• Communications for Statistical Applications and Methods
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• v.8 no.1
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• pp.73-85
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• 2001

The spatial population existing in a plane ares, such as an animal or aerial population, have certain relationships among regions which are located within a fixed distance from one selected region. We consider with the adaptive searching estimation in spatial sampling for a spatial population. The adaptive searching estimation depends on values of sample points during the survey and on the nature of the surfaces under investigation. In this paper we study the estimation by the adaptive searching in a spatial sampling for the purpose of estimating the area possessing a particular characteristic in a spatial population. From the viewpoint of adaptive searching, we empirically compare systematic sampling with stratified sampling in spatial sampling through the simulation data.

• The Korean Journal of Applied Statistics
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• v.13 no.2
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• pp.353-369
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• 2000

We systematized an stratified spatial sample design(SSSD) that uses the adequate stratification criteria such as the shapeness or the dispersion of an interesting region in a spatial population. And we proposed an adaptive searching estimation method in the SSSD to estimate the area of region of interest in two-dimensional surfaces. When wc adopt the proposed adaptive searching estimation method in SSSD, the observing sample size is more decreased than a classical sample design that all the designed sample size is observed. Nevertheless it has been shown that we can produce the moderate result but the efficiency is a slight reduced.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.7A
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• pp.828-835
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• 2004

An adaptive hexagon based search(AHBS) algorithm is proposed in this paper to perform block motion estimation in video coding. The AHBS evaluates the value of a given objective function starting from a diamond-shaped checking block and then continues its process using two hexagon-shaped checking blocks until the minimum value is found at the center of checking blocks. Also, the determination of which checking block is used depends on the position of minimum value occurred in previous searching step. The AHBS is compared with other fast searching algorithms including full search(FS). Experimental results show that the proposed algorithm provides competitive performance with slightly reduced computational complexity.

• Journal of Korea Multimedia Society
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• v.3 no.4
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• pp.372-379
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• 2000

In this paper, we propose a fast variable-size block matching algorithm for motion estimation based on bit-pattern. Motion estimation in the proposed algorithm is performed after the representation of image sequence is transformed 8bit pixel values into 1bit ones depending on the mean value of search block, which brings a short searching time by reducing the computational complexity. Moreover, adaptive searching methods according to the motion information of the block make the procedure of motion estimation efficient by eliminating an unnecessary searching of low motion block and deepening a searching procedure in high motion block. Experimental results show that the proposed algorithm provides better performance-0.5dB PSNR improvement-than full search block matching algorithm with a fixed block size.

• Proceedings of the IEEK Conference
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• 2002.07b
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• pp.999-1002
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• 2002

In this paper, we proposes an adaptive method for reducing the computational overhead of fine-to-coarse MRME at the finest resolution level by considering for the spatial and spectral characteristics between wavelet decomposition levels simultaneously. As we know, there is high correlation between the adjacent blocks and it can give the very important clue to estimate motion at finest level. So, in this paper, using the initial motion vector and the adjacent motion vector in the coarsest level, we determine the optimal direction that will be minimized the estimation error in the finest level. In that direction, we define the potential searching region within the full searching region that is caused to increase much computational overhead in the FtC method. Last, in that region, we process the efficient 2-step motion estimation. and estimate the motion vector at finest resolution level. And then, this determined motion vector is scaled to coarser resolutions. As simulation result, this method is similar to computational complexity of the CtF MRME method and very significantly reduces that of the FtC MRME method. In addition, they provide higher quality than CtF MRME, both visually and quantitatively

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.7C
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• pp.688-695
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• 2003

In this paper, the parallel sub-filter searching structure to be adapted that divides a filter into several sub filters and the parameter decision technique to control adaptive parameters with power of received signal in the code acquisition system using adaptive filter are proposed. The numerical results for the system probabilities are derived that the code acquisition system using parallel sub-filter searching structure is statistically analyzed. Also, characteristic of the parameters in adaptive code acquisition system is analyzed by simulations and the parameter decision technique through SNRc estimation is explained. The system with parallel sub-filter searching structure outperforms by 1∼l.5 dB for 16 taps, 5∼6 dB for 64 taps. And the system with parameter decision technique works efficiently with the reasonable degree of degradation about 1 ∼2.5dB for 16 and 32 taps.

• The Journal of the Korea Contents Association
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• v.3 no.2
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• pp.11-18
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• 2003

In this paper, we propose a fast variable block matching algorithm for motion estimation based on bit-patterns. Motion estimation in the proposed algorithm is peformed after the representation of image sequence is transformed 8-bit pixel values into 1-bit ones by the mean pixel value of search block, which brings a short searching time by reducing the computational complexity. Moreover, adaptive searching methods according to the motion information of the block make the procedure of motion estimation efficient by eliminating unnecessary searching processes of low motion block and deepening a searching procedure in high motion block. Experimental results show that the proposed algorithm provides bettor performance - average 0.5dB PSNR improvement and about 99% savings in the number of operations - than full search Hock matching algorithm with a fixed block size.

• Proceedings of the Korea Contents Association Conference
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• 2005.05a
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• pp.362-368
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• 2005

This paper is related to the fast block matching algorithm, especially a method for expanding the search pattern using the second local matching point in the adaptive hexagonal search. To reduce the local minima problem in fast motion estimation, the proposed method expands the search pattern by adding new searching points selected by using the second local matching point to conventional search pattern formed by the first local matching point in the adaptive hexagonal search. According to estimating the motion vector by applying block matching algorithm based on hexagonal search to the expanded search pattern, the proposed method can effectively carry out fast motion estimation to improve the performance in terms of compensated image quality.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.1C
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• pp.19-33
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• 2008

A method that is adaptively selecting among previous fast motion estimation algorithms and a newly proposed fast motion estimation algorithm(UCDS) is presented in this paper. The algorithm named AUDC and a newly proposed fast motion estimation algorithms are based on the Diamond Search(DS) algorithm and Three Step Search(TSS). Although many previous fast motion estimation algorithms have lots of advantages, those have lots of disadvantages. So we thought better adaptive selection of fast motion estimation algorithms than only using one fast motion estimation algorithm. Therefore, we propose AUDC that is using length of the MV, Search Point, SAD of the neighboring block and adaptively selecting among Cross Three Step Search(CTSS), Diamond Search(DS) and Ungraded Cross Diamond Search(UCDS). Experimental results show that the AUDC is much more robust, provides a faster searching speed, and smaller distortions than other popular fast block-matching at algorithms.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.43 no.6 s.312
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• pp.57-64
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• 2006

Motion estimation plays an important role for the compression of video signals. The proposed method utilizes an adaptive threshold and characteristics of a distribution of SAD (sum of absolute difference). Generally, the more complex the SAD distribution is, the larger SAD value tends to be. This proposed algorithm tries to reduce the search points in a simple distribution but increase them in a complex distribution to avoid local minima. A macro block is divided into 9 areas. One of them chosen using spatio-temporal correlation is called the primary area and the others are called the secondary area that will be searched to avoid local minima. The proposed algorithm decides if just one area (the primary area or the secondary area) will be enough to be searched or both areas should be searched, using adaptive threshold. Compared with famous motion estimation algorithms, the simulation result shows that the searching points per macro block and MSE decreases about 16.4% and 32.83 respectively on the average.