JPH04358290A - Graphic measuring device - Google Patents

Abstract

PURPOSE:To improve the graphic measuring accuracy by decreasing the number of subject points when the absolute maximum length or the enveloping length of a graphic is measured in order to increase the measuring speed and furthermore obviating the rotation of the graphic in regard of the absolute maximum length of the graphic. CONSTITUTION:A run coordinate measuring device 2 obtains the coordinates of both start and end points for each run of a graphic to be measured which is stored in an image memory 1. A feature point extracting part 41 (consisting mainly of a CPU 4) extracts the coordinates of the start and end points forming a projecting part in the subject graphic cut of the coordinates of the start and end points obtained by the device 2 as the coordinates of a feature point in accordance with the value of a (z) component of the outer product of a vector. Then the absolute maximum length or the enveloping length of the subject graphic are obtained based on the coordinates of the extracted feature point.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a figure measuring device suitable for determining the absolute maximum length and envelope circumference of a digitized figure.

0002

2. Description of the Related Art Conventionally, a figure measuring device for determining the absolute maximum length and envelope circumference of a digitized figure, such as a binary figure, has been known. Here, the absolute maximum length of a figure refers to the largest vector that the figure has, as shown in FIG. 9(a). Also, the envelope perimeter of a figure is
As shown in FIG. 9(b), it refers to the length of the envelope for the figure.

Conventionally, in order to find, for example, the absolute maximum length of a figure using this type of figure measuring device, first, while rotating the figure to be measured (binary figure) at a constant angle, the points of contact between the rotated figure and its circumscribed rectangle are measured. Find the distance between the two points. Then, the largest value among all the values found is set as the absolute maximum length.

However, this method has the problem that since the target figure is rotated, the figure is deformed and it is not possible to find accurate points of contact. Furthermore, since the rotation is made at a fixed angle, the angle at which an accurate contact point can be found may be lowered. Furthermore, there is a problem that the processing speed is slow because the measurement is performed while rotating the target figure.

On the other hand, in order to find the envelope perimeter of a figure using a conventional figure measuring device, draw a line at a fixed angle from each point of the figure to be measured, and find the point where the line becomes the envelope (envelope point). However, this method had a problem in that it took a long time to measure because the envelope points were determined from each point of the target figure to all points.

[0006]

[Problems to be Solved by the Invention] As mentioned above, conventional figure measuring devices have low measurement accuracy because they rotate the target figure at a fixed angle to determine the absolute maximum length of the figure. There was also the problem of slow speed.

[0007]Furthermore, the conventional figure measuring device uses a method of calculating the envelope point from each point of the target figure to all the points in order to find the envelope perimeter of the figure, so there is a problem that measurement time is required. there were.

The present invention has been made in view of the above-mentioned circumstances, and its purpose is to obtain points to be targeted when determining the absolute maximum length of a figure without rotating the figure, and to reduce the number of points. The object of the present invention is to provide a graphic measuring device that can quickly determine an accurate absolute maximum length.

Another object of the present invention is to provide a figure measuring device that can reduce the number of points (feature points) to be targeted when determining the envelope points of a figure, thereby quickly determining the envelope perimeter of the figure. There is a particular thing.

0010

[Means for Solving the Problems] As shown in FIG. 1, the present invention provides a run coordinate measuring device for sequentially determining the coordinates of the start point and end point of each run of a figure to be measured stored in an image memory 1. (Run coordinate measuring means) 2 and from the coordinates of the starting point and ending point for each run obtained by this run coordinate measuring device 2, the starting point and ending point that form a convex portion on the figure to be measured are determined. A feature point extraction unit (feature point extraction means) 41 is provided to extract the coordinates as the coordinates of the feature point, and based on the coordinates of the feature point extracted by the feature point extraction unit 41, the absolute maximum length of the figure to be measured, Alternatively, the method is characterized in that the envelope perimeter is determined.

