JPH0199185A - Diagram recognizing device - Google Patents

Abstract

PURPOSE:To determine a line segment representing a shape strictly in accordance with a specified dimension by making feature points on a linear graphic expressing the shape and the dimension information without contradiction and calculating the positional coordinates of said point from the numerical value of the specified dimension. CONSTITUTION:The title device is provided with a dimension line designating line/segment specifying point correspondence part 2 to make a dimension line designating line segment and the feature points on a linear graphic expressing a shape correspond to each other, a dimension line group extraction part 3, a competition settlement processing part 4 to determine the correspondence relation between the respective feature points and a dimension line designating line segment without contradiction, a dimension line group integrating processing part 5 which detects a dimension line designating line segment that is to be reference at the time of integrating different dimension line groups and which integrates them logically, a repetitious processing control part 6 which submits the control of processing to the part 4 when an integration processing is executed, and a shape dimension determination processing part 7 which calculates the positional coordinates of a feature points on a linear graphic from the numerical values of a specified size in order to determined line that represents a shape in accordance with the specified dimension. As a result, dimension information and the feature points on the linear graphic can be made correspond to each other without contradiction, and a linear graphic expressing a shape can be determined correctly and a linear graphic expressing a sharp can be determined correctly accordance with the specified size.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention provides information on the dimension information and the line figures representing the shape in drawings in which line figures representing shapes and characters/symbols and line figures representing the dimensions of the shapes coexist. A drawing recognition device that can determine a line figure representing a shape according to the entered dimensions by associating feature points without contradiction and calculating the position coordinates of the feature points of the line figure representing the shape from the entered dimension values. It is related to.

2. Description of the Related Art Conventional drawing recognition devices include systems for recognizing three-view views in mechanical drawings. A method of associating dimension information with feature points on a line figure representing a shape in a conventional example will be described below.

In the conventional example, as shown in FIG. 15, first, all vertices of a shape line segment are projected onto the X and Y axes, and each projected coordinate is normalized. Next, each of these projections, normalized vertices, and
The extension lines in the X and X directions are associated with each other. -66.1987).

Problems to be Solved by the Invention In the conventional method, all the vertices of the shape line segment, X,
Projected on the Y axis, normalized each projected coordinate, and associated each vertex with the extension line in the X and X directions,
There are the following problems.

For example, consider a case where the conventional method is applied to a drawing as shown in FIG. 16(a). For simplicity, here,
The explanation will be limited to the X direction.

FIG. 16(b) shows the result of projecting all the vertices N1 to 12 of the shape line segment onto the X-axis, and the projection point P1 is the projection f(Nl) of the vertices N1 and N12 onto the X-axis. ) and f
(N12). Similarly, P2 is f(NIO) and f(Nil), P3 is f(N4) and f(N5
), P4 is f (N8) and f (N9), P5 is f
(N2) and f (N3), P6ζif (N6)
and f (N7).

The same m (c) ζ shows the results of normalizing each of the above projection coordinates. Although the detailed contents of the normalization process are unknown in the above-mentioned literature, the projection points on each axis are adjusted in consideration of the tilt of the drawing that occurs during scanner input, the fluctuation of the shape line segments due to handwriting, etc. It seems that integration processing is performed on consecutive items within a threshold value. Therefore,
Projection point P2゜P3 and P4 are on Q2, P5 and P6
will be integrated into Q3. In this way, when the projection and normalized vertices are associated with the extension lines, the projection point Q1 corresponds to the extension lines ■1 and ■4,
Q2 is I3. I5 and ■6, Q3 is r2 and f7
As a result, there will be a contradiction between the dimensions of each vertex. Note that even if the threshold value in the normalization described above is changed, for example, the 16th [J(a
), the dimension value indicated by the dimension line DI is 59.9, D
Considering the case where 3 is 39.9 and D4 is 40.1,
It turns out that there is no real solution.

As described above, in the conventional example, when shape line segments are dense and complex, or when multiple dimension extension lines are drawn on almost the same coordinates, inconsistencies occur in the correspondence relationships and the drawn It is not possible to determine the shape line segment for the dimension groove.

