MC and design the structure by using highly regular, parallel, and pipeline processing elements. The main difference with others is removing the IDCT block by using to transform domain. Therefore, the performance of our algorithm is more efficient in practical image processing such as DVR (Digital Video Recorder) system. We present the simulation result which is compare with the spatial domain methods. it shows reducing the calculation cost. compression ratio. and peak signal to noise ratio (PSNR).

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2013.11a
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• pp.182-185
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• 2013

본 논문에서는 효과적인 홀로그래픽 비디오 서비스를 다양한 재생환경에서 제공하기 위한 스케일러블 코딩 방법을 제안한다. 이 방법은 홀로그램과 광원의 차영상을 사용하여 압축을 하는 방식으로 구성된다. 즉, 기존의 스케일러블 코딩방식인 홀로그램 해상도 스케일러블 코딩과 광원의 화질 스케일러블 코딩 방식을 조합하여 새로운 알고리즘을 제안한다. $1,024{\times}1,024$ 크기의 홀로그램의 차영상에 대해서는 손실압축, 광원의 차영상은 무손실 압축을 이용하여 스케일러블 코딩을 수행함으로써 적응적인 서비스가 가능하도록 한다.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 1998.06b
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• pp.116-121
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• 1998

As digital audio video data compression and transmission techniques are matured, huge amount of digital multimedia material is produced and delivered via broadcasting, digital storage media and world-wide web(WWW). Thus it became very important to provide a standardized way of multimedia data content description, so that efficient and effective access and reuse of valuable multimedia information can be possible. In this paper, enabling core technologies and our research directions on this are presented with brief introduction on the scope of the multimedia content description interface, called MPEG-7, in terms of objective, application and requirements.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.55 no.8
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• pp.369-374
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• 2006

Due to development of internet network environments and data compression techniques, the size and amount of multimedia data has greatly increased. They are compressed before transmission or storage. Dealing with these compressed data such as video retrieval or indexing requires decompression procedure in most cases. This causes additional computations and increases the processing time. In various applications a histogram is one of the most frequently used tools. Efficiency of extracting such histograms will drop down if decompression is involved. We propose a novel scheme for extracting histograms from images that are transformed into the compressed domain by 8x8 DCT(Discrete Cosine Transform). In this scheme an averaged version of original image is obtained by a simple linear combination of DCT coefficients with the sets of coefficients we designed.

• Transactions on Electrical and Electronic Materials
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• v.13 no.6
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• pp.278-282
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• 2012

Photovoltaic systems have emerged to be one of the cleanest energy systems. Therefore, many large scale solar parks and PV farms have been built to prepare for the post fossil fuel ages. However, due to their large scale, to efficiently manage and operate PV systems, they need to be visually monitored within the range of infrared ray through the Internet. To satisfy this need, the efficient implementation of a high performance video compression standard is required. This paper therefore presents an implementation of H.264 motion estimation, which is one of the most data-intensive and complicated functions in H.264. To achieve this, this work implements vector instructions in hardware and incorporates them in a generic RISC processor architecture, thus increasing the processing speed while minimizing hardware and software design efforts. Extensive simulation results show that this proposed implementation can process motion estimations up to 13 times faster.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.411-412
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• 2006

In this paper, we proposed a fast algorithm for inter prediction included the most complexity in H.264/AVC. It decide search range according to direction of predicted motion vector, and then perform adaptive candidate spiral search. Simultaneously, it perform motion estimation of variable loop with threshold for variable block size. Conclusively, it is implemented in JM FME with high complexity applying to rate-distortion optimization. Experimental results show that significant complexity reduction is achieved while the degradation in video quality is negligible.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.809-810
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• 2006

An H.264 algorithm is commonly used for video compression applications. This algorithm requires a large number of data computations, for example, the sum of absolute difference (SAD) operation. We analyzed H.264 reference encoding workloads. The H.264 encoding program has 8.78% SAD operation. The SAD operation is to sum up 16 difference-values in H.264 $4{\times}4$ sub-blocks. In order to accelerate SAD operations, we implemented an application specific instruction-set processor (ASIP) that can execute SAD and data transfer instructions. The proposed coprocessor has an absolute value generator and a carry save adder (CSA) unit to sum up 8 difference-values per one clock cycle. We completed SAD operation in 2 clock cycles. Experimental results show that the performance is improved by 34% of total execution time.