• The Transactions of the Korea Information Processing Society
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• v.7 no.12
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• pp.3885-3895
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• 2000

The emergence of digital imaging and digital networks has made duplication of original artwork easier. In order to protect these creations, new methods for signing and copyrighting visual data are needed. In the last few years, a large number of schemes have heen proposed for hiding copyright marks and other information in digital image, video, audio and other multimedia objects. In this paper, we propose a technique for embedding the watermark of visually recognizable patterns into the frequency domain of images. The embedded watermark can be retrieved from the decoded sequence witbout knowledge of the original. Because the source image is not required to extract the watermark, one cannot make the fake original that is invertible to watermarking scheme from the waternlarked image. In order to recover the embedded signature data without knowledge of the original, a prediction of the original value of the pixel containing the information is needed. The prediction is based on a averaging of amplitude values in a neighborhood around the pixel itself. Additionally the projxJsed technique could survive several kinds of image processings including JPEG lossy compression.

• Proceedings of the Korea Contents Association Conference
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• 2003.11a
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• pp.161-166
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• 2003

In this paper, we propose a novel method of design and implementation for the multimedia monitoring system using Web Camera. Recently WebCam is variously applied to many different areas and implemented as an improved performance using convenient functions of Web in this Internet era. Multimedia moving pictures has been popularly used in a variety of ways in different areas of monitoring systems in order to enhance the performance and the service with their data compression capability and the speed of the communication network these days. The design method of WebCam system presented in this paper might offer not only a convenient function of the monitoring system but great application capabilities. It can be used for a real time application of the multimedia picture and audio transmission so that the monitoring system can manage the security information in the sense for the reality. Tn addition, the monitoring system may be used as an inreal-time application using data storage and retrieval features of the Web. We offer both functions of monitoring in this structured form of implemented system.

• The Transactions of the Korea Information Processing Society
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• v.6 no.4
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• pp.1112-1119
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• 1999

Digital watermarking is to embed imperceptible mark into image, video, audio and text data to prevent the illegal copy of multimedia data, arbitrary modification, and also illegal sales of the copes without agreement of copyright ownership. The DCT(discrete Cosine Transforms) transforms of original image is conducted in this research and these DCT coefficients are expanded by Fourier series expansion algorithm. In order to embed the imperceptible and robust watermark, the Fourier coefficients(lower frequency coefficients) can be calculated using sine and cosine function which have a complete orthogonal basis function, and the watermark is embedded into these coefficients, In the experiment, we can show robustness with respect to image distortion such as JPEG compression, bluring and adding uniform noise. The correlation coefficient are in the range from 0.5467 to 0.9507.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.4 no.2
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• pp.149-154
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• 2004

In this research, we selected the speech recognition to implement the electric wheelchair system as a method to control it by only using the speech and used DTW (Dynamic Time Warping), which is speaker-dependent and has a relatively high recognition rate among the speech recognitions. However, it has to have small memory and fast process speed performance under consideration of real-time. Thus, we introduced VQ (Vector Quantization) which is widely used as a compression algorithm of speaker-independent recognition, to secure fast recognition and small memory. However, we found that the recognition rate decreased after using VQ. To improve the recognition rate, we applied ART2 (Adaptive Reason Theory 2) algorithm as a post-process algorithm to obtain about 5% recognition rate improvement. To utilize ART2, we have to apply an error range. In case that the subtraction of the first distance from the second distance for each distance obtained to apply DTW is 20 or more, the error range is applied. Likewise, ART2 was applied and we could obtain fast process and high recognition rate. Moreover, since this system is a moving object, the system should be implemented as an embedded one. Thus, we selected TMS320C32 chip, which can process significantly many calculations relatively fast, to implement the embedded system. Considering that the memory is speech, we used 128kbyte-RAM and 64kbyte ROM to save large amount of data. In case of speech input, we used 16-bit stereo audio codec, securing relatively accurate data through high resolution capacity.

• Journal of Digital Convergence
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• v.18 no.2
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• pp.377-383
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• 2020

Digital signage is constantly being researched as new digital video platform to replace existing signage market. Traditionally, It conveys various information combining still images with text. Nowadays, it is rapidly exchanging to multi digital platform by high specificaton system, improvement of internet speed and advancement of video and audio compression technology with HTML5 technology. Not only a single wide-screen display but also the combination and adjustment of screens with setop box, OLED, media facades, and lase beam projectors are transformed into various forms to enable creative and diverse attempts for graphic designers. This study focuses on the application of motion graphics in rapidly evolving future platform - digital signage, and looking forward to help digital video content creator, researchers, and motion graphic designers.