In view of the above-mentioned problems, the present invention relates dimension information and feature points on a line figure representing the shape without contradiction, and calculates the positional coordinates of the feature points on the line figure representing the shape from the entered dimension values. Accordingly, it is possible to determine a line indicating the shape according to the drawn dimensions.

Means to solve problems In order to solve the above problems, the present invention aims to solve the problems described above.

Dimension line instruction line segments indicated by dimension lines in each Y direction,
A dimension line indication line segment/dimension specification point correspondence unit that corresponds to feature points on a line figure representing the shape, and X, Y that are connected to each other.
a dimension line group extraction unit that extracts dimension lines and dimension line instruction segments in each direction; and a dimension line group extraction unit that extracts dimension lines and dimension line instruction segments in each direction; Conflict resolution processing unit that determines the correspondence relationship without contradiction when they are matched, and integrates different dimension line groups in each of the X and Y directions when there are multiple dimension line groups in each of the X and Y directions. In the dimension line group integration processing unit that detects and logically integrates the dimension line instruction line segments that serve as the reference, and in the dimension line group integration processing unit,
An iterative processing control unit that transfers processing control to the conflict resolution processing unit only when integration processing is performed for dimension line groups in each direction, and a repeating processing control unit that transfers processing control to the conflict resolution processing unit and It is equipped with a shape and dimension determination processing section that calculates from the entered dimension values and determines a line representing the shape according to the entered dimensions.

According to the above-described configuration, the present invention first extends the dimension line designation line segments in each of the X and Y directions, and associates feature points on the shape line segments within a certain width. Next, after extracting the dimension lines and dimension line designation lines in the X and Y directions that are connected to each other in the drawing as a dimension line group, the above mapping is performed to identify multiple lines belonging to the same dimension line group in the result. Detect feature points that are associated with dimension line designation segments, determine only one dimension line designation segment with the strongest connection relationship, and then connect the remaining dimension line designation segments with the feature points. Dissolve the correspondence relationship.

Next, if multiple dimension line groups are entered in each direction in the to be integrated into Next, if there is a feature point that is newly associated with multiple dimension line indicator segments belonging to the same dimension line group due to the logical integration of the dimension line groups, again, as before, the most connected relationship is After determining one dimension line instruction segment with a strong value, the correspondence between the remaining dimension line instruction segments and the feature points is resolved. The above process is
, Y until the dimension line groups in each direction are finally integrated into one. Thereafter, the position coordinates of the feature points on the line figure representing the shape are calculated from the entered dimension values, and the line figure representing the shape is determined according to the entered dimensions.

As described above, the dimension information and the feature points on the line figure representing the shape can be correlated without contradiction, and the line figure representing the shape can be determined according to the entered dimensions.

EXAMPLE Hereinafter, an example of the present invention will be described with reference to the drawings. FIG. 1 shows a block diagram of a drawing recognition device according to an embodiment of the present invention. In this embodiment, a computer automatically recognizes a hand-drawn mechanical drawing drawn by a scanner, and transfers shape line segments in the drawing to a connected CAD.

In FIG. 1, the mechanical drawing read by a scanner 8 is converted into a binary image consisting of white or black pixels and stored in an array as image data 9.

The image data 9 is processed in the image processing section 10 according to the following procedure and converted into vector information. First, the character string region extracting section 11 extracts all character string regions in arbitrary angle directions existing in the drawing, and then the approximate encoding section 12 extracts the character string regions in arbitrary angle directions.
All line figures except the character string area mentioned above are encoded with line figure description elements (hereinafter referred to as elements) consisting of straight lines, circles, and arcs, and open end points, branch points, connection points,
Feature points (hereinafter referred to as nodes) consisting of inflection points and inflection points are extracted, and the elements and nodes are represented in a graph structure.

The pattern recognition unit 13 performs various symbol recognition processes based on the element and node data obtained through the above procedure. First, the center line recognition part! In 4,
After all center lines in the drawing are extracted, center line intersection points where the center lines intersect are extracted. Next, the dimension line/dimension line instruction line segment recognition unit 15 extracts the arrowhead of the arrow, which is a terminal symbol, and also extracts the dimension line corresponding to the tip axis.

