JPH03271875A - Processing method for converting graphic to coordinates - Google Patents

Abstract

PURPOSE:To improve the reproducibility by extracting coordinates so that length of segments approximating a curve are automatically changed in accordance with the curvature of this curve with respect to an arbitrary curve graphic. CONSTITUTION:An input coordinate string according with the input graphic from a coordinate value input part 1 is processed in a processing part 2 to extract coordinate values indicating the input graphic, and they are stored in a storage part 3. Input coordinates of the input coordinate string are taken in to calculate the vector distance from preceding candidate point coordinates to input coordinates, and the vector dis tance is compared with the extracted distance, and input coordinates are extracted as a candidate point when the vector distance exceeds the extracted distance. The change vector between the vector of the candidate point and that of the preceding candidate point is calculated and is added to an integrated change vector, and the integrated change vector is updated, and the integrated change vector value is com pared with a selected value; and when the integrated change vector value exceeds the selected value, input coordinates of the candidate point are selected as coordinates to be stored, and the integrated change vector is set to 0. Thus, the reproducibility is improved.

Description

[Detailed description of the invention] [Table of contents] Overview Industrial field of application Conventional technology Problems to be solved by the invention Means for solving the problems (Fig. 1) Working example (1) Description of one example ( Figures 2 to 5) Φ) Description of other embodiments Effects of the invention [Summary] Figure coordinate processing method for converting a figure drawn freehand into a plurality of coordinate values that can approximate the figure C
Second Seki.

It is designed to be easy to input, requires less coordinate data, has good reproducibility of two curves, and is simple (to be able to reproduce varnished shapes).

A coordinate processing device processes an input coordinate string along an input figure from a coordinate value input unit in the processing unit, extracts coordinate values indicating the input figure, and stores them in a storage unit. a first step of capturing, a second step of calculating a vector distance from the previous candidate point coordinates to the input coordinates, comparing the vector distance with an extraction distance, and if the vector distance exceeds the extraction distance; A third step that extracts the input coordinates as a candidate point, otherwise returns to the first step, and calculates a change vector between the vector of the candidate point and the vector of the previous candidate point, and calculates the cumulative change vector C. A fourth step of adding two and updating the cumulative change vector, and comparing the cumulative change vector value with the selected value, and if the cumulative change vector value is less than or equal to the selected value, returns to the first step and returns to the cumulative change vector value. If the vector value exceeds the selection value, # the input coordinates of the candidate point are selected as storage coordinates, the cumulative change vector is set to zero, and the fifth step returns to the first step.

[Industrial application field]

The present invention relates to a figure coordinate processing method for converting a figure drawn in 7 lines into a plurality of coordinate values that can approximate the figure.

In recent years, personal computers, word processors, etc.
With the spread of information processing devices, document processing using these devices has become widespread, but techniques for handling not only documents but also graphics and images are required.

Ru.

For this reason, 9 figures, especially line drawings, are called line segments.

For a basic figure such as a rectangle, a circle, C2 is used so that one figure can be expressed in 9 coordinates simply by specifying the end points, center position, radius, etc., but for arbitrary curved figures ζ2, It is not possible to convert it into coordinates.

% requires coordinate processing of figures drawn freehand.

[Conventional technology]

As a method to coordinate such arbitrary curved shapes.

There was something like this:

■Using the basic figures mentioned above, divide the basic figures into two combinations C according to the input figure, and select the basic figures.

Specify the coordinates of the decomposition point and convert it into coordinates using a combination of basic shapes.

■The user records all input coordinates obtained by drawing along the input figure with a coordinate input device, and when reproducing the input figure, the figure is reproduced as a set of points of the recorded coordinates.

■ Mechanically thin out the input coordinates mentioned above at equal intervals, record only the extracted coordinate values, and interpolate those points with line segments when reproducing.

(2) When displaying only some coordinates specified by the user that pass through the curved figure (-) reproduce the curve passing through those coordinates using a mathematical function such as a spline function.

[Problem to be solved by the invention]

However, this conventional technique has the following problems.

■In the conventional method (■), since an arbitrary curved figure is input, it is necessary to input a plurality of basic line segments (Y) that can express the figure, which takes time and effort.

■The conventional method (■) requires no input effort, but requires a large amount of recorded coordinate data.

■In the conventional method (■), the amount of data increases when the interval of one thinning is made small, and vice versa, sharply curved curves cannot be expressed correctly.

(2) The conventional method (2) requires complex function processing such as a spline function, although the amount of coordinate data is reduced.

