JP4531155B2 - Line data creation method and apparatus - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a method and apparatus for creating line data for embossing a decorative sheet having a wood grain pattern for embossing to express a glossy pattern called “shine” from the dive angle of the wood fiber. .
[0002]
[Prior art]
For decorative sheets used for surface decoration of building materials such as wallpaper and flooring, and furniture surface decoration, embossing the line pattern directly on the decorative sheet to express the gloss called “shine”. Or embossing a line pattern on a transparent sheet to create an embossed sheet, and then sticking the embossed sheet on a decorative sheet printed with a pattern such as a wood grain pattern to make a laminated structure is widely performed. .
[0003]
The principle that “shine” can be expressed by embossing the line pattern will be described below. Generally, a pattern composed of a large number of 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 a sheet E on which a line groove G is formed by embossing a line pattern. In the sheet E, a large number of strips G having a width W1 are formed at intervals of W2. With respect to the total thickness D1 of the sheet E, the line groove G forms a groove with a depth D2, and a large number of line grooves G are arranged in parallel. Such a pattern composed of the multi-row grooves G has a two-step step structure of a concave portion having a width W1 and a convex portion having a width W2.
[0004]
It is known that the intensity of the reflected light obtained from the surface of the sheet E on which such a linear groove G is formed varies depending on the position. This is anisotropic reflection. When the line of sight of such a sheet E is continuously changed, a portion that is strongly reflected, that is, a portion that is high in brightness and shines brightly changes. This is called “shine movement”.
[0005]
As a line pattern that expresses “shine” and “movement of shine” described above, natural “shine” and “movement of shine” that natural wood can express when embossing is performed can be expressed. Things are desirable. Therefore, considering the principle that natural wood can express “shine” and “movement of illumination”, it is known that this is due to the fiber dive angle on the wood surface. This principle will be described below.
[0006]
FIG. 17 is a diagram showing the relationship between the orientation of the fiber on the surface of the timber board and the specular reflectance in a state where the viewpoint is fixed directly above. It is assumed that fibers F are arranged on the surface (cut plane J) of the timber board 100 with an orientation as shown as a fiber direction vector F in the figure. At this time, an angle ξ formed by the cut surface J and the fiber F is called a fiber dive angle.
[0007]
Then, assuming a virtual light source 200 (parallel light source) above the timber board 100, a light beam perpendicular to the surface of the timber board 100 is irradiated from the virtual light source 200, and diffuse reflection light and specular reflection light from this surface. Think about observing. In this case, the intensity of the diffuse reflected light to be observed depends on the color component of the wood grain pattern on the surface of the timber board 100, and the image by the diffuse reflected light is recognized as a so-called colored pattern. On the other hand, the intensity W (glossiness) of the specular reflected light that is observed depends on the fiber dive angle ξ, and usually when the wood surface is observed vertically with the line-of-sight direction coincided with the normal direction of the wood, FIG. The relationship is as shown in the graph. More precisely, the specular reflection light intensity in each part is determined by both the light irradiation direction and the fiber dive angle ξ. That is, as shown in FIG. 17, if the light direction vector L and the fiber direction vector F are defined at the point P on the cut surface J as shown in the figure, the intensity of the specular reflected light at the point P is determined by the intersection angle φ between the two vectors. Will be determined. In the case of a model in which the light direction vector L is perpendicular to the cutting plane J as in the above example, the vector crossing angle φ = 90 ° −ξ, and φ = 90 ° as shown in the graph of FIG. Sometimes the specular reflection light intensity becomes the highest, and becomes the lowest when φ = 0 °.
[0008]
The reason why the shimmer pattern is seen on the surface of the timber board cut out from the actual natural wood is that a different fiber dive angle ξ is obtained for each part on the cut surface, and a different fiber dive angle ξ is obtained for each part. Based on this, a shimmering pattern will appear. Further, for example, when the virtual light source 200 is moved without changing the observation position in FIG. 17 or when the position of the virtual light source 200 is fixed and the observation position is changed, the illumination of the timber board 100 is performed. It will be apparent that the position at which is expressed will change. This is the movement of shimmer.