The present invention also provides a start coordinate buffer (first buffer) 31 and an end coordinate buffer (second buffer) for storing the coordinates of the start point and end point extracted by the feature point extractor 41. 32, when the coordinates of the start point and end point of one run are determined by the run coordinate measuring device 2, the coordinates other than those forming the convex portion are calculated by adding the determined start point and end point. The coordinates of the obtained start point and end point are deleted from the start coordinate buffer 31 and end coordinate buffer 32, and the start point coordinate string and end point coordinate string remaining in the start coordinate buffer 31 and end coordinate buffer 32 are Another feature is that it is memorized at the end.

0012

[Operation] In the above configuration, when measuring a figure (absolute maximum length measurement, envelope perimeter measurement) stored in the image memory 1, for example, as shown in FIG. image data) is transferred from the image memory 1 to the run coordinate measuring device 2. Based on the transferred image data of the figure, the run coordinate measuring device 2 measures the run coordinates (the left end point of the figure, that is, the starting point) for each y-coordinate downward from the top of the figure, for example, as shown in FIG. 4(b). and the coordinates of the right end point of the figure, that is, the coordinates of the end point), and send them to the feature point extraction unit 41 mainly realized by the CPU 4.

The feature point extraction unit 41 (within the CPU 4) extracts the coordinates of the start point and end point forming a convex portion on the figure to be measured from among the coordinates of the start point and end point of each run coordinate sent. Extract only the coordinates of feature points. The coordinates of the feature points are stored in order from the start address of the start coordinate buffer 31 for the start point and in order from the start address of the end coordinate buffer 32 for the end point.

Here, the processing by the feature point extraction unit 41 is as follows:
Since the start point and end point are almost the same, here we will focus on the feature point extraction process for the start point.
Detailed operation will be explained. Note that if necessary, the starting point (
Please replace the start coordinate buffer 31 with the end coordinate buffer 32 and the end point (start coordinate) with the end point (end coordinate).

First, it is assumed that the feature point extraction section 41 is in a state of feature point extraction processing, and the coordinates (start coordinates) of the starting point of a certain run determined by the run coordinate measuring device 2 are input. Let this input start coordinate be Pi (Xi, Yi). Also, in the starting coordinate buffer 31 (starting coordinate array) at this time, the coordinates (minutiae point coordinates) of the starting points extracted as feature points from the first starting point to the starting point immediately before Pi are stored. ) are stored in order of decreasing y-coordinate. The state of this start coordinate buffer 31 is shown in FIG. 6 in correspondence with the figure to be measured. In FIG. 6, feature point coordinates Pm (Xm, Ym
) is the point whose x-coordinate value is the minimum (maximum in the feature point extraction process of the end coordinate) among the feature point coordinates in the array. This position in the array of Pm is a specific pointer Mi
Indicated by nP34.

Now, the feature point extraction unit 41 extracts the starting coordinates Pi
When (Xi, Yi) is input, if Xi < Xm (Xi ≥ P1 (X1, Y1)
In order from
Starting from the m+2 start coordinates Pm+1 (Xm+1, Ym+1) in 1 (position of buffer address "m+1"), the following search regarding the positional relationship between the coordinates (target coordinates) and the input start coordinates Pi is performed.

That is, as shown in FIG. 7, the feature point extraction unit 41 sets the search target coordinates (start coordinates) to
n ), and the coordinates of the previous array are Pn-1 (Xn-
1, Yn-1), then the value of n is 1 or m+1
Switch the target coordinates by incrementing from (1)
The straight line connecting Pn-1 and Pn at a certain value of n and P
The figure portion formed by the straight line connecting n and Pi (the part containing the target figure) is not convex; (2) Pn is the last of the array (the last of the feature point coordinate string in the start coordinate buffer 31) (This position is a specific pointer
33), the data in the start coordinate buffer 31 is updated as shown in FIG.

The above search is repeated for all input start coordinates, and the same search is repeated for all input end coordinates, and the feature point coordinates in the start coordinate buffer 31 and end coordinate buffer 32 are combined. The coordinates of all feature points are the coordinates of all feature points. In the case of measuring the absolute maximum length of a figure, the distance between each two of all the feature points is determined, and the maximum length among them is determined as the absolute maximum length. In addition, in the case of envelope perimeter measurement, the distance between each feature point is determined, for example, clockwise around the figure, and the total value is set as the envelope perimeter.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a block diagram showing the configuration of a graphic measuring device according to an embodiment of the present invention.

