• Journal of Korea Game Society
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• v.3 no.1
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• pp.86-93
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• 2003

In this paper, we propose a new antialiasing method using filtering technique which is base on morphological pixel structure Aliasing occurs along the edge of lines and polygons. This undesirable effect happens because there are not enough pixels available on a typical monitor to properly display mathematically smooth lines and polygon edges. Aliasing can be very distracting. In a typical graphic scene, aliasing artifact will be visible along the edges of all objects that greatly diminish of realism. The proposed antialiasing method attempts to smooth extreme jagged contour lines and edges by properly handling pixel's structure, surface type and adjusting the pixel color according to the amount of pixel coverage. Next, we use filtering technique considering morphological pixel structure. Experimental results have shown that the propose algorithm achieves better performance in reducing noise for antialiasing. The method will be widely applied to basic antialiasing technique for computer graphic applications.

• Journal of Korea Multimedia Society
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• v.7 no.1
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• pp.44-53
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• 2004

This paper aims at presenting high quality at low resolution apply by a new antialiasing method for voxelized implicit surfaces. Implicit surfaces create a unique type of 3D-modeling. Some use of implicit surfaces are scientific and medical visualization, animation, medical simulation and interactive modeling. One of previous antialiasing methods for implicit surfaces presented by raytracing or texture mapping is making use of a stochastic sampling. But this method requires more calculation time and costs which is caused by complicated and difficult implicit functions. In the meanwhile, voxelized implicit surfaces generally use high resolution for good quality images but it costs to generate. In order to this problem, this paper suggests a shifted double Z-buffer which is very simple, more efficient and easy. Tn addition, there are applied box-filter and tent-filter to the double Z-buffer antialiasing method for better images. For results this method generate high quality image and it is easy to apply to various filters and is able to extend to multi Z-buffer.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.422-425
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• 2004

This paper develops an octree-based algorithm for machining simulation. Most commercial machining simulators are based on the Z map model, which has several limitations in terms of achieving a high level of precision in five-axis machining simulation. Octree representation being a three-dimensional (3D) decomposition method, an octree-based algorithm is expected to be able to overcome such limitations. With the octree model, storage requirement is reduced. Moreover, recursive subdivision is processed in the boundaries, which reduces useless computations. The supersampling method is the most common form of antialiasing and is typically used with polygon mesh rendering in computer graphics. The supersampling technique is being used to advance the efficiency of the octree algorithm..

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.873-876
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• 2003

Z-map model is the most widely used model for NC simulation and verification. But it has several limitations to get a high precision, to apply 5 axis machining simulation. In this paper, we tried to use quadtree for searching cutting region. Quadtree representation of two dimensional objects is performed with a tree that describes the recursive subdivision. By using these quadtree model. storage requirements were reduced. And also, recursive subdivision was processed in the boundries, so, useless computation could be reduced, too. To get more high Accuracy, we applied the supersampling method in the boundaries. The Supersampling method is the most common form of the antialiasing and usually used with polygon mesh rendering in computer graphics To verify quadtree model we compared simulated results with z-map model and enhanced z-map model

• Journal of KIISE:Computer Systems and Theory
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• v.30 no.3_4
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• pp.205-212
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• 2003

In this paper, we propose a simple and efficient hardware-supported antialiasing algorithm and its rendering scheme. The proposed method can efficiently reduce the required memory bandwidth as well as memory size compared to a conventional supersampling when rendering 3D models. In addition, it can provide almost the same high quality scenes as supersampling does. In this paper, we have introduced the RUF (Recently Used Fragment) buffer that stores some or whole parts of a fragment or two more the merged results of fragments that recently used in color calculation. We have also proposed a color calculation algorithm to deteriorate the image quality as referencing the RUF buffer. Because of the efficiency presented in the proposed algorithm, the more number of sampling points increases the more memory saving ratio we can gain relative to the conventional supersampling. In our simulation, the proposed method can reduce the amount of memory size by 31% and the memory bandwidth by 11% with a moderate pixel color difference of 1.3% compared to supersampling for 8 sparse sampling points.

