• Proceedings of the Korea Contents Association Conference
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• 한국콘텐츠학회 2006년도 추계 종합학술대회 논문집
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• pp.499-502
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• 2006

H.264/MPEG4 Advanced Video coding joint standard needs deblocking filter of decoder. We propose a better deblocking algorithm ensuring picture quality even if it is low bit-rate and bandwidth in MPEG-4 video. The complexity diminishes in proposed deblocking algorithm because it uses only simple shift, addition and comparison. We handle dividing into complexity area, medium area and simple area after counting boundary intensity of mask block to identify presence of block effects. As a result of experiment, we make certain of that block effects reduces in proposed deblocking algorithm.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 한국해양정보통신학회 2011년도 추계학술대회
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• pp.930-933
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• 2011

This paper addresses an adaptive postprocessing method applied in the spatial domain for block-based discrete cosine transform (BDCT) coded images. The proposed algorithm is designed by a serial concatenation of a 1D simple smoothing filter and a 2D directional filter. The 1D smoothing filter is applied according to the block type, which is determined by an adaptive threshold. It depends on local statistical properties, and updates block types appropriately by a simple rule, which affects the performance of deblocking processes. In addition, the 2D directional filter is introduced to suppress the ringing effects at the sharp edges and the block discontinuities while preserving true edges and textural information. Comprehensive experiments indicate that the proposed algorithm outperforms many deblocking methods in the literature, in terms of PSNR and subjective visual quality evaluated by GBIM.

• The Journal of Korean Institute of Communications and Information Sciences
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• 제25권8B호
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• pp.1400-1412
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• 2000

In this paper, we propose a technique for image enhancement, especially for denoising and deblocking based on wavelets. In this proposed algorithm, frame wavelet system designed as a optimal edge detector was used. And our theory depends on Lipschitz regularity, spatial correlation, and some important assumptions. The performance of the proposed algorithm was compared with three popular test images in image processing area. Experimental results show that the performance of the proposed algorithm was better than other previous denoising techniques like spatial averaging filter, Gaussian filter, median filter, Wiener filter, and some other wavelet based filters in the aspect of both PSNR and human visual system, The experimental results also show approximately the same capability of deblocking as the previous developed techniques

• ETRI Journal
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• 제29권3호
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• pp.396-398
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• 2007

This letter presents an architecture based on a new double-filter strategy to perform the adaptive in-loop filtering process specified by the H.264/AVC standard. The proposed architecture shows considerable advantages, both in terms of hardware cost and latency, when compared with the approaches found in the most recent literature.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 한국방송∙미디어공학회 2016년도 하계학술대회
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• pp.235-236
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• 2016

본 논문에서는 로드밸런싱 (load balancing) 기반의 HEVC (High Efficiency Video Coding) 디블록킹 필터(deblocking filter) 병렬화 방법을 제안한다. 본 논문에서는 디블록킹 필터의 병렬화를 위해 TU (Transform Unit)의 경계 정보를 이용하여 픽쳐 단위로 디블록킹 필터의 작업량을 예측하고, 예측된 작업량을 기반으로 코어에 균등한 일을 할당함으로써 디블록킹 필터의 병렬화 효율을 향상 시켰다. 실험결과 제안하는 로드 밸런싱 기반 디블록킹 필터 병렬화 방법을 사용하여 균등 분할 디블록킹 필터 병렬화 방법에 비해 11%의 디블록킹 필터 속도를 향상시켰다.

• JSTS:Journal of Semiconductor Technology and Science
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• 제7권4호
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• pp.229-234
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• 2007

In this paper, we present an efficient instruction set architecture using vector register file hardware to accelerate operation of general matrix-vector operations in DSP microprocessor. The technique enables in-situ row-access as well as column access to the register files. It can reduce the number of memory access significantly. The technique is especially useful for block-based video signal processing kernels such as FFT/IFFT, DCT/IDCT, and two-dimensional filtering. We have applied the new instruction set architecture to in-loop deblocking filter processing in H.264 decoder. Performance comparisons show that the required load/store operations for the in-loop deblocking filter can be reduced about 42%. The architecture would improve the processing speed, and code density in DSP microprocessor especially for video signal processing substantially.

• JSTS:Journal of Semiconductor Technology and Science
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• 제5권4호
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• pp.237-242
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• 2005

H.264/AVC adopts new features compared with previous multimedia algorithms. It is inefficient to implement some of the new blocks using existing DSP instructions. Hence, new instructions are required to implement H.264/AVC. This paper proposes novel instructions for intra-prediction, in-loop deblocking filter, entropy coding and integer transform. Performance comparisons show that the required computation cycles for the in-loop deblocking filter can be reduced about $20{\sim}25%$. This paper also proposes new instructions for the integer transform. The proposed instructions can execute one dimension forward/inverse integer transform. The integer transform can be implemented using much smaller hardware size than existing DSPs.

• The Transactions of the Korean Institute of Electrical Engineers D
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• 제53권8호
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• pp.611-614
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• 2004

In this paper, we propose an adaptive blocking artifact reduction algorithm using characteristics of the block boundaries. Blocking artifacts contain the high frequency components near the block boundaries, so the lowpass filtering can remove them. But a simple lowpass filtering results into blurring by remove important features such as edges. To overcome this problem, we determine the modes depending on the characteristics around boundaries then proper filter is applied to each area. Simulation results show that the proposed method improves deblocking performance compared to that of MPEG-4.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 한국방송공학회 2013년도 하계학술대회
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• pp.354-356
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• 2013

ITU와 ISO/IEC가 공동으로 UHD급 영상 부호화를 위해 표준화를 진행하고 있는 HEVC 코덱은 H.264/AVC 대비 2배 이상의 압축 효율을 갖는 것을 목표로 정하고 있다. HEVC(High Efficiency Video Coding)는 In-Loop Filter 기술로 H.264/AVC에서 사용하고 있는 Deblocking Filter와 새롭게 추가 된 SAO(Sample Adaptive Offset)를 사용하고 있다. 본 논문에서는 HEVC의 In-Loop Filter 기술 중 하나인 SAO의 기술의 EO에서 Category를 조금 더 정확하게 판단하여 분류하는 방법을 제안을 한다.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 한국방송공학회 2015년도 하계학술대회
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• pp.557-559
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• 2015

움직임 보상 기반 프레임율 변환(Frame rate up-conversion based on motion compensation )에서 발생하는 블로킹 현상(Blocking artifact)을 줄여 영상의 화질을 높이기 위한 디블로킹 필터(De-blocking filter) 방법을 제안한다. 이 방법은 블록 단위로 동작하는 움직임 보상 과정에서 주변 블록과의 움직임이 급격히 달라지는 폐색영역에서 발생하는 블로킹 현상을 크게 줄일 수 있다. 제안하는 방법은 기존의 필터링을 하지 않는 방법보다 화질이 약 0.01db 향상하였다.