Therefore, it is an object of the present invention to provide a graphic coordinate processing method that does not require time and effort for inputting, can reduce the amount of coordinate data, has good reproducibility of curves, and can reproduce simple (varnished) shapes.

[Means to solve the problem]

FIG. 1 is a diagram showing the principle of the present invention.

As shown in FIG. 1(A), the present invention provides a coordinate value input section 1.
The processing unit 2 processes the input coordinate string along the input figure from , and extracts coordinate values indicating the input figure.

In the coordinate processing device stored in the storage unit 3, FIG. 81 (B
), a first step of taking the input coordinates of the input coordinate string, a second step of calculating the vector distance from the previous candidate point coordinates to the input coordinates, and comparing the vector distance with the extracted distance. # If the vector distance exceeds the extraction distance, the input coordinates are extracted as candidate points, otherwise the third step returns to the first step, and the vector of the kernel candidate point and the previous candidate point are extracted. A fourth step of calculating a change vector of the vector, adding it to the cumulative change vector, and updating the cumulative change vector, and comparing the cumulative change vector value with the selected value, and if the cumulative change vector value is less than or equal to the selected value. , first step (-return.

If the integrated change vector value exceeds the selected value.

A fifth step includes selecting the input coordinates of the candidate point as storage coordinates, setting the cumulative change vector to zero, and returning to the first step.

[Effect]

In the present invention, the first, second, . In the third step, input points are thinned out at equal intervals to extract candidate points.

Next C2, 4th. In the fifth step, the curvature of the curve from the previous selected point to the candidate point is determined. Those with 9 curvatures are stored as selected points, and those with small 9 curvatures are not selected as selected points.

That is, the change vector between the vector of the previous candidate point and the vector of that candidate point indicates the magnitude of the curvature of the nine curves.

Therefore, if we integrate the change vectors from the previous selected point, we get
The curvature of the curve from the previous selected point to the candidate point is obtained.

By determining this magnitude, if the curvature is large by one, it is stored as a selected point.

By doing this, when the candidate points obtained by thinning out at equal intervals have a large 9 curvature.

Adopting it as a selection point C: When the 9th curvature is a dog, the coordinates can be finely determined, and when the 1st curvature is small, the coordinates can be roughly expressed.

That is, for any curved figure, the coordinates are extracted so that the length of a line segment that approximates the curve is automatically changed according to the curvature of the curve.

For this reason, all you have to do is input a coordinate string along the input figure, which saves time and reduces the amount of coordinate data.Furthermore, the coordinate data is finely recorded for areas with large curvature, so curves can be Good reproducibility.

In addition, since no separate function is used for W, it can be realized easily, and since the curvature is not determined for all input coordinates, coordinate conversion and reproduction processing can be performed easily and at high speed.

〔Example〕

(a) Description of one embodiment FIG. 2 is a block diagram for one embodiment of the invention.

In the figure, the same parts as shown in Figure 1 are indicated by the same symbols, and 1a is the operator of the digitizer (coordinate input section) 1, which is operated by the user on the digitizer 1 surface. , 1b are buttons provided on the operator 1a to instruct the start and end of drawing, and the digitizer 1 outputs coordinates corresponding to the position of the operator la.

4 is a memory, and a processing unit (hereinafter referred to as C
(referred to as PU) stores the data necessary for processing 1. 2 selection point coordinates Pa, candidate point coordinates Pc, vector DI, D2. 5 is a display that stores the cumulative change vector DD between vectors, the extraction distance C1, and the selection value C2.

A bus 6 displays the drawing output of the digitizer 1 and the processing results of the CPU 1 on a monitor.

CPU2 and memory4. Display 5. A digitizer 1 and a storage section (floppy disk device) 3 are connected to exchange data.

In this embodiment, the CPU 2 converts input coordinates output by drawing a figure from the digitizer 1 into coordinates, displays them on the display 5, and displays the coordinates of 2 selected points at 70.
The information is stored in the Tuppy disk device 3.

FIG. 3 is a processing flow diagram of an embodiment of the present invention, and FIGS. 4 and 5 are operation explanatory diagrams of an embodiment of the present invention. In this example, as shown in FIG. Point P
It is assumed that curves shown by dotted lines up to 9 are drawn and input from the digitizer 1.

■ At the start of the drawing process, the CPU 2 sets the vectors DI and D2 in the memory 4 to r'Oj and the cumulative change vector DD.
Reset to "0".

Next, the CPU 2 monitors the output of the digitizer 1.

Detecting whether button 1b of digitizer 1 has been pressed 0 When starting drawing, the user presses button 1b of operator 1a.
Press to instruct to start drawing, and digitizer 1
The position of a is detected and its coordinates are output at regular intervals.

