JPH05108818A - Vector data optimizing device - Google Patents

Abstract

PURPOSE:To execute the analysis and display of vector data at high speed by setting a converting condition for simplifying the vector data of a complicated shape whose constituting points are in a large number, collating the constituting points in order to judge whether or not each constituting point satisfies the condition, and erasing the constituting points when the constituting point satisfies the condition in order to prepare the optimized vector data. CONSTITUTION:An interior angle theta1 between a segment P1 P2 and a segment P2 P3 is found, and compared with an angle beta. Then, the collation of a constituting P3 is operated. That is, the length of the segment P2 P3 and a segment P3 P4, (d)23 and (d)34, are found, and compared with a distance alpha. As for the vector data, (d)23>alpha, and (d)34<alpha, and then the converting condition can be satisfied. Therefore, a constitution P34 is newly added to the central point of the segments P2 P3 and the P3 P4, and the constituting points P3 and P4 are erased. This processing is repeated until the final constituting point. As a result, finally the constituting points P3 and P4 are converted into the constituting point P34, and the vector data whose constituting point P5 is erased are prepared, so that the analysis and display of the vector data can be operated at a high speed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vector data optimizing device.

[0002]

2. Description of the Related Art Generally, natural terrain such as terrain is
The shape is irregular and often complicated. When making a topographic map into vector data, the method of digitizing the constituent points along the shape of the topographic map is adopted, but at this time, if the shape is complicated, the number of constituent points will be huge. Sometimes.

Conventionally, when the vectorized data is processed for display or the like, the coordinates of all the constituent points are analyzed.

[0004]

As described above, in the conventional processing method for vectorized data, the coordinates of all the constituent points are analyzed. However, for the vector data that is precisely digitized, It often contains more constituent points than necessary, which requires a huge amount of processing time when processing that data, especially when displaying it on a display device, and also puts a heavy burden on the operator. It has the drawback of

An object of the present invention is to solve the above-mentioned drawbacks of the conventional vector data processing method and to create optimized vector data capable of speeding up the processing while maintaining the shape of the vector data. To provide a vector data optimization device for

[0006]

A vector data optimizing apparatus of the present invention is a vector data storage section for storing vector data to be converted, and a conversion condition storage section for storing conversion conditions of the vector data. And comparing the vector data with the conversion condition, and deleting the vector data when the angle formed by two adjacent sides of the vector data or the distance between two adjacent constituent points satisfies the conversion condition. A vector data optimizing unit for producing optimized vector data, and an optimized vector data output unit for outputting the vector data produced by the vector data optimizing unit.

[0007]

Embodiments of the present invention will now be described with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a flow chart showing the operation of the embodiment of FIG.
FIG. 3 is a schematic diagram showing an optimization process of vector data in the embodiment of FIG.

In the embodiment shown in FIG. 1, a vector data storage unit 1 for storing vector data to be converted, a conversion condition storage unit 2 for storing conversion conditions of vector data,
A vector data optimizing unit 3 which collates a series of vector data with a conversion condition and converts the series of vector data into a straight line when the series of vector data satisfies the conversion condition.
And an optimized vector data output unit 4 that outputs the vector data created by the vector data optimization unit 3.

The vector data storage unit 1 stores graphic data (constant point coordinates) of a line segment sequence or a closed area. The conversion condition storage unit 2 stores a determination method and a determination condition value used when optimizing the vector data stored in the vector data storage unit 1. The vector data storage unit 1 and the conversion condition storage unit 2 can be provided on the same storage device such as a magnetic disk device. The vector data optimization unit 3 reads the vector data to be converted from the vector data storage unit 1, further reads the conversion conditions of the vector data from the conversion condition storage unit 2 and collates them, and checks all the constituent points of the vector data. The weight is determined and the extra constituent points are deleted to convert the vector data into optimum vector data. The optimized vector data output unit 4 outputs the optimized vector data created by the vector data optimization unit 3 to a storage device or the like.

Next, the operation of the vector data optimizing apparatus configured as described above will be described with reference to FIGS. 2 and 3.

