JP2000351263A - Method and apparatus for generating ground tint data - Google Patents

Abstract

PROBLEM TO BE SOLVED: To represent a preferable 'gloss' on a sheet embossed using a ground tint pattern generated not to cause any gap or mass based the two-dimensional scalar field of fiber creep angle. SOLUTION: A two-dimensional scalar field where a fiber creep angle is defined at each point is inputted (Step S1) and two different temporary tint patterns are generated based on the two-dimensional scalar field (Step S2). A new tint pattern is then formed by performing exclusive OR operation of these two temporary tint patterns (Step S3). Since a new tint pattern is generated by exclusive OR operation, gaps and dense parts between the tint parts are reduced and undesired gloss of an embossed sheet can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for embossing data on a decorative sheet having a woodgrain pattern in order to express a glossy pattern called "shine", and to obtain a diving angle of a fiber of the woodgrain. And a method and apparatus for making the same.

[0002]

2. Description of the Related Art In decorative sheets used for surface decoration of building materials such as wallpaper and flooring, and surface decoration of furniture, in order to express gloss called "shine", a line pattern is directly decorated. Embossing a sheet, or embossing a line pattern on a transparent sheet to create an embossed sheet, and attaching the embossed sheet to a decorative sheet printed with a wood grain pattern etc. to form a laminated structure Widely used.

[0003] The principle by which "shine" can be expressed by embossing a line pattern will be described below.
Generally, a pattern composed of many fine lines is called a line pattern, and this line pattern is formed as a large number of line grooves on an embossed sheet by embossing. FIG. 16 is a perspective view of the sheet E in which the parallel-line groove G is formed by embossing the parallel-line pattern. In the sheet E, a large number of linear grooves G having a width W1 are formed at intervals of W2. Overall thickness D1 of sheet E
On the other hand, the linear groove G forms a groove having a depth D2,
A number of parallel groove grooves G are arranged in parallel. The pattern composed of such a linear groove G has a concave portion having a width W1 and a width W2.
Has a two-step structure with the convex portion.

[0004] It is known that the intensity of reflected light obtained from the surface of the sheet E on which such a linear groove G is formed differs depending on the position. This is anisotropic reflection. When the line of sight of such a sheet E is continuously changed, a part that reflects strongly, that is, a part that has high luminance and shines brightly changes. This is what is called “movement of illumination”.

[0005] As the line pattern expressing the above "shine" and "movement of shine", natural "shine" and "movement of shine" such as natural wood appears when embossing is performed. Is desirable. Considering the principle by which natural wood can exhibit "shine" and "movement of shine", it is known that it is caused by the fiber diving angle on the surface of the wood. This principle will be described below.

FIG. 17 is a diagram showing the relationship between the orientation of the fibrous material on the surface of the timber plate and the specular reflectance when the viewpoint is fixed directly above. It is assumed that the fibers F are arranged on the surface (cut surface J) of the timber board 100 with the orientation shown as the fiber direction vector F in the figure. At this time, the cut surface J
The angle ξ formed by the fiber F is called a fiber descent angle.

The virtual light source 2 is placed above the timber board 100.
Assuming that the light source is 00 (parallel light source), the virtual light source 200 irradiates a light beam perpendicular to the surface of the timber board 100, and observes diffuse reflected light and specular reflected light from this surface. In this case, the intensity of the observed diffuse reflected light is
The image is influenced by the color components of the grain pattern on the surface of the timber board 100, and the image based on the diffuse reflection light is recognized as a so-called colored pattern. On the other hand, the intensity W (glossiness) of the specular reflected light to be observed depends on the fiber dive angle ξ, and when the line of sight matches the normal direction of the wood and the wood surface is observed vertically, it is usually FIG. The relationship shown in the graph of FIG. More precisely, the specular reflected light intensity in each part is determined by both the light irradiation direction and the fiber descent angle ξ. That is, as shown in FIG. 17, when a ray direction vector L and a fiber direction vector F are defined as shown in FIG. 17 at a point P on the cut plane J, the intensity of the specular reflection light at the point P is determined by the intersection angle φ of both vectors. Will be determined. In the case of the model in which the ray direction vector L is perpendicular to the cutting plane J as in the above-described example, the vector intersection angle φ = 90 ° −ξ, and as shown in the graph of FIG. Sometimes the specular reflected light intensity is highest, φ
It becomes the minimum when = 0 °.

