• Title/Summary/Keyword: vector data compression

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The Compression of Normal Vectors to Prevent Visulal Distortion in Shading 3D Mesh Models (3D 메쉬 모델의 쉐이딩 시 시각적 왜곡을 방지하는 법선 벡터 압축에 관한 연구)

  • Mun, Hyun-Sik;Jeong, Chae-Bong;Kim, Jay-Jung
    • Korean Journal of Computational Design and Engineering
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    • v.13 no.1
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    • pp.1-7
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    • 2008
  • Data compression becomes increasingly an important issue for reducing data storage spaces as well as transmis-sion time in network environments. In 3D geometric models, the normal vectors of faces or meshes take a major portion of the data so that the compression of the vectors, which involves the trade off between the distortion of the images and compression ratios, plays a key role in reducing the size of the models. So, raising the compression ratio when the normal vector is compressed and minimizing the visual distortion of shape model's shading after compression are important. According to the recent papers, normal vector compression is useful to heighten com-pression ratio and to improve memory efficiency. But, the study about distortion of shading when the normal vector is compressed is rare relatively. In this paper, new normal vector compression method which is clustering normal vectors and assigning Representative Normal Vector (RNV) to each cluster and using the angular deviation from actual normal vector is proposed. And, using this new method, Visually Undistinguishable Lossy Compression (VULC) algorithm which distortion of shape model's shading by angular deviation of normal vector cannot be identified visually has been developed. And, being applied to the complicated shape models, this algorithm gave a good effectiveness.

Vector Map Data compression based on Douglas Peucker Simplification Algorithm and Bin Classification (Douglas Peucker 근사화 알고리즘과 빈 분류 기반 벡터 맵 데이터 압축)

  • Park, Jin-Hyeok;Jang, Bong Joo;Kwon, Oh Jun;Jeong, Jae-Jin;Lee, Suk-Hwan;Kwon, Ki-Ryong
    • Journal of Korea Multimedia Society
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    • v.18 no.3
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    • pp.298-311
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    • 2015
  • Vector data represents a map by its coordinate and Raster data represents a map by its pixel. Since these data types have very large data size, data compression procedure is a compulsory process. This paper compare the results from three different methodologies; GIS (Geographic Information System) vector map data compression using DP(Douglas-Peucker) Simplification algorithm, vector data compression based on Bin classification and the combination between two previous methods. The results shows that the combination between the two methods have the best performance among the three tested methods. The proposed method can achieve 4-9% compression ratio while the other methods show a lower performance.

A GIS Vector Data Compression Method Considering Dynamic Updates

  • Chun Woo-Je;Joo Yong-Jin;Moon Kyung-Ky;Lee Yong-Ik;Park Soo-Hong
    • Spatial Information Research
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    • v.13 no.4 s.35
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    • pp.355-364
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    • 2005
  • Vector data sets (e.g. maps) are currently major sources of displaying, querying, and identifying locations of spatial features in a variety of applications. Especially in mobile environment, the needs for using spatial data is increasing, and the relative large size of vector maps need to be smaller. Recently, there have been several studies about vector map compression. There was clustering-based compression method with novel encoding/decoding scheme. However, precedent studies did not consider that spatial data have to be updated periodically. This paper explores the problem of existing clustering-based compression method. We propose an adaptive approximation method that is capable of handling data updates as well as reducing error levels. Experimental evaluation showed that when an updated event occurred the proposed adaptive approximation method showed enhanced positional accuracy compared with simple cluster based compression method.

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Design and Implementation of Spatial Data Compression Methods for Improvement of Mobile Transmission Efficiency (모바일 전송 효율 향상을 위한 공간 데이터 압축 기법의 설계 및 구현)

  • Choi Jin-Oh
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.10 no.7
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    • pp.1253-1258
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    • 2006
  • In the mobile vector map service environments, there are problems like as terminal resource shortage and transmission delay for the characteristics of large spatial data. For the normal mobile vector map services, some techniques are required to overcome the problems. Spatial data compression approach is one of the techniques to reduce the bandwidth and the waiting time at clients. However it also must be considered that the effect on total efficiency caused by the overhead of compression and restoration time. This thesis proposes two spatial data compression techniques. First approach is to get relative coordinates to first coordinate of each object. The other approach is to compute client coordinates before transmission. Through the implementation and experiments, proposed techniques are evaluated the compression effects and efficiency.

Design of Spatial Data Compression Methods for Mobile Vector Map Services (모바일 벡터 지도 서비스를 위한 공간 데이터 압축 기법의 설계)

  • 최진오
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2004.05b
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    • pp.358-362
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    • 2004
  • According to the rapid advance of computer and communication techniques, the request of mobile internet services is highly increasing. However, the main obstacles for mobile vector map service environments, are large data volume and narrow wireless bandwidth. Among the many possible solutions, spatial data compression technique may contribute to reduce the load of bandwidth and client response time. This thesis proposes two methods for spatial data compression. The one is relative coordinates transformation method, and the other is client coordinates transformation method. And, this thesis also proposes the system architecture for experiments. The two compression methods could be evaluated the compression effect and the response time.

