Improved Interpolation Algorithm Research Articles

Generation and Optimization of interpolation approximation algorithm based on Laser Icon Contour Generation

Point-by-point comparison interpolation is a widely used algorithm in laser marking system. This algorithm plays a very important role in controlling the laser trajectory and fitting the image trajectory. Because the point-by-point comparison interpolation method has the characteristics of intuitive operation, uniform pulse output and convenient adjustment, it is a kind of interpolation algorithm which is more suitable for the application of marking machine system. In order to improve the marking efficiency of vector text in laser marking system, by analyzing the outline structure of TrueType font and the properties of Bezier curve, an optimization algorithm for straight line approximation of TrueType font outline is presented, and the theoretical analysis and experimental verification are carried out. Firstly, the Bezier curve in the TrueType font outline is segmented according to the deCasteljau recursive algorithm, and then the curve is replaced by the connection of the head and tail control points. Finally, the approximate line segment is interpolated to generate marking data, and the straight line approximation outline is compared with the standard TrueType font outline. The results show that under the condition of satisfying the accuracy, the algorithm has the advantages of simple calculation process and a small number of nodes, and improves the marking efficiency of vector text. The traditional point-by-point comparison interpolation algorithm has some problems such as low precision and slow speed. In order to improve the performance of the algorithm, the traditional point-by-point comparison interpolation algorithm is improved, and the calculation and simulation are carried out. The results show that the accuracy and speed of the improved interpolation algorithm are obviously improved. The patch is extracted from the point cloud data, and the feature patch is generated by patch growth and fusion, and the feature line is constructed quickly according to the proposed patch two-way index method, and finally the point cloud plane contour is generated. Experiments show that this algorithm can generate point cloud contours quickly, accurately and effectively.

Near-lossless image compression using an improved edge adaptive hierarchical interpolation

<span>In medical and scientific imaging, lossless image compression is recommended because the loss of minor details subject to medical diagnosis can lead to wrong diagniosis. On the other hand, lossy compression of medical images is required in the long run because a huge quantity of medical data needs remote storage. This, in turn, takes long time to search and transfer an image. Instead of thinking lossless or lossy image compression methods, near-loss image compression mehod can be used to compromise the two conflicting requirements. In the previous work, an edge adaptive hierarchical interpolation (EAHINT) was proposed for resolution scalable lossless compression of images. In this paper, it was enhanced for scalable near-less image compression. The interpolator of this arlgorithm swiches among one-directional, multi-directional and non-directional linear interpolators adaptively based on the strength of the edge in a 3x3 local casual context of the current pixel being predicted. The strength of the edge in local window was estimated using the variance of the the pixels in the local window. Although the actual predictors are still linear functions, the switching mechanism tried to deal with non-linear structures like edges. Simulation results demonstrate that the improved interpolation algorithm has better compression ratio over the the exsisting the original EAHINT algorithm and JPEG-Ls image compression standard. </span>

Design and Control of a Novel Single Leg Structure of Electrically Driven Quadruped Robot

In order to solve the defects of the large inertia and control difficulty of the electrically driven quadruped legs of robots, a novel leg structure and a control method are proposed in this paper. In terms of structure, the motor of the knee is arranged in the body of the robot to reduce the weight of the legs. In addition, this paper improves the PVT difference control algorithm embedded in the PMAC controller. Using the nonlinear control principle of the U-model, the optimized segmented Hermite difference method is used to implement the planning of the foot trajectory of the quadruped robot. Simulation and experiment show that the leg structure design is reasonable and the improved interpolation algorithm has good control effect.

An improved ionosphere interpolation algorithm for network RTK in low-latitude regions

A traditional interpolation algorithm with the linear interpolation method (LIM) using a fixed number of reference stations is widely used in network RTK to obtain the ionospheric delays for the users. In low-latitude regions, where the ionosphere is relatively active, however, large interpolation errors exist, especially for satellites at low elevation angles. Considering the characteristics of “coinciding ionospheric pierce points (CIPPs)” with a similar nature of ionospheric delays, an improved interpolation algorithm is proposed. In this algorithm, all stations with CIPPs are used to establish the interpolation model; thus, more precise interpolation model is achieved. To validate the performance of the proposed algorithm, data from some reference stations in Guangdong Province of China were used, and the results are compared with those with the traditional interpolation algorithm. Numerical analysis shows that the interpolation accuracy of the proposed algorithm increases by 10–30% compared with the traditional one. Since the number of reference stations is flexible, the proposed algorithm can also balance the model accuracy with the computation burdens. In addition, the proposed algorithm is less affected by the selection of master reference station. In terms of network RTK on-the-fly positioning, the time-to-first-fix is reduced when replacing the traditional interpolation algorithm with the proposed one.