The reason why the shining pattern is seen on the surface of the timber board cut from the actual natural wood is that a different fiber diving angle に is obtained for each part on the cut surface, and a different fiber diving angle is obtained for each part. An illuminated pattern will appear based on the angle ξ. Also, from the above, for example, when the virtual light source 200 is moved without changing the observation position in FIG. 17 or when the observation position is changed while the position of the virtual light source 200 is fixed, the lumber of the timber board 100 is changed. It will be clear that the position where is expressed will change. This is the movement of shine.

Therefore, in recent years, a two-dimensional distribution of fiber dive angles, that is, a two-dimensional scalar field, has been obtained, and a line pattern has been created based on the obtained two-dimensional scalar field of the fiber dive angle. Embossing has been used.

Here, as a method of obtaining the two-dimensional scalar field of the fiber dive angle, for example, a fiber bundle model having an appropriate grain, that is, a model of a fiber bundle having an appropriate orientation is assumed, and the model is used. A method of calculating the diving angle of the fiber appearing on the cut surface when the fiber is cut in a desired direction may be used.
The method proposed in No. 1 may be used. The method proposed in Japanese Patent Application No. 10-104831 will be described below.

In this method, as shown in FIG. 19, natural wood 101, light source 102, camera 103, processing device 10
4 is used. The wood 101 is an object to be measured for the fiber dive angle, and any wood may be used as long as it is natural wood. The wood 101 is fixedly arranged. A camera 103 is arranged directly opposite the wood 101. This camera 103 is also fixedly arranged. Camera 1
Reference numeral 03 may be a plate-making camera, a TV camera, a digital still camera, or any other device capable of capturing an image.
Here, a digital still camera is used for easy understanding. Then, an xyz rectangular coordinate system as shown in the figure is determined.

The light source 102 preferably emits parallel rays as much as possible. The color of the light beam may be white light. The light source 102 can be moved by appropriate means (not shown) in the yz plane of the drawing while keeping the distance from the origin of the coordinate system equal, and the light source 102 can be moved at any position. The light is emitted toward the origin of the coordinate system. That is, the angle of the light source 102 illuminating the wood 101 is variable.

In such a configuration, first, the light source 10
2 is placed at a certain angle θ ₁ , and the wood 103 is photographed by the camera 103. Digital data of an image taken by the camera 103 is taken into the processing device 104. In the case where a plate making camera is used as the camera 103, the photographed film may be developed, input to a scanner, digitized, and passed to the processing device 104.
When a TV camera is used, an image signal from the TV camera may be digitized and passed to the processing device 104.

As will be apparent from the description below, since only the luminance data is used in the processing device 104 for measuring the fiber dive angle, for example, the camera 103 is used for the three colors R, G, and B. In the case of outputting image data, the processing device 104 may take in only the G image data, or generate data representing the luminance from R, G, and B, and output only the data of the luminance. May be used.

Then, the processing device 104 registers that the image data is image data at the angle θ ₁ . As a result, the image data when the light source 102 is placed at the position of the angle θ ₁ is taken into the processing device 104. Next, the angle of the light source 102 is moved by Δθ, and the wood 103 is moved by the camera 103. Is taken, and the image data at that time is passed to the processing device 104. Hereinafter, similarly, the angle of the light source 102 is moved by Δθ to
1 and the image data at that time is
Is repeated a predetermined number of times.

Here, in what angular range the light source 102 is moved around the z-axis in FIG. 19 and how many times Δθ are determined can be arbitrarily determined.
Since the fiber dip angle ξ of natural wood is generally about ± 10 °, the angle range in which the light source 102 is moved may be about ± 30 ° about the z-axis in FIG. As for Δθ, accurate measurement can be performed by reducing the value of Δθ. However, since the measurement time is long, the measurement accuracy,
It may be determined in consideration of the measurement time and the like.

Now, the light source 102 is moved from the angular position of θ ₁ by θ _N.
(N is a natural number) Wood 1
Assuming that 01 has been photographed N times, the processing device 104 fetches the luminance data of N images and registers them in correspondence with the angle of the light source 102 when each image was photographed.

The processing unit 104 focuses on a pixel at a certain position, checks the luminance value of the N images at the pixel position, and determines the light source 1 for the image having the maximum luminance value.
An angle position of 02 is obtained, and a half of the angle of the light source 102 is set as a fiber dive angle に お け る at the pixel position, and the fiber dive angle ξ is registered at the pixel position.

For example, when attention is paid to a certain pixel position, when the luminance value of an image photographed when the angle of the light source 102 is θ _i (i = 1,..., N) is maximum, the processing device 104 ,
The fiber diving angle に お け る at the pixel position is determined and registered as θ _i / 2.