[0009]
Therefore, in recent years, a two-dimensional distribution of fiber diving angles, that is, a two-dimensional scalar field, is obtained, a line pattern is created based on the obtained two-dimensional scalar field of the fiber diving angle, and embossing is performed using the line pattern. Processing is done.
[0010]
Here, as a method for obtaining the two-dimensional scalar field of the fiber diving angle, for example, a fiber bundle model having an appropriate grain structure, that is, a fiber bundle model having an appropriate orientation is assumed, and the model is set in a desired direction. Alternatively, a method of calculating the fiber divergence angle appearing on the cut surface when the wire is cut may be used, or the method previously proposed by the present applicant in Japanese Patent Application No. 10-104831 may be used. The method proposed in Japanese Patent Application No. 10-104831 will be described as follows.
[0011]
In this method, natural wood 101, a light source 102, a camera 103, and a processing device 104 are used as shown in FIG. The wood 101 is an object for measuring the fiber dive angle, and any wood may be used as long as it is natural wood. This wood 101 is fixedly arranged. A camera 103 is arranged facing the wood 101. This camera 103 is also fixedly arranged. The camera 103 may be any camera that can capture images such as a plate-making camera, a TV camera, or a digital still camera. Here, a digital still camera is used to facilitate understanding. Then, an xyz orthogonal coordinate system as shown in the figure is determined.
[0012]
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 an appropriate means (not shown) while keeping the distance from the origin of the coordinate system equal in the yz plane of the figure. A light beam is emitted toward the origin of the coordinate system. That is, the angle at which the light source 102 illuminates the wood 101 is variable.
[0013]
In such a configuration, first, the wood 101 is photographed by the camera 103 with the light source 102 placed at a certain angle θ ₁ . Digital data of an image taken by the camera 103 is taken into the processing device 104. When a plate making camera is used as the camera 103, the photographed film is developed, input by a scanner, digitized, and transferred to the processing device 104. When a TV camera is used, the TV camera is used. The image signal may be digitized and passed to the processing device 104.
[0014]
As will be apparent from the description below, the processing device 104 uses only luminance data to measure the fiber dive angle. For example, the camera 103 generates image data of three colors R, G, and B. In the case of output, the processing device 104 may capture only G image data, or may generate data representing luminance from R, G, and B and use only the luminance data. Anyway.
[0015]
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 camera 103 moves the wood 101. The image data at that time is transferred to the processing device 104. Similarly, the operation of photographing the wood 101 by moving the angle of the light source 102 by Δθ and transferring the image data at that time to the processing device 104 is repeated a predetermined number of times.
[0016]
Here, in what angle range the light source 102 is moved around the z-axis in FIG. 19 and how many times Δθ is set can be arbitrarily determined. In general, the fiber latent angle ξ of natural wood Is generally about ± 10 °, the angle range for moving the light source 102 may be about ± 30 ° about the z-axis of FIG.
Further, Δθ can be measured with high accuracy if the value of Δθ is reduced, but the measurement time becomes longer, and therefore it may be determined in consideration of measurement accuracy, measurement time, and the like.
[0017]
Assuming that the light source 102 is moved N steps from the angle position θ _{1 to} the angle position θ _N (N is a natural number) and the wood 101 is photographed N times, the processing device 104 captures luminance data of N images. The registration is performed in correspondence with the angle of the light source 102 when each image is taken.
[0018]
Then, the processing device 104 pays attention to a pixel at a certain position, examines the luminance value at the pixel position of these N images, obtains the angular position of the light source 102 when the image has the maximum luminance value, and determines the light source. The half of the angle 102 is defined as the fiber dive angle ξ at the pixel position, and the fiber dive angle ξ is registered at the pixel position.
[0019]
For example, when attention is paid to a certain pixel position, when the luminance value of the image taken when the angle of the light source 102 is θ _i (i = 1,..., N) is the maximum, the processing device 104 determines that the pixel The fiber dive angle ξ at the position is registered as θ _i / 2.
[0020]
The validity of determining the fiber dive angle ξ in this way is clear. That is, for example, the luminance at the position indicated by A in FIG. 20 is maximized because the fiber dive angle ξ of the fiber A, the angle of illumination from the light source 102, and the direction taken by the camera 103 are shown in FIG. It is obvious that the fiber dive angle ξ of the fiber A at the position A is θ including the sign of the angle. In FIG. 20, B is a perpendicular to the fiber A at position A.
