• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.10a
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• pp.103-106
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• 2012

A memory access method that data are read with different sequences with writing order is a simple but important procedure in many image compression standards, such as JPEG, MPEG1/2/4, H.264, and HEVC. For real time processing, double buffering is widely used using two block sized buffers, that accesses buffers concurrently with alternative way to read and write. In some cases like a transpose memory in 2D DCT with a simple and regular access order, a single buffering which requires only single block sized buffer can be used. This paper shows that even in complex access orders there is a regularity among updating orders within a finite turns, and suggested an effective implementation method using a single block sized buffer to process concurrent read/write operation with different access orders.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.9B
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• pp.1713-1720
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• 1999

This paper presents a new key frame extraction technique, for scene change detection, using the proposed AHIM (Accumulative Histogram Intersection Measure) from the DC image constructed by DCT DC coefficients in the compressed video sequence that is video compression standard such as MPEG. For fast content-based browsing and video retrieval in a video database, we also provide a novel coarse-to-fine video indexing scheme. In the extracted key frame, we perform the region segmentation as a preprocessing. First, the segmented image is projected with the horizontal direction, then we transform the result into a histogram, which is saved as a database index. In the second step, we calculate the moments and change them into a distance value. From the simulation results, the proposed method clearly shows the validity and superiority in respect of computation time and memory space, and that in conjunction with other techniques for indexing, such as color, can provide a powerful framework for image indexing and retrieval.

• The Transactions of the Korea Information Processing Society
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• v.5 no.11
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• pp.2776-2785
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• 1998

An image retrieval system based on image content is a key issue for building and managing large multimedia database, such as art galleries and museums, trademarks and copyrights, and picture archiving and communication system. Therefore, the interest on the subject of content-based image retrieval has been greatly increased for the last few years. This paper proposes a feature-based image retrieval technique which uses a compound feature vector representing both of color and shape of an image. Color information for the feature vector is obtained using the algebraic moment of each pixel of an image based on the property of regional color distribution. Shape information for the feature vector is obtained using the Improved Moment Invariant(IMI) which reduces the quantity of computation and increases retrieval efficiency. In the preprocessing phase for extracting shape feature, we transform a color image into a gray image. Since we make use of the modified DCT algorithm, it is implemented easily and can extract contour in real time. As an experiment, we have compared our method with previous methods using a database consisting of 150 automobile images, and the results of the experiment have shown that our method has the better performance on retrieval effectiveness.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.8
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• pp.104-113
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• 2014

The existing rough mode decision (RMD) algorithm, used in HEVC standard loses the coding efficiency and wastes encoding time when encoding using transform skip mode (TSM) because the RMD algorithm in HEVC uses a selection method that is designed for DCT, not for TSM. This paper proposes a new RMD algorithm for TSM in HEVC. Our proposed RMD algorithm enhances the coding efficiency by employing a new cost function to increase the probability of selecting the best intra prediction mode for TSM. In addition, it reduces the encoding time by skipping the encoding process of least feasible TSM based on a newly proposed threshold value. The experiment results show that the proposed method achieves coding gains of -0.3% for screen contents with a 10% reduction in encoding time compared to those of the HEVC standard.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.12
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• pp.5855-5877
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• 2017

In view of personal health and disease management based on cost effective healthcare services, there is a growing need for real-time monitoring services. The electrocardiogram (ECG) signal is one of the most important of health information and real-time monitoring of the ECG can provide an efficient way to cope with emergency situations, as well as assist in everyday health care. In this system, it is essential to continuously collect and transmit large amount of ECG data within a given time and provide maximum user convenience at the same time. When considering limited wireless capacity and unstable channel conditions, appropriate signal processing and transmission techniques such as compression are required. However, ISO/IEEE 11073 standards for interoperability between personal health devices cannot properly support compressed data transmission. Therefore, in the present study, the problems for handling compressed data are specified and new extended agent and manager are proposed to address the problems while maintaining compatibility with existing devices. Extended devices have two PM-stores enabling compression and a novel transmission scheme. A variety of compression techniques can be applied; in this paper, discrete cosine transformation (DCT) is used. And the priority of information after DCT compression enables new transmission techniques for performance improvement. The performance of the compressed signal and the original uncompressed signal transmitted over the noisy channel are compared in terms of percent root mean square difference (PRD) using our simulation results. Our transmission scheme shows a better performance and complies with 11073 standards.