Furthermore, the line segment directly indicated by the terminal symbol is extracted as a dimension line indicated line segment. The dimension line indication line segment consists of a dimension extension line, a center line, and some outline lines. String/
In the dimension line centering section 16, the above-mentioned character string area extraction section 1
Processing is performed to associate each character string extracted in step 1 with the dimension line extracted in the dimension line/dimension line indication line segment recognition unit 15 on each list. Thereby, the writing angle of a character string written in an arbitrary direction can be determined from the angle of the associated dimension line.

The character string recognition unit 17 uses the angle of the dimension line to recognize each character in the character string and interpret the meaning of the entire character string.

The drawing recognition device 1 of this embodiment recognizes drawings by comprehensively determining the data extracted as described above. Note that the recognition result is converted by the CAD command string generation unit 18 into a command for the connected CAD 19 and then delivered.

In the drawing recognition apparatus of one embodiment configured as described above, the operation of each processing section will be explained below.

(1) Dimension line indication line segment/dimension specification point correspondence unit 2 This processing unit processes the dimension line indication line segment extracted by the dimension line/dimension line indication line segment recognition unit 15 and the characteristics of the outline line. Correspondence with dimension specifying points (including centerline intersections) is processed.

The processing differs depending on whether the dimension line designation line segment is a dimension extension line, an outline line, or a center line.

([) When the dimension line indication line segment is a dimension extension line In this case, all features on the outline line that exist within a certain width centered on the line segment that is a virtual extension of the dimension line indication line segment. Extract points as dimension specification points and make correspondences. In the dimension line designation line segment 1 shown in FIG. 2(a), a range (hatched portion) is set for correspondence as shown in FIG. 2(b). Therefore, dimension line indication line segment II includes dimension specifying point N4. N3
, N2 and N1 are associated with each other. In addition, for each associated dimension specification point, the distance from the end point of the dimension line indicator segment ■l (hereinafter referred to as the extension direction distance) and the length of the perpendicular line to the extended virtual line (hereinafter referred to as (referred to as the perpendicular distance in the extension direction) are added as auxiliary information.

(ii) When the dimension line specification line segment is an outline line In this case, both end points of the extracted dimension line specification line segment are defined as dimension specification points. That is, N7. in FIG. 3(a). N8, same figure (
N9 in b). NIO and N in the same figure (c)
12. N13 is each dimension line instruction line segment I2. I3
．． It is extracted and associated as a dimension specification point of I4.

However, when the dimension line designation segment is a circle, since the dimension line defines only the diameter or radius, there is no dimension definition point associated with the dimension line designation segment. That is, in FIG. 3(d), there is no dimension specifying point associated with the dimension line specifying line segment.

(i i i) When the dimension line specification line segment is a center line In this case, without performing the extension process of the virtual line segment as in l) above, the center line intersection point where the center lines intersect is set as the dimension specification point. Correlate it as Therefore, in FIG. 4, the dimension line specification line segment 6 is associated with the dimension specification point N15.

FIG. 6 shows the result of applying the above processing to the example shown in FIG. FIG. 6(a) shows the dimension specifying points associated with the dimension line designation line segments 11 to 117 in each direction of X and Y, and conversely, FIG. 6(b) shows each dimension in the drawing. The specified point is
, Y directions correspond to each other.

(2) Dimension line group extraction unit 3 This processing unit performs a process of extracting dimension lines and dimension line instruction segments that are connected to each other and registering them as a dimension line group.

The dimension line/dimension line indication line segment recognition unit 15 extracts line segments directly connected to the terminal symbol of each dimension line as dimension line indication line segments, and the results are stored in a list. For example, in FIG. 5, the dimension line DI in the X direction is
The dimension line instruction segments It, I2 and D2 are connected to II, I3, respectively. Therefore, the dimension lines DI and D2 and the dimension line indication segments If, T2, and 13, which are connected to each other via the dimension line indication line segment 1, are extracted as the same dimension line group Gl. Similarly, dimension line D3. D4 and dimension line instruction line segment I4. Extract I5 and 16 as dimension line group G2. Furthermore, the same applies when the dimension line instruction segment is an outline line or a center line, and the dimension line D5. D6 and dimension line indication line segment ■5, I6. Extract I7 as dimension line group G3.

