Block Interpolation Research Articles

Detection method based on a coupled illumination correction algorithm for the detection of surface defects in ZrO2 ceramic bearing balls.

To address the problem of feature texture loss in defective images of zirconia bearing balls on unbalanced illumination backgrounds, a coupled algorithm of the local gamma function transform-block interpolation balancing equation is designed. A combination of a light reflection imaging model and a three-dimensional Gaussian surround function is used to extract the illumination estimate of the original image. Subsequent illumination balance correction is performed in the value color space. The contrast between the edges of the feature texture and the background is analyzed to construct a locally adaptive gamma function transformation model. We establish local block interpolation balance equations to eliminate the effects caused by illumination that is too high or too low. The experimental results show that the information entropy of the images after illumination correction changes in the range of 5% or less. The standard deviation and mean gradient can be increased by 15.21% and 14.78%, respectively.

Fine-Grained Dichotomies for the Tutte Plane and Boolean #CSP

Jaeger et al. (Math Proc Camb Philos Soc 108(1):35–53, 1990) proved a dichotomy for the complexity of evaluating the Tutte polynomial at fixed points: the evaluation is #P-hard almost everywhere, and the remaining points admit polynomial-time algorithms. Dell, Husfeldt, and Wahlén (in: ICALP 2010, vol. 6198, pp. 426–437, Springer, Berlin, Heidelberg, 2010) and Husfeldt and Taslaman (in: IPEC 2010, vol. 6478, pp. 192–203, Springer, Berlin, Heidelberg, 2010) in combination with the results of Curticapean (in: ICALP 2015, pp. 380–392, Springer, 2015), extended the #P-hardness results to tight lower bounds under the counting exponential time hypothesis #ETH, with the exception of the line $$y=1$$ , which was left open. We complete the dichotomy theorem for the Tutte polynomial under #ETH by proving that the number of all acyclic subgraphs of a given n-vertex graph cannot be determined in time unless #ETH fails. Another dichotomy theorem we strengthen is the one of Creignou and Hermann (Inf Comput 125(1):1–12, 1996) for counting the number of satisfying assignments to a constraint satisfaction problem instance over the Boolean domain. We prove that the #P-hard cases cannot be solved in time unless #ETH fails. The main ingredient is to prove that the number of independent sets in bipartite graphs with n vertices cannot be computed in time unless #ETH fails. In order to prove our results, we use the block interpolation idea by Curticapean and transfer it to systems of linear equations that might not directly correspond to interpolation.

Block interpolation: A framework for tight exponential-time counting complexity

We devise a framework for proving tight lower bounds under the counting exponential-time hypothesis #ETH introduced by Dell et al. (2014) [18]. Our framework allows us to convert classical #P-hardness results for counting problems into tight lower bounds under #ETH, thus ruling out algorithms with running time 2o(n) on graphs with n vertices and O(n) edges. As exemplary applications of this framework, we obtain tight lower bounds under #ETH for the evaluation of the zero-one permanent, the matching polynomial, and the Tutte polynomial on all non-easy points except for one line. This remaining line was settled very recently by Brand et al. (2016) [24].

Deformable image registration for temporal subtraction of chest radiographs.

Temporal subtraction images constructed from image registration can facilitate the visualization of pathologic changes. In this study, we propose a deformable image registration (DIR) framework for creating temporal subtraction images of chest radiographs. We developed a DIR methodology using two different image similarity metrics, varying flow (VF) and compressible flow (CF). The proposed registration method consists of block matching, filtering, and interpolation. Specifically, corresponding point pairs between reference and target images are initially determined by minimizing a nonlinear least squares formulation using grid-searching optimization. A two-step filtering process, including least median of squares filtering and backward matching filtering, is then applied to the estimated point matches in order to remove erroneous matches. Finally, moving least squares is used to generate a full displacement field from the filtered point pairs. We applied the proposed DIR method to 10 pairs of clinical chest radiographs and compared it with the demons and B-spline algorithms using the five-point rating score method. The average quality scores were 2.7 and 3 for the demons and B-spline methods, but 3.5 and 4.1 for the VF and CF methods. In addition, subtraction images improved the visual perception of abnormalities in the lungs by using the proposed method. The VF and CF models achieved a higher accuracy than the demons and the B-spline methods. Furthermore, the proposed methodology demonstrated the ability to create clinically acceptable temporal subtraction chest radiographs that enhance interval changes and can be used to detect abnormalities such as non-small cell lung cancer.

