• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 1998.06b
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• pp.10-15
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• 1998

In Japan, digital HDTV services via broadcasting satellite are planned to start in 2000. NHK has developed an HDTV codec conforming to the MPEG-2 $MPHL$ and estimated the coded picture quality with diverse image sequences. This paper shows the codec specifications and presents the result of the picture quality assessment.

• Proceedings of the IEEK Conference
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• 2001.06b
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• pp.333-336
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• 2001

This paper describes the design and implementation results of 40, 32, 24 and 16kbps ADPCM encoder and decoder circuit, based on the protocol CCITT G.726. We verified the ADPCM algorithm using C language and designed the RTL circuit with Verilog HDL. The circuit has been simulated by Verilog-XL, synthesized by Design Compiler and verified using Xilinx FPGA. Since the synthesized circuit includes a small number of gates, it is expected to be used as a core module in the digital voice and image processing SOC.

• Proceedings of the IEEK Conference
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• 2002.07a
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• pp.466-469
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• 2002

Using intelligent information contained within the speech to identify the specific hidden data in the watermarked multimedia data is considered to be an efficient method to achieve the speech digital watermarking. This paper presents the performance comparison between various types of speech codec in order to determine an appropriate one to be used in digital watermarking applications. In the experiments, the speech signal encoded by four different types of speech codec, namely CELP, GSM, SBC and G.723.1codecs is embedded into a grayscale image, and theirs performance in term of speech recognition are compared. The method for embedding the speech signal into the host data is borrowed from a watermarking method based on the zerotrees of wavelet packet coefficients. To evaluate efficiency of the speech codec used in watermarking applications, the speech signal after being extracted from the attacked watermarked image will be played back to the listeners, and then be justified whether its content is intelligible or not.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.33A no.5
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• pp.155-164
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• 1996

The architecture of a programmable video codec IC is described that employs multiple vector processors in a single chip. The vector processors operate in parallel and communicate with one another through on-chip shared memories. A single scalar control processor schedules each vector processor independently to achieve real-tiem video coding with special vector instructions. With programmable interconnection buses, the proposed architecture performs multi-processing of tasks and data in video coding. Therefore, it can provide good parallelism as well as good programmability. especially, it can operate multithread video coding, which processes several independent image sequences simultaneously. We explain its scheduling, multithred video coding, and vector processor architectures. We implemented a prototype video codec with a 0.8um CMOS cell-based technology for the multi-standard videophone. This codec can execute video encoding and decoding simultaneously for the QCIF image at a frame rate of 30Hz.

• Journal of the Korea Society of Computer and Information
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• v.14 no.8
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• pp.51-58
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• 2009

In this paper. we propose search algorithm using Low Peak Feature of audio and image color value by which similar movies can be identified. Combing through entire video files for the purpose of recognizing and retrieving matching movies requires much time and memory space. Moreover, these methods still share a critical problem of erroneously recognizing as being different matching videos that have been altered only in resolution or converted merely with a different codec. Thus we present here a similar-video-retrieval method that relies on analysis of audio patterns, whose peak features are not greatly affected by changes in the resolution or codec used and image color values. which are used for similarity comparison. The method showed a 97.7% search success rate, given a set of 2,000 video files whose audio-bit-rate had been altered or were purposefully written in a different codec.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2020.11a
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• pp.377-379
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• 2020

The hologram data is having a dependence on the pixel pitch of the SLM (spatial light modulator) and the wavelength of light, and the quality of the digital hologram is proportional to the unit pixel pitch and the total resolution. In addition, since each pixel has a complex value, the amount of data in the digital hologram also increases exponentially, and the size is bound to be very large. Therefore, in order to efficiently handle digital hologram files, it is essential to reduce the file size through a codec and store it. Recently, research on enhancing image quality damaged by the codec is actively underway. In this paper, the hologram image of JPEG Pleno, which is the standard hologram data, was used, and the image quality damage that occurs whenthe holographic image is encoded and decoded through the JPEG2000, AVC, and HEVC codec is enhanced with a deep learning network to find out whether the image quality can be improved. we also compare and quantitatively find out the degree of improvement in image quality.

• Journal of Korea Society of Industrial Information Systems
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• v.23 no.6
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• pp.59-66
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• 2018

In this paper, we experimented how long distance voice communication is possible After implemented PTT(Push to talk) Bi-directional radio using open source project Codec 2, which is a low speed voice codec for digital amateur radio and 900MHz FSK transceiver. In case of a general digital radio, the AMBE+2 codec, which is regarded as an industry standard in terms of performance, is expensive and has the monopoly of technology. Using the 400MHz band in terms of frequency, narrow bandwidth of DMR(12.5kHz) and DPMR(6.25kHz) is used, so the data rate is low. In the 900MHz bandwidth can be extended, which is advantageous in terms of data transmission. As a result of the voice quality and distance field test, we could find that the communication takes place within about 500m. In this paper, only voice communication is reviewed. if a review of data transmission such as a simple image is added, this solution can be used in various fields as a low cost IOT radio.

• Journal of Korea Multimedia Society
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• v.4 no.1
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• pp.75-81
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• 2001

A EBCOT(Embedded Block Coding with Optimized Truncation) is image compression codec using in JPEG2000, currently the new standard for still image coding. this paper proposes multi-channel video transfer system with EBCOT using a single codec to transfer video to difference band-width channel. This parer testify that compression rate of EBCOT higher than ordinary VLC using RLC and Huffman codec and apply EBCOT to JPEG structure. this structure increases parallelism and error resilience using black coding method. finally it looks into difficult to apply MPEG structure to multi channel video transfer system, and proposes solution using EBCOT.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2001.10a
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• pp.567-570
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• 2001

In this paper, we proposed flash memory design method for image and voice recoder based on the standard imageㆍvoice codec algorithm. For implementation of this method we designed image voice browser which is application system of flash memory and card using GDS30C6001 USB controller. To process image and voice data we designed root directory of image and voice files repectively. To extend application of image and voice data we added various information to the system.

• Proceedings of the IEEK Conference
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• 2003.07c
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• pp.2577-2580
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• 2003

In this paper we present a teleoperation system of an internet-based mobile robot based on H.263 image compression algorithm. We control remotely the networked mobile robot with vision over the internet under unknown environments in the real time. The main feature of this system is that local operators need to download and install a client program and so they can command the robot in a remote location. Image information of remote location is compressed by H.263 video codec algorithm and then transmitted to a local operator. We constructed and tested a networked autonomous mobile robot in the real field. The experimental results show the usefulness of the robot under test.