JPH03230201A - Method and device for compression processing for machining shape data - Google Patents

Abstract

PURPOSE:To decrease the amount of data by deleting loops which are less than a preset number of points as necessary loops, deleting points which are considered as noise around one point, and limiting points which determine a straight part or curved part to points which are sufficient to determine one straight line or one curved line. CONSTITUTION:The path of input data is searched to delete loops consisting of points which are less than the preset number and other points in an extremely small area determined around one point are deleted; and segments connecting two points at the straight part are traced in order, successive segments which are on one straight line are replaced with one segment, and arcs set by three points of the curved part are traced in order to delete unnecessary points so that respective points for arc determination are arranged at distances larger than a constant interval. Consequently, unnecessary points are deleted including noise of machining shape vector data read by an image scanner and data can be compressed properly for an automatic programming device.

Description

[Detailed Description of the Invention] [Purpose of the Invention (Industrial Application Field) The present invention relates to shape processing such as laser machining and electrical discharge machining (prior art). The generated drawings are read by an image scanner, converted to vector data, and provided to an automatic programming device.
Here, the program is converted into an NC program and provided to each processing machine.

Vector data read by an image scanner represents outline data of pictures, characters, etc. as fine line segments or spline curves. A line segment is represented by both end points, and a spline curve is represented by a starting point, an ending point, and a plurality of intermediate points.

The automatic programming device analyzes vector data of line segments and spline curves represented by these many points,
NC program data for controlling the processing machine is automatically generated so that each point is processed along a path defined by each line segment or spline curve.

Conventionally, in a method for processing this type of shape data, data read by an image scanner is converted into vector data, and this data is provided as is to an automatic programming device or to other devices.

(Problem to be solved by the invention) However, when using the vector data as it is read by an image scanner as described above, pictures, characters, and curves are reproduced as they are, including points obtained due to noise. The problem is that the data becomes redundant because a large number of points are generated.

If the machining shape data is redundant, not only the data storage capacity increases, but also the N
There is also a problem that the C program data becomes redundant.

In addition, for example, in a straight line, one straight line is actually expressed as a combination of many line segments with rarely different slopes, and this is expressed as N
If C program data is used, there is a problem in that control errors may overlap during the process, resulting in further deterioration of product accuracy.

Therefore, an object of the present invention is to remove unnecessary points including noise from vector data of a machined shape read by an image scanner, and to compress the vector data appropriately for an automatic programming device.

[Structure of the Invention] (Means for Solving the Problems) To achieve the above object, the present invention provides processing shape data that compresses data by deleting unnecessary points from vector data of a processing shape read by an image scanner. In the compression processing method, a path is searched for the input data, loops consisting of points less than a preset number are deleted, and for a minute area defined around one point, other points included in this area are For straight parts, line segments connecting two points are sequentially traced, and for multiple consecutive line segments, line segments that can be recognized to be on a straight line are replaced with one line segment, and for curved parts, line segments connecting two points are replaced with one line segment. It is characterized by sequentially tracing the arcs that are set and removing unnecessary points so that the points for arc determination are arranged at a distance of at least a certain interval.

In addition, in a processing shape data compression processing device that deletes unnecessary points from vector data of a processed shape read by an image scanner and compresses the data, a loop is searched for the input data and the data is composed of points that are less than or equal to a preset number of points. An unnecessary loop deletion processing unit that deletes loops that occur in the area, a minute section noise deletion processing unit that deletes other points included in this area as noise for a minute area defined around one point, and 2 for each straight line section. A straight line tracing processing unit that sequentially traces line segments connected between points and replaces multiple consecutive line segments that can be recognized as being on a straight line into one line segment, and a curved part is determined by three points. The present invention is characterized by comprising a curve tracing processing unit that sequentially traces the circular arcs to be determined and deletes unnecessary points so that the points for determining the circular arc are arranged at a constant distance.

Now, we will process the vector data read by the image scanner, delete loops with less than a preset number of points as unnecessary loops, delete points that are considered to be noise around one point, and remove straight or curved sections. Limit the points that define the point to enough points to define a straight line or curve, and delete other points.

(Example) The present invention will be explained in detail below.

FIG. 1 is a block diagram showing the configuration of a compression processing device for processed shape data according to an embodiment of the present invention.

As shown in the figure, the compression processing device 1 of this example reads X,
It has a storage section 2 that stores Y vector data.

Read X, Y vector data is the outline data of pictures, characters, etc. read by an image scanner, expressed as fine line segments or spline curves. Line segments have both end points, and spline curves have starting points, end points, and intermediate points. There are multiple points on the XY plane, and the coordinates of these points are X,
It is expressed by the value of Y.

It is assumed that this data is sent from an image scanner, which is a human-powered device.

