矩形方向约束的邻域空间推理

Neighborhood Reasoning of Rectangular Direction Constraints

  • 摘要: 在空间计算过程中,空间物体常被描述为其最小外包矩形,因此矩形间的方向约束是空间关系的一个关键子集。在矩形代数基础上,使用一个2×2的特征矩阵来描述矩形间的169种方向约束关系,并构建矩形方向约束邻域网格,以邻域网格上对应顶点间的最短网格路径分析矩形方向约束关系间的距离。进而,分析当两个矩形的其中一个发生缩放和平移等渐变时,一种矩形方向约束关系转变为其邻近约束关系的过程,并使用特征值元组区间的笛卡尔乘积来表示矩形变形过程中所形成矩形约束的特征矩阵,最后分析总结了矩形变形时对应特征矩阵的变化特点。

     

    Abstract: In the process of spatial calculation, spatial object is often described as minimum bounding rectangle (MBR), which makes the rectangular constraint a key subset of spatial relationship. On the basis of rectangular algebra, we illustrate the 169 rectangular direction constraints with a 2×2 matrix, which is called F-matrix, basing on the interval relations between projected intervals of rectangles. According to the neighborhood relation between rectangular direction constraints, we build the neighbor grid for rectangular directions using a 4-dimensional coordinate system. In the research, we calculate the distance between rectangular directions via the shortest path between the corresponding vertexes in the grid. The relational distance indicates the neighborhood of two relations, and analyzes how a rectangular direction turns into another one due to the deformation of rectangles, such as sca-ling and translation. During the rectangular deformation, a set of new rectangular relations will be created. According to the initial and final rectangular constraints, we use the Cartesian products of corresponding feature value tuple intervals, to calculate the F-matrixes of newly created rectangular relations. Besides, we also explore and predict the corresponding rectangular directions during the rectangular deformation, for example, if the current constraint is meeting, the next rectangular constraint must be disjointed or overlaid. In the last section of paper, we analyze and conclude the characteristics of corresponding F-matrixes during the deformation of rectangles. According to the current rectangular constraint and impending deformation, more detailed predictions can be made.

     

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