• Journal of Broadcast Engineering
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• v.21 no.3
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• pp.319-329
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• 2016

Internet Video Coding (IVC) is a royalty-free codec currently being developed in MPEG. Coding efficiency of IVC codec has been steadily enhanced and it was reported that the performance of Committee Draft (CD) version is comparable to H.264/AVC High Profile (HP) in terms of objective and subjective qualities. In this paper, we present some coding tools that have been proposed for enhancing the coding efficiency of IVC during the developing process in MPEG along with brief overview of IVC codec architecture and coding algorithms. The coding tools include both of normative tools and informative tools such as non-reference P frame coding, DC mode intra prediction, Lagrange multiplier selection, and extension of chroma intra prediction modes. Improvement obtained by each tool is presented in terms of algorithm and coding gain based on the experiments. As a result of the experiment, the coding tools give the average bit saving of 8.8%, 0.4%, 0.4%, and 0.0%, respectively, in the low-delay coding mode.

• Proceedings of the IEEK Conference
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• 2000.09a
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• pp.281-285
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• 2000

This paper proposes context-based coding methods for variable length coding of inter-frame DCT coefficients. The proposed methods classify run-level symbols depending on the preceding coefficients. No extra overhead needs to be transmitted, since the information of the previously transmitted coefficients is used for classification. Two entropy coding methods, arithmetic coding and Huffman coding, are used for the proposed context-based coding. For Huffman coding, there is no complexity increase from the current standards by using the existing inter/intra VLC tables. Experimental results show that the proposed methods give ～ 19% bits gain and ～ 0.8 dB PSNR improvement for adaptive inter/intra VLC table selection, and ～ 37% bits gain and ～ 2.7dB PSNR improvement for arithmetic coding over the current standards, MPEG-4 and H.263. Also, the proposed methods obtain larger gain for small quantizaton parameters and the sequences with fast and complex motion. Therefore, for high quality video coding, the proposed methods have more advantage.

• ETRI Journal
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• v.26 no.2
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• pp.122-135
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• 2004

Although frame-based MPEG-4 video services have been successfully deployed since 2000, MPEG-4 video coding is now facing great competition in becoming a dominant player in the market. Object-based coding is one of the key functionalities of MPEG-4 video coding. Real-time object-based video encoding is also important for multimedia broadcasting for the near future. Object-based video services using MPEG-4 have not yet made a successful debut due to several reasons. One of the critical problems is the coding complexity of object-based video coding over frame-based video coding. Since a video object is described with an arbitrary shape, the bitstream contains not only motion and texture data but also shape data. This has introduced additional complexity to the decoder side as well as to the encoder side. In this paper, we have analyzed the current MPEG-4 video encoding tools and proposed efficient coding technologies that reduce the complexity of the encoder. Using the proposed coding schemes, we have obtained a 56 percent reduction in shape-coding complexity over the MPEG-4 video reference software (Microsoft version, 2000 edition).

• International Journal of Advanced Culture Technology
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• v.10 no.4
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• pp.175-180
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• 2022

To develop computational thinking skills, university students are learning how to solve problems with algorithms, program commands and grammar, and program writing. Because non-computer majors have difficulty with computer programming-related content, they need a learning method to acquire coding knowledge from the process of understanding, interpreting, changing, and improving source codes by themselves. This study explored clone coding, refactoring coding, and coding methods using reconstruction tools, which are practical and effective learning methods for improving coding skills for students who are accustomed to coding. A coding learning process with the code reconstruction principle was designed to help non-computer majors use it to understand coding technology and develop their problem-solving ability and applied the coding technology learning method used in programmer education.

