• The KIPS Transactions:PartA
• /
• v.14A no.3 s.107
• /
• pp.151-158
• /
• 2007

Quadtree, which is a hierarchical data structure, is a very important data structure to represent images. The linear quadtree representation as a way to store a quadtree is efficient to save space compared with other representations. Therefore, it has been widely studied to develop efficient algorithms to execute operations related with quadtrees. The computation of block location is one of important geometry operations in image processing, which extracts a component completely including a given block. In this paper, we present a constant time algorithm to compute the block location of images represented by quadtrees, using three-dimensional $n\times n\times n$ processors on RMESH(Reconfigurable MESH). This algorithm has constant-time complexity by using efficient basic operations to deal with the locational codes of quardtree on the hierarchical structure of $n\times n\times n$ RMESH.

• The KIPS Transactions:PartA
• /
• v.10A no.3
• /
• pp.207-214
• /
• 2003

Quadtree, which is a hierarchical data structure, is a very important data structure to represent binary images. The linear quadtree representation as a way to store a quadtree is efficient to save space compared with other representations. Therefore, it has been widely studied to develop efficient algorithms to execute operations related with quadtrees. The linear translation is one of important operations in image processing, which moves the image by a given distance. In this paper, we present an algorithm to perform the linear translation of binary images represented by quadtrees, using three-dimensional $n{\times}n{\times}n$ processors on RMESH (Reconfigurable MESH). This algorithm has constant-time complexity by using efficient basic operations to route the locational codes of quardtree on the hierarchical structure of n${\times}$n${\times}$n RMESH.

• The Transactions of the Korea Information Processing Society
• /
• v.5 no.11
• /
• pp.2845-2854
• /
• 1998

Median filter can be implemented in the binary domain based on threshold decomposition, stacking property, and linear separability. In this paper, we develop one-dimensional and two-dimensional parallel algorithms for the median filter on a reconfigurable mesh with buses(RMESH) which is suitable for VLSI implementation. And we evaluate their performance by comparing the time complexities of RMESH algorithms with those of algorithms on mesh-connected computer. When the length of M-valued 1-D signal is N and w is the window width, the RMESH algorithm is done in O(Mw) time and mesh algorithm is done in $O(Mw^2)$ time. Beside, when the size of M-valued 2-D image is $N{\times}N$ and the window size is $w{\times}w$, our algorithm on $N{\times}N$ RMESH can be computed in O(Mw) time which is a significant improvement over the $O(Mw^2)$ complexity on $N{\times}N$ mesh.

• The Transactions of the Korea Information Processing Society
• /
• v.5 no.7
• /
• pp.1746-1758
• /
• 1998

계층적 자료구조인 사진트리는 이진 영상을 표현하는데 매우 중요한 자료구조이다. 사진트리를 메모리에 저장하는 방법중 선형 사진트리 표현 방법은 다른 표현 방법과 비교할 때 저장 공간을 매우 효율적으로 절약할 수 있는 이점이 있기 때문에 사진트리와 관련된 연산의 수행을 위해 선형 사진트리를 사용하는 효율적인 알고리즘 개발에 많은 연구가 진행되어 왔다. 본 논문에서는 REMSH(Reconfigurable MESH) 구조에서 3-차원 n$\times$n$\times$n 프로세서를 사용하여 선형 사진트리로 표현된 이진 영상의 면적과 둘레 길이를 계산하는 알고리즘을 제안한다. 이 알고리즘은 0(1) 시간 복잡도를 갖는다.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.20 no.2
• /
• pp.401-407
• /
• 2016

We can consider the following problems for two given points p and q in a simple polygon P. (1) Compute the set of points of P which are visible from both p and q. (2) Compute the set of points of P which are visible from either p or q. They are corresponding to the problems which are to compute the intersection and the union of two visibility polygons. In this paper, we consider algorithms for solving these problems on a reconfigurable mesh(in short, RMESH). The algorithm in [1] can compute the intersection of two general polygons in constant time on an RMESH with size O($n^3$), where n is the total number of vertices of two polygons. In this paper, we construct the planar subdivision graph in constant time on an RMESH with size O($n^2$) using the properties of the visibility polygon for preprocessing. Then we present O($log^2n$) time algorithms for computing the union as well as the intersection of two visibility polygons, which improve the processor-time product from O($n^3$) to O($n^2log^2n$).

• Journal of KIISE:Computer Systems and Theory
• /
• v.26 no.11
• /
• pp.1344-1352
• /
• 1999

본 논문에서는 두 단순 다각형의 교차 영역을 구하는 문제를 재구성메쉬(RMESH) 상에서 상수 시간에 해결하는 두 개의 알고리즘을 제시한다. 먼저, 두 다각형이 모두 볼록 다각형일 때, N$\times$N RMESH에서 상수 시간에 교차 영역을 구하는 알고리즘을 제시한다, 여기서 N은 두 다각형의 정점의 개수의 합이다. 그리고, 두 일반적인 단순 다각형의 교차 영역을 구하는 문제에 대해서 (N+T)$\times$(N+T)2 RMESH에서 수행되는 상수 시간 알고리즘을 제시한다, 여기서 T는 최악의 경우 두 다각형의 경계선 상의 교차점의 개수로서 두 다각형의 정점의 개수가 각각 n과 m일 때 n.m에 해당한다. 두 다각형 중 하나가 볼록 다각형인 경우는 T = 2.max{n, m}이다. 이 알고리즘은 두 다각형의 모든 교차 영역 조각들을 구한 후 RMESH의 0번째 열에 차례로 배치해 준다. Abstract In this paper, we consider two constant time algorithms for polygon intersection problems on a reconfigurable mesh(in short, RMESH). First, we present a constant time algorithm for computing the intersection of two convex polygons on an N$\times$N RMESH, where N is the total number of vertices in both polygons. Second, we present a constant time algorithm for computing the intersection of two simple polygons on an (N+T)$\times$(N+T)2 RMESH, where T is the worstcase number of intersection points between the boundaries of them. T = n m, where n and m are the numbers of vertices of two polygons respectively. If either of them is convex, then T = 2 max{n,m}. The algorithm computes the intersection of them, and then arranges each intersection component onto the 0-th column of the mesh.

• The KIPS Transactions:PartA
• /
• v.11A no.3
• /
• pp.173-180
• /
• 2004

Quadtree, which 11 a hierarchical data structure, is a very important data structure to represent images. The linear quadtree representation as a way to store a quadtree is efficient to save space compared with other representations. Therefore, it has been widely studied to develop efficient algorithms to execute operations related to quadtrees. The region expansion is an operation to expand images by a given distance and the scaling If an operation to scale images by a given scale factor. In this paper, we present algorithms to perform the region expansion and scaling of images represented by quadtrees, using three-dimensional n${\times}$n${\times}$n processors on RMESH(Reconfigurable MESH). These algorithms have constant time complexities by using efficient basic operations to route the locational codes of quadtree on the hierarchical structure of n${\times}$n${\times}$n RMESH.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2013.10a
• /
• pp.773-775
• /
• 2013

In this paper, we consider the problem for finding a vertex sequence of the directed cycle graph from the individual neighborhood information on a reconfigurable mesh(in short, RMESH). This problem can be solved in linear time using a sequential algorithm. However, it is difficult to develop a sublinear time parallel algorithm for the problem because of its sequential nature. All kinds of polygons can be represented by directed cycles, hence a solution of the problem may be used to solving problems in which a polygon should be constructed from the adjacency information for each vertex. In this paper, we present a constant time $n{\times}n^2$ RMESH algorithm for the problem with n vertices.