• Journal of Korea Multimedia Society
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• v.15 no.9
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• pp.1093-1101
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• 2012

Multi-view video is obtained by capturing one three-dimensional scene with many cameras at different positions. Multi-view video coding exploits inter-view correlations among pictures of neighboring views and temporal correlations among pictures of the same view. Multi-view video coding which uses many cameras requires a method to reduce the computational complexity. In this paper, we proposed an efficient prediction structure to improve performance of multi-view video coding. The proposed prediction structure exploits an average distance between the current picture and its reference pictures. The proposed prediction structure divides every GOP into several small groups to decide the maximum index of hierarchical B layer and the number of pictures of each B layer. Experimental results show that the proposed prediction structure shows good performance in image quality and bit-rates. When compared to the performance of hierarchical B pictures of Fraunhofer-HHI, the proposed prediction structure achieved 0.07~0.13 (dB) of PSNR gain and was down by 6.5(Kbps) in bitrate.

• Journal of The Institute of Information and Telecommunication Facilities Engineering
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• v.1 no.2
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• pp.19-29
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• 2002

This paper deals with heterogeneous video transcoding, which is one of key technologies for the MPEG-21 digital item adaptation. It is noted that motion vector reuse Is necessarily required for computationally efficient implementation of the transcoder. But conventional transcoder employs the motion vector reuse methods only for P-pictures. In this paper, we propose two new motion vector reuse method for B-pictures. By using the proposed methods, we can produce the MPEG bitstream, which is encoded in a I/B/P picture mode. Computer simulation results show that the proposed methods can reduce the computational burden of the transcoder significantly, while allowing only a small amount of performance degradation.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.5C
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• pp.536-541
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• 2007

In video coding standard H.264/AVC, motion estimation using multiple reference pictures improves compression efficiency but the efficiency depends upon image content not the number of reference pictures. So, the motion estimation includes a large amount of computation of no worth according to image. This paper proposes fast motion estimation algorithm that removes worthless computation in the motion estimation using multiple reference pictures. The proposed algorithm classifies a block into valid and invalid blocks for the multiple reference pictures and removes the workless computation by applying a single reference picture to the invalid block. To estimate the proposed algorithm's performance, image quality, bit rate, and motion estimation time are compared with ones of the conventional algorithm in the reference software JM 9.5. The simulation results show that the proposed algorithm can considerably save about 38.67% the averaged motion estimation time while keeping the image quality and the bit rate, whose are average values are -0.02dB and -0.77% respectively, as good as the conventional algorithm.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.04a
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• pp.727-734
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• 2008

This research presents a laboratory study about difference of subjective response between with and without pictures. A main source is impulsive sound caused by leisure shooting. The sources are sampled from outdoor noise and their levels range from 40 to 75 dB at the interval of 5dB. The noise unit is based on A-weighted sound exposure level (ASEL; $L_{AE}$). To make equal ASEL of outdoor noise, finite impulse response (FIR) filter is applied to the originally sampled source to include the effect of distance attenuation. The evaluation method of the jury test adopted a Semantic Difference(SD) Method. The intersection point which two lines crossed was used as reference point. The intersecting point of mean response rating between with and without pictures was approximately 44ASEL and that of %HA was about 60ASEL. In the result of the test, the negative effect of pictures was given at a lower levels than intersection point while the positive effect was given at a higher levels than that.

• Journal of KIISE
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• v.41 no.11
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• pp.900-910
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• 2014

Multi-view video is obtained by capturing one three-dimensional scene with many cameras at different positions. The computational complexity of multi view video coding increases in proportion to the number of cameras. To reduce computational complexity and maintain the image quality, improved prediction structure and motion estimation method is proposed in this paper. The proposed prediction structure exploits an average distance between the current picture and its reference pictures. The proposed prediction structure divides every GOP into several groups to decide the maximum index of hierarchical B layer and the number of pictures of each B layer. And the proposed motion estimation method uses a hierarchical search strategy. This strategy method consists of modified diamond search pattern, progressive diamond search pattern and modified raster search pattern. Experiment results show that the complexity reduction of the proposed prediction structure and motion estimation method over JMVC (Joint Multiview Video Coding) reference model using hierarchical B pictures of Fraunhofer-HHI and TZ search method can be up to 40~70% while maintaining similar video quality and bit rates.