In FIG. 1, reference numeral 1 denotes an image memory for storing image data (binary figure data) of, for example, figures to be measured, and 2 denotes a run coordinate measuring device. The run coordinate measuring device 2 calculates the starting point and each run (each y coordinate in this case) of the same figure based on the image data of the figure to be measured stored in the image memory 1 according to instructions from the CPU 4, which will be described later. The coordinates of the ending point (starting coordinates, ending coordinates) are calculated.

3 is a storage area for various programs including a program for extracting feature points necessary for measuring the absolute maximum length and envelope perimeter (feature point extraction program), data, etc., and various work areas. This is the main memory provided.

In the main memory 3, a start coordinate buffer 31 and an end coordinate buffer 32 are placed. The start coordinate buffer 31 stores coordinates necessary for measuring the absolute maximum length or envelope perimeter of the start coordinates for each run obtained by the run coordinate measuring device 2 as feature point coordinates in the input order. used for. Similarly, the end coordinate buffer 32 stores the absolute maximum length or the coordinates necessary for measuring the envelope perimeter among the end coordinates for each run determined by the run coordinate measuring device 2 as feature point coordinates in the order of input. used to do.

Note that the reason why the two start coordinate buffers 31 and the end coordinate buffers 32 are provided is that the number of coordinates of the start point and end point of each run of the object figure measured by the run coordinate measuring device 2 is the same. However, this is because the number of coordinates stored as feature points is not necessarily equal.

The main memory 3 also includes a starting coordinate buffer 3.
A pointer (hereinafter referred to as EP) for specifying the storage location of the last coordinate of the start coordinate string stored in 1, and the storage location of the coordinate with the minimum run direction (here x direction) coordinate. A pointer for specifying (hereinafter referred to as MinP
) 34, and a pointer (referred to as
(hereinafter referred to as CP) 35 is placed.

[0025] The main memory 3 also contains the above-mentioned EP33, MinP34, CP
A pointer similar to 35, that is, a pointer (EP) for specifying the storage destination of the last coordinate of the end coordinate string stored in the end coordinate buffer 32;
A pointer (MaxP) for specifying the storage location of the coordinate with the largest coordinate (in the x direction) and a pointer (CP) for specifying the buffer address when searching within the end coordinate buffer 32 are placed. It is omitted in FIG.

[0026] 4 is a CPU that forms the core of the device. C.P.
U4 includes a functional block (hereinafter referred to as a feature point extraction unit) 41 that is realized by executing a feature point extraction program stored in the main memory 3.

Reference numeral 5 represents an image bus used for transferring image data, and 6 represents a control bus used for controlling various parts within the apparatus by the CPU 4. An image memory 1 and a run coordinate measuring device 2 are connected to the image bus 5, and a control bus 6 includes:
A CPU 4, an image memory 1, and a run coordinate measuring device 2 are connected. Note that in FIG. 1, an image input device for inputting images (image data) stored in the image memory 1 and the like are omitted.

Next, the operation of the figure measuring device shown in FIG.
Taking the measurement of the absolute maximum length of a figure as an example, a description will be given with appropriate reference to the flowcharts of FIGS. 2 and 3. First, image memory 1
It is assumed that the image data of the binary figure to be measured shown in FIG. 4(a) is stored. The CPU 4 (and the feature point extraction unit 41 realized by the feature point extraction program) controls the image memory 1 and the run coordinate measuring device 2 via the control bus 6 to determine the shape of the figure to be measured for the absolute maximum length. Image data is transferred from an image memory 1 to a run coordinate measuring device 2 via an image bus 5.

The run coordinate measuring device 2 calculates each scan line (line for each y-coordinate) based on the image data transferred from the image memory 1, as shown by black circles and white circles in FIG. 4(b). The run coordinates (pair of the coordinates of the left end point of the figure, ie, the start point, and the coordinates of the right end point, ie, the end point of the figure) of the line are acquired in order from the first scan line (the first run).