On the other hand, similarly regarding the X direction, dimension lines D7 to DIO and dimension line instruction lines 110 to 114 are connected to dimension line group G.
4. Dimension lines Dll, DI2 and dimension line instruction line segment 115
-117 are each extracted as dimension line group G5.

However, this process is not performed on dimension lines that give the diameter or radius of a circle or arc, or dimension lines that indicate a chamfer or fillet, such as dimension lines D13 and D14, for example.

In addition, in this process, a center line formed by repeating long and short dashed lines is logically regarded as one dimension line instruction line segment.

(3) Conflict resolution processing unit 4 In general, dimension line instruction segments within the same dimension line group are entered because there is a relative dimensional difference between the dimension specification points that should originally correspond to each other. . Therefore, it is considered that a certain dimension specifying point will not be associated with a plurality of different dimension line designation line segments within the same dimension line group.

For example, in the example shown in FIG. 7(a), the dimension line designation line segment
In section 2, dimension specification point correspondence is provided for dimension specification point N2. N
3 and N4 are dimension line indication line segments II in the X direction, respectively.
It is assumed that the dimension line instruction line segments If, I2, and ■3 are extracted as the same dimension line group by the dimension line group extraction unit 3.

In such a case, each dimension specified point N2. N3. Each of N4 should originally be associated with either II or ■2, and if the correspondence is not corrected, it will be difficult to determine the dimensions of the shape line segment in the later shape and dimension determination processing section 20. This will create a contradiction. Also, Fig. 7(b)
In the example shown in FIG. 3, the correspondence between the dimension line designation line i and the dimension specification point is in part 2, and the dimension specification point N7. N8. N9 and NIO
are associated with the dimension line designation segments I4 and ■5 in the X direction, respectively, and in the dimension line group extraction unit 3, the dimension line designation segment I4. It is assumed that I5 and ■6 are extracted as the same dimension line group. Even in such a case, it is possible that the numerical values of the dimensions indicated by the dimension lines D3 and D4 are slightly different, so it is necessary to correct the correspondence as before.

In this way, in this processing section, in the above-mentioned dimension line specification line segment/dimension specification point correspondence section 2, each dimension specification point is associated with a plurality of different dimension line specification line segments within the same dimension line group. Only when the relationship is specified, processing is performed to eliminate inconsistencies in the correspondence relationship. In this processing section, a repeating process control section 6, which will be described later, repeatedly performs the process until all dimension line groups in the X and Y directions are finally integrated.

In FIG. 6(b), which shows the result of processing the dimension line designation line segment/dimension specification point correspondence for the example shown in FIG.
Dimensional point N2. N3. N6. It can be seen that N7 and N8 are respectively associated with the dimension line designation line segments ■5 and ■6 within the same dimension line group G2 in the X direction.

In this manner, a procedure for determining the unique dimension line instruction line segment that should originally be associated with each dimension specifying point with a conflicting correspondence relationship, and correcting the correspondence relationship will be described.

The most important information when performing such processing is the distance information from the dimension line indicating line segment added to each dimension specifying point in Part 2 of the above-mentioned dimension line indicating line/dimension specifying point correspondence. It is. That is, as shown in FIG. 8(a), the distance LHI in the extension direction of the dimension line indication line segment 1 from the end point E1, and the length of the perpendicular line to the virtual extension line of the dimension line indication line segment Extension direction distance distance! It is LVI. The extension distance is small,
In addition, it is thought that the smaller the vertical distance in the extension direction, the more accurate the correspondence relationship, which also seems to match the intuition that Admission had when looking at the drawing. Therefore, as shown in FIG. 8(b), when the dimension specification point N2 is associated with a plurality of dimension line instruction segments I2 and ■3 belonging to the same dimension line group,
The extension direction and the extension direction vertical paths atLH2, LV2 and LH3, L3 are comprehensively evaluated to uniquely determine the dimension line instruction segment that should originally correspond.