• International Journal of Advanced Culture Technology
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• v.8 no.3
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• pp.186-191
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• 2020

Artificial Intelligence (AI) technology is used in a variety of fields because it can make inferences and plans through learning processes. In the field of coding technologies, AI has been introduced as a tool for personalized and customized education to provide new educational environments. Also, it can be used as a virtual assistant in coding operations for easier and more efficient coding. Currently, as coding education becomes mandatory around the world, students' interest in programming is heightened. The purpose of coding education is to develop the ability to solve problems and fuse different academic fields through computational thinking and creative thinking to cultivate talented persons who can adapt well to the Fourth Industrial Revolution era. However, new non-computer science major students who take software-related subjects as compulsory liberal arts subjects at university came to experience many difficulties in these subjects, which they are experiencing for the first time. AI based coding technologies can be used to solve their difficulties and to increase the learning effect of non-computer majors who come across software for the first time. Therefore, this study examines the current state of AI based coding technologies and suggests the direction of future coding education.

• Journal of Advanced Navigation Technology
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• v.16 no.6
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• pp.1044-1051
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• 2012

This paper proposed a new Hangul Jeongum Jamo coding system. To do it, the current Hangul Jeongum coding system was analyzed with the source coding rule of character. As a result of the study, the current Hangul Jeongum coding system should be changed because there are many violated codes in the coding system. When the proposed coding system for Hangul Jeongum coding system is applied, the datacommunication efficiency could be increased to 19.78%.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.3
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• pp.1093-1104
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• 2014

The High Efficiency Video Coding (HEVC) is a new video coding standard that can provide much better compression efficiency than its predecessor H.264/AVC. However, it is computationally more intensive due to the use of flexible quadtree coding unit structure and more choices of prediction modes. In this paper, a fast intraframe coding scheme is proposed for HEVC. Firstly, a fast bottom-up pruning algorithm is designed to skip the mode decision process or reduce the candidate modes at larger block size coding unit. Then, a low complexity rough mode decision process is adopted to choose a small candidate set, followed by early DC and Planar mode decision and mode filtering to further reduce the number of candidate modes. The proposed method is evaluated by the HEVC reference software HM8.2. Averaging over 5 classes of HEVC test sequences, 41.39% encoding time saving is achieved with only 0.77% bitrate increase.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2016.06a
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• pp.264-266
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• 2016

During the $2^{nd}$ JVET (Joint Group on Future Video Coding Technology Exploration) meeting, up to 22 coding tools focusing on Future Video Coding (FVC) were proposed. Despite that the application of proposed coding tools has a considerable performance enhancement, however, the encoding time of Joint Exploration Model (JEM) software is over 20 times for All Intra coding mode, 6 times for Random Access coding mode, of HEVC reference model (HM), and decoding time is 1.6 times for All Intra coding mode, 7.9 times for Random Access coding mode, of HM. This paper focuses on analyzing the complexity of the JEM software compared with HM.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.6B
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• pp.1050-1059
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• 2000

In this paper, we propose a method to improve JBIG2 compression ratio which can be applied to Hangul text. Hangul character is composed of a few symbols which is called JASO, which needs inevitable increase of position information to be transmitted. To reduce this disadvantage, we have proposed an algorithm that generate aggregated symbol in combination of JASO symbols. Proposed algorithm shows better performance in Huffman coding than in arithmetic coding. In lossless coding, proposed algorithm showed 4.5∼16.7(%) improvement for Huffman coding and 2.9∼10.4(%) improvement for arithmetic coding. In lossy coding, proposed algorithm showed 3.7∼17.0(%) improvement for Huffman coding and 2.1∼10.5(%) improvement for arithmetic coding.

• Journal of Information Processing Systems
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• v.13 no.1
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• pp.114-127
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• 2017

This paper proposes a color image coding algorithm based on shape-adaptive all phase biorthogonal transform (SA-APBT). This algorithm is implemented through four procedures: color space conversion, image segmentation, shape coding, and texture coding. Region-of-interest (ROI) and background area are obtained by image segmentation. Shape coding uses chain code. The texture coding of the ROI is prior to the background area. SA-APBT and uniform quantization are adopted in texture coding. Compared with the color image coding algorithm based on shape-adaptive discrete cosine transform (SA-DCT) at the same bit rates, experimental results on test color images reveal that the objective quality and subjective effects of the reconstructed images using the proposed algorithm are better, especially at low bit rates. Moreover, the complexity of the proposed algorithm is reduced because of uniform quantization.