DECISION METHOD FOR ALIGNMENT OF TWO LINE SEGMENT STRINGS

摘要

PURPOSE:To accelerate decision for similarity by calculating a total area as dividing the overlapped area of two line segment strings into triangular areas, and calculating mean distance between the line segments set as criterion for the similarity. CONSTITUTION:The line segment string targeted to decide the similarity consists of the one in which plural line segments a0, a1,... defined by a pair of start point and end point specified by (X,Y) coordinates are connected and the one in which plural line segments b0, b1,... are connected. Firstly, the overlapped area setting the start point of the line segment a0 and a point where the orthogonal component of the point crosses with the line segment b1 as start terminal side, and the end point of the line segment b3 and a point where the orthogonal component of the point crosses with the line segment a3 as termination side is extracted. Next, the length of the center line of the overlapped area is calculated, and the total area is calculated as dividing the overlapped area into the triangular areas. After that, the mean distance between the line segments is calculated based on the length of the center line and the total area of the overlapped area. Alignment between the two line segment strings can be decided setting the size of calculated mean distance as reference, which accelerates the decision for the similarity.