JP3382546B2 - Coordinate group curvature correction device and coordinate group curvature correction 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 coordinate group curving correction device and a coordinate group curving correction method, and in particular, a series of coordinate points is input as a coordinate group by a pointing device such as a mouse and connects the coordinate groups. The present invention relates to a coordinate group curving correction device and a coordinate group curving correction method for smoothly correcting a curve formed by a drawing locus of a coordinate group when a curve is drawn on a display screen by a line.

[0002]

2. Description of the Related Art When drawing a figure or a picture by using a computer, for example, when a paint program is started and a line tool is drawn by using a pencil tool in the program processing, a drawing operation is performed on a display screen. In that case, as a means for specifying the position of the drawing point on the display screen, the operator usually uses a pointing device such as a mouse or a light pen to input a series of coordinate groups and perform an operation of drawing. .

In this case, for example, when a character is drawn on the display screen, or when a handwriting-like line drawing such as a check mark is drawn, the mouse is moved to input a series of coordinate groups for drawing. In most cases, the locus drawn by the mouse pointer (the line connecting the series of input coordinate groups) is not smooth and, as a result, is not beautiful. This is because camera shake occurs when the coordinate group is input by operating the mouse.

In particular, drawing a trajectory exactly as the operator imagines by inputting with a mouse of a pointing device is, for example, a drawing which is not much different from an image drawn with a pencil on paper on a display screen. Very difficult to draw.

Conventionally, using a pencil tool of a paint program, a general method of drawing a locus that a mouse pointer has passed on a canvas on a display screen as a line figure is as shown in FIG. This is a method in which the passed coordinate points are acquired at a certain interval (time interval or space interval), and a series of acquired coordinate groups are connected by a straight line.

If all (or partial) input coordinate groups are stored in a storage device and appropriate conditions are added, theoretically, a series of input and stored coordinate groups are passed. Alternatively, if an approximated curve equation can be obtained, for example, as shown in FIG.
It is possible to smoothly interpolate between coordinate groups.

However, when such a method is used, the operation of actually moving the mouse cannot be performed smoothly in many cases. Therefore, the given coordinate group is distorted in the drawing trajectory in which the awkward operation is performed. In this case, a simple curve connecting the distorted coordinate groups is drawn, and this is not a fundamental solution for image stabilization of mouse operation. 12 and FIG. 1
In the example shown in 3, but an example of distribution of the coordinate group, labeled by circles (input coordinate group) are substantially evenly distributed (arranged) are shown <br/>, by awkward manipulation, the If the distribution of coordinate groups has a distorted distribution, a smooth curve cannot be obtained.

[0008]

SUMMARY OF THE INVENTION The present invention has been made to solve the above conventional problems.
An object of the present invention is to perform a drawing on the display screen that is not much different from an image drawn by an operator with a pencil on paper, and therefore coordinates for correcting a coordinate group input by an input operation using a pointing device such as a mouse. An object is to provide a group curving correction device and a coordinate group curving correction method.

Another object of the present invention is to draw a line figure in a handwriting style by using a pointing device such as a mouse in order to draw a visually good line figure. It is an object to provide a coordinate group curving correction device and a coordinate group curving correction method for correcting position data.

[0010]

In order to achieve the above object, a coordinate group curving correction device according to the present invention stores a series of coordinate points input by a pointing device as a coordinate group storage. Unit, an initial condition setting unit that sets the initial parameters for simulating the movement of a coupled spring that connects the coordinate points of the coordinate group with the coordinate points of the coordinate points as the mass point positions, and the initial condition setting unit. According to the parameters set by, the equation of motion of the coupled spring in which each coordinate point of the coordinate group is the position of the mass point is added to the damping term to solve the calculation under the fixed end condition to obtain the moving position of the mass point. The present invention is characterized by including an arithmetic processing unit for outputting and a coordinate group drawing processing unit for drawing a coordinate group with the moving position of the mass point output by the arithmetic processing unit as each coordinate point on the display screen.