• Journal of Digital Contents Society
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• v.10 no.1
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• pp.87-96
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• 2009

Digital Broadcast Service is being very popular and the delivery mechanism for digital broadcast content through IP network has progressed constantly, due to the advance of video and audio compression and network technologies. From these trends, in Korea, the commercial IPTV service starts in this year after the law related to IPTV is enacted last year. Since IPTV service, which integrates broadcast and communication services, can give an infrastructure for fusion of communication and interactive multimedia data service, IPTV service is attractive. Recently, by the advent of various wireless connection technologies and the mobile devices of high capability, Mobile IPTV, which has an advantage of not only IPTV but also mobile TV, has gained much interest. In this paper, we review a necessary ingredient for Mobile IPTV in the next generation wired/wireless convergence network environment which consists of heterogeneous wireless access networks. In addition, we propose the scheme for user mobility and service session mobility management using RTSP protocol and introduce the service gateway concept to guarantee the extension of IPTV service platform.

• Journal of the Korea Society of Computer and Information
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• v.15 no.7
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• pp.27-32
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• 2010

We can cut and paste portions of MPEG coded bitstream efficiently to rearrange the audio and video sequences using our proposed method. The proposed method decodes the MPEG stream within just only one GOP(Group of Picture), edits the decoded video frames, and encodes it back to a MPEG stream. In this method, precise editing is possible. A pre-processing step is specially designed to provide easy cut and paste processing. In the pre-processing step for editing MPEG streams, the detail information is extracted. In addition, video quality is not degraded after the proposed editing process is applied. Consequently, the experimental results show significant improvements compared with traditional algorithms for video editing method in terms of the efficiency and exactness.

• Journal of the Institute of Convergence Signal Processing
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• v.10 no.4
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• pp.214-219
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• 2009

This paper proposes a watermarking algorithm considering the frequency characteristics of Haegeum sounds for copyright protection of digital Haegeum sound contents. The harmonics of Haegeum sounds commonly have large magnitude values in 1500Hz~2000Hz and 2800Hz~3500Hz so that those bands are selected to embed a watermark. The proposed method computes the FFT (fast Fourier transform) of the original sound signal and embeds the watermark bits generated by PN (pseudo noise) sequence into the harmonics in the selected bands. Furthermore, the proposed method is robust to lowpass filter, bandpass filter, cropping, noise addition, MP3 compression attacks and the maximum BER (bit error rate) is 1.41% after lowpass filter attack. To measure the quality of the watermarked sound, subjective listening test, MUSHRA (multiple stimuli with hidden reference and anchor), was conducted. The mean value of MUSHRA listening test is bigger than 98 and 96.67 for every Haegeum sounds and Korean classical music with Haeguem, respectively.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.30 no.3
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• pp.5-30
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• 2019

The purpose of this study is to suggest an improvement of digitization criteria for records that can faithfully reproduce the contents and properties of original records by complementing the problems and deficiencies of "NAK 26:2018(v2.0) Digitization Criteria for records". Thus, this study proposes a technical standard improvement that should be applied to the digitization process for records not produced in the form of digital files by comparing and analyzing the criteria for digitization of records in Korea with overseas digitization criteria, guidelines, recommendations, and so on. In addition, verifying the validity on this study by interviewing experts from the record-related institutions. As a result, suggested a final improvement of criteria for digitization of records such as applying non compression-Lossless codecs, proposing appropriate resolution values for each type of records, audio channels, frame rates, scan methods, and criteria for microform types.

• The Journal of the Acoustical Society of Korea
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• v.42 no.5
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• pp.395-401
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• 2023

Sound Event Detection (SED) aims to identify not only sound category but also time interval for target sounds in an audio waveform. It is a critical technique in field of acoustic surveillance system and monitoring system. Recently, various models have introduced through Detection and Classification of Acoustic Scenes and Events (DCASE) Task 4. This paper explored how to design optimal parameters of DenseNet based model, which has led to outstanding performance in other recognition system. In experiment, DenseRNN as an SED model consists of DensNet-BC and bi-directional Gated Recurrent Units (GRU). This model is trained with Mean teacher model. With an event-based f-score, evaluation is performed depending on parameters, related to model architecture as well as model training, under the assessment protocol of DCASE task4. Experimental result shows that the performance goes up and has been saturated to near the best. Also, DenseRNN would be trained more effectively without dropout technique.