JPH0640346B2 - Connection method between unconnected end points of line figure vector - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a connection method between unconnected end points of line drawing vectors, and particularly selects connection candidate points from a pair of unconnected end points and connects the connection candidate points to each other. The present invention relates to a connection method between unconnected end points of a line figure vector that connects candidate points that are candidate points.

(B) Background of technology In image processing, line figure processing in figure recognition, etc., the drawing in which the line figure is drawn is read by a scanner,
A technique of obtaining dot data and then converting the dot data into a vector is used. The line converted into a vector by this technique is the shade of the figure, fading at the time of reading, or the line of the line figure drawn due to the overlapping of colors in the figure written in multiple colors It does not become a faithful vector and a disconnection occurs.

Since such disconnection hinders subsequent processing, it is necessary to connect the disconnection prior to starting the processing.

(C) Object of the invention The present invention was devised to meet the above-described technical problems, and the purpose thereof is to connect vectors in which disconnection has occurred to reduce the disconnection as much as possible and to perform subsequent processing. An object of the present invention is to provide a connection method between unconnected end points of a line drawing vector that can eliminate an obstacle to the extent possible.

(D) Structure of the Invention And, in order to achieve this object, the first method of the present invention is
An unconnected end point extraction unit that extracts an unconnected end point from the vector data of the input line figure line, an unconnected end point that is a connection candidate point selection target, and an unconnected end point that is a connection candidate selection target The slope of each vector extending from each of the unconnected end points selected as the end points is equal to the slope of at least one of the original vectors from both end points, and the lines do not form an acute angle. Among the unconnected end points to be selected from the connection candidate points that match the combination conditions, the connection candidate point selection unit that selects the unconnected end point that minimizes the distance as the connection candidate point, and the connection candidates that are mutually connection candidate points A connection vector generating unit for newly generating vector data connecting between points is provided to connect between unconnected end points, and the second method thereof is
An unconnected end point extraction unit that extracts an unconnected end point from the vector data of the input line figure line, an unconnected end point that is a connection candidate point selection target, and an unconnected end point that is a connection candidate selection target The slope of each vector extending from each of the unconnected end points selected as the end points is equal to the slope of at least one of the original vectors from both end points, and the lines do not form an acute angle. Among the unconnected end points to be selected from the connection candidate points that match the combination conditions, the connection candidate point selection unit that selects the unconnected end point that minimizes the distance as the connection candidate point, and the connection candidates that are mutually connection candidate points The connection vector generator that newly generates the vector data that connects the points and the means that is repeated from the beginning when the unconnected end points remain are provided to connect the unconnected end points. It is obtained by way.

(E) Embodiments of the Invention Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 shows an embodiment of the present invention. In this figure,
Reference numeral 1 denotes an unconnected end point extraction unit, whose input 2 is supplied with all the vector data obtained from the line figure line, and whose output 3 generates unconnected end point data. 4 receives the unconnected end point data, evaluates the possibility of connection while advancing the processing between the evaluation table memory 5 and the distance calculation unit 6, selects a connection candidate point for each unconnected end point, and outputs it. 7 is an end-point connection evaluation unit for sending to 7. Reference numeral 8 is a connection vector generation unit that responds to the connection candidate points for each unconnected end point to newly generate vector data for connecting the connection candidate points that are connection candidate points to each other, and sends it to its output 9. is there.

Next, the operation of the present invention having the above configuration will be described.

The vector data of the line figure is given to the unconnected end point extraction unit 1 via the input 2. The data is generated as follows. That is, the line is 0 °, 45 with respect to the x-axis.
It is drawn with only 4 kinds of inclinations of °, 90 °, 135 °, and ± 22.5 for the above 4 kinds of inclinations in consideration of the actual inclination change factors such as displacement when drawing and distortion when vectorizing.
Those within the range of ° are regarded as belonging to any one of the above-mentioned four types of inclination and processed. Then, the end point number of the line is given as shown in FIG. 2 according to the slope of the line and which side the end point is on the line, and the coordinates of the end points of the vectorized line are given as follows.

In the vector data generated as described above, (x
A pair of i, yi) that appears more than once means that an endpoint of a vector is connected to another vector, and a coordinate that appears only once means an unconnected endpoint. Therefore, the unconnected end point extraction unit 1 that has received the vector data as described above extracts all the unconnected end points or the unconnected end points in a predetermined area using the vector data, and also obtains the end point number and then The unconnected end point list as described above is created and sent to the end point connection evaluation section 4.

The end-point connection evaluation unit 4 requires processing with the evaluation table memory 5 as described above, and the table is created in advance as follows. That is, when a vector can be generated between a certain unconnected end point A and another unconnected end point B, combinations of possible end point numbers for the unconnected end point A for this vector (provided that vector data Is generated as described above.) Is 8 × 8 × 8 = 512 ways. When the unconnected end point A is fixed to a specific end point, for example, the end point with the end point number of 1 as described above, there are 8 × 8 possible combinations of end point numbers for the unconnected end point A. Further, considering the case that cannot occur due to the relationship between the line connecting the two points and the line extending on both sides of the two points due to the property of the drawn line figure and the property of disconnection due to blurring, the following condition (this is This is an example.), 1. Lines never run on the same line twice.