• The Journal of the Acoustical Society of Korea
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• v.16 no.3E
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• pp.7-13
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• 1997

This paper addresses traffic prediction issues on MPEG. A new adaptive traffic prediction scheme is proposed using MPEG picture characteristic that picture traffic depends on the coding mode of that picture, that is, I, P, and B mode. Our prediction scheme, which is based n picture decomposition (PD) and the cross-correlation of the different types of pictures, has better performance in predicting bursty MPEG traffic than that of the first-order autoregressive (AR) prediction scheme. Our simulation results show that the performance is further improved about 15% by utilizing the cross-correlations between pictures.

• Bulletin of the Korean Mathematical Society
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• v.58 no.5
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• pp.1301-1314
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• 2021

In this paper, firstly, we work on the presentation of the crossed product of groups of general types. After that we find the generating pictures (Second Homotopy Group) of this product by looking the relations from a geometric viewpoint. Finally, we give some applications.

• The Transactions of the Korea Information Processing Society
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• v.6 no.4
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• pp.868-876
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• 1999

In this paper, an efficient automatic video parsing technique on MPEG-compressed video that is fundamental for content-based indexing is described. The proposed method detects scene changes, regardless of IPB picture composition. To detect abrupt changes, the difference measure based on the dc coefficient in I picture and the macroblock reference feature in P and B pictures are utilized. For gradual scene changes, we use the macroblock reference information in P and B pictures. the process of scene change detection can be efficiently handled by extracting necessary data without full decoding of MPEG sequence. The performance of the proposed algorithm is analyzed based on precision and recall. the experimental results verified the effectiveness of the method for detecting scene changes of various MPEG sequences.

• Hwankyungkyoyuk
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• v.14 no.2
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• pp.1-14
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• 2001

This study analyzed and compared the number of students activities, contents scope, and organizing system of the three textbooks(A, B, and C) which had been developed and published for the 'Environment'subject in the 7th National Curriculum. The results of this study can be summarized as follows; There were differences in the size, the total number of pages and the quality of print between two groups of 'Environment'textbooks of the 6th and the 7th national curriculum. New textbooks were found bigger than the previous ones by 125%. The total number of pages increased by the average of 16.4%. A and C textbooks were composed of three parts, seven chapters, and 17 sections, whereas B textbook consisted of ten chapters and 23 sections. All of the three textbooks appeared to put an emphasis on the chapters of 'environment protection'and 'environmental problems of the Earth ' A comparative analysis on the number of data included in the three textbooks showed that almost half of data took a form of picture, averaging 48% of the total. A had 297 pictures, and 234 pictures for B, 194 pictures for C, respectively. In terms of the number of students'activities, C was found to include the largest number of activities that is 91, comparing to text A of 85, text B of 78. The number of students'activities in every content is found'environment awaiting protection', tile 'environmental problems of the earth'and'things to be done for the protection of environment'much more than any other parts. It should be noted that this study focused ell only a set of quantitative measures so that teachers are recommended to consider detailed contents that each textbook contains as well as environmental conditions of the school region.

• Journal of Korea Multimedia Society
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• v.15 no.7
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• pp.859-869
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• 2012

The Multi-view Video Coding (MVC) which is exploiting disparities between views has been developed to improve the coding efficiency of multi-view video. But MVC has a problem of having high computing complexities because of disparity estimation. This paper propose a fast mode decision for non-anchor picture to reduce the computational time of MVC. The proposed method uses two phases. Anchor pictures in hierarchical B picture structure have a higher correlation with prediction mode selection of non-anchor pictures, so in the first phase, prediction mode of non-anchor pictures is selected by exploiting the macro-block regions in anchor picture. In the second phase, we select a reference direction of inter prediction mode exploiting a higher correlation among reference directions of inter prediction modes of 7 block sizes. Experimental results show that the proposed method could save average about 44% in the encoding time with negligible coding efficiency losses.