The validity of defining the fiber descent angle ξ in this manner is clear. That is, for example, the brightness at the position indicated by A in FIG. 20 is maximized because the fiber descent angle の of the fiber A, the angle of illumination from the light source 102, and the direction photographed by the camera 103 are shown in FIG. It ’s time to become a relationship
At this time, it is clear that the fiber descent angle の of the fiber A at the position A becomes θ including the sign of the angle. In addition, in FIG. 20, B is a perpendicular to the fiber A at the position A.

Then, the processing device 104 performs the above processing for all pixel positions. With this, camera 1
The fiber dive angle ξ can be obtained for all the pixel positions of the image captured in 03, and a two-dimensional scalar field in which the fiber dive angle is registered for each pixel position can be generated. And according to such a fiber dive angle measuring method, it becomes possible to measure the fiber dive angle at each position of the natural wood directly from natural wood.

As described above, there are various methods for obtaining the two-dimensional scalar field of the fiber dive angle. However, in any conventional method, after obtaining the two-dimensional scalar field of the fiber dive angle, The line pattern for embossing is directly created based on the two-dimensional scalar field of the fiber dive angle obtained.

There are various methods for creating a line pattern based on the two-dimensional scalar field of the fiber dive angle.
As an example, there is a method as disclosed in JP-A-10-287033. In the method disclosed in JP-A-10-287033, a direction vector is calculated based on a two-dimensional scalar field of a fiber dive angle, and the direction of a line is determined according to the direction vector from a start point set on an image forming surface. By doing so, a binary line pattern is created.

[0024]

However, according to the above-described conventional technique, in the created line pattern, the line-to-line lines may be largely apart from each other or may be densely formed. It is known that, when an embossed sheet is created using such a line pattern, a specular reflection occurs in a portion where many lines are gathered, so that preferable “shine” cannot be expressed. Ideally, the area ratio between the parallel lines and the other portions is about 1 to 1 and it is good to arrange the parallel lines without bias (more preferably, without regularity), but in the process of creating the parallel line pattern, There is a problem that it is difficult to get close to the ideal because it includes random number processing. Therefore, the present invention provides a method of generating line data that can generate a preferable line pattern by generating a line pattern in which no gaps or lumps are generated, based on a two-dimensional scalar field of a fiber dive angle. And an apparatus.

[0025]

According to the first and second aspects of the present invention, a two-dimensional scalar field for creating a line pattern is input and the input two-dimensional scalar field is input.
A plurality of different temporary lines are generated based on the dimensional scalar field, and a new line is created by performing an exclusive OR operation between the generated temporary lines. According to the first and second aspects of the present invention, a plurality of temporary lines are generated based on a two-dimensional scalar field that is a two-dimensional distribution of the fiber dive angle, and exclusive OR of the temporary lines is calculated. In order to create line data by setting the value as a new line, in particular, in order to prepare a plurality of provisional lines that were conventionally output as they are and to perform an exclusive OR operation on them,
This has the effect of reducing gaps and lump between lines.

[0026]

Embodiments of the present invention will be described below in detail with reference to the drawings. First, a method of creating line data according to the present invention will be described. FIG. 1 is a flowchart showing the processing operation of the line data creation method. First, a two-dimensional scalar field is input (step S
1).

Next, a temporary line pattern is generated (step S2). The provisional line pattern is a line pattern that has been conventionally created, and is a binary bitmap image like the line pattern finally obtained by the present invention. In order to distinguish it from a pattern, it will be referred to as a temporary line pattern. Here, two provisional line patterns are obtained from one two-dimensional scalar field for later processing.

When two temporary line patterns are obtained from step S2, an exclusive OR of the two temporary line patterns is obtained to create a line pattern (step S2).
3). In step S2 shown in FIG. 1, a first method of directly creating line data of a bitmap, and a second method of temporarily creating pseudo line data in a vector format and then converting the data to line data of a bitmap Since there is a method, below
It will be described individually.

(First Method in Step S2) The first method in step S2 will be schematically described with reference to the flowchart in FIG. First, in step S11, the size of the created image for drawing the temporary line pattern is set, and the pixel values of all the pixels of the created image are set to 0. Here, the width is w (hereinafter, referred to as x direction), and the height is h (hereinafter, referred to as y direction). This size may be the same size as the two-dimensional scalar field of the fiber dive angle, but may be a different size. However, it is assumed that there is a one-to-one correspondence between the position of the two-dimensional scalar field of the fiber dive angle and the position of the created image.

