• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.9
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• pp.2091-2098
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• 2010

This paper proposes a hologram data compression scheme that uses the existing image/video compression techniques, in which the existing techniques are modified appropriately to fit to the characteristics of hologram. In this paper we use CGH as the hologram data. The proposed scheme uses the generation characteristics of a CGH to consist of a pre-processing, spatial segmentation of a CGH, frequency-transformation with 2D-DCT (2-dimensional discrete cosine transform), and motion estimation and residual image generation in the frequency-domain. It uses H.264/AVC, the lossless compressor BinHex, and a linear quantizer that we have made. From the experiments the proposed scheme showed the image quality of about 25.4 dB at the compression ratio of 10:1 and about 16.5dB at 90:1 compression ratio.

• Journal of the Korea Society of Computer and Information
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• v.16 no.2
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• pp.71-81
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• 2011

In order to easily create video tutorials, the algorithm is needed that video camera recording, white board images, video attachments, and document data are combined in real-time. In this study, we implemented the video lecture content creation system using wavelet-based lossless compression to composite multimedia objects in real-time and reproduce the images. Using commercially available PC can be useful when lecturers want to make video institutional contents, it can be operated easily and fastly. Therefore, it can be very efficient system for e-Learning and m-Learning. In addition, the proposed system including multimedia synthesis technology and real-time lossless compression technology can be applied to various fields, different kinds of multimedia creation, remote conferencing, and e-commerce so there are highly significant.

• Journal of Korea Society of Industrial Information Systems
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• v.20 no.5
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• pp.53-60
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• 2015

In this paper, the DCT based lossless image compression system which selects a limited number of DCT coefficients is proposed for the Lenna, Camerman, and Baboon image. The number of DCT coefficients to obtain a suitable image quality for the reconstructed image is computed by simulation. The image size of $256{\times}256$ are used in the experiment. The PSNR values for the reconstructed image by selecting limited number of DCT coefficients are found. It is shown that the minimun number of the coefficients for Lenna, Cameramen Baby and Babbo image to obtain PSNR=30 are N=16, 32, 37, 55, respectively. The result can provide the guideline of the importance of the DCT coefficient toward the compression for the tested image of the Lena, Cameraman, and Baboon.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.31B no.9
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• pp.124-132
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• 1994

An image data compression method for a digital VCR must satisfy special requirements such as high speed playback. various edting capabilities and error concealment to provide immunity to tape dropouts. Taking these requirements requirements into consideration, this paper proposes a new interframe subband coding algorithm for a digital VCR. In the proposed method, continuous input images are fist partitioned into four frequency bands. The lowest frequency subband is coded with 3-D block adaptive quantization that removes the level redundancy within each level. The other higher frequency subbands are coded by an intraframe coding method using the property of the human visual system. To keep reasonable image quality in high speed palyback, a segment forming method in the frequency domaing is also proposed Computer simulation results demonstrate that the proposed algorithm has the potential of achieving virtually lossless compression in normal play and produces an image with less mosaic errors in high speed play.

• Journal of Biomedical Engineering Research
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• v.12 no.3
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• pp.215-222
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• 1991

In this paper, we present a result of our study on how to construct a pilot MPACS (medical hic lure archiving and communication System) based on X -Window system. The proposed MPACS Is composed of image acquisition units, image archiving and processing units, display units, and all units are Interfaced with a LAN The image management is done according to the TIFF (Tagged Image File Format) , and the dis- play system is built upon generally accepted software packages, namely the X -Window system. Also, lossless and lossy digital image compression methods were implemented and tested with X -ray and CT images.

• Journal of Broadcast Engineering
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• v.19 no.2
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• pp.174-183
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• 2014

This paper is to propose a scalable video coding scheme for adaptive digital hologram video service for various reconstruction environments. It uses both the light source information and digital hologram at both the sending side and the receiving side. It is a resolution-scalable coding method that scales the resolution, that is, the size of the reconstructed image. The method compresses the residual data for both the digital hologram and the light source information. For the digital hologram, a lossy compression method is used, while for the light source information, a lossless compression method is used. The experimental results showed that the proposed method is superior to the existing method in the image quality at the same compression ratio. Especially it showed better performance than the existing method as the compression ratio becomes higher.

• Proceedings of the KSRS Conference
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• 2005.10a
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• pp.264-267
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• 2005

COMS (Communication, Ocean, and Meteorological Satellite) will be launch at end of year 2008. For speedy and security communication of COMS, KARl (Korea Aerospace Research Institute) decided encryption and compression design. Encryption design is based on DES (Data Encryption Standard), so that encryption key generation and management are important issues in COMS operation. And Compression is based on loss and lossless JPEG (Joint Photographic Export Group) standard. JPEG is one of generally using compression algorithm in image.

• Proceedings of the KOSOMBE Conference
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• v.1991 no.11
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• pp.54-56
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• 1991

Many techniques have been used for medial image compression. Its first requirement is "Errorless" or, "Completely Reversible". Under this condition, we have increased the performance of compression using Space Filling Curve. This method converts source image in direction of Hilbert's curve path in order to ate average length longer thar in traditoinal horizental normal path. After that, we have applied RLC and reduced statistical redundancy by Huffman Coding. By this method, we have obtained more efficient results of RLC.

• Proceedings of the IEEK Conference
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• 2001.09a
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• pp.129-132
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• 2001

영역 기반의 영상 압축 방법으로 quadtree 분할 압축 방법이 있다[1][2]. 이 방법은 낮은 bpp환경의 손실 압축에서 우수한 압축성능을 나타내지만 무손실이나 혹은 손실이 거의 없는 그레이 영상 압축에는 적당하지 않다. 본 논문에서는 quadtree 분할 압축을 예측자 및 F함수와 함께 사용하여 무손실이면서 우수한 압축성능을 가지는 무손실 압축 방법을 제안한다.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 1998.06b
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• pp.165-170
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• 1998

This paper presents a new prediction method RBP region-based prediction model where the context used for prediction contains regions instead of individual pixels. There is a meaningful property that RBP can partition a cartoon image into two distinctive types of regions, one containing full-color backgrounds and the other containing boundaries, edges and home-chromatic areas. With the development of computer techniques, synthetic images created with CG (computer graphics) becomes attactive. Like the demand on data compression, it is imperative to efficiently compress synthetic images such as cartoon animation generated with CG for storage of finite capacity and transmission of narrow bandwidth. This paper a lossy compression method to full-color regions and a lossless compression method to homo-chromatic and boundaries regions. Two criteria for partitioning are described, constant criterion and variable criterion. The latter criterion, in form of a linear function, gives the different threshold for classification in terms of contents of the image of interest. We carry out experiments by applying our method to a sequence of cartoon animation. We carry out experiments by applying our method to a sequence of cartoon animation. Compared with the available image compression standard MPEG-1, our method gives the superior results in both compression ratio and complexity.