• The Transactions of the Korean Institute of Electrical Engineers D
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• v.53 no.4
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• pp.258-264
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• 2004

This paper propose a method that GOP structure based on the picture complexity change realtime adaptive without pre-analysis or time delay. Proposed algorithm calculates the complexity of pictures at first, and the ratio of the complexity( X$\sub$p/ /X$\sub$i/) between P picture and I picture is calculated. The suitable M value for the three picture select by comparing with predetermined threshold. Used bit and vbv_delay the value of GOP is calculated according to selected M. Experimental results show that the prediction error is reduce than the fixed GOP structure. Since the complexity distribution of the sequence is different, applied limits of threshold value is changed, also.

• Proceedings of the IEEK Conference
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• 2003.11a
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• pp.125-128
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• 2003

In this paper, we propose two methods for complexity reduction of intra prediction in H.264/AVC. One is skipping of intra prediction using inter prediction cost at current macroblock in current P picture, average of intra prediction cost in previous I picture, and average of inter prediction cost in previous P picture. The other is skipping of intra 16$\times$16 prediction using intra 4$\times$4 prediction cost and modes. As a result, complexity of intra prediction in P picture and that of intra 16$\times$16 prediction in intra prediction macroblock can be reduced by about 80~99％ and 50~93％, respectively.

• Proceedings of the IEEK Conference
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• 2003.07e
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• pp.1811-1814
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• 2003

In this paper, a novel watermarking technique is proposed to authenticate the owner-ship of copyright for the digital contents. Using the 2-level DWT(Discrete Wavelet Transform) we divide a specific frequency band into detailed blocks and apply PIM(picture information measure). After the complexity is calculated, the watermark is embedded in only on high complexity areas. Conventional watermarking technique damages to the original image, because it does not consider the feature of the whole area or a specific frequency band. Easily affected by noise and compression, it is difficult to extract the watermark. However, the proposed watermarking technique, considering the complexity of input image, does not damage to the original image Simulation result show that the proposed technique has the robustness of JPEG compression, noise and filtering such as a general signal processing

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.10
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• pp.5063-5073
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• 2016

In this paper, an efficient texture compression method is proposed for fast rendering, which exploits the spatial correlation among blocks through intra-picture block matching. Texture mapping is widely used to enhance the visual quality of results in real-time rendering applications. For fast texture mapping, it is necessary to identify an effective trade-off between compression efficiency and computational complexity. The conventional compression methods utilized for image processing (e.g., JPEG) provide high compression efficiency while resulting in high complexity. Thus, low complexity methods, such as ETC1, are often used in real-time rendering applications. Although these methods can achieve low complexity, the compression efficiency is still lower than that of JPEG. To solve this problem, we propose a texture compression method by reducing the spatial redundancy between blocks in order to achieve the better compression performance than ETC1 while maintaining complexity that is lower than that of JPEG. Experimental results show that the proposed method achieves better compression efficiency than ETC1, and the decoding time is significantly reduced compared to JPEG while similar to ETC1.

• Journal of Broadcast Engineering
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• v.17 no.1
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• pp.140-151
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• 2012

In Wyner-Ziv coding, key picture is encoded by conventional H.264/AVC intra coding which has low complexity. Although inter coding is more efficient than intra coding, its complexity is much higher than intra coding due to its motion estimation. Since the main feature of Wyner-Ziv coding is low complexity of encoder, inter coding is not suitable to encode key picture in Wyner-Ziv coding. However, inter picture coding with zero motion vector can be usable for Wyner-Ziv key picture coding instead of intra coding. Moreover, while current transform-domain Wyner-Ziv residual coding only utilizes temporal correlation of WZ picture, if zero motion coding is jointly used to encode key picture in transform-domain Wyner-Ziv residual coding, there will be a significant improvement in R-D performance. Experimental results show that the complexity of Wyner-Ziv coding with the proposed zero motion key picture coding is higher than conventional Wyner-Ziv coding with intra key picture coding by about 9%, however, there are BDBR gains up to 54%. Additionally, if the proposed zero motion key coding is implemented on top of the transform-domain Wyner-Ziv residual coding, the result shows rate gains up to 70% in BDBR compared to conventional Wyner-Ziv coding with intra key picture coding.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.22 no.4
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• pp.675-684
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• 1997