An Efficient Interpolation Hardware Architecture for HEVC Inter-Prediction Decoding

This paper proposes an efficient hardware architecture for high efficiency video coding (HEVC), which is the next generation video compression standard. It adopts several new coding techniques to reduce the bit rate by about 50% compared with the previous one. Unlike the previous H.264/AVC 6-tap interpolation filter, in HEVC, a one-dimensional seven-tap and eight-tap filter is adopted for luma interpolation, but it also increases the complexity and gate area in hardware implementation. In this paper, we propose a parallel architecture to boost the interpolation performance, achieving a luma <TEX>$4{\times}4$</TEX> block interpolation in 2-4 cycles. The proposed architecture contains shared operations reducing the gate count increased due to the parallel architecture. This makes the area efficiency better than the previous design, in the best case, with the performance improved by about 75.15%. It is synthesized with the MagnaChip <TEX>$0.18{\mu}m$</TEX> library and can reach the maximum frequency of 200 MHz.

블록 보간법을 이용한 산업용 로봇의 3차원 위치 보정기법

This paper proposes a self-calibration method of robots those are used in industrial assembly lines. The proposed method is a position compensation using laser sensor and vision camera. Because the laser sensor is cross type laser sensor which can scan a horizontal and vertical line, it is efficient way to detect a feature of vehicle and winding shape of vehicle's body. For position compensation of 3-Dimensional axis, we applied block interpolation method. For selecting feature point, pattern matching method is used and 3-D position is selected by Euclidean distance mapping between 462 feature values and evaluated feature point. In order to evaluate the proposed algorithm, experiments are performed in real industrial vehicle assembly line. In results, robot's working point can be displayed 3-D points. These points are used to diagnosis error of position and reselecting working point.

An Algebraic Multigrid Method for Linear Elasticity

We present an algebraic multigrid (AMG) method for the efficient solution of linear block-systems stemming from a discretization of a system of partial differential equations (PDEs). It generalizes the classical AMG approach for scalar problems to systems of PDEs in a natural blockwise fashion. We apply this approach to linear elasticity and show that the block interpolation, described in this paper, reproduces the rigid body modes, i.e., the kernel elements of the discrete linear elasticity operator. It is well known from geometric multigrid methods that this reproduction of the kernel elements is an essential property to obtain convergence rates which are independent of the problem size. We furthermore present results of various numerical experiments in two and three dimensions. They confirm that the method is robust with respect to variations of the Poisson ratio $\nu$. We obtain rates $\rho<0.4$ for $\nu<0.4$. These measured rates clearly show that the method provides fast convergence for a large variety of discretized elasticity problems.

Integrating surface georadar and crosshole radar tomography: A validation experiment in braided stream deposits

We have used a combination of surface ground‐penetrating radar (GPR) profiling, crosshole radar tomography, and natural gamma‐ray logging to characterize a gravelly braided stream deposit. In a gravel pit, we conducted a survey using 300‐MHz surface GPR, 250‐MHz crosshole radar, and densely sampled gamma‐ray logging at single‐borehole locations. After excavation, we validated the geophysical results by comparison with the sedimentological and hydrogeological information obtained from the corresponding outcrop wall. We found the visual lithofacies boundaries agreed very well with the images provided by applied geophysical techniques. Our results illustrate how GPR reflector images are improved using tomographic velocity information. In addition, the structural interpretation of tomographic velocity fields is guided by the GPR reflector images in combination with natural gamma‐ray logging results.Groundwater flow and transport modeling was also performed on different subsurface models. The hydrogeological response of parameter distributions derived from a digitized outcrop image are compared with the response of a parameter field derived from the combined geophysical data and with the response of a simple block interpolation between the boreholes. Comparison of cumulative particle arrival times (breakthrough curves) indicates that the characterization of an appropriate real aquifer would benefit from incorporating high‐resolution geophysical data into the analysis.

Development of a field-level geographic information system

A field-level geographic information system (FIS) was developed to meet the need for a research tool to analyze agricultural data relevant to precision agriculture. FIS is a compact, raster-based geographic information system designed specifically for precision-agriculture applications. FIS can load, graphically display, manipulate, and save numerical data representing either circular (center-pivot irrigated) or irregularly shaped crop fields. The developers used the C++ language and object-oriented programming (OOP) concepts to implement a variety of spatial analysis capabilities, such as creating fields from GPS boundary data, point and block interpolation, simple statistics and correlation, data manipulation/region partition through logic queries and buffering, spatial pattern analysis in both Cartesian and polar coordinate systems, and remote sensing data analysis.

A Method for Exactly Decodable PCM Color Television

A method is described for PCM encoding of the Y, I, and Q components of an NTSC signal in such a way that exact recovery of the components is possible, while compatibility with NTSC standards is approximately preserved. With this method, a digital decoder can separate Y, I, and Q exactly from the PCM signal; with a digital-to-analog conversion, the same PCM signal could be broadcast to standard analog NTSC receivers. The basis of the method is a block interpolation which increases the sampling rate of each component (to 4× subcarrier in the example presented here). Proper choice of the interpolation coefficients can produce a signal which approximates an NTSC standard signal. How good the approximation can be is an open question, but an example is given which demonstrates the concept and the design methods.