The coordinate group curving correction method of the present invention is
The position data of a series of coordinate points input by the pointing device is stored, and when a predetermined number of position data are stored, the stored position data of a series of coordinate points is connected by a spring with the adjacent mass points. It is input as position data of the coupled oscillator that is present.In the initial state, the coupled oscillator is set such that each mass point is connected by springs with the spring being slightly stretched from its natural length. Calculate the natural length of each spring in the oscillator, apply a resistance force to the mass to settle the vibration of the mass, and numerically integrate the equation of motion using the molecular dynamics method to create a new coordinate point. Is calculated, and the calculated position data of the coordinate points is replaced with the position data of the series of coordinate points input by the pointing device.

In the coordinate group curving correction device having such characteristics, when the coordinate group storage unit stores a series of coordinate points input by the pointing device as a coordinate group,
The initial condition setting unit sets the initial parameters for moving each mass point by simulating the movement of the coupled spring connecting the mass points with each coordinate point of the coordinate group as the position of the mass point. Then, the arithmetic processing unit solves the equation of motion of the coupled spring in which each coordinate point of the coordinate group is the position of the mass point according to the parameter set by the initial condition setting unit by adding a damping term under the fixed end condition. Processing is performed to obtain and output the moving position of the mass point.
The coordinate group drawing unit draws on the display screen a coordinate group with the moving position of the mass point output by the arithmetic processing unit as each coordinate point. With this, when drawing a handwriting-like line figure using a pointing device, when drawing a figure as a coordinate group of a series of input coordinate points, a line figure that is distorted due to camera shake at the time of input is drawn. It is possible to perform smooth correction, and it is possible to draw a visually good line figure on the display screen.

Further, according to the coordinate group curving correction method of the present invention, the position data of a series of coordinate points input by the pointing device is stored, and when a predetermined number of position data are stored, the stored series of coordinate data is stored. The position data of the coordinate points of is input as the position data of the coupled oscillator in which the adjacent mass points are connected by the spring, and in the initial state, the coupled oscillator has the spring stretched slightly from the natural length. Set that each mass point is connected with a spring in the state of
Calculate the natural length of each spring in the coupled oscillator,
A resistance force is applied to the mass point to settle the vibration of the mass point, the equation of motion is numerically integrated using the molecular dynamics method to calculate the position data of the new coordinate point, and the position data of the calculated coordinate point is calculated. The position data of a series of coordinate points input by the pointing device is replaced.

Thus, when the coordinate point is input by the pointing device, the line figure distorted due to the hand movement at the time of input can be smoothly corrected, and a visually good line figure can be drawn on the display screen. You can As a result, it is possible to draw on the display screen a handwriting-like line drawing that is similar to the image drawn with a pencil on paper, so it can be used as a drawing correction tool for supplementary explanation in education and review using a computer. be able to.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment for carrying out the present invention will be specifically described below with reference to the drawings. FIG. 1 is a block diagram showing a configuration of a main part of a coordinate group curving correction drawing tool according to an embodiment of the present invention. As shown in FIG. 1, the coordinate group curving correction drawing tool uses a series of coordinate points input by a pointing device as a coordinate group, a coordinate group storage unit 11 that stores the coordinate values, and a coordinate group storage unit 11 that stores the coordinate values. An initial condition calculation processing unit 12 for calculating an initial condition necessary for numerically integrating the equation of motion from the coordinate value of each coordinate point.
And a motion equation calculation processing unit 13 for numerically integrating the motion equation under a given initial condition to calculate a new coordinate group using the molecular dynamics method, and a motion equation calculation processing unit 13 newly obtained. The coordinate group drawing processing unit 14 for drawing the coordinate group on the display screen is a main component.

In the coordinate group curving correction drawing tool of FIG. 1, the coordinate group storage unit 11 collects position data of a series of coordinate points input by a pointing device,
Store as a coordinate group. As will be described later, the initial condition calculation processing unit 12 uses the motion equation calculation processing unit 13 to move each mass point by simulating the movement of a coupled spring that connects the mass point with each coordinate point of the coordinate group as the position of the mass point. As the parameters of the initial condition, the reduction rate ε, the mass m, the spring constant k, the damping rate η, the time interval Δt, and the number of calculations N are set.

The motion equation calculation processing unit 13 adds the damping term to the motion equation of the coupled spring in which each coordinate point of the coordinate group is the position of the mass point according to the parameter set by the initial condition calculation processing unit 12, and the fixed end condition is applied. The calculation processing for solving the problem is performed to obtain and output the moving position of the mass point. The coordinate group drawing processing unit 14 draws on the display screen a coordinate group in which the moving position of the mass point output by the calculation processing unit is used as each coordinate point. The process of moving a series of coordinate points input by the pointing device in this way will be specifically described in order.