[0021]
Then, the processing device 104 performs the above processing for all pixel positions. As a result, the fiber dive angle ξ can be obtained for all pixel positions of the image photographed by the camera 103, 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 in each position of the natural wood directly from natural wood.
[0022]
As described above, there are various methods for obtaining the two-dimensional scalar field of the fiber diving angle. Conventionally, after obtaining the two-dimensional scalar field of the fiber diving angle, any method can be obtained. Based on the two-dimensional scalar field of the fiber dive angle, a line pattern for embossing was directly created.
[0023]
There are various methods for creating a line pattern based on the two-dimensional scalar field of the fiber dive angle, and as an example, there is a method as disclosed in JP-A-10-287033. In the method disclosed in Japanese Patent Laid-Open No. 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 the start point set on the image forming surface. By going, a binary line pattern is created.
[0024]
[Problems to be solved by the invention]
However, in the above conventional technique, in the created line pattern, the distance between the lines may be widened or conversely dense. It is known that when an embossed sheet is created using such a line pattern, regular reflection occurs in a portion where a lot of lines are gathered, so that preferable “shine” cannot be expressed. Ideally, the area ratio between the line and other parts is about 1: 1, and it is good to arrange the line (and more preferably without regularity), but in the process of creating the line pattern, Since random number processing is included, there is a problem that it is difficult to approach the ideal.
Therefore, the present invention generates a line pattern that does not generate a gap or a lump based on a two-dimensional scalar field of a fiber dive angle, and a line data creation method capable of expressing a preferable “shine”. Another object is to provide a device.
[0025]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, in the first and second aspects of the invention, a two-dimensional scalar field that is a two-dimensional distribution of fiber dive angles, which are angles formed by the surface of the timber board and the fibers, is input and input 2 A direction vector defined on the basis of the fiber dive angle on a three-dimensional scalar field is defined, and a large number of pixels are created by a set of pixel bands having a flow along the direction vector and composed of a pixel group composed of adjacent pixels. A value that is defined by q corresponding to a position p on the line, which defines a line and prepares a function k · H (q) composed of a different coefficient k and a one-dimensional scalar field H (q) for each pattern. Two different binary temporary line patterns are generated by deforming the line based on k · H (q), and exclusive OR operation is performed between each pixel of the generated temporary line pattern. Create a new line pattern Characterized in that the so that. According to the first and second aspects of the present invention, a plurality of temporary line patterns are generated based on a two-dimensional scalar field that is a two-dimensional distribution of fiber dive angles, and the exclusive logic between the pixels of the temporary line patterns is provided. Line data is created by calculating the sum and using the value as a new line pattern. In particular, multiple provisional line patterns that were output in the past are prepared and exclusive. Since the logical OR operation is performed, there is an effect that the gaps and lumps of the line are reduced.
[0026]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
First, a method for 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 S1).
[0027]
Next, a temporary line pattern is generated (step S2). This provisional line pattern is a line pattern that has been created in the past, and is a binary bitmap image similar to the line pattern finally obtained by the present invention. In order to distinguish it from a pattern, it will be called a temporary line pattern. Here, two temporary line patterns are obtained from one two-dimensional scalar field for later processing.
[0028]
When two temporary line patterns are obtained from step S2, a line pattern is created by taking the exclusive OR of the two temporary line patterns (step S3). In step S2 shown in FIG. 1, a first method for directly creating bitmap line data, and a second method for temporarily generating vector line pseudo-line data and then converting it into bitmap line data. Since there is a method, it demonstrates separately below.
[0029]
(First method in step S2)
The first method in step S2 will be schematically described with reference to the flowchart of 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.
[0030]
As described above, since the fiber submerged angle at each position is defined in the two-dimensional scalar field of the fiber submerged angle, the fiber can be applied to the pixel P (i, j) at an arbitrary position of the created image. The fiber diving angle defined at the position (i, j) of the two-dimensional scalar field of the diving angle can be associated.
