JP3236410B2 - Contour line forming method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a contour forming method, and more particularly, to a contour forming method for forming a contour based on contour dots extracted from bit map data.

[0002]

2. Description of the Related Art Heretofore, a bit map representing a figure, a character, and the like (hereinafter, these are collectively simply referred to as a "graphic") controlled by a microcomputer or the like and output from a host computer or the like has been conventionally used. A cutting plotter that cuts out the figure from a sheet based on data is known.

[0003] In such a cutting plotter, for example, as disclosed in Japanese Patent Laid-Open No. 2-222264, contour dots are extracted from bit map data and contour dots formed based on the extracted contour dots. The original contour line where fine irregularities are conspicuous is divided into a plurality of straight lines and curves to form a smooth contour line having the characteristics of the original contour line, and cutting is performed along the smooth contour line thus formed It has been proposed to.

[0004] By performing the above-described processing, fine irregularities due to contour dots are not noticeable on the cutting line of the sheet, and it is expected that high quality cutting can be provided.

[0005]

However, in order to divide the original contour line into a plurality of straight lines and curves as described above, it is necessary to perform a large amount of complicated calculations.
And the use of a high-performance CPU becomes necessary, resulting in an increase in cost and a reduction in processing speed due to a large amount of processing of complicated calculations. There was a point.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and has as its object to reduce the characteristics of an original contour line based on contour dots without performing a large amount of complicated calculations. An object of the present invention is to provide a contour line forming method capable of forming a smooth contour line having no contour dots and having fine irregularities.

[0007]

In order to achieve the above object, a contour line forming method according to the present invention extracts a contour dot from bit map data and forms a contour line based on the contour dot. In the line forming method,
(1) extracting, from the contour dots, predetermined contour dots indicating characteristics of an original contour line based on the contour dots;
(2) detecting, from the predetermined contour dots, the contour dots forming the vertices of the corners of the original contour line; and (3) determining the vertices of the corners between the contour dots forming the vertices of the corners. An outline is formed by interpolating a straight line and a curve corresponding to the predetermined outline dot located between the outline dots to be formed.

[0008]

According to the present invention, a predetermined contour dot indicating the characteristic of the original contour line is used.
Detect contour dots that form the vertices of the corners of the original contour,
A contour line is formed by interpolating between the contour dots forming the vertices of the corners of the detected original contour line using straight lines and curves corresponding to predetermined contour dots located between the contour dots forming the vertices of the corner portion. Therefore, even if the figure is enlarged, fine irregularities due to contour dots do not appear on the contour line. In addition, the contour holds the characteristics of the original contour.

Further, since only the contour dots forming the vertices of the corners of the original contour line are interpolated by straight lines and curves, there is no need to perform complicated calculations, and it is possible to suppress an increase in the load on the CPU. it can.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a contour forming method according to the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a block diagram showing a processing system for implementing a contour forming method according to an embodiment of the present invention.

This processing system is configured to control the entire operation by using a central processing unit (CPU) 10.

The CPU 10 has a read only memory (ROM) 14 via the bus 12 for storing a predetermined program for controlling the overall operation and executing the processing described later. Random access memory (RA) as a working area in which various registers required when executing
M) 16 and a bit for storing bit map data output from a host computer or the like (not shown).
A map data memory 18; a contour dot data memory 20 for storing contour dot data indicating contour dots of a figure based on the bit map data stored in the bit map data memory 18; A contour data memory 22 for storing the obtained contour data;
An input / output interface 24 for inputting bit map data output from a host computer or the like and for outputting contour data stored in the contour data memory 22 to an external device is connected. ing.

FIG. 2 is a flow chart of a process relating to the contour line forming method of the present invention.
02, the bit map data stored in the bit map data memory 18 based on a known technique.
From the data, the contour dot of the figure indicated by the bit map data is extracted, and the contour dot data indicating the contour dot is stored in the contour dot data memory 20.
Will be stored. When the processing in step S202 ends, the process proceeds to step S204.

In step S204, from the contour dots based on the contour dot data stored in the contour dot data memory 20, contour dots representing the characteristics of the original contour represented by the contour dots based on the contour dot data are determined. It is extracted as a representative point of the original contour line.

The following two methods can be appropriately used as a method for extracting the contour dots representing the features of the original contour line as representative points.