FIG. 2 is a diagram showing an example of a coordinate group composed of a series of coordinate points input by a pointing device. First, each coordinate value of these coordinate groups is stored in the coordinate group storage unit 11. Is stored. In FIG. 2, numbered circles indicate coordinate points input by operating the pointing device, and a series of coordinate points are input in the order shown by the numbers, and the coordinate group storage unit 11
Stored in.

Next, the calculation processing performed by the initial condition calculation processing unit 12 and the motion equation calculation processing unit 13 will be described. Here, as described above, the process of moving each mass point by simulating the movement of the coupled spring connecting the mass points with each coordinate point of the series of coordinate groups input by the pointing device as the position of the mass point is performed.

FIG. 3 is a view for explaining a state of a coupled oscillator connected to a spring having a series of coordinate points input by a pointing device as a mass point, and FIG. 4 is a coordinate x _i (vector) of the mass point i. It is a figure explaining the relationship of the distance d _i between the value), the mass point i, and the mass point (i + 1). In addition, FIG.
FIG. 6 is a diagram showing a drawing example of a coordinate group before correction and a drawing example of a curve by a coordinate group after correction. Description will be made with reference to these figures.

A series of coordinate points input by the pointing device are collectively set as a coordinate group. As shown in FIG. 3, each coordinate point in the coordinate group is a mass point 31, and adjacent mass points 31 are springs. The calculation processing is performed by interpreting the coordinate values of each mass point 31 in the coupled oscillators connected by 32. In that case, as an initial state, in this coupled oscillator, each spring 32 connected between each mass point 31 is assumed to be in a state of being stretched a little more than the natural length of each spring. Further, the positions of the first and last mass points are spatially fixed (fixed end condition). With such a setting, the initial movement direction of each mass point becomes the direction shown by the arrow in FIG. 3, and when the movement between each mass point 31 is pulled by the spring 32 to move so as to contract, each mass point is moved. Three
The curve connecting 1 is expected to be corrected to a smoother curve group.

Here, as an initial state, as shown in FIG. 4, the distance d _i between the mass point i and the mass point (i + 1) of each coordinate point in the input coordinate group is the natural distance of each spring. If the length L _i is set to be stretched at a common ratio 1 / ε, the natural length L _i of the spring between the adjacent mass points i and (i + 1) is given by the following (Equation 1). Desired.

[Equation 1] In order to perform smooth correction, it is necessary to set the reduction ratio ε in the range of 0 <ε <1, and the smaller the reduction ratio ε is set, the smaller the natural length L _i of each spring is set. Therefore, the coordinate points (mass points) after correction move so as to approach a straight line.

In the initial condition calculation processing unit 12, first, as a first process, the natural lengths L _i of all springs at each coordinate point (mass point) of the given coordinate group are calculated by (Equation 1). . Further, the mass of all the mass points is regarded as m, and all the springs between the mass points are regarded as linear springs having a spring constant k, and in order to settle the vibration of the mass point, the velocity v _{i of} the mass point (vector value) Add a vibration damping term that is proportional to. A motion equation describing the motion of the mass point i in this case is as shown in the following (formula 2).

[Equation 2] Here, the coefficient η is the damping rate, and if this value is set large,
In the equation-of-motion calculation processing unit 13, the number of calculations N required for correction increases, but a stable correction result can be obtained. In the initial condition calculation processing unit 12, as the second process, the force f _i acting on all the mass points i of the given coordinate group is calculated by (Equation 2). Then, as the third processing, all mass points i required by the molecular dynamics method are
By substituting zero as the initial velocity for the velocity v _{i of} , the value of each coefficient of the mass m of the mass point, the spring constant k, and the damping rate η, and the value of the time interval Δt used in the molecular dynamics method are set.

Next, the calculation processing performed by the motion equation calculation processing section 13 will be described. Motion equation calculation processing unit 1
In 3, the motion equation given by (Equation 2) is numerically integrated by the molecular dynamics method using the set value of the initial condition obtained by the initial condition calculation processing unit 12, and the position x _i of each mass point is calculated. Let us evolve over time. Here, as a molecular dynamics method,
It is calculated using the Verlet algorithm.
This Verlet algorithm is represented by the following (Formula 3).