[0031]
In the next step S12, the positions of the representative pixels for creating the line pattern are defined in the first row of the pixel array of the created image, and the pixels continuously arranged in the vicinity of these representative pixels. A process of defining each pixel band composed of groups is performed. At this time, the pixel value 1 is written to the representative pixel and the pixels in the pixel band. It is arbitrary how many representative pixels are defined in the first row and in what arrangement, but a plurality of representative pixels may be defined at a predetermined interval.
[0032]
An example is shown in FIG. FIG. 3 shows a state in which representative pixels R11 and R12 are defined from a large number of pixels arranged in the first row of the created image. In the example of this figure, the pixel P (1,7) in the seventh column is defined as the first representative pixel R11, and hereinafter, the pixels P (1,17), P (1,27), which appear at a pitch of 10 pixels, P (1, 37),... Are defined as representative pixels R12, R13, R14,. A pixel band is defined in the vicinity of each representative pixel. For example, FIG. 4 shows a state in which pixel bands H11, H12,..., Each including five pixels including two pixels adjacent to the left and right of each representative pixel are defined. In this example, the pixel band is always set to be composed of 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.
[0033]
In the next step S13, the parameter y indicating the number of rows in the pixel array of the created image is set to an initial value 1, and thereafter, the processes in steps S14 and S15 are repeatedly executed. That is, in step S16, the parameter y is incremented by 1 in step S17 until the parameter y = n-1 (where n is the total number of rows) is determined, and the processes in steps S14 and S15 are repeated. .
[0034]
In step S14, for each representative pixel in the y-th row, a pixel in the (y + 1) -th row located in the direction determined based on the fiber latent angle defined at the point in each representative pixel is obtained. The obtained pixels are defined as representative pixels in the (y + 1) -th row, and a process for defining a pixel band composed of a continuously arranged pixel group in the vicinity of the representative pixels in the (y + 1) -th row is executed. Is done. For example, when y = 1, as shown in FIG. 5, the representative pixels R21, R22,... In the second row are determined based on the representative pixels R11, R12,. As shown in FIG. 6, pixel bands H21, H22,... Of the second row are defined based on the representative pixels R21, R22,. The representative pixels R21 and R22 in the second row are determined based on the fiber dive angles ξ ₁₁ and ξ ₁₂ defined for the representative pixels R11 and R12 in the first row. Specifically, as shown in FIG. 5, among the pixels in the second row, the pixel having the center point closest to the direction vector V11 determined based on the fiber dive angle ξ ₁₁ is selected as the representative pixel R21. Similarly, a pixel having the closest center point direction vector V12 determined based on fibers diving angle xi] ₁₂ is selected as a representative pixel R22. In this example, the pixel bands H21 and H22 in the second row are defined as pixel bands 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 pixels in the pixel band.
[0035]
As described above, when the representative pixel and the pixel band in the second row are defined in step S14, the adjustment process is performed in subsequent step S15. This adjustment process will be described later. Subsequently, after steps S16 and S17, y = 2 is updated, and the process of step S14 is executed again. This time, the representative pixels R31, R32,... In the third row are determined based on the fiber dive angles defined in the representative pixels R21, R22,. Based on R31, R32,..., Pixel bands H31, H32,. If the above processing is repeated until y = n−1, for example, lines M1, M2,... As shown in FIG. It will be. Eventually, the above-described repetitive process is a process of extending individual lines downward in the drawing. 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 in the (i + 1) -th row cannot be determined based on the representative pixel in the i-th row, neither the representative pixel nor the pixel band is defined in the (i + 1) -th row, and the i-th row The end of the corresponding line is to be the pixel band.
[0036]
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, suppose that when the two lines M1 and M2 are gradually extended downward in the figure as in the example shown in FIG. 8, the distance between the lines M1 and M2 gradually increases. In such a case, leaving it as it is is not preferable because a large gap region is generated between the two lines M1 and M2. Therefore, as shown in the figure, it is preferable to perform adjustment processing for generating a new line M3 between the lines M1 and M2. The second purpose of the adjustment process in step S15 is to terminate a line sandwiched between a pair of lines approaching each other. For example, as shown in FIG. 9, when the three lines M1, M2, M3 are gradually extended downward in the figure, the distance between the lines M1, M3 gradually decreases. Let's say. In such a case, it is not preferable that the three lines M1, M2, and M3 come into contact with each other if left as they are. Therefore, as shown in the figure, adjustment processing for terminating the central line M2 is performed.
