• Proceedings of the KIEE Conference
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• 1999.11c
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• pp.781-783
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• 1999

A storage or transmission of image is difficult without image compression processing because the numbers of generated or reborned image data are very much. In case of the random signal, image compression efficiency is low doing without loss of image information, but compressibility by using JPEG is better. We used Huffman code of JPEG, it assigne the low bit value for data of a lot of generated frequency, assigne the high bit value for data of a small quantity. This paper improved image compression efficiency with transformming Q-factor and certified the results with compressed image. A proposed method is very efficience for continuos a color tone image.

• Proceedings of the Korean Information Science Society Conference
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• 2012.06b
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• pp.77-79
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• 2012

본 논문에서는 임베디드 시스템으로의 적용을 위한 균형이진트리 방식의 허프만 코딩 복호화 방법에 대하여 논한다. 그리고 구현된 전체 시스템의 간단한 코드 최적화(code optimization)를 추가하여 시스템 전체의 처리 속도를 감소시키고자 하였다. 본문에서는 구현된 복호화 성능 향상의 정확한 측정을 위하여 하드웨어 시뮬레이터를 사용했다. 이를 통해서 실질적인 환경에서 어느 정도의 duration으로 동작될 수 있는지, 그리고 해당 환경에서 얼마나 성능을 향상시킬 수 있을지를 비교적 정확하게 판단할 수 있도록 했다. 본문의 마지막에 명시된 대로, 최적화의 결과로, 허프만 코드를 표에서 찾는 기존의 방법에 비하여, 복호화 부분과 복호화 부분을 제외한 시스템 코드 최적화 각각 36%, 2%의 duration 횟수의 감소를 확인할 수 있었다.

• Convergence Security Journal
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• v.7 no.2
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• pp.129-134
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• 2007

This paper proposes multiple burst error detection and correction scheme for transmission of Huffman coded string. We use bidirectionally decodable codes and introduce insertion of forbidden symbol to find errors. Additional bits are added to original bit streams to correct errors. The total file size id increased but it can detect errors and recover errors real time.

• The Journal of the Korea institute of electronic communication sciences
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• v.7 no.5
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• pp.1017-1026
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• 2012

Due to acceleration of the IT industry and the environment for a variety of media in modern society, such as real-time video images 3D-TV is a very important issue. These high-quality live video is being applied to various fields such as CCTV footage has become an important performance parameters. However, these high quality images, even vulnerable because of shortcomings secure channel or by using various security algorithms attempt to get rid of these disadvantages are underway very active. These shortcomings, this study added extra security technologies to reduce the processing speed image processing itself, but by adding security features to transmit real-time processing and security measures for improving the present.

• Proceedings of the Korea Information Processing Society Conference
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• 2005.05a
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• pp.1445-1448
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• 2005

국내 디지털 방송 방식이 결정되고 본격적인 디지털 방송 서비스가 시행되면서, 전자프로그램가이드 (EPG: electronic program guide), 주식 및 일기예보등의 문자 방송이 활성화 되고 있다. 특히, 지상파 디지털 방송, 위성 방송, 및 최근 대두되고 있는 DMB (Digital Media Broadcasting) 지상파/위성 방송 등에서 기존의 단순 방송 서비스외에 양방향을 위한 새로운 서비스 개발을 확대하면서 문자방송의 역할은 점점 넓어지고 있다. 본 논문은 한글 데이터의 압축 방법에 관한 것으로, 디지털 방송의 문자 방송 서비스에서 사용되는 문자들을 효율적으로 압축하는 방법을 제안한다. 특히, 현재 서비스 되고 있는 방송의 문자 정보를 분석하고 한글의 특성과 글자간의 상관관계를 고려한 2 차 한글 허프만 부호 설계 기법을 제안한다. 본 논문에서 제안한 방법은 디지털 방송에서 점점 늘어나는 문자 방송의 문자를 효율적으로 압축함으로써 제한된 대역폭을 최대한 활용할 수 있는 방법을 제공한다.

• Journal of Biomedical Engineering Research
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• v.15 no.2
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• pp.175-182
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• 1994

The international standard for digital compression and coding of continuous-tone still image known as JPEG (Joint Photographic Experts Group) standard is investigated for medical image archiving and communication. The JPEG standard has widely been accepted in the areas of electronic image communication, computer graphics, and multimedia applications, however, due to the lossy character of the JPEG compression its application to the field of medical imaging has been limited. In this paper, the JPEG standard is investigated for medical image compression with a series of head sections of magnetic resonance (MR) images (256 and 4096 graylevels, $256 {\times}256$size). Two types of Huffman codes are employed, i. e., one is optimized to the image statistics to be encoded and the other is a predetermined code, and their coding efficiencies are examined. From experiments, compression ratios of higher than 15 were obtained for the MR images without noticeable distortion. Error signal in the reconstructed images by the JPEG standard appears close to random noise. Compared to existing full-frame bit-allocation technique used for radiological image compression, the JPEG standard achieves higher compression with less Gibb's artifact. Feature of the progressive image build-up of the JPEG progressive coding may be useful in remote diognosis when data is transmitted through slow public communication channel.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.2C
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• pp.182-192
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• 2010

This paper proposes the hardware IP design of JBIG2 encoder. In order to facilitate the next generation FAX after the standardization of JBIG2, major modules of JBIG2 encoder are designed and implemented, such as symbol extraction module, Huffman coder, MMR coder, and MQ coder. ImpulseC Codeveloper and Xilinx ISE/EDK program are used for the synthesis of VHDL code. To minimize the memory usage, 128 lines of input image are processed succesively instead of total image. The synthesized IPs are downloaded to Virtex-4 FX60 FPGA on ML410 development board. The four synthesized IPs utilize 36.7% of total slice of FPGA. Using Active-HDL tool, the generated IPs were verified showing normal operation. Compared with the software operation using microblaze cpu on ML410 board, the synthesized IPs are better in operation time. The improvement ratio of operation time between the synthesized IP and software is 17 times in case of symbol extraction IP, and 10 times in Huffman coder IP. MMR coder IP shows 6 times faster and MQ coder IP shows 2.2 times faster than software only operation. The synthesized H/W IP and S/W module cooperated to succeed in compressing the CCITT standard document.