The bit rate control algorithm which is capable of handing scene change is proposed. In MPEG-2 TM5, block variance is used to measure block activity. But block variance is not consistent with human visual system and does not differenciate the distribution of pixel values within the block. In target bit allocation process of TM5, global complexity, obtained by results of previous coded pictures, is used. Since I pictures are spaced relatively far apart, their complexity estimate is not very accurate. In the proposed algorithm local variance is used to measure block activity and detect scene change. Local variance, using deviation from the mean of neighboring pixels, well represents the distribution of pixel values within the block. If scene change is detected, the local variance information is used for target bit allocation process. Allocating target bits for I picture, the average local variance difference between previous and current I picture is considered. The experimental results show that the proposed algorithm can detect scene change very precisely and gives better picture quality and higher PSNR values than MPEG-2 TM5.

• ETRI Journal
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• v.31 no.2
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• pp.151-161
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• 2009

In this paper, we propose an adaptive multiview video coding scheme based on spatiotemporal correlation analyses using hierarchical B picture (AMVC-HBP) for the integrative encoding performances, including high compression efficiency, low complexity, fast random access, and view scalability, by integrating multiple prediction structures. We also propose an in-coding mode-switching algorithm that enables AMVC-HBP to adaptively select a better prediction structure in the encoding process without any additional complexity. Experimental results show that AMVC-HBP outperforms the previous multiview video coding scheme based on H.264/MPEG-4 AVC using the hierarchical B picture (MVC-HBP) on low complexity for 21.5%, on fast random access for about 20%, and on view scalability for 11% to 15% on average. In addition, distinct coding gain can be achieved by AMVC-HBP for dense and fast-moving sequences compared with MVC-HBP.

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07a
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• pp.799-802
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• 2005

This paper described a 2.2" $QCIF^+$ ($176{\times}RGB{\times}220$) active matrix organic light-emitting diode display (AMOLED) using low-temperature poly-silicon (LTPS) technology. We have designed the OLED pixel to match the OLED material characteristic with COG specification and optimized pixel structure to improve color gamma adjustment and simplify signal complexity.

• The KIPS Transactions:PartB
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• v.9B no.3
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• pp.311-318
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• 2002

Document image layout analysis contains the process to segment document image into detailed regions and the process to classify the segmented regions into text, picture, table or etc. In the region classification process, the size of a region, the density of black pixels, and the complexity of pixel distribution are the bases of region classification. But in case of picture, the ranges of these bases are so wide that it's difficult to decide the classification threshold between picture and others. As a result, the picture has a higher region classification error than others. In this paper, we propose document image layout analysis method which has a better performance for the picture and text region classification than that of previous methods including commercial softwares. In the picture and text region classification, median filter is used in order to reduce the influence of the size of a region, the density of black pixels, and the complexity of pixel distribution. Futhermore the classification error is corrected by the use of region expanding filter and constrained conditions.

• Journal of Broadcast Engineering
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• v.22 no.2
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• pp.240-252
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• 2017

Multi-view video codec based on the High Efficiency Video Coding (MV-HEVC) has high encoding complexity because it exploits an additional reference picture for disparity compensation prediction (DCP) when the picture of dependent view is encoded. In this paper, we propose an efficient method to reduce the complexity of disparity motion vector search for the MV-HEVC. The proposed method includes the initial search point decision method using affine transform and the adaptive search range decision method. The simulation results show that the proposed method reduces the complexity of disparity motion vector search up to 90.78% with negligible coding efficiency degradation. Also the results show that the proposed method outperforms other conventional techniques reducing complexity.