2. The lines do not form an acute angle.

3. The slope of the line drawn between the end points matches the slope of at least one of the lines extending from both ends.

When the unconnected end point A is fixed to the specific end point 1, there are nine possible combinations of end point numbers for the unconnected end point A as shown in FIG. The connection table below shows this relationship as a table.

In the above table, B is the end point number on the end point B side, A is the end point number of the end point A when a vector is generated between AB,
O marks indicate possible combinations, and X marks indicate those that do not meet the combination conditions.

The evaluation table memory 5 also creates and stores a table similar to the above table for the endpoint numbers 2 to 8 of the endpoint A.

Eight from the end point number of one end point (this is A ₁ ) of the unconnected end points in the unconnected point list input using the evaluation table of the memory 5 in the end point connection evaluation section 4. Determine one of the tables. It is possible to use the table and use the endpoint numbers of other unconnected endpoints (this is referred to as B ₁ ) and the endpoint numbers of the endpoints on the A ₁ side when it is assumed that a vector is generated between A _{1 and} B ₁ . Check whether there is a combination (marked with O).

Between unconnected end points (A ₁ B
_The distance calculation unit 6 calculates the distance (between ₁ ). On the contrary, if there is no possible combination, the process proceeds to the next unconnected end point B ₂ .

In this way, the shortest distance among the distances between the end point A ₁ and the end point Bi that can be another possible combination is determined as the connection candidate point for the unconnected end point A ₁ .

This process continues until all unconnected endpoints have been reached.

The connection candidate point data thus obtained is sent to the connection vector generation unit 8, and new vector data for connecting the connection candidate points that are mutually connection candidate points among the connection candidate point data is newly generated, and the connection vector is generated. Output from the generator 8.

By such a process, it is possible to connect the discontinuous vectors.

However, if the unconnected end points are densely packed, they may not be connection candidate points. For example, the fourth
As shown in the figure, there may occur a case where Ai is Ci, Bi is Ai, Ci is Di, and Di is Ci as connection candidate points. In this case, a vector is created between Ci and Di, but both Ai and Bi remain as unconnected end points. In such a case, Ai and Bi can be connected by repeating the above-described series of processes again from the beginning for the vector data of the line figure including the newly generated vector data. In this way, the number of unconnected end points can be reduced.

In the above embodiment, the connection candidate points are selected in consideration of the distance between the evaluated end points and the inclination of the vector extending from the end points, but the present invention is not limited to this.

(F) Effects of the invention As is clear from the above description, according to the present invention, the connection between unconnected end point pairs is generated only when the connection candidate points are mutually connected, so that the occurrence of erroneous connection is reduced. By repeating the connection process, the number of unconnected end points can be reduced, and the desired purpose can be achieved with simple processes such as table reference, distance calculation, and comparison.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of the present invention, FIG. 2 is a diagram illustrating a constraint condition when vectorizing a line, and FIG. 3 is an example for creating a table used in the present invention. Figure,
FIG. 4 is a diagram illustrating a problem that occurs when unconnected end points are densely packed. In the figure, 1 is an unconnected end point extraction unit, 4 is an end point connection evaluation unit,
Reference numeral 5 is an evaluation table memory, 6 is a distance calculation unit, and 8 is a connection vector generation unit.

Front page continued (72) Inventor Hiroaki Harada 1015 Kamiodanaka, Nakahara-ku, Kawasaki-shi, Kanagawa Fujitsu Limited (56) References JP-A-56-92685 (JP, A) JP-A-55-69878 (JP, A) JP-A-58-159186 (JP, A) JP-A-55-124873 (JP, A) JP-A-54-153535 (JP, A)

Claims (2)

[Claims] 1. An unconnected end point extraction unit for extracting an unconnected end point from vector data about an input line figure line, and an unconnected end point for which a connection candidate point is selected for each unconnected end point for which a connection candidate is selected. And the gradient of each vector extending from each of the unconnected endpoints and the unconnected endpoint selected as the selection target matches the gradient of at least one of the original vectors from both endpoints, and the lines form an acute angle. The connection candidate point selection unit that selects the unconnected end point that minimizes the distance as the connection candidate point among the unconnected end points that are the objects of selection of the connection candidate point that matches the combination condition that does not exist A line figure vector characterized by connecting between unconnected end points with a connection vector generating unit for newly generating vector data connecting connection candidate points Connection endpoint-to-endpoint connection method. 2. An unconnected end point extraction unit for extracting an unconnected end point from vector data about an input line graphic line, and an unconnected end point for which a connection candidate point is selected for each unconnected end point for which a connection candidate is selected. And the gradient of each vector extending from each of the unconnected endpoints and the unconnected endpoint selected as the selection target matches the gradient of at least one of the original vectors from both endpoints, and the lines form an acute angle. The connection candidate point selection unit that selects the unconnected end point that minimizes the distance as the connection candidate point among the unconnected end points that are the objects of selection of the connection candidate point that matches the combination condition that does not exist A connection vector generation unit that newly generates vector data that connects between the connection candidate points that are points, and a means for re-starting from the beginning if an unconnected end point remains Unconnected endpoint-to-endpoint connection method of linear graphic vector is characterized in that so as to connect the points.