The run coordinates of each scan line acquired by the run coordinate measurement device 2, that is, the pair of start coordinates (start point coordinates) and end coordinates (end point coordinates) of each run are transmitted from the measurement device 2 to the control bus. 6, the data is sequentially transferred to the CPU 4.

The CPU 4 temporarily stores the start coordinates and end coordinates of each run transferred from the run coordinate measuring device 2 in an input buffer (not shown) on the main memory 3 in order from the first run.

[0032] As a result, the CPU 4 (feature point extraction unit 4
In step 1), the process of extracting the coordinates of feature points required for absolute maximum length measurement from the start and end coordinates of each run is executed separately for each of the start and end coordinates. The procedure of this process is almost the same for the start coordinates and the end coordinates. Therefore, in this embodiment, we will mainly explain the process for extracting the coordinates of feature points from the start coordinates of each run (as shown in the flowcharts of FIGS. 2 and 3), and we will explain the process of extracting feature points with respect to the end coordinates. Omitted.

If necessary, in the following explanation of the process of extracting the coordinates of a feature point from the start coordinates, start coordinates will be changed to end coordinates, start coordinate buffer 31 will be changed to end coordinate buffer 32, MinP will be changed to MaxP, I want each to be replaced. However, if there is a difference in processing content between the start coordinate and the end coordinate, the difference will be explained each time.

First, the CPU 4 (feature point extracting unit 41 therein) sets an initial value "0" indicating the start address (start buffer address) of the start coordinate buffer 31 to the EP33, and stores the data in the start coordinate buffer 31 pointed to by this EP33. The start coordinates of the first run (first run) are written into the area as feature point coordinates (steps S1 and S2 in FIG. 2).

Next, the CPU 4 increments the value of EP33 by 1,
The start coordinates of the second run are written as feature point coordinates in the area within the start coordinate buffer 31 pointed to by the EP 33 after +1 (buffer address "1" here) (steps S3 and S4 in FIG. 2).

When the CPU 4 writes the start coordinates of the first run and the second run into the start coordinate buffer 31, the x
The magnitude of the coordinate values is compared, and the buffer address (buffer pointer value) of the start coordinate buffer 31 in which the start coordinate with the smaller x coordinate value (the larger one in the end coordinate processing) is stored is set in MinP34 (Fig. 2 steps S5,
S6). Start coordinate buffer 31 pointed to by this MinP34
The starting coordinates stored in Pm (Xm, Ym)
shall be. Here, the subscript m matches the value of MinP34, and the corresponding start coordinate Pm is stored at address "m" (m+1st area) of the start coordinate buffer 31, that is, the beginning of the start coordinate array. This indicates that it is the m+1th coordinate from .

Next, the CPU 4 inputs the start coordinates of the next run (here, the third run) from the input buffer on the main memory 3 (step S7 in FIG. 2). Let these input starting coordinates be Pi (Xi, Yi).

Next, the CPU 4 inputs the input start coordinates Pi (
Xi, Yi) and the start coordinate Pm stored in the start coordinate buffer 31 pointed to by MinP34.
The x coordinate Xm of (Xm, Ym), that is, the x of the starting point stored in the starting coordinate buffer 31 at that point
Among the coordinates, the coordinate having the smallest value (the largest value in the end coordinate processing) is compared to check the magnitude of Xi and Xm (steps S8 and S9 in FIG. 2).

Next, the CPU 4 executes X in step S9.
Feature point extraction (feature point discrimination) processing is performed according to the result of comparing the magnitudes of i and Xm. This process consists of (a)
The case where i<Xm and the case where (b) Xi ≧Xm are different as described below.

(a) When Xi <Xm First, Xi
<Xm (Xi ≧Xm in the end coordinate processing), the CPU 4 sets the initial value "0" indicating the start position of the start coordinate buffer 31 to the CP35, and stores the data in the start coordinate buffer 31 pointed to by this CP35. The starting coordinates are read (steps S10 and S11 in FIG. 2). Let this starting coordinate be Pn-1 (Xn-1, Yn-1).