[0037]
Specifically, in step S15, the following check is performed on the pixel band in the (i + 1) th row generated in step S14, and adjustment processing may be performed as necessary. First, it is checked whether or not there is a pair of pixel bands that are separated from each other by a predetermined reference or more. If 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, the predetermined reference is d1, and d1 = 11 pixels is set. In the 12th row where the distance between the pair of pixel bands M1 and M2 is equal to or greater than d1, a new representative pixel RR is set. And a new pixel band including this is generated, and a new line M3 is generated. It is also 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 is close to a predetermined reference or less. If such a pixel band exists, an adjustment process for eliminating the pixel band and its representative pixel is performed. In the example shown in FIG. 9, the predetermined reference is d2, and d2 = 10 pixels is set. The pixel band M1 adjacent to the left side of the pixel band M2 and the pixel band M3 adjacent to the right side of the pixel band M2 In the 11th row in which the interval is d2 or less, the pixel band and its representative pixel RR are extinguished.
[0038]
Next, a one-dimensional scalar field is generated (step S18). The one-dimensional scalar field is for deforming the shape of each line created in the processing up to step S17 in the next step S19. The reason for deforming the shape of each line is as follows. by.
[0039]
Based on the binary line pattern created by the processing up to step S17, it is natural that irregularities can be formed in the cylinder for the embossing plate by, for example, a general direct etching method. When embossing is performed on a transparent sheet with the formed embossed plate to create an embossed sheet, or when embossing is directly applied to a decorative sheet printed with a wood grain pattern, the shimmering of the wood grain is more realistic than before. However, it was difficult to obtain a gentle wood texture of natural grain because the shine was too sharp and glaring.
[0040]
The cause of this is that the direction vectors of the line created by the above-described processing are neatly aligned, and therefore, the direction vector of the line pattern has a fluctuation by slightly deforming each line pattern. If this is done, the sharpness of shimmering can be reduced, thereby obtaining a line pattern that can express the gentle wood texture of natural grain. That is, matting is performed by deforming the line pattern.
[0041]
For this purpose, a one-dimensional scalar field is used, and this one-dimensional scalar field is applied to each line pattern and deformed. Any one can be used as this one-dimensional scalar field, but it is for deforming the line pattern, and it is desirable to have a natural fluctuation as the deformation. A fractal field should be used. In order to generate a one-dimensional fractal field, for example, a midpoint displacement method may be used.
[0042]
The size of this one-dimensional scalar field can be set arbitrarily. Further, any value range may be used, but here it is assumed that the range is normalized to the range [-1, 1] for easy understanding.
[0043]
Once the one-dimensional scalar field is prepared in this way, the one-dimensional scalar field is then deformed by acting on each line pattern (step S19). First extracts the single line pattern M _i in the line pattern created, as shown in FIG. 10, the position of the one-dimensional scalar field in the y direction of the line pattern on a one-to-one Make it correspond. For this purpose, the lengths of both may be normalized. If the position indicated by p of the line M _i corresponds to the position indicated by q in the one-dimensional scalar field, and the scalar value at this position is H (q), for example, the line pattern The position of the representative pixel and the pixel band at the position p is moved by [k · H (q)]. Here, [k · H (q)] takes a maximum integer value not exceeding k · H (q). As for the moving direction, if k · H (q) is a positive value, it is moved in the right direction in the figure, that is, in the direction in which the x coordinate value increases, and if it is negative, the left direction in the figure, that is, x What is necessary is just to make it move to the direction where a coordinate value becomes small. Further, k is a coefficient, and an appropriate value can be used. However, when the range of the one-dimensional scalar field is normalized to the range [-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 size of the deformation is determined, it is desirable that the value be relatively small. This is because when the value of k is increased, the line pattern is greatly deformed, and such a line pattern may not be able to express the gentle wood texture of natural grain. As described above, the deformation of the line pattern need only have a slight fluctuation in the direction vector, so 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 oblique lines in FIG. 11 (a), [k · H If (q)] = 3 and k · H (q) is a positive value, the representative pixel and the pixel band are moved by 3 pixels in the right direction of the figure as shown in FIG. Will be.