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ECG Data Compression Technique Using Wavelet Transform and Vector Quantization on PMS-B Algorithm (웨이브렛 변환과 평균예측검색 알고리즘의 벡터양자화를 이용한 심전도 데이터 압축기법)

  • Eun, J.S.;Shin, J.
    • Proceedings of the KOSOMBE Conference
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    • v.1996 no.11
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    • pp.225-228
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    • 1996
  • ECG data are used for the diagnostic purposes with many clinical situations, especially heart disease. In this paper, an efficient ECG data compression technique by wavelet transform and high-speed vector quantization on PMS-B algorithm is proposed. In general, ECG data compression techniques are divided into two categories: direct and transform methods. The direct data compression techniques are AZTEC, TP, CORTES, FAN and SAPA algorithms, besides the transform methods include K-L, Fourier, Walsh, and wavelet transforms. In this paper, we applied wavelet analysis to the ECG data. In particular, vector quantization on PMS-B algorithm to the wavelet coefficients in the higher frequency regions, but scalar quantized in the lower frequency regions by PCM. Finally, the quantized indices were compressed by LZW lossless entropy encoder. As the result of simulation, it turns out to get sufficient compression ratio while keeping clinically acceptable PRD.

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Multispectral image data compression using classified vector quantization (영역분류 벡터 양자화를 이용한 다중분광 화상데이타 압축)

  • 김영춘;반성원;김중곤;서용수;이건일
    • Journal of the Korean Institute of Telematics and Electronics B
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    • v.33B no.8
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    • pp.42-49
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    • 1996
  • In this paper, we propose a satellite multispectral image data compression method using classified vector quantization. This method classifies each pixel vector considering band characteristics of multispectral images. For each class, we perform both intraband and interband vector quantization to romove spatial and spectral redundancy, respectively. And residual vector quantization for error images is performed to reduce error of interband vector quantization. Thus, this method improves compression efficiency because of removing both intraband(spatial) and interband (spectral) redundancy in multispectral images, effectively. Experiments on landsat TM multispectral image show that compression efficiency of proposed method is better than that of conventional method.

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Vector Map Simplification Using Poyline Curvature

  • Pham, Ngoc-Giao;Lee, Suk-Hwan;Kwon, Ki-Ryong
    • Journal of Multimedia Information System
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    • v.4 no.4
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    • pp.249-254
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    • 2017
  • Digital vector maps must be compressed effectively for transmission or storage in Web GIS (geographic information system) and mobile GIS applications. This paper presents a polyline compression method that consists of polyline feature-based hybrid simplification and second derivative-based data compression. Experimental results verify that our method has higher simplification and compression efficiency than conventional methods and produces good quality compressed maps.

Design of Spatial Data Compression Methods for Improvement of Mobile Transmission Efficiency (모바일 전송 효율 향상을 위한 공간 데이터 압축 기법의 설계)

  • 최진오;김진덕;문상호
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.8 no.4
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    • pp.950-954
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    • 2004
  • According to the rapid advance of computer and communication techniques, the request of mobile internet services is highly increasing. However, the main obstacles for mobile vector map service environments, are large data volume and narrow wireless bandwidth. Among the many possible solutions, spatial data compression technique may contribute to reduce the load of bandwidth and client response time. This thesis proposes two methods for spatial data compression. The one is relative coordinates transformation method, and the other is client coordinates transformation method. And, this thesis also proposes the system architecture for experiments. The two compression methods could be evaluated the compression effect and the response time.

Hybrid Polyline Simplification for GIS Vector Map Data Compression (GIS 벡터맵 데이터 압축을 위한 혼합형 폴리라인 단순화)

  • Im, Dae-Yeop;Jang, Bong-Joo;Lee, Suk-Hwan;Kwon, Seong-Geun;Kwon, Ki-Ryong
    • Journal of Korea Multimedia Society
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    • v.16 no.4
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    • pp.418-429
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    • 2013
  • This paper presents a GIS vector map data compression scheme based on hybrid polyline simplification method and SEC(spatial energy compaction). The proposed method extracts all layers which contain polylines in the GIS vector map and compress all polylines in extracted layers by the hybrid polyline simplification and SEC based on MAE(minimum area error) for each segment in the line. The proposed simplification and SEC increase the compression ratio while preserving the shape quality. We analyze the visual aspects and compression efficiency between the original GIS vector map and the compressed map. From experimental results, we verify that our method has the higher compression efficiency and visual quality than conventional methods.