• Title/Summary/Keyword: Interpolation

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A Study on the GIS for The Sea Environmental Management I - Focus on the Study of A Interpolation on The Application of LDI Algorism - (GIS를 활용한 해양환경관리에 관한 연구 I - LDI 알고리즘 적용을 위한 보간법에 관한 연구 -)

  • Lee, Hyoung Min;Park, GI Hark
    • Journal of Environmental Impact Assessment
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    • v.15 no.6
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    • pp.443-452
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    • 2006
  • Today, satellite remote sensing (RS) and geographic information systems (GIS) plays an important role as an advanced science and technology. This study was developed a Line Density Algorithm which was clarify and describe the thermal front by using NOAA SST (sea surface temperature) and GIS spatial analysis for systemic and effective management of fish raising industry and sea environmental pollution by land reclamation program. Before this, a study about a interpolation method was carry out which was very important for estimate the hidden value between a special point. For this study Inverse Distance Weighted interpolation, Spline interpolation, Kriging interpolation methods were choose and SST data from 2001 to 2004 in spring (March, April, May) were analyzed. According to the study Kriging interpolation method was the very adaptive method from a practical point of view and excellent in description and precision then others. Finally, the result of this study will be use for develope the Line Density Index Algorism.

Edge Adaptive Hierarchical Interpolation for Lossless and Progressive Image Transmission

  • Biadgie, Yenewondim;Wee, Young-Chul;Choi, Jung-Ju
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.5 no.11
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    • pp.2068-2086
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    • 2011
  • Based on the quincunx sub-sampling grid, the New Interleaved Hierarchical INTerpolation (NIHINT) method is recognized as a superior pyramid data structure for the lossless and progressive coding of natural images. In this paper, we propose a new image interpolation algorithm, Edge Adaptive Hierarchical INTerpolation (EAHINT), for a further reduction in the entropy of interpolation errors. We compute the local variance of the causal context to model the strength of a local edge around a target pixel and then apply three statistical decision rules to classify the local edge into a strong edge, a weak edge, or a medium edge. According to these local edge types, we apply an interpolation method to the target pixel using a one-directional interpolator for a strong edge, a multi-directional adaptive weighting interpolator for a medium edge, or a non-directional static weighting linear interpolator for a weak edge. Experimental results show that the proposed algorithm achieves a better compression bit rate than the NIHINT method for lossless image coding. It is shown that the compression bit rate is much better for images that are rich in directional edges and textures. Our algorithm also shows better rate-distortion performance and visual quality for progressive image transmission.

A Proposal of an Interpolation Method of Missing Wind Velocity Data in Writing a Typical Weather Data (표준기상데이터 작성 시 누락된 풍속 데이터의 보간 방법 제안)

  • Park, So-Woo;Kim, Joo-wook;Song, Doo-sam
    • Journal of the Korean Solar Energy Society
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    • v.37 no.6
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    • pp.79-91
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    • 2017
  • The meteorological data of 1 hour interval are required to write a typical weather data for building energy simulation. However, many meterological data are missing and the interpolation method to recover the missing data is required. Especially, lots of meterological data are replicated by linear interpolation method because the changes are not significant. While, the wind velocity fluctuates with the time or locations, so linear interpolation method is not appropriate in interpolation of the wind velocity data. In this study, three interpolation methods, using surrounding wind velocity data, Inverse Distance Weighting (IDW), Revised Inverse Distance Weighting (IDW-r), were analyzed considering the characteristics of wind velocity. The Revised Inverse Distance Weighting method, proposed in this study, showed the highest reliability in restoration of the wind velocity data among the analyzed methods.