Next, the CPU 4 increments the value of CP35 by +1 and reads the start coordinate stored in the start coordinate buffer 31 pointed to by CP35 after this +1, that is, the start coordinate of the next array of Pn-1 (step S12 in FIG. 2). , S13). Let this starting coordinate be Pn (Xn, Yn).

Next, the CPU 4 selects Pn-1, Pn, P
From the coordinates of the three points of i, Pn part (line segment Pn-1Pn
and the line segment Pn Pi ) is shown in FIG.
Examine whether it is a convex part as shown in (a) or not a convex part (a concave part) as shown in FIG. 5(b) (Fig.
Steps S14, S15). Here, the convex portion is the line segment Pn
-1 The angle of the measurement target figure formed by Pn and line segment PnPi is less than 180°, and a concave portion is defined by line segment P
The angle of the figure portion formed by n-1 Pn and line segment Pn Pi is 180° or less.

[0043] In the above process, if the Pn part is a convex part,
The Pn point is saved as a point that may be a target when calculating the absolute maximum length, that is, a feature point (a point that satisfies the conditions), and if it is not a convex part, the Pn point is the absolute maximum length. This is done in order to delete points from the start coordinate buffer 31 (array) as points that have no possibility of becoming a target when determining , that is, as points that are not feature points.

In this embodiment, the determination as to whether or not the Pn portion is a convex portion (whether or not the Pn point is a feature point) is made using the vector Pn-1 Pn and the vector Pn Pi, as shown in FIG. cross product (points Pn-1, Pn, Pi
The z-coordinate value of is assumed to be 0). In other words, when searching the target figure counterclockwise (clockwise in the process of end point coordinates) to find the outer product of each vector, as in the process of the start coordinates described above, the z component is negative (in the process of the end point coordinates, If it is positive), it is determined to be a feature point, and if it is positive or zero (negative or zero in the processing of end point coordinates), it is determined that it is not a feature point.

[0045] In step S15, the CPU 4
If it is determined that the point is a feature point (Pn part is a convex part), compare EP33 and CP35 and check whether the values match (steps S16 and S17 in FIG. 2).
.

If the values of EP33 and CP35 do not match, the CPU 4 assumes that the point (starting coordinates) for which feature point determination is to be performed is still within the starting coordinate buffer 31 (array), and executes the process in step S11 above. Execute the following process again. As a result, it is possible to determine whether or not the next Pn is a feature point from Pn-1, which is the point previously treated as Pn, the feature point discrimination target point Pn, which is the next point in the array, and Pi. It is determined in the same way.

On the other hand, if the values of EP33 and CP35 match, the CPU 4 completes the feature point discrimination process for the start coordinates of all points in the start coordinate buffer 31 (array), and all of the points are Assuming that E
P33 is increased by +1 (step S18 in FIG. 2).

[0048] Then, the CPU 4 selects EP33 after this +1.
Set the value of MinP34 (FIG. 2 step S19)
. Next, the CPU 4 writes the start coordinates Pi (Xi, Yi) input in the previous step S7 as feature point coordinates into the area in the start coordinate buffer 31 pointed to by the EP 33 after +1 (step S20 in FIG. 2). That is, the CPU 4 inputs the input start coordinates Pi (Xi, Y
i) is written as the feature point coordinate whose x-coordinate value is the smallest (the largest in the end coordinate processing) at that point.

On the other hand, in step S15, Pn
If the CPU 4 determines that the point is not a feature point (the Pn part is a convex part), the CPU 4 determines that the point is not a feature point (the Pn part is a convex part), even if the point is
Even if the start coordinates (start coordinates of ) are still in the start coordinate buffer 31 (array), it is determined that they are unlikely to become feature points.

In this case, the CPU 4 does not return to the feature point determination processing from step S11 onwards, and instead stores the value of CP35 at that time (that is, the storage location in the start coordinate buffer 31 of the start coordinates of the point that is initially determined to be not a feature point). address) to the EP 33 (step S21 in FIG. 2).