When the CPU 2 detects that the button 1b has been pressed, it determines that the user has started drawing, reads the detected input coordinates of the digitizer 1, stores them in the candidate point coordinates Pb of the memory 4, and uses these as the starting point. and records it in the recording section 3.

Then, the CPU 2 moves the candidate point coordinates Pb in the memory 4 to the selected point coordinates Pa.

(2) The CPU 2 takes in the input coordinates of the digitizer 1 and stores them in the input coordinates Pc of the memory 4.

Next, the CPU 2 determines whether the button 1b of the two-manipulator 1a has been pressed to instruct the end of drawing.

When it is determined that the drawing is completed, the process proceeds to step (3).

On the other hand, it is determined that the button 1b is not pressed.

Determining that drawing has not ended, the CPU 2 calculates a vector between the candidate point P in the memory 4 and the input coordinate Pc, and stores the vector in the memory 4.
is stored as a vector D2.

(2) Next, the CPU 2 calculates the distance /D2/ of the vector D2.

The distance /D2/ is determined by a quadratic equation.

/D2/=V/(pcx-Pbx)2+(Pcy-Pb
y)"'-"""'(1) CP tJ 2 is the fourth
As shown in Figure CB), this vector distance /D2/ is compared with the extracted distance C1 of the memory 4.

This extraction distance C1 divides 7 curves into equally spaced candidate points t7
．． This is to thin out the input points (coordinates) between them. .

Therefore, if CPU2 is not /D2/>C1.

Return to step 2 to thin out these input points.

-J, if 2, /D2/> CI, the CPU 2 adopts this input point as a candidate point and enters the 51st-order curvature determination (selected point extraction) step.

■ CP LJ 2 is the difference between the vector DJ of the previous candidate point in the memory 4 and the vector D2 of that candidate point (D2 - Dl)
seek.

Figure 4 (as shown in q, the difference between vectors D2 and Dl is 2
This is a change vector indicating a change between both vectors, and corresponds to two curvatures.

Then, the CPU 2 calculates the integrated change vector D in the memory 4.
This change vector (D2-DI) is added to D to update the integrated change vector DD.

As will be described later, this cumulative change vector DD is reset to "0" when the previous candidate point is selected as the selection point (-2), and if the previous candidate point is not selected as the selection point, it will be reset to 0. There is no error.

This means that the integrated change vector DD is an integrated value from the change vector at the next candidate point after the two selected points.

For example, at the candidate point P, shown in Figure 4, is selected as the selection point, and at the candidate point P2, the integrated change vector [)■) is the vector PQ - Pi and P2 - P.
The difference between 9 and l, that is, the vector of selection point P1 and the candidate mAPzO vector, hC(>m).

- On the other hand, if candidate point P2 is not selected as the selection point, the change vector at candidate point P2 is the vector of candidate point P3 (P2-P3) and the vector of candidate point P2 (Pl-P2). and the cumulative change vector D
D is the difference (change vector) between the vector of the two selection points P1 and the vector of the candidate point P2, plus the change vector of the candidate point P3.

Therefore, the cumulative change vector DD is the cumulative change vector based on the vector of the previous selection point P1.

This is done because if candidate point P2 is not selected, it is necessary to return to selected point P1 and judge the curvature.

(2) Next, the CPU 2 calculates the absolute value (distance) of the integrated change vector DD and compares it with the selected value C2 of the memory 4.

The absolute value of the cumulative change vector DD is large.

It shows that the curvature is a dog, and if it is small, it shows that the 9 curvature is also small.

When CPU2 determines that /DD/>C2 is not the case.

Since the curvature is small, it is determined that this candidate point does not need to be selected as a selection point, and the process proceeds to step (2).

(2) On the other hand, if the CPU 2 determines that /DD/>C2, the 2 curvature is large, so this candidate point Pc is adopted as the selected point and recorded in the recording unit 3.

At the same time, a line segment Pa-Pc is drawn on the display 5, which displays the locus of the input coordinate Pc, as shown in FIG. 4(5), and is displayed as shown in FIG. 4(5).

Then, the CPU 2 transfers this input coordinate Pc to the selected point coordinate Pa in the memory 4, and sets the cumulative change vector DD in the memory 4.
Reset to "0" and proceed to step ■.

(2) Next, the CPU 2 stores the input coordinates Pc as the candidate point in the candidate point coordinates Pb of the memory 4, transfers the vector D2 of the candidate point to the vector D11- of the previous candidate point, and returns to step (2).