Using the extension direction and extension direction perpendicular distance obtained as described above, the correspondence relationship with dimension line designation line segments I5 and ■6 in the same dimension line group G2 in the X direction as shown in FIGS. 5 and 6 The dimension specifying point N2. N3. N6. N
7 and N8, the results of correcting the correspondence relationships are shown in the first
Figure 0 (a).

Shown in (b).

As shown in the example shown in FIG. 9, for the dimension specification point N2, the end point E1 of the dimension line specification line segment ■1 that should originally correspond to the dimension specification point N2.
Since the distance in the extending direction from the end point E2 is larger than the distance in the extending direction from the end point E2 of the dimension line indication line segment 2, it is possible that the above judgment may be made incorrectly. In preparation for such a case, this processing unit avoids the above-mentioned erroneous judgment by detecting an alternative node and substituting its distance. In other words, when calculating the extension direction and vertical distance in the extension direction between the dimension specification point of interest and the dimension line specification line segment, there is a line segment connected to the dimension specification point of interest that has the same angle as the dimension line specification line segment of interest. If a line segment exists, and the other end point of the line segment is a dimension specification point that is associated with the dimension line specification line segment of interest, and the distance in the extension direction becomes small, the dimension specification of interest is applied. Evaluation is performed by replacing the extension direction of a point and the distance perpendicular to the extension direction with the distance to the dimension specifying point. That is, in FIG. 9, the distance evaluation to the dimension specifying points Nl and N2 is
Nl is used for the dimension line indication line segment ■1, and N2 is used for I2, respectively. On the other hand, the distance evaluation to the dimension specification points N3 and N4 is performed using N3 for the dimension line indication line segment [l, respectively. , I2 is performed at N4. By performing such processing, it is possible to evaluate not the physical distance but the logical distance, which is very useful in determining the correspondence relationship.

(4) Dimension line group integration processing unit 5 In general, in mechanical drawings, dimension lines are often written dispersedly within the drawing, so in order to determine the dimensions of shape lines, it is necessary to use the dispersed dimension information described above. It is necessary to logically combine the two.

This processing section logically integrates each dimension line group that is dispersed in the drawing using the correspondence between dimension line designation lines and dimension specification points obtained so far, and information on dimension line groups. Perform the processing to do. Note that in this processing section, when the number of dimension line groups is three or more, instead of performing the integration process at once as described later, it always integrates the two dimension line groups that are described with the strongest connection relationship. conduct. Therefore, this process and the conflict resolution processing unit 4 described above are repeated ((number of dimension line groups)−1) times in each of the X and X directions by the iterative process control unit 6, which will be described later.

The integration process of dimension line groups will be described below.

First, a process is performed to extract two dimension line instruction segments that are candidates to become connection lines when integrating each dimension line group from the correspondence between dimension line instruction segments and dimension specification points. That is, in FIG. 10(b), the dimension specifying points Nl, N2 . N3.
N6. N7. N8° At N9 and N, 10, the combination of dimension line designation line segments in the X direction (I L I4), (
I 1, 17), (14, I7), (13, I5) and (I3, I6), the combination (IIO, [15) of the dimension line indication line segment in the Extract as a candidate combination of dimension line designation line segments. In order to accurately extract connecting lines from such candidates, we focus on the following features. First of all, the connecting line that connects each dimension line group is originally a line (plane) that should be the reference during processing, so the dimension line instruction line segment that is the connecting line can connect relatively many dimension lines. Often receives instructions. Further, since connection lines are often taken at end faces, dimension line instruction line segments that are connection lines are often located at the ends of the dimension line group to which they belong. Finally, the dimension line designation line segments that are connecting lines should be associated with common dimension specification points, and the vertical distances added to the correspondence relationships should both be less than the threshold value. It should be.

The above characteristics are evaluated according to the following procedure, and connection line extraction processing is performed. Combinations of two dimension line designation segments that are associated with common dimension specification points have already been extracted as candidates. Next, the sum of the number of dimension lines for each combination of dimension line instruction line segments that are connection line candidates is calculated. Among the combinations of all the previously determined dimension line designation segments, the combination that maximizes the sum of the number of dimension lines is determined. If they are both located at the ends of their respective dimension line groups, and the vertical distances are both less than or equal to the threshold, these two dimension line indicator segments are determined to be connection lines, and each Integrate dimension line groups to which dimension line indicator segments belong.

