• The Journal of Korean Institute of Communications and Information Sciences
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• v.22 no.3
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• pp.469-480
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• 1997

For moving image coding, the variable size of region coding based on local motion is more efficient than fixed size of region coding. It can be applied well to complex motions and is more stable for wide motions because images are segmented according to local motions. In this paper, new image coding method using the segmentation of motion vectors is proposed. First, motion vector field is smoothed by filtering and segmented by smoothed motion vectors. The region growing method is used for decomposition of regions, and merging of regions is decided by motion vector and prediction errors of the region. Edge of regions is excluded because of the correlation of image, and neighbor motion vectors are used evaluation of current block and construction of region. The results of computer simulation show the proposed method is superior than the existing methods in aspect of coding efficiency.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.14 no.6
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• pp.2554-2575
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• 2020

Data hiding technology hides secret information into the carrier, so that when the carrier is transmitted over network, it will not attract any malicious attention. Using data compression, it is possible to reduce the data size into a small compressed code, which can effectively reduce the time when transmitting compressed code on the network. In this paper, the main objective is to effectively combine these two technologies. We designed a data hiding scheme based on two techniques which are turtle-shell information hiding scheme and absolute moment block truncation coding. The experimental results showed that the proposed scheme provided higher embedding capacity and better image quality than other hiding schemes which were based on absolute moment block truncation coding.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.1
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• pp.425-428
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• 2005

This paper is made up Advanced Image Coding(AIC) that combines algorithms from next generation image coding standard, H.264/MPEG-4 Part 10 advanced video coding(AVC) and still image compression standard, JPEG(Joint Photographic Experts Group). AIC combines intra frame block prediction from H.264 with a JPEG style discrete cosine transform and quantization, followed by Context-based Adaptive Binary Arithmetic Coding(CABAC) as used in H.264. In this paper, we analyzes the efficiency of the AIC algorithm and JPEG and JPEG-2000, and it presents of result.

• Proceedings of the KIEE Conference
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• 2004.11c
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• pp.190-192
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• 2004

In this paper, we propose a low bit-rate embedded video compression scheme with 3-D block partition coding in the wavelet domain. The proposed video compression scheme includes multi-level 3-dimensional dyadic wavelet decomposition, raster scanning within each subband, formation of block, 3-D partitioning of block, and adaptive arithmetic entropy coding. Although the proposed video compression scheme is quit simple, it produces bit-stream with good features, including SNR scalability from the embedded nature. Experimental results demonstrate that the proposed video compression scheme is quit competitive to other good wavelet-based video coders in the literature.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.12
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• pp.4588-4603
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• 2014

In this paper, we present a high-quality image authentication scheme based on absolute moment block truncation coding. In the proposed scheme, we use the parity of the bitmap (BM) to generate the authentication code for each compressed image block. Data hiding is used to authenticate whether the content has been altered or not. For image authentication, we embed the authentication code to quantization levels of each image block compressed by absolute moment block truncation coding (AMBTC) which will be altered when the host image is manipulated. The embedding position is generated by a pseudo-random number generator for security concerned. Besides, to improve the detection ability we use a hierarchical structure to ensure the accuracy of tamper localization. A watermarked image can be precisely inspected whether it has been tampered intentionally or incautiously by checking the extracted watermark. Experimental results demonstrated that the proposed scheme achieved high-quality embedded images and good detection accuracy, with stable performance and high expansibility. Performance comparisons with other block-based data hiding schemes are provided to demonstrate the superiority of the proposed scheme.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.12
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• pp.2538-2541
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• 2009

H.264/AVC High 4:4:4 Intra/Predictive profiles supports RGB 4:4:4 sequences for high fidelity video. RGB color planes rather than YCbCr color planes are preferred by high-fidelity video applications such as digital cinema, medical imaging, and UHDTV. Several RGB coding tools have therefore been developed to improve the coding efficiency of RGB video. In this paper, we propose a new method to extract more accurate correlation parameters for inter-plane prediction. We use a searching method to determine the matched macroblock (MB) that has a similar inter-color relation to the current MB. Using this block, we can infer more accurate correlation parameters to predict chroma MB from luma MB. Our proposed inter-plane prediction mode shows an average bits saving of 15.6% and a PSNR increase of 0.99 dB compared with H.264 high4:4:4 intra-profile RGB coding. Furthermore, extensive performance evaluation revealed that our proposed algorithm has better coding efficiency than existing algorithms..

• Journal of Broadcast Engineering
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• v.15 no.3
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• pp.434-453
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• 2010

In this paper, we propose 3DTE(3-Dimensional Transform Environment) that is based on 3DT(Dimensional Transform) that performs 2-dimensional integer DCT(Discrete Cosine Transform) based on $4{\times}4$ block and 1-dimensional integer DCT based on $4{\times}1$ block after collecting same frequency coefficients in neighboring $4{\times}4$ block and supports it's additional coding tools for high performance. The transform of 3DT can keep prediction error by using $4{\times}4$ block and reduce spatial redundancy additionally. The proposed 3DTE can provide coding tools to improve the coding efficiency with using 3DT. The performance of 3DTE compared to JM11.0 is average 3.58% and 5.40% bit savings for all test sequences and HD sequences, respectively, with keeping subjective video quality in High profile.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.7C
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• pp.681-686
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• 2009

In H.264/Ave, an intra prediction added to the P-frame coding slightly improves both of image quality and bit rate, but greatly increases an amount of computation. In order to reduce the increase in computation, this paper proposes an image contents based intra prediction coding using characteristics that the best intra block mode depends on the image content of a macro block. The proposed algorithm estimates the image content with image complexity and the best inter block mode, and then selects or excludes a intra block mode on the basis of it. The simulation results show that the proposed algorithm reduces average O.OldB in image quality, and increases average 0.38% in the bit rate, but reduces average 37.02% in computation time compared with the conventional algorithm.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.2C
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• pp.172-180
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• 2003

This paper propose a new change detection algorithm based on macro block unit for selective video coding scheme. The conventional method badly decides a macro block of unchanged region into a changed macro block due to a noise of the difference images. To solve the problem of the conventional method, we propose a new test statistic which is robust to the noise of the difference image. As shown in experimental results(Fig. 1∼3), the proposed algorithm shows more accurate segmentation results than the conventional method. Also, because the proposed detection method reduces the average numbers of changed macro block per frame to 55∼60% than the conventional method, it can improve the performance of the selective video coding at lower bit rates.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.73-74
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• 2008

In this paper, we suggest a new video coding method using hierarchical block mode structure extension. It is based on the conventional H.264 block modes but adds hierarchically extended block modes to cover large resolution sequences. It is shown by experimental results that the proposed method can achieve a higher coding gain for HD sequences.