[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. In this way, if all the line patterns created in the process up to step S17 are subjected to the deformation process, a line pattern having a matte effect can be obtained and a gentle wood texture with natural grain can be 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.
[0046]
Note that 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 depends on the generated one-dimensional scalar field or the like. Of course, it can be determined appropriately. In the above description, the same coefficient k is used for deformation of all line patterns. However, different coefficients may be used for deformation of each line pattern. For this purpose, for example, as many coefficients as the number of line patterns may be determined in step S19. Alternatively, in step S19, one-dimensional scalar fields corresponding to the number of line patterns are generated, the line patterns and the one-dimensional scalar fields are made to correspond, and when a certain line pattern is deformed, the associated one-dimensional scalar fields are generated. You may make it act.
[0047]
After all the line patterns have been deformed in this way, adjustment processing is performed again (step S20). This adjustment process is the same as the adjustment process in step S15. The reason why the adjustment process is performed again is that, as a result of the deformation of the line pattern, there is a possibility that a large gap area may be generated between adjacent line lines, or adjacent line lines may come into contact with each other. It is. When this adjustment process ends, the line pattern creation process ends, and a line pattern having a matte effect is obtained. Here, the obtained line pattern is transferred to step S3 and treated as a temporary line pattern.
[0048]
(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 pseudo parallel line start points are set in the two-dimensional plane. It is assumed 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.
[0049]
Here, the positions of the start points of the pseudo parallel lines may be set randomly by generating a random number, or may be set in a grid pattern at desired intervals in the vertical and horizontal directions. Note that the “generation of pseudo lines” is not used here as a binary bit map pattern as it is in the past, but is actually used as a binary pattern later. This is because the process is to obtain the coordinate values of the control points used to create each line when creating a line pattern of the bitmap.
[0050]
FIG. 12 shows an example of pseudo line generation processing. The flowchart shown in FIG. 12 is a process for generating one pseudo line. Therefore, by executing the process shown in FIG. 12 for the start points of all the pseudo lines, all the pseudo lines are generated. Will be generated.
[0051]
First, in the parameter setting in step S21, one start point is extracted from the start points of the pseudo parallel lines set previously. Here, it is assumed that the starting point of the pseudo parallel line is (s _x , s _y ). Further, a function F (ξ) for calculating a direction vector at a position from the fiber dive angle ξ at a position where the two-dimensional scalar field of the fiber dive angle exists is defined. This function F (ξ) may be an appropriate function. Further, a line length L in the y-axis direction of the pseudo line and a drawing step Δd for generating the pseudo line are set.
[0052]
Next, an initial value is determined in step S22. First, a first control point P ₀ (x ₀ , y ₀ ) of the pseudo line is determined. Since the first control point is nothing but the start point of the pseudo line, x ₀ = s _x , y ₀ = s. _y . Next, the number n of control points and the drawing length d of the pseudo parallel lines are determined. At this first control point, n = 1 and d = 0.
[0053]
Next, the process of step S23 is repeated until d> L is satisfied. The process of step S23 is a process for obtaining the coordinate value of the nth control point, and the fiber dive angle of 2 corresponding to the position ( _xn-1 , yn _-1 ) of the (n-1) th control point. When the fiber dive angle at the position of the three-dimensional scalar field is ξ, for example, calculation may be performed by the following (Equation 1).
[0054]
(Formula 1)
x _n = x _n-1 + Δd × F (ξ)
y _n = y _n-1 + Δd
[0055]
Subsequently, the number n of control points is increased to (n + 1), and similarly, the drawing length d of the pseudo parallel line is increased to (d + Δd). The process in step S23 is repeated until d> L in step S24 is satisfied. In addition, according to the process of step S23, the line length d of the pseudo 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. So there is no problem.
[0056]
And when it is judged as yes by the judgment process of step S24, the coordinate value of the 1st control point determined in step S22 and the coordinate value of the 2nd control point-nth control point calculated | required by step S23 are obtained. Output (step S25). It should be noted that the line length L of the pseudo line set in step S21 and the value of the drawing step Δd may be the same for all the pseudo lines, or an appropriate value may be set for each pseudo line. is there.