As described above, the fiber diving angle at each position is defined in the two-dimensional scalar field of the fiber diving angle.
The fiber dive angle defined at the position (i, j) in the two-dimensional scalar field of the fiber dive angle can be associated with (i, j).

In the next step S12, the positions of the representative pixels for forming the line pattern are defined in the first row of the pixel array of the created image, and the positions of the representative pixels are continuously arranged in the vicinity of these representative pixels. A process for defining a pixel band composed of the pixel groups thus performed is performed. At this time, the pixel value 1 is written to the representative pixel and the pixels in the pixel band. The number of representative pixels and the arrangement of the representative pixels in the first row are arbitrary, but a plurality of representative pixels may be defined at predetermined intervals.

FIG. 3 shows an example. FIG. 3 shows a representative pixel R among a large number of pixels arranged in the first row of the created image.
11 and R12 are defined. In the example of this figure, the pixel P (1,7) in the seventh column is replaced with the first representative pixel R
11 and a pixel P appearing at a 10-pixel pitch.
(1,17), P (1,27), P (1,37), ...
Are defined as representative pixels R12, R13, R14,... Then, a pixel band is defined near each of the representative pixels. For example, FIG. 4 shows a state in which pixel bands H11, H12,... Composed of a total of five pixels including two pixels each adjacent to the left and right of each representative pixel are defined. In this example, the setting is made such that the pixel band is always constituted by a pixel group consisting of all five pixels centered on the representative pixel. Here, the pixels constituting the pixel band are shown with a black circle at the center.

In the next step S13, a parameter y indicating the number of rows in the pixel array of the created image is set to an initial value 1, and
Hereinafter, the processes of steps S14 and S15 are repeatedly executed. That is, until it is determined in step S16 that the parameter y = n-1 (where n is the total number of rows),
In step S17, the parameter y is incremented by one, and the processes in steps S14 and S15 are repeated.

In step S14, for each representative pixel in the y-th row, the (y +) th pixel located in the direction determined based on the fiber dive angle defined at a point in each representative pixel.
1) The pixels in the row are obtained, and these obtained pixels are assigned to the (y +
1) The representative pixel in the row is defined, and a process of defining a pixel band including a pixel group arranged continuously is executed near the representative pixel in the (y + 1) th row. For example, y
= 1, the representative pixel R in the first row is
, R22,... In the second row are determined based on 11, R12,..., And as shown in FIG. 6, the representative pixels R21, R22,. , The pixel bands H21, H22,... In the second row are defined. Representative pixels R21, R in the second row
22, the first row of the representative pixel R11, R12 and it has fibers diving angle xi] ₁₁ that are defined for, is determined based on xi] _12. Specifically, FIG. 5 as shown in, among the second row pixels, pixels representative pixel R2 having the closest center point in the direction vector V11 determined based on fibers diving angle xi] ₁₁
Is selected as 1, similarly, the pixel having the closest center point direction vector V12 determined based on fibers diving angle xi] ₁₂ is selected as a representative pixel R22. Also, the second
In this example, the pixel bands H21 and H22 in the row are defined as a pixel band including a total of five pixels including two pixels adjacent to the left and right of the representative pixels R21 and R22. At this time, the pixel 1 is written to the defined representative pixel and the pixel in the pixel band.

As described above, when the representative pixels and the pixel bands in the second row are defined in step S14, the adjustment process is performed in the following step S15. This adjustment processing will be described later. Subsequently, steps S16 and S17
Is updated to y = 2, and the process of step S14 is executed again. This time, the representative pixels R31, R32,... In the third row are based on the fiber dive angles defined in the representative pixels R21, R22,.
Are determined, and pixel bands H31, H32,... In the third row are defined based on these representative pixels R31, R32,. If the above processing is repeated until y = n−1, for example, the lines M1, M2, and M2 shown in FIG.
.. Are created. Eventually, the above-described repetitive processing is processing of extending individual parallel lines downward in the figure. The characteristic of the line thus obtained is that it has a flow along the fiber dive angle defined for each pixel. If the representative pixel on the (i + 1) -th row cannot be determined based on the representative pixel on the i-th row, neither the representative pixel nor the pixel band is defined on the (i + 1) -th row. Is set as the end of the line.