• Journal of KIISE:Computer Systems and Theory
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• v.32 no.5
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• pp.232-242
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• 2005

This paper concerns automatic hardware synthesis from data flow graph (DFG) specification for fast HW/SW cosynthesis. A node in BFG represents a coarse grain block such as FIR and DCT and a port in a block may consume multiple data samples per invocation, which distinguishes our approach from behavioral synthesis and complicates the problem. In the presented design methodology, a dataflow graph with specified algorithm can be mapped to various hardware structures according to the resource allocation and schedule information. This simplifies the management of the area/performance tradeoff in hardware design and widens the design space of hardware implementation of a dataflow graph compared with the previous approaches. Through experiments with some examples, the usefulness of the proposed technique is demonstrated.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.36S no.10
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• pp.83-93
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• 1999

In MPEG-2 video standard, there are many parameters to support profiles and levels. It is necessary to verify that a decoder is compliant with the MPEG-2 standard. This paper proposes a design principle of the test bitstreams which confirms that an MPEG video decoder is correct by observing the final image of the decoder under test. The presented test bitstream is composed of two parts. The first part generates a test pattern by varying a selected test parameter. And the following predictive coded picture generates a complementary pattern to the previous image by motion compensation and DCT coefficients. Then it will result in a uniform pattern. We present several bitstreams following the proposed principle. Also we analyze and compare the characteristics of the test bitstreams presented in the MPEG conformance test and the proposed test bistreams.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.23 no.5
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• pp.1299-1309
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• 1998

In this paper, we propose a new approach for reducing the blocking artifact that is one of drawbacks of the block-based Discrete Cosine Transform (DCT) without introducing additional information or significant blurring. We modify the inter-block discontinuity minimization technique to preserve edges within a block as well as to reduce visible block boundaries. The homogeneity of each block is decided by the threshold value reated to Q-factor, which is included in a JPEG as well as MPEG streams. The quantization error is estimated by minimizing the discontinuity, which is weighted in proportion to block discontinuity and added to each pixel in the block to compensate block artifacts. The proposed algorithm reconstructs images which have less noticeable block boundaries from a subjective viewpoit without anyconstraints.

• The Journal of the Korea Contents Association
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• v.12 no.5
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• pp.1-9
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• 2012

The popularity of digital music and smart phones led to develope noise-robust real-time audio fingerprinting system in various ways. In particular, The Multiple Hashing(MLH) of fingerprint algorithms is robust to noise and has an elaborate structure. In this paper, we propose a filter engine based on MLH to achieve better performance. In this approach, we compose a energy-intensive filter to improve the accuracy of Q/R from music database and a statistic filter to remove continuity and redundancy. The energy-intensive filter uses the Discrite Cosine Transform(DCT)'s feature gathering energy to low-order bits and the statistic filters use the correlation between searched fingerprint's information. Experimental results show that the superiority of proposed algorithm consists of the energy and statistical filtering in noise environment. It is found that the proposed filter engine achieves more robust to noise than Philips Robust Hash(PRH), and a more compact way than MLH.

• Journal of the Institute of Electronics and Information Engineers
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• v.49 no.10
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• pp.91-101
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• 2012

DNA watermarking have been interested for both the security of private genetic information or huge DNA storage information and the copyright protection of GMO. Multimedia watermarking has been mainly designed on the basis of frequency domain, such as DCT, DWT, FMT, and so on, for the robustness and invisibility. But a frequency domain watermarking for coding DNA sequence has a considerable constraint for embedding the watermark because transform and inverse transform must be performed without completely changing the amino acid sequence. This paper presents a coding sequence watermarking on lifting based DWT domain and brings up the availability of frequency domain watermarking for DNA sequence. From experimental results, we verified that the proposed scheme has the robustness to until a combination of 10% point mutations, 5% insertion and deletion mutations and also the amino preservation and the security.