[0057]
Through the processes in steps S21 to S25 described above, pseudo parallel lines are generated from all start points set on the two-dimensional plane, and the coordinate values of the control points for these pseudo multi lines are output. .
[0058]
Following step S25, data reduction is performed in the process of step S26.
However, the process in step S26 is not an indispensable process, and the coordinate values of the control points of each pseudo parallel line output in step S25 may be registered as they are. We are going to reduce.
[0059]
This data reduction process is performed by thinning out the number of control points at appropriate intervals for each pseudo line output in step S25. Actually, it is only necessary to leave about 10 control points finally for one pseudo parallel line.
[0060]
Thus, according to the second method, instead of creating a binary line pattern of binary bitmap directly from the two-dimensional scalar field of the fiber diving angle, a desired number of pseudo lines are once generated, The coordinate values of the control points of each of these pseudo parallel lines are stored as line data. That is, since the line data is held in the vector format, the handling becomes easier as compared with the first method that directly handles the line pattern of the binary bitmap.
[0061]
Next, how to create a binary bit map line pattern from vector line data generated by the above processing will be described with reference to FIG.
[0062]
In the process shown in FIG. 13, 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 process, that is, 1 One line data in which each line data is converted into a vector format is read out (step S28). As fluctuation, a one-dimensional fractal field may be generated as described in step S18 in FIG.
[0063]
In the line pattern creation process in step S29, the vector-format line data read in step S28 and the rotation angle, fluctuation, and line width parameters set in step S27 for the line. , Generate a spline curve based on the coordinate values of the control points of the imported line data, draw a line, and rotate the drawn curve based on the set rotation angle parameter The fluctuation is given based on the fluctuation parameter, and the line width set for the curve is given. In order to give fluctuation to the curve, for example, a process similar to the process of step S19 in FIG. 2 may be performed. In addition, it is obvious to those skilled in the art that in order to draw a line curve from the coordinate values of the control points of the line data, an appropriate function can be used in addition to the spline curve. Here, the created line pattern is also passed to step S3 and treated as a temporary line pattern, as in the first method.
[0064]
(About Step S3)
In either of the first and second methods, a binary bit map temporary line pattern is created. In either case of using the first or second method, 1 Two two-dimensional scalar fields are input and processed twice to obtain two temporary line patterns. Since random numbers act in the process of creating the temporary line pattern, even if the same two-dimensional scalar field is input in step S1, the two temporary line patterns obtained are different.
[0065]
If two binary bitmap temporary line patterns are obtained, a new line pattern is obtained by performing an exclusive OR of the pixels of the two temporary 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”, otherwise, the pixel value in the new line pattern is set to “0”. . An example of taking an exclusive OR of binary bitmap images in this way will be described with reference to FIG. In FIG. 14, for convenience of explanation, an image A having a horizontally long pattern and an image B having a vertically long pattern will be described instead of the line pattern. Here, when the exclusive OR of the images A and B is taken, an image C as shown in FIG. When comparing image C with image A, it can be seen that the pattern is scattered throughout. Similarly, it can be seen that the pattern is 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 taken, the pattern is scattered throughout. When this is applied to the line pattern, both the gaps and lumps of the line are reduced.
[0066]
Since the line pattern is obtained by the processing of the above steps S1 to S3, an embossed plate is created based on the line pattern and the embossed plate is embossed on the desired sheet. Process it.
[0067]
(Device configuration)
Next, a line data creation apparatus according to the first embodiment will be described. As shown in FIG. 15, the apparatus includes a two-dimensional scalar field input unit 1, a provisional line generation unit 2, an exclusive OR calculation 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 used to input a two-dimensional scalar field of the fiber dive angle created by an appropriate method as already described. . The provisional 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 performs the processing of step S3 in FIG. 1, and the output means 4 is for outputting the created line data.
[0068]
Each component of these two-dimensional scalar field input means 1, provisional line generation means 2, exclusive OR operation means 3, and output means 4 is constructed using a computer. Line data will be output from this computer.