Next, the adjustment process shown as step S15 in FIG. 2 will be described. The first purpose of this adjustment process is to generate a new line. For example, FIG.
When the two lines M1 and M2 are gradually extended downward in the figure, as in the example shown in FIG. 1, it is assumed that the interval between the lines M1 and M2 gradually increases. In such a case, if left as it is, a large void region is generated between the two lines M1 and M2, which is not preferable. Therefore, it is preferable to perform an adjustment process for generating a new line M3 between the two lines M1 and M2 as shown in the figure. Also,
The second purpose of the adjustment processing in step S15 is to terminate a line between a pair of lines approaching each other. For example, as shown in an example shown in FIG.
Suppose that when M2 and M3 are gradually extended downward in the figure, the interval between the two lines M1 and M3 is gradually narrowed. In such a case, if left as it is, 3
The lines M1, M2 and M3 of the book come into contact with each other, which is not preferable. Therefore, as shown in the figure, the central line M2
Is terminated.

More specifically, in step S15, the following check is performed on the (i + 1) -th pixel band generated in step S14, and an adjustment process may be performed as necessary. First, it is checked whether or not there is a pair of pixel bands spaced apart from each other by a predetermined reference or more. Then, when such a pixel band exists, a new representative pixel is defined between the pair of pixel bands, and an adjustment process for generating a new pixel band based on the new representative pixel is performed. In the example shown in FIG. 8, d1 = d1 = d1
11 pixels are set, and a pair of pixel bands M1, M
In the twelfth row in which the interval 2 is equal to or longer than d1, a new representative pixel RR and a new pixel band including the same are generated, and a new line M3 is generated. Also, it is checked whether there is a pixel band in which the distance between the pixel band adjacent to the left side of the self and the pixel band adjacent to the right side of the self approaches a predetermined reference or less. Then, if such a pixel band exists, an adjustment process for extinguishing the pixel band and its representative pixel is performed. In the example illustrated in FIG. 9, d2 is set to 10 pixels, with d2 as a predetermined reference, and the pixel band M1 adjacent to the left side of the pixel band M2
In the eleventh row where the distance between the pixel band M3 and the pixel band M3 adjacent to the right side of the pixel band M2 is d2 or less, the pixel band and its representative pixel RR are eliminated.

Next, a one-dimensional scalar field is generated (step S18). This one-dimensional scalar field is used in the next step S19 to deform the shape of each line created in the processing up to step S17. The reason for deforming the shape of each line is as follows. by.

The 2 created by the processing up to step S17
Naturally, it is possible to form irregularities on the cylinder for the embossing plate by, for example, a general direct etching method based on the line pattern of the values, but the embossing plate formed in this way embosses the transparent sheet. When embossed sheets are created by processing, or when embossing is applied directly to a decorative sheet printed with a wood grain pattern, the grain of wood can be expressed more realistically than before, but the sharpness of the grain is sharp. It was too glaring, and it was difficult to obtain a mild wood texture with natural grain.

The reason for this is that the direction vectors of the lines created by the above-described processing are too finely aligned. Therefore, by slightly deforming each line pattern, the direction vectors of the line patterns can be changed. With fluctuations, the sharpness of the shining can be reduced, and thereby a line pattern that can express the gentle woody texture of natural wood grain can be obtained. That is, matting is performed by deforming the line pattern.

For this purpose, a one-dimensional scalar field is used, and the one-dimensional scalar field is deformed by acting on each line pattern. Any one of the one-dimensional scalar fields may be used, but the one-dimensional scalar field is used to deform the line pattern, and it is desirable that the deformation has a natural fluctuation. It is better to use a fractal field. In order to generate a one-dimensional fractal field, for example, a midpoint displacement method may be used.

The size of the one-dimensional scalar field can be set arbitrarily. Also, the range may be any, but here, for ease of understanding, [-1,1]
Is assumed to be normalized to the range

After the one-dimensional scalar field is prepared in this way, the one-dimensional scalar field is applied to each line pattern and deformed (step S19). First extracts the single line pattern M _i in the line pattern created,
As shown in FIG. 10, the position of the line pattern in the y direction and the position of the one-dimensional scalar field are made to correspond one-to-one. For this purpose, the lengths of both may be normalized. And
The position indicated by p of the line M _i corresponds to the position indicated by q of the one-dimensional scalar field, and the scalar value at this position is H
(Q), for example, p of the line pattern
[K · H]
(Q)]. Here, [kH
(Q)] takes a maximum integer value not exceeding k · H (q). For the moving direction, k · H (q)
If is a positive value, it is moved in the right direction of the figure, that is, the direction in which the x-coordinate value is increased. good. Also, k is a coefficient, and an appropriate value can be used. When the value range of the one-dimensional scalar field is normalized to the range of [-1,1] as in this case, k is Since the maximum width of the movement amount of the representative pixel and the pixel band, that is, the magnitude of the deformation is determined, it is desirable that the value is set to a relatively small value. This is because if the value of k is increased, the line pattern will be greatly deformed, and such a line pattern may not be able to express a calm wood texture with natural grain. As described above, since the deformation of the line pattern is sufficient if the direction vector has only a slight fluctuation, the value of k may be a relatively small value.