Through the above process, in FIG. 5, the combination of dimension line designation segments in the X direction (If, I4) and the combination of dimension line designation segments in the X direction (110, ll5) are extracted as connecting lines, and the dimension line group G1 and G2, and G4 and G5 are each logically coupled.

In addition, in FIG. 5, the reason why the three-dimensional line designation line segments If, 14, and I7, which eventually become connection lines, are not extracted and integrated at the same time will be described below. For example, FIGS. 11(a) and (b)
The two examples shown in 2 are almost the same in the shape of the bottom and the method of drawing dimension lines (a difference of 0.01 mm cannot be distinguished).

However, the 3 dimension line instruction line segment I2 in FIG. 11(a)
．． I3 and I4 are the same connecting line, whereas in FIG. 2(b), dimension line designation line segments I7 and I9 and I5 and I6 constitute connecting lines, respectively. In this way, in mechanical drawings, it is necessary to comprehensively judge not only a part of the information but also the entire information. A method that integrates groups sequentially is considered desirable.

(5) Repetitive processing control unit 6 In a drawing in which multiple dimension line groups in each of the X and Y directions are entered, the dimension line group integration processing unit 5
By merging different dimension line groups, multiple dimension line specification lines that are associated with dimension specification points that were previously subjected to conflict resolution processing may be newly combined into the same dimension line group. . Therefore, it is necessary to perform the above-mentioned conflict resolution process again, and then, if there are multiple dimension line groups in each of the X and Y directions, it is necessary to repeat the process of integrating dimension line groups.

In this way, in this processing section, the processing flow is transferred to the conflict resolution processing section 4 described above until the dimension line groups in each of the X and Y directions are finally integrated into one. 1st
The flow of processing when the conflict resolution processing unit 4 and the dimension line group integration processing unit 5 are repeatedly performed on drawing 0 is shown below.

In FIG. 10(b), dimension specifying point N2. N3, N6
and N7 are multiple dimension line instruction lines ■3 and I5 in the same dimension line group in the X direction, and similarly N8 and N
9 corresponds to I3 and I6, respectively. Therefore, the conflict resolution processing unit 4 evaluates the extension direction and the perpendicular distance in the extension direction, and corrects the correspondence with respect to each of the dimension specification points. The results are shown in FIG.

In addition, in FIG. 10(b), the dimension line designation lines ■1 and I7 in the X direction, which correspond to the dimension specification points N1 and NIO, respectively, and the dimension specification points N1 and NIO
Dimension line instruction line segment 110 in the X direction associated with 2
Although ``15'' and ``15'' belong to the same dimension line group, the combination of these dimension line instruction segments is a connecting line extracted when integrating dimension line groups,
There is no competition between the corresponding personnel. Therefore, conflict resolution processing is not performed for the above combination of dimension line designation segments.

Next, the flow of processing moves to the dimension line group integration processing section 5. In Fig. 12(b), the two dimension line groups G4 and G5 in the X direction (see Fig. 5 @) have already been integrated, but the three dimension line groups CI, C; 2 and G3 in the X direction are , G1 and G2 are just integrated,
It is necessary to roughly integrate with G3. Therefore, the dimension line group integration processing unit 5 extracts the combination of dimension line instruction segments (If, I7) ((I4.I7) is also acceptable) as a connecting line, and extracts the dimension line group G1 and G3.
are logically integrated. As a result, along with the previous result, dimension line group 01. G2 and G3 are all logically integrated via the dimension line indicator segments [1, 14 and I7, which are the respective connection lines.

Now, as mentioned above, due to the new integration of dimension line groups, it is possible that a new competitive relationship will occur as described above, so the iterative processing control unit 6 restarts the processing flow. The content is transferred to the conflict resolution processing section 4. In this example,
As shown in FIG. 12(b), since no new competitive relationships have arisen in either the X or Y directions, no processing is actually performed and the process moves to the next dimension line group integration processing section 5. However, since all dimension line groups have already been integrated in both the X and Y directions, the dimension line group integration processing section 5 does not perform integration processing. The iterative processing control section 6 detects that all the integration processing has been completed and ends the iterative processing, so the flow of processing is changed to the subsequent shape and dimension determination processing section 7.
will move to.