[Equation 3] By repeatedly calculating (Equation 3), the position x _i of the mass point and the velocity v _i are time-developed, and a coordinate group consisting of smoothly corrected new coordinate points is obtained. By replacing this with the coordinate group consisting of a series of coordinate points input by the pointing device (before correction) and the coordinate group by the calculation result (after correction), a series of coordinate points input by the pointing device with a smooth curve You can draw with.

Finally, the coordinate group drawing processing unit 14 connects the new coordinate groups obtained by the motion equation calculation processing unit 13 with straight lines one by one and draws them on the display screen. For example, as shown in FIG. As described above, when the alphabet “b” is drawn in the handwriting style (cursive) by the input operation of a series of coordinate points by the pointing device, the drawn figure is corrected so as to cause the hand shake as shown on the left side. Then, it is corrected smoothly as shown on the right side.

FIG. 6 is a diagram for explaining the degree of correction due to changes in the reduction ratio ε. In the drawing example shown in FIG. 6, the parameters of the initial condition are mass m = 1, spring constant k = 10,
Attenuation rate η = 5, time interval Δt = 0.1, number of calculations N = 5
An example in which the reduction ratio ε is changed by setting it to 00 is shown. Here, the curve of the drawing example before calculation, the curve of the drawing example calculated at the reduction rate ε = 0.8, and the curve of the drawing example calculated at the reduction rate ε = 0.5 are also shown. As is clear from the curve of the drawing example of FIG. 6, the curve changes more smoothly as the reduction ratio ε is reduced.

FIG. 7 is a diagram showing changes in the degree of correction due to changes in the number of calculations N. In the drawing example shown in FIG. 7, as the parameters of the initial condition, mass m = 1 and spring constant k =
10, damping rate η = 5, time interval Δt = 0.1, reduction rate ε
= 0.1 and the number of calculations N is changed. Here, the curve of the drawing example before calculation and the number of calculations N =
The curve of the drawing example calculated at 50, the curve of the drawing example calculated at N = 100, and the curve of the drawing example calculated at N = 200 are shown together. As is clear from the curve of the drawing example of FIG. 7, the curve changes more smoothly as the number of calculations N increases.

FIG. 8 is a diagram showing an example of a coordinate group in which a series of coordinate points is acquired by an input operation of a handwritten character. Figure 8
As shown in, the coordinate group when the coordinate point is input by drawing the alphabetic character "Hello" by a mouse operation so as to draw in a handwriting style. The density of coordinate points is high in the portion input by slowly dragging, and the density of the acquired coordinate points is low in the portion input by dragging fast.

If the coordinate points of the input coordinate group are simply connected by straight lines, the curve of the drawing example as shown in FIG. 9 is obtained. The curve of the drawing example illustrated in FIG.
FIG. 9 shows a curve of a drawing example in which the coordinate group shown in FIG. 8 is drawn without correction, and the line is distorted due to camera shake at the time of input, which is an unnatural drawing example.

However, when the coordinate group curving correction device of the present invention performs coordinate group curving correction on each coordinate point of the coordinate group thus input, each coordinate point in the coordinate group moves. Then, as shown in FIG. 10, the correction is smoothly performed as a curve connecting the coordinate points with straight lines. In the correction example of the coordinate group shown in FIG. 10, as parameters of initial conditions, mass m = 1, spring constant k = 10, damping rate η = 5, time interval Δt = 0.1, reduction rate ε = 0.8, Number of calculations N = 500
It is an example of drawing in which each coordinate point of the coordinate group is connected by a straight line after the calculation. It can be seen that the correction is clearly made in comparison with the curve of the drawing example shown in FIG.

Further, FIG. 11 shows an example of drawing in which the coordinate group shown in FIG. 8 is corrected with parameters of different initial conditions. In the correction example of the coordinate group in this case, as parameters of the initial condition, mass m = 1, spring constant k = 10, damping rate η = 5, time interval Δt = 0.1, reduction rate ε = 0.1,
This is an example of drawing in which each coordinate point of the coordinate group is connected by a straight line after the number of calculations N = 50. By setting the reduction rate ε to a small value (= 0.1), the distance that the coordinate point moves increases in one calculation, and the calculation converges quickly, which reduces the number of calculations N required for correction. be able to. The number of calculations N is (1/10) in the case of FIG.
However, the drawing result is almost the same as that of the drawing example of FIG. 9 described above.