Adaptive Image Interpolation Using Pixel Embedding (화소 삽입을 이용한 적응적 영상보간)

  • Han, Kyu-Phil;Oh, Gil-Ho
    • Journal of Korea Multimedia Society
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    • v.17 no.12
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    • pp.1393-1401
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    • 2014
  • This paper presents an adaptive image interpolation method using a pixel-based neighbor embedding which is modified from the patch-based neighbor embedding of contemporary super resolution algorithms. Conventional interpolation methods for high resolution detect at least 16-directional edges in order to remove zig-zaging effects and selectively choose the interpolation strategy according to the direction and value of edge. Thus, they require much computation and high complexity. In order to develop a simple interpolation method preserving edge's directional shape, the proposed algorithm adopts the simplest Haar wavelet and suggests a new pixel-based embedding scheme. First, the low-quality image but high resolution, magnified into 1 octave above, is acquired using an adaptive 8-directional interpolation based on the high frequency coefficients of the wavelet transform. Thereafter, the pixel embedding process updates a high resolution pixel of the magnified image with the weighted sum of the best matched pixel value, which is searched at its low resolution image. As the results, the proposed scheme is simple and removes zig-zaging effects without any additional process.

Reducing Decoding Complexity by Improving Motion Field Using Bicubic and Lanczos Interpolation Techniques in Wyner-Ziv Video Coding

  • Widyantara, I Made O.;Wirawan, Wirawan;Hendrantoro, Gamantyo
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.6 no.9
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    • pp.2351-2369
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    • 2012
  • This paper describes interpolation method of motion field in the Wyner-Ziv video coding (WZVC) based on Expectation-Maximization (EM) algorithm. In the EM algorithm, the estimated motion field distribution is calculated on a block-by-block basis. Each pixel in the block shares similar probability distribution, producing an undesired blocking artefact on the pixel-based motion field. The proposed interpolation techniques are Bicubic and Lanczos which successively use 16 and 32 neighborhood probability distributions of block-based motion field for one pixel in k-by-k block on pixel-based motion field. EM-based WZVC codec updates the estimated probability distribution on block-based motion field, and interpolates it to pixel resolution. This is required to generate higher-quality soft side information (SI) such that the decoding algorithm is able to make syndrome estimation more quickly. Our experiments showed that the proposed interpolation methods have the capability to reduce EM-based WZVC decoding complexity with small increment of bit rate.

An Improved Rayleigh Fading Compensation Algorithm with Modified Sinc Interpolation (수정된 Sinc 보간법을 이용한 새로운 Rayleigh 페이딩 보상 알고리즘)

  • 이창재
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.25 no.10A
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    • pp.1492-1498
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    • 2000
  • Pilot symbol aided modulation (PSAM) using the conventional sinc interpolation (CSI) achieves nearly the same BER performance as Caver' optimal Wiener interpolation but with much less complexity. The CSI, however, has to use a non-rectangular window function that is applied to the sinc function to smooth out the abrupt truncation of rectangular window. In this paper, we propose the modified sinc interpolation (MSI). With the weighting factor the MSI scheme with no window has almost the same BER performance as the CSI scheme using window, In addition, if we use the MSI with a window its BER performance gets close to that of the theoretical one. We assume the multicarrier QAM system and an optimal frame structure for performance evaluation.

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Accuracy Comparison of Air Temperature Estimation using Spatial Interpolation Methods according to Application of Temperature Lapse Rate Effect (기온감률 효과 적용에 따른 공간내삽기법의 기온 추정 정확도 비교)

  • Kim, Yong Seok;Shim, Kyo Moon;Jung, Myung Pyo;Choi, In Tae
    • Journal of Climate Change Research
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    • v.5 no.4
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    • pp.323-329
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    • 2014
  • Since the terrain of Korea is complex, micro- as well as meso-climate variability is extreme by locations in Korea. In particular, air temperature of agricultural fields is influenced by topographic features of the surroundings making accurate interpolation of regional meteorological data from point-measured data. This study was carried out to compare spatial interpolation methods to estimate air temperature in agricultural fields surrounded by rugged terrains in South Korea. Four spatial interpolation methods including Inverse Distance Weighting (IDW), Spline, Ordinary Kriging (with the temperature lapse rate) and Cokriging were tested to estimate monthly air temperature of unobserved stations. Monthly measured data sets (minimum and maximum air temperature) from 588 automatic weather system(AWS) locations in South Korea were used to generate the gridded air temperature surface. As the result, temperature lapse rate improved accuracy of all of interpolation methods, especially, spline showed the lowest RMSE of spatial interpolation methods in both maximum and minimum air temperature estimation.

