• Journal of Information Processing Systems
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• v.16 no.3
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• pp.688-698
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• 2020

Point clouds have ability to express the spatial entities, however, the point clouds redundancy always involves some uncertainties in computer recognition and model construction. Therefore, point clouds thinning is an indispensable step in point clouds model reconstruction and other applications. To overcome the shortcomings of complex classification index and long time consuming in existing point clouds thinning algorithms, this paper proposes a point clouds fast thinning algorithm. Specifically, the two-dimensional index is established in plane linear array (x, y) for the scanned point clouds, and the thresholds of adjacent point distance difference and height difference are employed to further delete or retain the selected sample point. Sequentially, the index of sample point is traversed forwardly and backwardly until the process of point clouds thinning is completed. The results suggest that the proposed new algorithm can be applied to different targets when the thresholds are built in advance. Besides, the new method also performs superiority in time consuming, modelling accuracy and feature retention by comparing with octree thinning algorithm.

• Journal of information and communication convergence engineering
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• v.8 no.5
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• pp.570-574
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• 2010

A thinning algorithm changes a binary fingerprint image to one pixel width. A thinning stage occupies 40% cycle of 32-bit RISC microprocessor system for a fingerprint identification algorithm. Hardware block processing is more effective than software one in speed, because a thinning algorithm is iteration of simple instructions. This paper describes an effective hardware scheme for thinning stage processing using the Verilog-HDL in $160\times192$ Pixel Array. The ZS algorithm was applied for a thinning stage. The hardware scheme was designed and simulated in RTL. The logic was also synthesized by XST in FPGA environment. Experimental results show the performance of the proposed scheme.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.46 no.1
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• pp.1-6
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• 2009

A Thinning algorithm is a very Important factor in order to recognize the character, figure, and drawing. Until comparatively lately, the thinning algorithm was proposed by various methods. In this paper, we ascertain the point at issue of ZS(Zhang and Suen), LW(Lu and Wang) and WHF(Wang, Hui and Fleming) algorithms that are the parallel thinning algorithms. The parallel thinning algorithm means the first processing doesn't have to influence to the second processing. ZS algorithm has a problem which loses pixels in slanting lines and LW algorithm doesn't have one pixel width in slanting lines. So I propose an advanced parallel thinning algorithm that connects the pixels each other and preserve the end point.

• Journal of information and communication convergence engineering
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• v.8 no.6
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• pp.716-720
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• 2010

This paper proposes an effective fingerprint identification system with hardware block for thinning stage processing of a verification algorithm based on minutiae with 39% occupation of 32-bit RISC microprocessor cycle. Each step of a fingerprint algorithm is analyzed based on FPGA and ARMulator. This paper designs an effective hardware scheme for thinning stage processing using the Verilog-HDL in $160{\times}192$ pixel array. The ZS algorithm is applied for a thinning stage. The logic is also synthesized in $0.35{\mu}m$ 4-metal CMOS process. The layout is performed based on an auto placement-routing and post-simulation is performed in logic level. The result is compared with a conventional one.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.60.2-60
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• 2001

In this paper, manufacturing system and Internet are combined and NC milling machine engraves image and text on nameplate. Image and text are input through Internet. And NC tool path is obtained by thinning algorithm and NC part program is generated. Thinning algorithm detects center lines from image and text by using connectivity and tool path is obtained along the center line. Actually experiments are performed and thinning algorithm and G-code generation module are verified.

• Journal of Computational Design and Engineering
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• v.3 no.1
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• pp.63-70
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• 2016

Deep drawing is a forming process in which a blank of sheet metal is radially drawn into a forming die by the mechanical action of a punch and converted to required shape. Deep drawing involves complex material flow conditions and force distributions. Radial drawing stresses and tangential compressive stresses are induced in flange region due to the material retention property. These compressive stresses result in wrinkling phenomenon in flange region. Normally blank holder is applied for restricting wrinkles. Tensile stresses in radial direction initiate thinning in the wall region of cup. The thinning results into cracking or fracture. The finite element method is widely applied worldwide to simulate the deep drawing process. For real-life simulations of deep drawing process an accurate numerical model, as well as an accurate description of material behavior and contact conditions, is necessary. The finite element method is a powerful tool to predict material thinning deformations before prototypes are made. The proposed innovative methodology combines two techniques for prediction and optimization of thinning in automotive sealing cover. Taguchi design of experiments and analysis of variance has been applied to analyze the influencing process parameters on Thinning. Mathematical relations have been developed to correlate input process parameters and Thinning. Optimization problem has been formulated for thinning and Genetic Algorithm has been applied for optimization. Experimental validation of results proves the applicability of newly proposed approach. The optimized component when manufactured is observed to be safe, no thinning or fracture is observed.

• IE interfaces
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• v.15 no.1
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• pp.20-25
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• 2002

In this research, a nameplate engraving system for images and texts downloaded through Internet on nameplate is developed. The system consists of two subsystems: thinning algorithm and NC code generation module. In the thinning algorithm, the concept of connectivity is used and center lines of images and texts, which will be used as NC tool paths, can be obtained successfully. Because the center lines are composed of a lot of pixels, NC code would be too long. In the NC code generation module, many useless pixel data are removed and linear interpolation algorithm is applied to only the remaining pixels. By performing actual experiments, the thinning algorithm and the NC code generation module are verified.

• Journal of the Korean Mathematical Society
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• v.44 no.6
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• pp.1479-1503
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• 2007

In this paper, we study a strong k-deformation retract derived from a relative k-homotopy and investigate its properties in relation to both a k-homotopic thinning and the k-fundamental group. Moreover, we show that the k-fundamental group of a wedge product of closed k-curves not k-contractible is a free group by the use of some properties of both a strong k-deformation retract and a digital covering. Finally, we write an algorithm for calculating the k-fundamental group of a dosed k-curve by the use of a k-homotopic thinning.

• Journal of the Korean Association of Geographic Information Studies
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• v.2 no.1
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• pp.45-53
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• 1999

Geographic Information System(GIS) which facilitates efficient storage and retrieval of geographic information is very useful tools. It is of extreme importance to develop automated vectorizing system as input method for GIS, because it takes a large amount of time and effort in constructing a GIS. In all kinds of map processed by GIS, contour line map specially takes a large amount of effort. In this paper we have considered an optimal thinning algorithm for the contour line vectorizing in the GIS. Based on the experimental results, it has been proved that thinning algorithm using the connection value is most excellent algorithm in the similarity and connectivity.

• Journal of the Korean Association of Geographic Information Studies
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• v.2 no.1
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• pp.54-62
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• 1999

Vectorizing for input processing of map is the most time and cost consuming task, and the quality of vector data depends on that processing result. Therefore, it is an important task to develop a good vectorizing system in the GIS. Thinning algorithm is the most important technology for deciding the quality of vector data in the vectorizing system. In this paper, as a suitable algorithm for map vectorizing we considered several algorithms that preserve topological and geometric characteristics, and have no distortion of the contour line. As a results, we implemented WPTA4 and well known thinning algorithm, and compared WPTA4 execution results with the others.