The storage section 2 is connected to a data compression processing section 3, and the compressed results are stored in a compressed data storage section 4.

The data compression processing section 3' is provided with a compression control section 5, to which are connected an unnecessary loop processing section 6, a small section noise removal processing section 7, a straight line tracing processing section 8, and a curve tracing processing section 9. has been done.

In addition, a parameter setting unit 10 composed of a keyboard or the like is connected to the data compression processing unit 3, and the parameters include “route unit” A “noise” B “straight line distance” C “straight line width”D “curved distance °E” The “curve width” F is set numerically. The contents of each parameter will be described later.

FIG. 2 is a main flow showing the processing method of the data compression processing section.

In this example, when the vector data read by the image scanner is input and set in the storage unit 2 in step 201, the process moves to step 202, in which unnecessary loop deletion processing is first performed, and then in step 203, minute section noise The deletion process is performed, and then steps 204,
While tracking the straight line portion and curved line portions in steps 205 and below, unnecessary point removal processing for the straight line portions and curved portions is executed in steps 206 and 207.

If it is determined in step 208 that the processing for all loops has been completed, the entire processing is completed and the compressed machining shape data is stored in the compressed data storage section 4. Step 2
In step 09, it is determined that the loop has ended, and the process returns to step 204 until the loop ends. At step 210, the next loop is set upon completion of the loop.

3 to 5 show loop deletion processing, minute section noise deletion processing, and unnecessary point deletion processing on straight and curved sections.

In the loop deletion process shown in FIG. 3, a loop search is performed in step 302 until it is determined in step 301 that all loops have ended, and the number A' of points constituting the searched loop is counted in step 303.

Next, in step 304, the count number A' and the set number A
If A'≦A, the process moves to step 305 and the loop is deleted. After A->A is determined in step 304 or the loop is deleted in step 305, the process returns to step 301 and subsequent steps.

Loop refers to an open or closed loop made with a brush and consisting of at least two points.

In this process, the setting value A as a “route unit” is
This value is set so that a loop with a number of constituent points less than this is impossible or will not be processed.

Therefore, in this example, unnecessary loops as drawings to be processed are deleted, and data can be compressed accordingly. For example, in a processing machine that processes polygons with four or more sides, the set number is set to three, and unnecessary line segments, circles, and triangles, including noise, are removed.

In the minute section noise removal process shown in FIG.
Step 402 searches for a loop until all loops are completed at step 01. Step 403 sets an arbitrary point on the searched loop as a starting point, and step 404 searches for a "noise B area" around that point. Delete points contained within.

For example, as shown in FIG. 6, a square with one side length B is set on the front side and to the right of the starting point po in the delay direction 11, and points included within this square are deleted.

Next, proceed along the route in a certain direction and step 40
5, the next point P1 is searched, a similar square is considered, and the points included in it are deleted. This is repeated for all points in one loop until the starting point is determined in step 406. In step 407, the process moves to the next loop.

Here, the value B set as "noise" may be set as a value close to the machining accuracy, taking into consideration the machining content.
In addition, for polygonal figures that do not include pictures or characters, it is impossible to have a value thicker than this, for example 0.1 to 0.
．． It is set to about 5 mm.

Therefore, in the minute section noise removal process of this example, noise around one point is removed.

In the unnecessary point deletion process of the straight line section shown in FIG.
In step 01, as shown in Fig. 8, any one point on one route is set as the starting point po, and the nearest point PI that is more than the parameter "straight line distance °C" is searched in a certain direction on the route from the starting point po. Draw a straight line 0 between points Pa and P.

Next, in step 502, 2 is translated from this straight line io to the left and right by half of the parameter "in the straight line" D.
Linear intersection + , (Considering A2, in step 505, this 2
Between the straight lines (lb, (delete the points included in A2.

Next, among the points deleted in step 506, P2, which is the farthest from the starting point PO, is restored, and the same process is repeated using that point P2 as the starting point, and is performed for all points on one route. However, as shown in FIG. 9, two straight lines 11. (If there is a point P3 that is not included between A2, this is determined as a protruding point in step 503, and the process moves to step 504, and the point P3 is
3 as the starting point, the processing from step 501 onwards is performed.

Here, the "straight line distance" C is set to, for example, 1 mm as the minimum value of the distance between each point, and the "straight line width" D is set to about the allowable range of processing accuracy.

Therefore, the deletion of the points shown in FIG. 8 is equivalent to replacing a plurality of line segments connecting each point with one line segment within a range that does not cause any problem in processing accuracy.

On the other hand, in step 601 of FIG. 6, which shows the processing of a curved section, as shown in FIG. The closest point P1, which is more than the "curve distance" E, is searched and set as the intermediate point.