A Study on the Improvement of Digital Periapical Images using Image Interpolation Methods (영상보간법을 이용한 디지털 치근단 방사선영상의 개선에 관한 연구)

  • Song Nam-Kyu;Koh Kawng-Joon
    • Journal of Korean Academy of Oral and Maxillofacial Radiology
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    • v.28 no.2
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    • pp.387-413
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    • 1998
  • Image resampling is of particular interest in digital radiology. When resampling an image to a new set of coordinate, there appears blocking artifacts and image changes. To enhance image quality, interpolation algorithms have been used. Resampling is used to increase the number of points in an image to improve its appearance for display. The process of interpolation is fitting a continuous function to the discrete points in the digital image. The purpose of this study was to determine the effects of the seven interpolation functions when image resampling in digital periapical images. The images were obtained by Digora, CDR and scanning of Ektaspeed plus periapical radiograms on the dry skull and human subject. The subjects were exposed to intraoral X-ray machine at 60kVp and 70 kVp with exposure time varying between 0.01 and 0.50 second. To determine which interpolation method would provide the better image, seven functions were compared; (1) nearest neighbor (2) linear (3) non-linear (4) facet model (5) cubic convolution (6) cubic spline (7) gray segment expansion. And resampled images were compared in terms of SNR(Signal to Noise Ratio) and MTF(Modulation Transfer Function) coefficient value. The obtained results were as follows ; 1. The highest SNR value(75.96dB) was obtained with cubic convolution method and the lowest SNR value(72.44dB) was obtained with facet model method among seven interpolation methods. 2. There were significant differences of SNR values among CDR, Digora and film scan(P<0.05). 3. There were significant differences of SNR values between 60kVp and 70kVp in seven interpolation methods. There were significant differences of SNR values between facet model method and those of the other methods at 60kVp(P<0.05), but there were not significant differences of SNR values among seven interpolation methods at 70kVp(P>0.05). 4. There were significant differences of MTF coefficient values between linear interpolation method and the other six interpolation methods (P< 0.05). 5. The speed of computation time was the fastest with nearest -neighbor method and the slowest with non-linear method. 6. The better image was obtained with cubic convolution, cubic spline and gray segment method in ROC analysis. 7. The better sharpness of edge was obtained with gray segment expansion method among seven interpolation methods.

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Selecting of Interpolation for Extraction of Optimal Submarine Topographic Information. (최적해저지형정보 추출을 위한 보간법 선정)

  • 이종출;김희규;김남식;김성호
    • Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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    • 2004.04a
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    • pp.571-576
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    • 2004
  • In this study, we selected the most effective interpolation method using both the data of sounding the depth of submarine topography and volume-production computer program. After processing the data by volume-production program, and then we selected the most effective interpolation method which nearest actual value of dredged soil quantity. Thus, these interpolation could be used for describing the optimal submarine topography.

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A New Method of the Global Interpolation in NURBS Surface (NURBS Surface Global Interpolation에 대한 한 방법)

  • 정형배;나승수;박종환
    • Korean Journal of Computational Design and Engineering
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    • v.2 no.4
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    • pp.237-243
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    • 1997
  • A new method is introduced for the interpolation in NURBS Surface. This method uses the basis functions to assign the parameter values to the arbitrary set of geometric data and uses the iteration method to compute the control net. The advantages of this method are the feasible transformation of the data set to the matrix form and the effective surface generation as a result, especially to the design engineer.

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