• Journal of Korea Multimedia Society
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• v.8 no.2
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• pp.249-257
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• 2005

This paper aims at reducing aliasing in pixel-based rendering for 3D implicit surfaces by shifted multi Z-buffers. The voxelized implicit surfaces with high resolution take so much time in generating high Quality image without aliasing. So in rendering a voxelized implicit surfaces, a new antialiasing method which can generate a high quality image at a lower resolution is required. Therefore, this paper suggests that a method which get various sampling values by shifting several z-buffers in each voxel and average them, The advantages are effective memory, simple calculation and easy convergence with various filters. But, the increase of number of z-buffer also increase the consuming time rapidly. Therefore, the research for representing the relation the degree of image quality with the consumption of time as a number is required.

• Proceedings of the Korea Multimedia Society Conference
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• 2002.11b
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• pp.497-502
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• 2002

레이 트레이싱이나 텍스쳐 맵핑에 의한 Implicit 곡면에서의 앤티 앨리어싱을 위한 방법으로 일반적으로 stochastic 샘플링 방법이 많이 사용되고 있다. 하지만 이 방법은 복잡한 함수로 표현된 Implicit 곡면에 더 많은 복잡한 계산을 요구하며 이에 따라 처리 시간과 비용이 많이 든다. 본 논문에서는 복셀(voxel)로 표현되는 Implicit 곡면에서 효율적인 방법 및 계산으로 앨리어싱을 감소시키기 위하여 shifted 더블 Z-버퍼를 이용하였으며, 또한 box-filter와 tent-filter를 적용함으로써 양질의 Implicit 곡면 이미지를 표현하였다.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.05a
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• pp.551-554
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• 2002

The paper discusses new approach for machining operation simulation using enhanced Z map algorithm. To extract the required geometric information from NC code, suggested algorithm uses supersampling method to enhance the efficiency of a simulation process. By executing redundant Boolean operations in a grid cell and averaging down calculated data, presented algorithm can accurately represent material removal volume though tool swept volume is negligibly small. Supersampling method is the most common form of antialiasing and usually used with polygon mesh rendering in computer graphics. The key advantage of enhanced Z map model is that the data structure is same with conventional Z map model, though it can acquire higher accuracy and reliability with same or lower computation time. By simulating machining operation efficiently, this system can be used to improve the reliability and efficiency of NC machining process as well as the quality of the final product.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.956-959
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• 2005

The overall goal of this thesis is to develop a new algorithm based on the octree model for geometric and mechanistic milling operation at the same time. Most commercial machining simulators are based on the Z map model, which has several limitations in terms of achieving a high level of precision in five-axis machining simulation. Octree representation being a three-dimensional (3D) decomposition method, an octree-based algorithm is expected to be able to overcome such limitations. With the octree model, storage requirement is reduced. Moreover, recursive subdivision is processed in the boundaries, which reduces useless computations. To achieve a high level of accuracy, fast computation time and less memory consumption, the advanced octree model is suggested. By adopting the supersampling technique of computer graphics, the accuracy can be significantly improved at approximately equal computation time. The proposed algorithm can verify the NC machining process and estimate the material removal volume at the same time.

• Proceedings of the KIEE Conference
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• 2001.07a
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• pp.249-251
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• 2001

This paper presents performance analysis on a low pass filter of a CT saturation detecting algorithm using difference. At the instants of beginning/end of saturation, the shapes of the secondary current are changed significantly though secondary currents are continuous. At the instants, the second-order or third-order difference of the secondary current has big values because of discontinuity of the first order difference. Thus, the third difference of the current is used to detect the beginning/end of CT saturation. An antialiasing low pass filter removes high frequency components and causes phase lag. A CT saturation detecting algorithm using difference of CT secondary currents is affected by the low pass filter. The algorithm is tested with cutoff frequencies of the filter for the two sampling rates of 64[S/C] and 32 [S/C]. The results of various test cases indicate satisfactory performance of the algorithm.