[First Method] The first method is a method of extracting, as a representative point, a contour dot at a place where the trajectory of the contour dot, that is, the original contour line is bent in a specific direction.

For example, taking the English character "a" as a figure as an example, as shown in FIG. 3 (a), the locus of the outline dot of the English character "a" is fine irregularities in which one dot is represented by a square. Original contour line with When extracting a representative point from the contour dots indicating such an original contour line, the tracing of the contour dot trajectory is started so as to proceed in the direction of the arrow α which is the counterclockwise direction, and the contour dot at the left turn point with respect to the traveling direction is started. May be extracted as a representative point.

When the above processing is performed, the outline dot
As representative points of the contour dots extracted from the data, FIG.
In (b), the outline dots at the locations indicated by the circles are extracted. The extracted contour dot has the characteristics of the original contour line.

[Second Method] The second method is a method in which contour dots in the same direction are divided into blocks, and contour dots located at the center point of the block are extracted as representative points. In such a method, in FIG.
The contour dot at the location represented by the mark is extracted as a representative point, and the extracted contour dot has the characteristics of the original contour line.

In the first method and the second method, the positions of the outline dots extracted as the representative points are different, but both of them represent the characteristics of the original outline.

When the process of step S204 is completed, the process proceeds to step S206, where the pattern analysis of the contour dot extracted as the representative point is performed, and the representative point located at the vertex of the corner formed by the original contour line is detected. As a method of this pattern analysis, the following two methods can be used as appropriate, and as in FIGS. 3B and 3C, the representative points are indicated by circles in FIGS. 4A and 4B. It will be described based on the following.

[First Method] As shown in FIG.
From a representative point to the next representative point, the increment dx of the change in the x coordinate and the increment dy of the change in the y coordinate
"Positive (plus)" when changes in the increasing direction
, And the case of a change in the decreasing direction is referred to as a “negative (minus)” sign.

If the sign of the increment dx and the sign of the increment dy do not change when a trajectory is detected from a representative point to the next representative point, the representative point is located at the vertex of the corner. is not.

On the other hand, when a trajectory is detected from a certain representative point to the next representative point, if both the sign of the increment dx and the sign of the increment dy change, or if one of the signs changes, the representative The point is a representative point located at the vertex of the corner.

In FIG. 4A, the outline dot of the representative point located at the vertex of the corner is indicated by a black circle.

[Second Method] In addition to the above-described first method, when a trajectory is detected from one representative point to the next representative point, the magnitudes (absolute values) of the increments dx and dy are compared. When the magnitude relationship between the two changes, the representative point is set as a representative point located at the vertex of the corner (FIG. 4).
(B)).

In FIG. 4B, the outline dot of the representative point located at the vertex of the corner is indicated by a black circle.

When the process of step S206 is completed, the process proceeds to step S208, where interpolation is performed between the contour dots set as the vertices of the corners, and a contour to be cut is formed by a cutting plotter. The following two methods can be used as appropriate as a method of interpolating between the contour dots defined as the vertices of the corners.

[First Method] FIGS. 5A to 5E
As shown in FIG. 5, a single arc (FIG. 5A) based on a single arc data stored in the ROM 14 in advance is converted into a representative point located between the contour dots that are the corner vertices. It is deformed according to the curvature of the dot locus, and is interpolated by the deformed arc. As the arc, an arc showing about 1/8 of the circle may be used.

That is, when the representative point and the outline dot of the vertex of the corner are arranged in the state shown in FIG. 5B, as shown in FIG. It rotates by an angle β in the direction of the horizontal line HH around the contour dot at the vertex, and detects the contour dot (hereinafter referred to as the top contour dot) γ of the representative point at the highest position with respect to the horizontal line HH. . Next, the arc of FIG.
The deformed arc (FIG. 5D) is deformed so as to match the top contour dot γ shown in (c) and between the contour dots at the corner vertices, along the contour dot at the representative point. (FIG. 5E).

Thereafter, the deformed arc fitted as described above is rotated by an angle β in the vertical direction about the contour dot at the vertex of one corner, and FIG.
(FIG. 5 (f)).

[Second Method] Unlike the first method, the second method is not a single arc but a contour determined as a vertex of a corner from a plurality of curve data such as an arc and a parabola. In accordance with the shape of the arrangement curve of the contour dots of the representative points located between the dots, the one with the closest shape is selected, and the selected one is applied between the contour dots that are the vertices of the corners.