[0044] Figure 11 is a diagram showing an example of deformation of the line pattern, the representative pixel and the pixel zone position p of the line pattern M _i is at as indicated by hatching in FIG. 11 (a),
Assuming that [k · H (q)] = 3 and k · H (q) is a positive value, the representative pixel and the pixel band are shown in FIG.
As shown in (b), it is shifted by three pixels to the right in the figure.

[0045] The above processing is performed for all the positions of the line pattern M _i, When transformation processing of the line pattern M _i is completed, the deformation in the same manner for the other line pattern. By performing deformation processing on all line patterns created in the process up to step S17 in this way, a line pattern having a matting effect can be obtained, and a gentle woody texture with natural grain is expressed. A line pattern that can be obtained is obtained. The degree of matting can be easily controlled by the one-dimensional scalar field generated in step S18 or the coefficient k.

The above-described calculation for deforming the line pattern is merely an example, and the calculation for determining the movement amount of the representative pixel and the pixel band is performed using a one-dimensional scalar field or the like to be generated. Can be determined appropriately according to Further, in the above description, the same coefficient k is used when deforming all line patterns, but it is also possible to use different coefficients when deforming each line pattern. For this purpose, for example, in step S19, it is sufficient to determine the same number of coefficients as the number of line patterns. Alternatively, in step S19, one-dimensional scalar fields corresponding to the number of line patterns are generated, and the line patterns and the one-dimensional scalar fields are associated with each other. You may make it act.

After all the line patterns have been deformed in this way, the adjustment process is performed again (step S20).
This adjustment processing is the same as the adjustment processing in step S15. Here, the adjustment process is performed again because, as a result of deforming the line pattern, a large void area may be generated between adjacent lines, or the adjacent lines may come into contact with each other. It is. Then, when this adjustment processing is completed, the line pattern creation processing ends, and a line pattern having a matting effect is obtained. Here, the obtained line pattern is passed to step S3 and is treated as a temporary line pattern.

(Second Method in Step S2) Next, the second method in step S2 will be described. In the second method, first, a two-dimensional plane having a desired size is set, and a desired number of starting points of the pseudo line is set in the two-dimensional plane. Note that the horizontal axis of the two-dimensional plane is the x axis, the vertical axis is the y axis, and the pseudo parallel lines are generated in the y axis direction.

Here, the position of the start point of the pseudo line may be set at random by generating a random number, or may be set in a grid pattern at desired intervals vertically and horizontally. Here, what is referred to as "generation of a pseudo line" is not to use the line generated here as it is as a binary bitmap pattern as in the past, but to actually
This is because when a line pattern of a value bitmap is created, the coordinate value of a control point used to create each line is determined.

FIG. 12 shows an example of processing for generating a pseudo parallel line.
Shown in The flowchart shown in FIG. 12 is a process for generating one pseudo line, and therefore, by executing the process shown in FIG. 12 for the start points of all the pseudo lines, all the pseudo lines are displayed. Is generated.

First, in the parameter setting of step S21,
One of the starting points of the pseudo line set earlier
Extract the starting point. Here, the starting point of the pseudo line is
(S _x, S_y). Also, two-dimensional fiber dive angle
From the fiber dive angle ξ at a certain position of the scalar field,
Function F for calculating direction vector at position
(Ξ) is defined. This function F (ξ) may be an appropriate function.
No. Further, a line length L of the pseudo line in the y-axis direction and a pseudo line
A drawing step Δd for generating a similar line is set.

Next, in step S22, an initial value is determined. First, the first control point P ₀ (x ₀ , y ₀ ) of the pseudo parallel line
While defining a first control point because none other than the start point of the pseudo-parallel line, which is _{x 0 = s x, y 0} = s y. Next, the number n of control points and the drawing length d of the pseudo parallel line are determined. At the first control point, n = 1 and d = 0.

Next, the process of step S23 is repeated until d> L is satisfied. The processing in step S23 is performed in the
This is a process for obtaining the coordinate value of the control point.
1) When the fiber dive angle at the position of the two-dimensional scalar field of the fiber dive angle corresponding to the position (x _n-1 , y _n- 1) of the control point is ξ, for example, the calculation is performed by the following (Formula 1) Just do it.