Next, in step 602, a search is made for the closest point P2 on the curve in the same direction from the intermediate point PI by a distance of "curve distance" E or more and set as the end point.

Also, in step 603, start point PO1 intermediate point P1 end point P
Consider a circle with radius `` passing through the three points in 2, and for this radius r,
Two circles with radii rl and r2, which are given by increasing or decreasing the value of half [%] of the “curve width” F, are set, and in step 604, these two circles are set.
The intermediate point P1 included between the circles is deleted, and one point P3 is added at the center.

Next, in step 605, similar processing is performed for all curved portions of one route using the end point P2 as the starting point.

Here, the parameters “curve distance” E and “curve width” F
is set in the same way as the straight line distance "C" and the "straight line width" D above, so it is possible to shape the arc part and remove unnecessary points including noise, and the processing accuracy is also good. In the example, since the curved portion is processed while setting the center point P3 between the starting point Po and the ending point 22, the next processing starting from the ending point P2 is not affected and the curved portion is not distorted.

The compression processing device 1 configured as described above may be used in connection with an image scanner. It may also be incorporated into an image scanner.

It may also be incorporated into an automatic programming device to preprocess vector data before creating NC program data.

The present invention is not limited to the above-mentioned embodiments, but can be implemented as appropriate by making appropriate design changes.

[Effects of the Invention] As described above in detail, the present invention is a processing method and apparatus for compressing processing shape data as described in the claims, so that noise in vector data read by an image scanner can be reduced. The data can be compressed by deleting unnecessary points, reducing the amount of data and creating shape data suitable for processing.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a compression processing device for machining shape data according to an embodiment of the present invention, FIG. 2 is a main flowchart showing the compression processing method, FIG. 3 is a flowchart showing details of loop deletion processing, and FIG. Figure 4 is a flowchart showing minute section noise removal processing, Figure 5 is a flowchart showing unnecessary point deletion processing in a straight section, Figure 6 is a flowchart showing unnecessary point deletion processing in a curved section, and Figure 7 is minute section noise deletion. FIGS. 8 and 9 are explanatory diagrams showing the operation of the process, FIGS. 8 and 9 are explanatory diagrams showing the operation of the unnecessary point deletion process on a straight section, and FIG. 10 is an explanatory diagram showing the operation of the unnecessary point deletion process on a curved section. 6... Unnecessary loop deletion processing section 7... Minute section noise deletion processing section 8... Straight line tracking processing section 9... Curve tracking processing section 10... Parameter setting section Fig. 4 1'fl Straw Figure 5

Claims (5)

[Claims] (1) In a machining shape data compression processing method that deletes unnecessary points from the vector data of a machining shape read by an image scanner and compresses the data, a path is searched for the input data and the data is composed of points that are less than or equal to a preset number of points. For a minute area defined around one point, other points included in this area are deleted, and for a straight line, line segments connecting two points are sequentially traced, and continuous multiple lines are created. Replace the line segments that can be recognized as being on a straight line with one line segment, and sequentially trace the arcs set at three points for each curved part, so that each point for determining the arc is at a distance of at least a certain distance. A compression processing method for machining shape data, characterized by deleting unnecessary points so that the points are arranged with the same distance. (2) In claim 1, in tracing the straight line, a half straight line connecting the start point and the extension point is set as the extension point at a point located in front of the start point at a predetermined distance from the start point. Then, delete the points outside the starting point that are within a preset width for this half-line, and then restore the deleted point farthest from the starting point, and use this point as the starting point for the next line segment. A compression processing method for machining shape data characterized by data transfer. (3) In claim 1, in tracking the curved portion, a point on the front side of the curved portion at a predetermined distance from the starting point is set as an intermediate point, and a preset constant distance is set in advance for this intermediate point. Calculate an arc passing through the start point, intermediate point, and end point with a point ahead of the distanced position as the end point, and delete points within a preset width inside and outside of the calculated arc, A processing method for compressing machining shape data characterized by tracing a curved portion using an end point as the next starting point. (4) A processing method for compressing processing shape data according to claim 3, wherein the intermediate point is replaced with a center point between a starting point and an ending point. (5) In a machining shape data compression processing device that deletes unnecessary points from vector data of a machining shape read by an image scanner and compresses the data, a loop is searched for the input data and the data is composed of points equal to or less than a preset number of points. An unnecessary loop deletion processing unit that deletes loops that are generated by a single point; a minute section noise deletion processing unit that deletes other points included in this area as noise for a minute area defined around one point; A straight line tracing processing unit that sequentially traces line segments connected between two points and replaces continuous line segments that can be recognized as being on a straight line into one line segment; A process for compressing machining shape data, comprising: a curve tracing processing unit that sequentially traces determined circular arcs and deletes unnecessary points so that each point for determining the circular arc is placed at a constant distance. Device.