(6) Shape and Dimension Determination Processing Unit 7 In mechanical drawings, dimension lines indicating the dimensions between dimension specifying points are often drawn in scattered locations, so in order to determine the position of the shape lines, It is necessary to logically combine these scattered dimensional information. The dimension line group integration processing unit 5 extracts dimension line instruction line segments, which are connection lines that govern logical connections, from within each physically separate dimension line group. In this processing section, in order to facilitate the subsequent calculation of dimensions between dimension specification points, we first introduce the concept of dimension specification virtual lines, and create one line for multiple dimension line specification lines registered as connecting lines. , and for all remaining dimension line indication lines,
Assign one dimension defining virtual line to each. As a result, the distance between the dimension line designation line segment and the dimension definition virtual line is combined with the result of part 2, and the dimension definition virtual line and the dimension definition point are indirectly associated on the list. The result of performing this processing on the example shown in FIG. 5 is shown in FIG. 13(a).

FXI to FX7 are dimension defining virtual lines in the X direction, and FYI to FY7 are dimension defining virtual lines in the X direction.

Next, from among the dimension defining virtual lines in each of the X and Y directions, reference dimension defining virtual lines in each of the X and Y directions, which serve as reference lines for determining the position coordinates of the outline line, are determined. In mechanical drawings, drafters generally design with reference lines in each of the X and Y directions in mind, and often write dimensions from the reference lines. Therefore, in this system, among all the dimension specification virtual lines in each of the X and Y directions, the dimension specification virtual line on which the largest number of dimension lines are written is used as the reference dimension specification virtual line in each of the X and Y directions. It is extracted as In the example of FIG. 13(b), dimension defining virtual lines FXI and FYI (see FIG. 5) to which the largest number of dimension lines are associated are
, Y directions as standard dimension defining virtual lines.

Finally, the dimension values between the reference dimension defining virtual lines in each of the X and Y directions and all the dimension defining virtual lines in each direction are calculated. In the example of FIG. 13(b), the reference dimension defining virtual line FXI in the X direction and the dimension defining virtual line FX2. FX3. FX
4. FX5. Since the dimension values between FX6 and FX7 are written directly on the drawing, there is no need to newly calculate the dimension values.

However, in the X direction, the reference dimension definition virtual line FYI
Since the dimension values of the dimension specification virtual line FY4 leap are not directly entered, the dimension values are calculated. That is, the dimension values D (FYI, FY4) of the reference dimension defining virtual line FYI and the dimension defining virtual line FY4 are determined by the calculations shown below.

D (FYI, FY4) = D (FYI, FY3) + D (FY3.FY4)
FIG. 13(c) shows the dimension values between the reference dimension defining virtual lines in each of the X and Y directions and other dimension defining virtual lines in each direction, which are determined by the above processing.

Finally, determine the circle, arc radius, center coordinates, and starting and ending angles that make up the outline. First, the dimension line designation line segment is extracted as a circle or arc on the outline line, and the radius of the circle or arc can be determined from the dimension auxiliary symbol and dimension value shown in the associated character string. . Next, the coordinates of the center line intersection have already been determined and are taken as the center coordinates.

Note that the starting and ending angles of the arc can be easily calculated because the coordinates of both end points and the center coordinates have already been determined.

As described above, by associating dimension information and feature points on the line figure representing the shape without contradiction, and calculating the position coordinates of the feature points on the line figure representing the shape from the entered dimension values,
It is possible to create shape line segment data that matches the entered dimensions.

Effects of the Invention As described above, according to the present invention, the following effects can be obtained.

(1) Even in a complex drawing with dense shape line segments, each dimension extension line and feature points on the shape line segments can be correlated without contradiction. (For example, Fig. 14 (a)) (2) For each dimension extension line in each of the X and Y directions, unless it is ultimately necessary, it is necessary to Even in a drawing in which a plurality of dimension extension lines are drawn on the same coordinates, accurate correspondence can be made (for example, FIG. 14(b)).