[0069]
【The invention's effect】
As described above, according to the present invention, a plurality of temporary lines are generated based on a two-dimensional scalar field that is a two-dimensional distribution of fiber dive angles, and an exclusive OR of the temporary lines is calculated. The line data is created by setting the value as a new line, and in particular, to prepare multiple temporary lines that were output as they were in the past, and to perform an exclusive OR operation on them. This has the effect of reducing the gaps and lumps of the line. Thereby, in the embossed sheet obtained by embossing this line pattern, undesirable reflection does not occur.
[Brief description of the drawings]
FIG. 1 is a flowchart showing a processing operation of a method for creating line data according to the present invention.
FIG. 2 is a flowchart showing details of a first method for generating temporary lines in step S2 of FIG. 1;
FIG. 3 is a diagram showing representative pixels defined in the first row in step S12 of FIG. 2;
FIG. 4 is a diagram showing a pixel band defined in the first row in step S12 of FIG.
FIG. 5 is a diagram showing representative pixels defined in the second row based on the representative pixels in the first row in step S14 of FIG. 2;
6 is a diagram showing a pixel band defined in the 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 generated by the procedure of the flowchart of FIG. 2. FIG.
FIG. 8 is a diagram showing a state in which a new line M3 has been generated by the adjustment process in step S15 of FIG.
FIG. 9 is a diagram showing a state in which a line M2 is terminated by the adjustment process in step S15 of FIG.
FIG. 10 is a diagram for explaining a line deformation process in step S19 of FIG. 2;
11 is a diagram for explaining an example of a case where a representative pixel and a pixel band are moved and deformed by the deformation processing of the line in step S19 of FIG. 2; FIG.
12 is a flowchart showing details of a second method for generating temporary lines in step S2 of FIG. 1; FIG.
FIG. 13 is a flowchart showing details of a second method for generating temporary lines in step S2 of FIG. 1;
FIG. 14 is a diagram for explaining an exclusive OR operation in step S3 of FIG.
FIG. 15 is a block diagram showing the configuration of the line data creation apparatus of 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 is endlessly processed.
FIG. 17 is a side sectional view showing a relationship between a fiber direction vector F and a light vector L in a general wood block.
FIG. 18 is a graph showing a relationship between a vector crossing angle φ (fiber submerged angle ξ) and specular reflection light intensity W in a general timber board.
FIG. 19 is a diagram for explaining a method of generating a two-dimensional scalar field of fiber submerged angle from natural wood proposed by the present applicant in Japanese Patent Application No. 10-104831.
FIG. 20 is a diagram for explaining a method of generating a two-dimensional scalar field of fiber submerged 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)

A two-dimensional scalar field, which is a two-dimensional distribution of fiber dive angles, which are the angles formed by the surface of the timber board and the fibers, is input, and a direction vector determined based on the fiber dive angles on the two-dimensional scalar field is defined. It has a flow along the direction vector, as well as define a number of parallel line that is created by a set of pixel zone constituted by the pixel group of adjacent pixels, and different coefficients k for each pattern, one-dimensional scalar field H A function k · H (q) comprising (q) is prepared, and two different points are obtained by deforming the line based on the value k · H (q) specified by q corresponding to the position p on the line. A method for creating line data, comprising: generating a binary line pattern and creating a new line pattern by performing an exclusive OR operation between the pixels of the temporary line pattern. . Two-dimensional scalar field input means for inputting a two-dimensional scalar field that is a two-dimensional distribution of fiber dive angles, which are angles formed by the surface of the timber board and the fibers ;
A direction vector defined based on the fiber dive angle on the two-dimensional scalar field input by the two-dimensional scalar field input means is defined, and has a flow along the direction vector and is composed of a pixel group composed of adjacent pixels. thereby defining a number of parallel line that is created by a set of pixel zones, the coefficient k varies for each pattern, prepared a one-dimensional scalar field function consisting H (q) k · H ( q), on the parallel line Temporary line generating means for generating two different binary temporary line patterns by deforming the line based on the value k · H (q) specified by q corresponding to the position p ;
An exclusive OR operation means for creating a new line pattern by performing an exclusive OR operation between the pixels of the temporary line pattern generated by the temporary line generation means;
A device for creating line data, comprising:

Images