(Equation 1) x _n = x _n-1 + Δd × F (ξ) y _n = y _n-1 + Δd

Subsequently, the number of control points n is increased (n + 1)
Similarly, the drawing length d of the pseudo parallel line is increased to (d + Δd). Then, the process of step S23 is repeated until d> L of step S24 is satisfied. According to the processing in step S23, the line length d of the pseudo parallel line generated depending on the value of Δd may be larger than the value of L set in step S21, but the difference is small. There is no problem.

If the determination in step S24 is affirmative, the coordinates of the first control point determined in step S22 and the coordinates of the second to nth control points determined in step S23 are determined. The coordinate value is output (Step S25). Note that the line length L of the pseudo line and the value of the drawing step Δd set in step S21 may be the same for all the pseudo lines, or an appropriate value may be set for each pseudo line. is there.

By the processing of steps S21 to S25, pseudo lines are generated from all the start points set on the two-dimensional plane, and the coordinate values of the control points for these pseudo lines are output. Will be.

After step S25, data is reduced in step S26. However, the processing in step S26 is not an indispensable processing, and the coordinate values of the control points of the respective pseudo parallel lines output in step S25 may be registered as they are. It is to be reduced.

This data reduction processing is performed in step S25.
This is performed by thinning out the number of control points at appropriate intervals for each pseudo parallel line output in step (1). Actually, about 10 control points may be finally left for one pseudo parallel line.

As described above, according to the second method, a desired number of pseudo line is temporarily formed instead of directly forming a line pattern of a binary bit map from the two-dimensional scalar field of the fiber dive angle. It generates and has the coordinate value of the control point of each pseudo line as line data. That is, since the line data is stored in the vector format, the handling is easier than in the first method in which the line pattern of the binary bitmap is directly handled.

Next, how to create a binary bitmap line pattern from the vector line data created by the above processing will be described with reference to FIG.

In the processing shown in FIG. 13, the parameters of the rotation angle, fluctuation, and line width are set as desired for each line (step S27), and the line data obtained by the above-described processing is set. That is, one line data in which the data of each line is in the vector format is read out (step S28). As the fluctuation, a one-dimensional fractal field may be generated as described in step S18 of FIG.

Then, in the process of creating a line pattern in step S29, the vector line data read out in step S28 and the rotation angle, fluctuation, and line set in step S27 with respect to the line. The width parameter is fetched, a spline curve is generated based on the coordinate values of the control points of the fetched line data, and the line is drawn.
The drawn curve is subjected to a rotation process based on the set rotation angle parameter, is given a fluctuation based on the fluctuation parameter, and is given the set line width. In order to make the curve fluctuate, for example, a process similar to the process of step S19 in FIG. 2 may be performed. It is obvious to those skilled in the art that an appropriate function other than the spline curve can be used to draw a line curve from the coordinate values of the control points of the line data. Here, similarly to the first method, the created line pattern is passed to step S3 and is treated as a temporary line pattern.

(Regarding Step S3) In either of the first and second methods, a provisional line pattern of a binary bitmap is created. Is used, one two-dimensional scalar field is input and the process is performed twice to obtain two temporary line patterns. Since a random number acts in the process of creating this temporary line pattern, even if the same two-dimensional scalar field is input in step S1, the two temporary line patterns obtained will be different.

When the provisional line pattern of the two binary bitmaps is obtained, a new line pattern is obtained by taking the exclusive OR of each pixel of the two provisional line patterns (step S3). . That is, when only one of the pixels takes the value "1", the pixel value in the new line pattern is set to "1", and in the other cases, the pixel value in the new line pattern is set to "0". . An example of taking an exclusive OR of a binary bitmap image in this manner will be described with reference to FIG. In FIG. 14, for convenience of description, an image A having a horizontally long pattern and an image B having a vertically long pattern are described instead of a line pattern. Here, when the exclusive OR of the image A and the image B is calculated, an image C as shown in FIG. 14C is obtained. When the image C is compared with the image A, it can be seen that the patterns are scattered throughout.
Similarly, it can be seen that the patterns are scattered even when the image C is compared with the image B. As described above, when the exclusive OR of the binary bitmap images is obtained, the patterns are scattered throughout. When this is applied to the line pattern, the line gap,
Both lumps will decrease.

Since a line pattern is obtained by the processing of steps S1 to S3, an embossing plate is created based on the line pattern, and a desired embossing plate is formed by the embossing plate. The sheet may be embossed.