[0032]

As described above, according to the coordinate group curving correction device or the coordinate group curving correction method of the present invention,
In hand-drawn line drawing using a pointing device such as a mouse, it is possible to smoothly correct a line drawing that is distorted due to camera shake during input, and draw a visually good line drawing on the display screen. Can be made.
As a result, it is possible to draw on the display screen a handwritten wind line figure that is similar to the image drawn with a pencil on paper, so it can be used as a tool for supplementary explanation in education and review using a computer. .

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a main part of a coordinate group curving correction drawing tool according to an embodiment of the present invention;

FIG. 2 is a diagram showing an example of a coordinate group composed of a series of coordinate points input by a pointing device,

FIG. 3 is a diagram illustrating a state of a coupled oscillator connected to a spring having a series of coordinate points input by a pointing device as mass points;

FIG. 4 is a diagram illustrating a relationship between coordinates x _i of a mass point i and a distance d _i between the mass point i and the mass point (i + 1).

FIG. 5 is a diagram showing a drawing example of a coordinate group before correction and a drawing example of a curve by a coordinate group after correction;

FIG. 6 is a diagram for explaining the degree of correction due to a change in reduction ratio ε;

FIG. 7 is a diagram for explaining changes in the degree of correction due to changes in the number of calculations N;

FIG. 8 is a diagram showing an example of coordinate groups in which coordinate points are acquired by an input operation of handwritten characters;

9 is a diagram showing a drawing example in which the coordinate group shown in FIG. 8 is drawn without correction;

10 is a diagram showing a drawing example in which the coordinate group shown in FIG. 8 is corrected with parameters of a predetermined initial condition;

11 is a diagram showing a drawing example in which the coordinate group shown in FIG. 8 is corrected with parameters of another initial condition;

FIG. 12 is a diagram for explaining a general method of drawing a trajectory that a mouse pointer has passed as a line figure;

FIG. 13 is a diagram for explaining drawing when smooth interpolation is performed between coordinate points.

[Explanation of symbols]

11 ... Coordinate group storage unit, 12 ... Initial condition calculation processing unit, 13 ... Motion equation calculation processing unit, 14 ... Coordinate group drawing processing unit, 31 ... mass, 32 ... Spring.

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-6-243220 (JP, A) JP-A-9-106321 (JP, A) JP-A-2-285476 (JP, A) JP-A-3- 222025 (JP, A) JP-A-4-223573 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) G06F 3/00 G06F 3/03-3/037 G06F 3/14- 3/153 G06T 1/00-1/00 200 G06T 11/00-17/50

Claims (2)

(57) [Claims] 1. A coordinate group storage unit for storing a series of coordinate points input by a pointing device as a coordinate group, and a movement of a coupled spring connecting the mass points with each coordinate point of the coordinate group as the position of the mass point. Then, the initial condition setting unit that sets the initial parameters for moving each mass point, and the equation of motion of the coupled spring in which each coordinate point of the coordinate group is the position of the mass point is damped according to the parameters set by the initial condition setting unit. A calculation processing unit that adds a term and performs a calculation process to solve under a fixed-end condition, and obtains and outputs the moving position of the mass point, and coordinates that use the moving position of the mass point output by the calculation processing unit as each coordinate point. A coordinate group curving correction device comprising a coordinate group drawing processing unit for drawing a group on a display screen. 2. The position data of a series of coordinate points input by a pointing device is stored, and when a predetermined number of position data are stored, the stored position data of the series of coordinate points are It is input as position data of coupled oscillators connected by springs, and in the initial state, the coupled oscillators are in a state in which the springs are slightly stretched from their natural length and each mass point is connected by springs. To calculate the natural length of each spring in the coupled oscillator, apply a resistance force to the mass point to settle the vibration of the mass point, and numerically integrate the equation of motion using the molecular dynamics method. Coordinate data by calculating position data of new coordinate points and replacing the calculated position data of the coordinate points as position data of a series of coordinate points input by the pointing device. Group curvature correction method.