(3) After associating the dimension extension line in the drawing with the feature points on the shape line segment, the shape line segment is determined according to the dimension values entered, so the actual shape line segment on the drawing The length and the dimension value entered do not need to match. Therefore, even if dimensions are changed, a shape line segment that matches the dimension values can be obtained by simply changing the dimension values.

(4) In order to extend the dimension extension lines in each of the X and Y directions and correlate them with the feature points of the shape line segments that exist within a certain width, the inclination of the manual image that occurs when drawing the drawing manually using a scanner is I underestimate the need for correction. 4, it becomes possible to perform high-speed correspondence processing.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a drawing recognition device according to an embodiment of the present invention, FIG. 2 is a diagram showing a method for associating dimensions with dimension specifying points when a dimension line designation line segment is a dimension extension line, and FIG. Figure 3 shows the method of correspondence with dimension specifying points when the dimension line indicating line segment is a shape line segment, and Fig. 4 shows the correspondence with dimension specifying points when the dimension line indicating line segment is a dashed-dotted line. The correspondence is a diagram showing the method, FIG. 5 is a diagram showing a sample for detailed explanation of the present invention, and FIG. Figure 7 is a diagram showing a sample that requires modification of the correspondence relationship, Figure 8 is a diagram showing the definition of the extension direction and the perpendicular distance to the extension direction, and Figure 9 is a diagram showing the extension direction and the perpendicular distance to the extension direction. FIG. 10 is a diagram showing the switching, and the correspondence shown in FIG.
Figure 1.1 is a diagram showing the reason for merging dimension line groups two by two, Figure 12 is a diagram showing the results modified by
FIG. 13 is a diagram showing the correspondence between dimension line designation segments and dimension specification points finally obtained for the figure, and FIG.
14 is a diagram showing the effect of the drawing recognition device of the present invention, FIG. 15 is a diagram showing the operation in the conventional example, and FIG. 16 is a diagram showing problems in the conventional example. DESCRIPTION OF SYMBOLS 1... Drawing recognition device, 8... Scanner, 9... Image data, 10... Image processing section, 13... Pattern recognition section, 18... CAD command string control section, 19...
・CAD. Name of agent Patent attorney Toshio Nakao Figure 1 Book Figure 5 Figure 6 (a) Figure 6<b) Figure 10 (+2) Figure 10 (b) Figure 117 (a) ( b) Tq nl/6 N13 N14
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Claims (1)

[Claims] All character string areas in the drawing in which line figures representing the shape and characters, symbols, and line figures representing the dimensions of the shape are mixed are extracted, and the feature points on the line figure are extracted and the features are extracted. The line figure connecting points is approximately encoded into a line element, and all center lines, dimension lines, and dimension line indicating line segments indicated by the dimension lines in the drawing are recognized, and , in the image data in which each character in the character string is recognized and the meaning of the entire character string is interpreted by associating the character string area with the adjacent dimension line, the size in each of the X and Y directions. a dimension line indicating line segment/dimension specifying point correspondence unit that associates the dimension line indicating line segment indicated by a line with the feature point on the line figure representing the shape; a dimension line group extraction unit that extracts the dimension line and the dimension line instruction line segment;
a conflict resolution processing unit that determines correspondence relationships without contradiction when each of the feature points is associated with a plurality of different dimension line instruction segments within the same dimension line group in each of the X and Y directions; , when there are multiple dimension line groups in each of the X and Y directions, detecting a dimension line instruction line segment that serves as a reference when integrating different dimension line groups in each of the X and Y directions;
The conflict resolution described above is performed only when the dimension line group integration processing unit that logically integrates the dimension line groups and the dimension line group integration processing unit perform the integration processing on the dimension line groups in each of the X and Y directions. A repetitive processing control unit that transfers processing control to a processing unit, and a shape and size determination unit that calculates the position coordinates of feature points on a line figure representing the shape from the entered dimension values and determines a line that represents the shape according to the dimensions. The processing unit is equipped with a processing unit, which matches dimension information and feature points on a line figure representing the shape without contradiction,
A drawing recognition device characterized in that a line representing a shape is determined according to the entered dimensions by calculating positional coordinates of feature points on a line figure representing the shape based on entered dimension values.