An Optimized Interpolation Algorithm for Bayer Pattern CFA Images based on Gradient

Digital cameras acquire images by using color filter array, each pixel contains information of only one color channel. In order to get the rest color channel information, interpolation of the image is needed. The interpolation algorithm directly affects the image quality, and most of the current algorithms have defects in some way. Some interpolation algorithms are very simple, thus causing image distortion, some perform well but are too complex to implement. This paper proposes an improved interpolation algorithm for the most widely used color filter array, Bayer array. The proposed algorithm can achieve both interpolation efficiency and interpolation effect. Based on bilinear interpolation algorithm and edge oriented interpolation algorithm, applying gradient method and color difference rule, the proposed algorithm makes full use of the correlation between color channels, and the algorithm doesn’t have great complexity. The experimental results show that the improved interpolation algorithm performs well.

A Study on Removing the Stripe Noises in MODIS1B Images

Stripe noise is one of the most important factors, which influence the qualities of MODIS 1B images. In this paper, the main causes and the characteristics of the stripe noises in MODIS 1B images are deeply analyzed. To remove the stripe noises, three kinds of algorithms, the improved Fourier Transform, Wavelet Transform and the Interpolation Algorithm, are developed based on the above analysis. On academic level, the abilities to remove the stripe noises and their limitations are compared. Analyzed from the processed results, the three kinds of algorithms can more or less remove the stripe noises in MODIS 1B images, but have great differences among them: the improved Fourier Transform has more influences on non-noises region than the other two and the Interpolation Algorithm has the less negative influences on MODIS 1B images in removing the stripe noises. Based on the comparation of the mean value, standard deviation and the edge information of the images processed by above three kinds of algorithms, the conclusion that in removing the MODIS stripe noises, the improved Interpolation Algorithm is the best, and the Wavelet Transform is better than the Fourier Transform can be made.

On the Modeling and Analysis of an Improved CNC Interpolation Algorithm

An improved interpolation method is presented based on B-spline curve back calculation which regards data points as control points. First, a B-spline surface reconstruction is done, and a favorable condition for real-time interpolation can be provided for NC machining. Then, by prejudging the trajectory feedrate, the tangent vectors of spline curve junction can be calculated, which can be used to establish the spline curve equations based on time. At last, with the equations mentioned above, the trajectory and feedrate profile can be generated simultaneously by the improved interpolation algorithm. An error analysis is also discussed and the feasibility of the improved algorithm is verified by the simulation results.

Convergence of realization-based statistics to model-based statistics for the LU unconditional simulation algorithm: some numerical tests

In geostatistics, stochastic simulation is often used either as an improved interpolation algorithm or as a measure of the spatial uncertainty. Hence, it is crucial to assess how fast realization-based statistics converge towards model-based statistics (i.e. histogram, variogram) since in theory such a match is guaranteed only on average over a number of realizations. This can be strongly affected by the random number generator being used. Moreover, the usual assumption of independence among simulated realizations of a random process may be affected by the random number generator used. Simulation results, obtained by using three different random number generators implemented in Geostatistical Software Library (GSLib), are compared. Some practical aspects are pointed out and some suggestions are given to users of the unconditional LU simulation method.

Further development and clinical application of the stereotactic operating microscope.

Implementation of a Vicom-VME image processing workstation for the frameless stereotactic operating microscope system has allowed an improved interpolation algorithm for more accurate reconstruction of three-dimensional data, the integration graphically of multimodality imaging information, an additional stereotactic graphics display outside of the microscope optics and optional three-dimensional displays through communication with a Convex mini-supercomputer. A precision-milled coupling for reproducible attachment of the spark gap bracket to the microscope has eliminated the need for that transformation calculation during each case. Clinical utility has been greatest in providing navigational guidance to small subcortical or deep lesions and in defining the extent of preoperatively planned resection of larger, infiltrating tumors. Mean accuracy in the past 17 cases has been 3.5-6.5 mm. The frameless methodology has also enabled extracranial stereotactic surgical procedures in 7 patients.