Therefore, by the processing of steps S204 to S208 described above, it is possible to form a smooth contour line having features such as corners in the original contour line and inconspicuous fine irregularities of the contour dot.

Upon completion of the process in step S208, the process proceeds to step S210, in which the contour data indicating the contour formed by interpolating between the contour dots that are the vertices of the corners is stored in the contour data memory 22. . Then, the contour data stored in the contour data memory 22 is output via the input / output interface 24 so that fine irregularities due to contour dots do not appear in the cutting line of the sheet, and the characteristics of the original contour line can be obtained. The sheet is cut in the prepared state.

In step S204 to step S208, two processing methods are described for each step. In each step, either one of these two processings is appropriately selected as described above. Become. Such selection may be arbitrarily set for each step by using an operation element or the like.

In steps S204 to S208, only one of the processes may be fixedly performed.

Further, according to the present invention, since high-quality contour data that does not need to be corrected at the time of cutting can be obtained by low-cost means, if the present invention is incorporated in a cutting plotter, it is possible to directly receive a scanner output. This makes it possible to easily realize a dedicated system that does not require the use of an expensive computer.

Furthermore, in the above-described embodiment, the case where the present invention is applied to a cutting plotter has been described. However, it goes without saying that the present invention may be applied not only to the cutting plotter but also to a printer or the like. .

[0040]

Since the present invention is configured as described above, it has the following effects.

From predetermined contour dots indicating the features of the original contour line, the contour dots forming the vertices of the corners of the original contour line are detected, and the detected contour dots forming the vertices of the corners of the original contour line are detected. Since the contour is formed by interpolating with a straight line and a curve corresponding to a predetermined contour dot located between the contour dots forming the apex of the corner, the feature of the original contour is provided, and the figure is enlarged. Even if it is, a contour line in which fine irregularities due to the contour dot do not appear can be formed.

Since the contour dots forming the vertices of the corners of the original contour line are interpolated by a straight line and a curve, there is no need to perform a complicated operation, and an increase in the load on the CPU can be suppressed. Can be.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a processing system for realizing a contour line forming method according to an embodiment of the present invention.

FIG. 2 is a flowchart showing an embodiment of a contour line forming method according to the present invention.

FIGS. 3A and 3B show a case where an English character “a” is processed. FIG. 3A is an enlarged view of an outline of the English character “a” and a predetermined region of the outline, and FIG. FIG. 4 is an enlarged explanatory view corresponding to the enlarged view of (a) showing the representative points extracted by the first method, and (c) represents the representative points extracted by the second method for extracting the representative points. It is an enlarged explanatory view corresponding to the enlarged view of (a) shown.

4A is an explanatory diagram illustrating a first method for detecting a vertex of a corner, and FIG. 4B is an explanatory diagram illustrating a second method for detecting a vertex of a corner. is there.

5A is an explanatory diagram illustrating an arc based on arc data, FIG. 5B is an explanatory diagram illustrating an arrangement of corner vertices and a contour dot of a representative point between the corner vertices, and FIG. () Is an explanatory diagram showing a method of detecting a top contour dot from (b), (d) is an explanatory diagram showing a state in which the arc of (a) is deformed, and (e) is a diagram showing (d) as ( It is explanatory drawing which shows the state applied to (c), (f) is explanatory drawing which shows the state which returned the (e) to the positional relationship shown to (b), and formed the outline.

[Explanation of symbols]

 10 CPU 12 bus 14 ROM 16 RAM 18 bit map data memory 20 contour dot data memory 22 contour data memory 24 input / output interface

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G06T 3/00 500 G06T 7/60 250

Claims (1)

(57) [Claims] 1. A contour line forming method for extracting a contour dot from bit map data and forming a contour line based on the contour dot, comprising: (1) an original contour based on the contour dot from the contour dots; (2) detecting a contour dot that forms a vertex of a corner of the original contour line from the predetermined contour dot; and (3) extracting a vertex of the corner. A contour line forming method, wherein a contour line is formed by interpolating between contour dots to be formed with a straight line and a curve corresponding to the predetermined contour dot located between the contour dots forming the vertices of the corners. .