Then, the CPU 4 sets the value of EP33 (that is, the value of CP35) at this time to MinP34 (step S19 in FIG. 2), and furthermore sets the value of EP33 at this time (that is, the value of CP35) to MinP34 (step S19 in FIG. The start coordinates Pi (Xi, Yi) inputted in are written as feature point coordinates (step S20 in FIG. 2). That is, the CPU 4 stores the input start coordinates Pi (Xi, Yi) in the start coordinate buffer 31 of the start coordinates of the point that is first determined to be not a feature point in the series of feature point determination processes after step S11.
At that point, the x-coordinate value is written as the smallest (largest in processing end coordinates) and as the feature point coordinate located at the end of the array.

[0052] As a result, until then, the starting coordinate buffer 3
Among the start coordinate strings stored as feature point coordinates in 1, the start coordinates from the point that was first determined not to be a feature point in a series of feature point discrimination processing to the last point in the array are stored in the start coordinate buffer 31. It will be deleted.

After executing step S20, the CPU 4 refers to the input buffer on the main memory 3 and starts the next run (
Check whether there is a run coordinate (step S22 in FIG. 2).
). If there is a next run, the CPU 4 returns to step S7, inputs the start coordinates of that run, and narrows down the feature points of the figure to be measured by performing feature point extraction processing in the same manner as described above. On the other hand, if there is no next run, the CPU 4 ends the series of feature point extraction processing.

(b) When Xi ≧Xm Next, Xi
The feature point extraction process in the case of ≧Xm (Xi <Xm in end coordinate processing) will be described.

In this case, the CPU 4 sets the value of MinP34 to CP35 (step S31 in FIG. 3). Next, C
PU4 compares EP33 and CP35 and checks whether the values match (steps S32 and S33 in FIG. 3).
).

If the values of EP33 and CP35 do not match, the CPU 4 assumes that the (starting coordinates of) the point for which the feature point is to be determined is within the starting coordinate buffer 31 (array), and executes the step S11 described above. ~A feature point determination process similar to S15 (steps S34 to S38 in FIG. 3) is executed. As a result, in the first feature point discrimination process, the point Pm with the smallest x-coordinate value in the starting coordinate buffer 31 (array)
is set as Pn-1, and the next point in the array is set as a feature point determination target point Pn, and it is determined from these Pn-1, Pn, and Pi whether or not Pn is a feature point.

If it is determined that Pn is a feature point (convex portion), the process returns to step S32, and a feature point discrimination process is performed in which the next array point is set to Pn. On the other hand, if it is determined that Pn is not a feature point (convex), the CPU 4 determines that the point to be determined as a feature point (
Even if the start coordinates (start coordinates of ) are still in the start coordinate buffer 31 (array), it is determined that they are unlikely to become feature points, and the process proceeds to step S40.

[0058] In step S40, the CPU 4 performs a process of setting the value of CP35 at that time to EP33. Then, the CPU 4 writes the start coordinates Pi (Xi, Yi) input in the previous step S7 as feature point coordinates into the area within the start coordinate buffer 31 pointed to by this EP33 (
FIG. 2 step S20). That is, the CPU 4 writes the input start coordinates Pi (Xi, Yi) as the feature point coordinates to the storage location in the start coordinate buffer 31 of the point that is (first) determined to be not a feature point.

[0059] As a result, until then, the starting coordinate buffer 3
Among the start coordinate strings stored as feature point coordinates in 1, the start coordinates from the point that was first determined not to be a feature point in a series of feature point discrimination processing to the last point in the array are stored in the start coordinate buffer 31. It will be deleted.

On the other hand, in step S33 above, EP3
If it is determined that the values of 3 and CP35 match, the CPU 4 assumes that there is no point (starting coordinates of) for which feature points should be determined in the starting coordinate buffer 31 (array). Alternatively, assuming that the feature point discrimination process for each starting coordinate from the next point to the last point of Pm in the array has been completed, and all of them are feature points, first select EP33 as +
1 (step S39 in FIG. 3).