■ On the other hand, if it is determined that drawing is finished in step ■.

The CPU 2 unconditionally adopts the input coordinate Pc as the end point, records it in the recording section 3, and displays the line segment P on the display 5.
a - Subtract Pc.

Then the drawing ends.

In this way, candidate points are extracted at equal intervals from the input coordinate string along the two figures, and the curvature with respect to the previous selected point is determined, and if the two curvatures are dog, the candidate points are selected as the selected points.

This will be explained using FIG. 5 using an example of the fourth section. By inputting the starting point PO, each data in the memory 4 becomes as shown by Sl.

Next, the coordinates are input, and the judgment is made in steps ■ and ■.

When candidate point P1 is extracted, each data changes as shown at 82 in FIG.

Here, when the candidate point P1 is determined to be the selected point in steps ■ to ■, that is, /Po−+Px / > CI, each data changes as shown in 83 in FIG. 5, and the cumulative change vector DD
becomes "0".

Next, the coordinates are input, and the candidate point P2 is extracted by the judgments in steps ■ and ■. When the change vector is calculated in step 4, each data becomes 84 in FIG. 5, and the cumulative change vector DD is Pl. -P2- Pg→P1.

This integrated change vector DD is changed to C2 by step
If it is determined to be less than 2, the curvature is small.

Candidate point P2 is not selected as a selection point, and becomes data 85 in FIG. 5 in step (3).

Furthermore, coordinates are input and candidate point P3 is extracted.

When the change vector is calculated and the cumulative change vector DD is determined, the data 86 in FIG. 5 is obtained.

Thereafter, each data in the memory 4 is updated in the same manner.0 As a result, the PI of the dog with two curvatures among the candidate points P1 to P8 as in the fourth section, Pal Pal P6. P7t
pa is selected as the selection point and tP2. P4 is excluded because of its small curvature.

Therefore, selection points can be roughly obtained in the small portion of two curvatures, and finely in the dog portion.

(b) Description of other embodiments In addition to the above-described embodiments, the present invention can be modified in the following two ways.

(2) Although the coordinate input unit 1 has been described as a digitizer, it may be a mouse, a light pen, or the like, or it may be a device that reads a rose figure and detects the coordinate values of a line segment.

At this time, the CPU may detect the coordinates after storing the read input in the memory.

■ The selected value C2 is a constant that determines the degree of curvature of the two curves,
The smaller it is, the more the proportion of coordinate values adopted increases.

It is possible to generate selection points that can reproduce gentler curves.

■ Also, the reproduction of two figures becomes a straight line approximation curve connecting the two selected points with a straight line.

Although the present invention has been described above using examples, the present invention can be modified in various ways according to the gist of the present invention.

These are not excluded from the present invention.

〔Effect of the invention〕

As explained above, according to the present invention, the following effects can be achieved.

■ The user only needs to draw two curves and the coordinate data for polygonal line approximation is automatically created, so there is no need for input.

(2) Since the number of selected points changes automatically according to the curvature, the number of coordinate data is small and the reproducibility of the curve is good.

■ Since no special function is required for reproduction, reproduction processing is easy and fast.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the principle of the present invention. FIG. 2 is a block diagram for one embodiment of the present invention. FIG. 3 is a processing flow diagram of an embodiment of the present invention. FIGS. 4 and 5 are explanatory diagrams of the operation of one embodiment of the present invention. In the figure, l: coordinate value input section. 2...processing section. 3... Recording department.

Claims (1)

[Claims] The input coordinate string along the input figure from the coordinate value input unit (1) is processed by the processing unit (2), coordinate values indicating the input figure are extracted, and the coordinate values are stored in the storage unit (3). A coordinate processing device that stores input coordinates in a coordinate processing device, comprising: a first step of importing input coordinates of an input coordinate string; a second step of calculating a vector distance from the previous candidate point coordinates to the input coordinates; and a second step of calculating the vector distance from the previous candidate point coordinates to the input coordinates. , and if the vector distance exceeds the extraction distance, a third step extracts the input coordinates as a candidate point, otherwise returns to the first step, a vector of the candidate point and the previous candidate. A fourth step of calculating a change vector with respect to the point vector, adding it to the cumulative change vector, and updating the cumulative change vector, and comparing the cumulative change vector value with the selected value, and determining that the cumulative change vector value is selected. If it is less than the value, return to the first step,
If the cumulative change vector value exceeds the selected value, a fifth step includes selecting the input coordinates of the candidate point as storage coordinates, setting the cumulative change vector to zero, and returning to the first step. A figure coordinate processing method characterized by the following.