First, the vector data optimizing unit 3 reads the conversion condition for optimizing the vector data from the conversion condition storage unit 2 (step 11). The exchange condition is a condition for determining a weight of a constituent point of vector data, and for example, a specific judgment such as an angle formed by two adjacent sides forming the vector data and a distance between two constituent points. It is a value.

Next, the coordinates of the constituent points of the vector data are read from the vector data storage unit 1 (step 12). Next, the conversion conditions read in step 11 are compared with the coordinates of the constituent points of the vector data read in step 12 (step 13). Constituent points P ₁ · P as shown in FIG.
_In the case of vector data consisting of ₂ · P ₃ ……, if the distance between two adjacent constituent points is smaller than a constant value α,
Alternatively, when the internal angle (≦ 180 degrees) formed by two adjacent sides is larger than the constant value β, the matching is performed by giving a conversion condition of deleting the constituent point that is the vertex. The matching is first performed on the constituent point P ₂ , and then the line segment P ₁ P ₂ and the line segment P ₂ P ₃
Then, the lengths d ₁₂ and d ₂₃ of the are calculated and compared with the distance α (step 14). In the case of the vector data of FIG. 3A, since (d ₁₂ > α) (d ₂₃ > α), the conversion condition is not satisfied. Then, the internal angle θ ₁ formed by the line segments P ₁ P ₂ and P ₂ P ₃ is obtained and compared with the angle β (step 14). In the case of the vector data in FIG. 3A, (θ ₁
Since <β), the conversion condition is not satisfied. Therefore, the constituent point P ₂ is not deleted.

Subsequently, the constituent point P ₃ is collated. That is, the lengths d ₂₃ and d ₃₄ of the line segment P ₂ P ₃ and the line segment P ₃ P ₄ are obtained and compared with the distance α (step 14). In the case of the vector data of FIG. 3A, (d ₂₃
> Α), but the conversion condition is satisfied because (d ₃₄ <α). Therefore, a new constituent point P ₃₄ is added to the central points of the line segments P ₂ P ₃ and P ₃ P ₄ and the constituent points P ₃ and P ₄ are deleted (step 15). Such processing is repeated until the final constituent point (step 16).

As a result, finally, as shown in FIG. 3B, the constituent points P ₃ and P ₄ are converted into constituent points P _34, and vector data in which the constituent points P ₅ are deleted are created. As a result, this is output from the optimization vector data output unit 4 (step 16).

[0016]

As described above, the vector data optimizing device of the present invention sets conversion conditions for simplifying vector data having a large number of constituent points and a complicated shape, Performs analysis and display of vector data at high speed by collating whether or not each constituent point satisfies the conversion condition, and if it satisfies, creating the optimized vector data by deleting the constituent point. There is an effect that it is possible to reduce the burden on the operator.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

FIG. 2 is a flowchart showing the operation of the embodiment of FIG.

FIG. 3 is a schematic view showing a vector data optimization process in the embodiment of FIG.

[Explanation of symbols]

 1 vector data storage unit 2 conversion condition storage unit 3 vector data optimization unit 4 optimized vector data output unit 11 to 17 steps

Claims (2)

[Claims] 1. A vector data storage unit for storing vector data to be converted, a conversion condition storage unit for storing conversion conditions of the vector data, and the vector data and the conversion conditions are collated. A vector data optimizing unit that creates optimized vector data by deleting the vector data when the vector data satisfies the conversion condition, and an optimization that outputs the vector data created by the vector data optimizing unit. A vector data optimization device comprising: a vector data output unit. 2. A vector data storage unit for storing vector data to be converted, a conversion condition storage unit for storing conversion conditions of the vector data, and the vector data and the conversion conditions are collated. A vector data optimizing unit that creates optimized vector data by deleting the vector data when an angle formed by two adjacent sides of the vector data or a distance between two adjacent constituent points satisfies the conversion condition. And a vector data output unit that outputs the vector data created by the vector data optimization unit.