[0061] Then, the CPU 4 selects EP33 after this +1.
The area in the start coordinate buffer 31 pointed to by the previous step S
The start coordinates Pi (Xi, Yi) input in step 7 are written as feature point coordinates (step S20 in FIG. 2). That is, C.P.
U4 writes the input start coordinates Pi (Xi, Yi) as feature point coordinates immediately after the start coordinates that had been the tail end of the start coordinate string in the start coordinate buffer 31.

After executing step S20, the CPU 4 refers to the input buffer on the main memory 3 and starts the next run (
check whether there is a run coordinate (step S22 in FIG. 2).
, if there is a next run, the process returns to step S7. On the other hand, if there is no next run, the CPU 4 ends the series of feature point extraction processes described above.

At the end of this series of feature point extraction processing, the start coordinate buffer 31 contains the coordinates (start coordinates) of the start point of each run measured by the run coordinate measuring device 2 that are extracted as feature points. Only the coordinates of the starting point are left. The above feature point extraction process is similarly performed for the end coordinates, and at the end of the process, the end coordinate buffer 3
2, among the coordinates (end coordinates) of the end point of each run measured by the run coordinate measuring device 2, only the coordinates of the end point extracted as feature points are left.

When the CPU 4 finishes the series of feature point extraction processing for the start point and end point, it extracts any two of the feature points indicated by the coordinate groups left in the start coordinate buffer 31 and the end coordinate buffer 32. Find the distance between them, and take the maximum value as the absolute maximum length of the target figure. It is also possible to find the width of the target figure by finding a line perpendicular to the chord that has the absolute maximum length.

Although the measurement of the absolute maximum length of a figure has been described above, the measurement of the envelope perimeter of a figure can also be performed in the same manner. However, the operations after the series of feature point extraction processes for the start and end points of each run are different. That is, in the case of envelope perimeter measurement, each feature point indicated by the coordinate group left in the start coordinate buffer 31 is connected in turn with a straight line, and each feature point indicated by the coordinate group left in the end coordinate buffer 32 is connected in turn. Connect the points with straight lines in order. and,
The feature points indicated by the first coordinates in the start coordinate buffer 31 and the end coordinate buffer 32, respectively, and the feature points indicated by the last coordinates are connected by straight lines, and the sum of the lengths of these straight lines is calculated as the envelope circumference. be long. Furthermore, it is also possible to obtain the envelope area using the feature points of the envelope perimeter.

In the above embodiment, the description has been made assuming that the feature point extraction process is performed by the feature point extraction section 41 after all run coordinates of the figure to be measured are determined by the run coordinate measuring device 2. It is not limited to. For example, the run coordinate measuring device 2 and the feature point extracting section 41 are operated in parallel, and each time one run coordinate is determined by the run coordinate measuring device 2, the feature point extracting section 41 inputs the run coordinate and responds accordingly. It is also possible to perform processing, and in this case, the processing speed can be further increased.

Further, in the above embodiment, the case where one figure to be measured exists in one image has been explained, but even when a plurality of figures exist, the start coordinate buffer 31 and the end coordinate buffer for the number of figures are By preparing 32 pairs, it is possible to simultaneously perform measurements for each figure (absolute maximum length measurement, envelope perimeter measurement).

[0068]

[Effects of the Invention] As detailed above, according to the present invention,
The coordinates of the start point and end point of each run of the figure to be measured are determined in order, and from those coordinates, the coordinates of the start point and end point that form a convex part on the figure to be measured are extracted as the coordinates of the feature point. Then, based on the coordinates of the extracted feature points,
Since the absolute maximum length or envelope perimeter of the figure to be measured is determined, the number of points to be considered when determining the absolute maximum length or envelope perimeter can be reduced to the necessary minimum.
Absolute maximum length or envelope circumference can be measured at high speed.

Further, according to the present invention, since the feature points necessary for measuring the absolute maximum length can be found without rotating the figure, accurate features can be found, and therefore the absolute maximum length can be found accurately. Can be done. This makes it possible to apply it to inspection of non-defective products based on width. Additionally, since the envelope perimeter can be determined at high speed, it can be efficiently applied to inspections of products for dents, etc.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of a graphic measuring device according to an embodiment of the present invention.

FIG. 2 is a diagram showing a part of a flowchart for explaining the procedure of feature point extraction processing in the embodiment.