(Apparatus Configuration) Next, an apparatus for creating line data according to the first embodiment will be described. As shown in FIG. 15, the present apparatus includes a two-dimensional scalar field input unit 1, a temporary line generating unit 2, an exclusive OR operation unit 3, and an output unit 4. The two-dimensional scalar field input means 1 performs the processing of step S1 in FIG. 1, and is for inputting the two-dimensional scalar field of the fiber dive angle created by an appropriate method as described above. . Temporary line generating means 2
Performs the process of step S2 in FIG. 1, and has a function of executing the two methods of the first method and the second method as described above. The exclusive OR operation means 3 is shown in FIG.
The output means 4 is for outputting the created line data.

The two-dimensional scalar field input means 1, the temporary line generating means 2, the exclusive OR operation means 3, and the output means 4
Are constructed using a computer, and the computer finally outputs line data.

[0069]

As described above, according to the present invention,
Generating a plurality of temporary lines based on a two-dimensional scalar field that is a two-dimensional distribution of fiber dive angles, calculating the exclusive OR of these temporary lines, and using the value as a new line In particular, multiple temporary lines, which were previously output as they are, are prepared, and exclusive OR operation is performed on them. This reduces the gaps and lump between lines. To play. Thereby, in the embossed sheet obtained by embossing the line pattern, undesired reflection does not occur.

[Brief description of the drawings]

FIG. 1 is a flowchart showing a processing operation of a method of creating line data according to the present invention.

FIG. 2 is a diagram illustrating a first example of temporary line creation in step S2 of FIG. 1;
5 is a flowchart showing details of the method.

FIG. 3 is a diagram showing representative pixels defined in a first row in step S12 of FIG. 2;

FIG. 4 is a diagram showing a pixel band defined in a first row in step S12 of FIG. 2;

FIG. 5 is a diagram showing representative pixels defined in a second row based on representative pixels in a first row in step S14 of FIG. 2;

FIG. 6 is a diagram illustrating a pixel band defined in a second row based on the representative pixels in the first row in step S14 of FIG. 2;

FIG. 7 is a diagram showing a line created by the procedure of the flowchart of FIG. 2;

FIG. 8 is a diagram showing a state where a new line M3 has been generated by the adjustment processing in step S15 of FIG. 2;

FIG. 9 illustrates a line M by the adjustment processing in step S15 of FIG. 2;
FIG. 2 is a diagram showing a state where 2 is terminated.

FIG. 10 is a diagram for explaining the parallel line deformation processing in step S19 in FIG. 2;

11 is a diagram for explaining an example in which a representative pixel and a pixel band are moved and deformed by the parallel line deformation processing in step S19 in FIG. 2;

FIG. 12 is a flowchart illustrating details of a second method of generating a provisional line in step S2 of FIG. 1;

FIG. 13 is a flowchart illustrating details of a second method of generating a provisional line in step S2 of FIG. 1;

FIG. 14 is a diagram for explaining an exclusive OR operation in step S3 of FIG. 1;

FIG. 15 is a block diagram illustrating a configuration of a line data creating apparatus according to the present invention.

FIG. 16 is a perspective view showing a structure of a line groove G formed on the surface of a sheet on which a line pattern has been subjected to endless processing.

FIG. 17: Fiber direction vector F in a general lumber slab
FIG. 6 is a side sectional view showing a relationship between the light beam vector L and the light beam vector L.

FIG. 18: Vector intersection angle φ in a general timber board
6 is a graph showing a relationship between (fiber diving angle ξ) and the intensity of specular reflected light W.

FIG. 19 is a view for explaining a method proposed by the present applicant in Japanese Patent Application No. 10-104831 to generate a two-dimensional scalar field of a fiber dive angle from natural wood.

FIG. 20 is a diagram for explaining a method of generating a two-dimensional scalar field of a fiber dive angle from natural wood proposed by the present applicant in Japanese Patent Application No. 10-104831.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Two-dimensional scalar field input means 2 ... Temporary line generation means 3 ... Exclusive OR operation means 4 ... Output means

Claims (2)

[Claims] 1. A two-dimensional scalar field for creating a line pattern is inputted, a plurality of different temporary lines are generated based on the two-dimensional scalar field, and exclusive OR operation of these temporary lines is performed. , A new line is created, thereby creating a new line. 2. A two-dimensional scalar field input means for inputting a two-dimensional scalar field for creating a line pattern, and a plurality of different temporary lines based on the two-dimensional scalar field input by the two-dimensional scalar field input means. Temporary line generating means for generating the same, and exclusive OR operation means for performing an exclusive OR operation between the temporary lines generated by the temporary line generating means to create a new line. An apparatus for creating line data.