FIG. 3 is a diagram showing the rest of the flowchart for explaining the procedure of the feature point extraction process.

FIG. 4 is a diagram for explaining run coordinates of a figure to be measured.

FIG. 5 is a diagram for explaining points that are feature points (protrusions) of a figure and points that are not.

FIG. 6 is a diagram showing the correspondence between the contents of the start coordinate buffer 31 and the figure to be measured in the state of feature point extraction processing.

FIG. 7 is a diagram for explaining feature point extraction (search) processing.

FIG. 8 is a diagram for explaining updating of data in the start coordinate buffer 31 accompanying feature point extraction (search) processing.

FIG. 9 is a diagram for explaining the absolute maximum length and envelope perimeter of a figure.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1... Image memory, 2... Run coordinate measuring device, 3... Main memory, 4... CPU, 5... Image bus, 6... Control bus, 31... Start coordinate buffer, 32... End coordinate buffer, 33... EP
(pointer), 34...MinP (pointer), 35...C
P (pointer), 41... Feature point extraction unit.

Claims (5)

[Claims] Claim 1: An image memory in which image data of a figure is stored, and coordinates of a start point and an end point for each run of a figure to be measured based on the image data stored in this image memory. From the run coordinate measuring means to be sought and the coordinates of the starting point and ending point for each run found by this run coordinate measuring means, the coordinates of the starting point and ending point forming the convex portion on the measurement target figure are determined. feature point extraction means for extracting the coordinates of the feature point, and based on the coordinates of the feature point extracted by the feature point extraction means, the maximum distance between any two feature points is determined in absolute terms. A figure measuring device characterized by determining the maximum length. 2. An image memory in which image data of a figure is stored, and coordinates of the start point and end point of each run of the figure to be measured based on the image data stored in this image memory. From the run coordinate measuring means to be sought and the coordinates of the starting point and ending point for each run found by this run coordinate measuring means, the coordinates of the starting point and ending point forming the convex portion on the measurement target figure are determined. a feature point extracting means for extracting the coordinates of the feature point, and an envelope perimeter of the figure to be measured is determined based on the coordinates of the feature point extracted by the feature point extracting means. Characteristic figure measuring device. 3. A first buffer for storing the coordinates of the starting point extracted by the feature point extracting means, and a second buffer for storing the coordinates of the end point extracted by the feature point extracting means. and a buffer, and the feature point extracting means is configured to, when the coordinates of a start point and an end point of one run are determined by the run coordinate measuring means, extract a convex portion by adding the determined starting point. The coordinates other than the coordinates to be formed are deleted from the first buffer, and the coordinates of the obtained starting point are stored at the end of the starting point coordinate string left in the first buffer, and the coordinates of the obtained starting point are stored at the end of the starting point coordinate string remaining in the first buffer, and Delete coordinates other than those that form a convex part by adding points from the second buffer, and store the coordinates of the end point obtained above at the end of the end point coordinate string remaining in the second buffer. The figure measuring device according to claim 1 or 2, characterized in that the figure measuring device is configured to: 4. The feature point extracting means extracts two consecutive starting point coordinates from the starting point coordinate string left in the first buffer.
Find the outer product of vectors in a certain direction from the three points indicated by the starting point coordinates and the coordinates of the starting point obtained above, and use the sign of the component perpendicular to the figure to be measured of the outer product to calculate
It is determined whether or not a convex portion is formed based on the presence of an intermediate point among the three points, and two successive end point coordinates of the end point coordinate string left in the second buffer are determined. Find the cross product of vectors in a certain direction from the three points indicated by the coordinates of the end point found above, and use the sign of the component perpendicular to the figure to be measured of the cross product to determine the convexity due to the existence of a midpoint among the three points. 4. The graphic measuring device according to claim 3, wherein the device determines whether or not a portion is formed. 5. The measuring means detects the first and second points when the feature point extraction means has completed all feature point extraction processing targeting the start point and end point of each run of the measurement target figure. 5. The graphic measuring device according to claim 3, wherein the measuring process is performed based on the contents of the second buffer.