JP2000218719A - Embossed sheet making method and image processor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and apparatus for making an embossed sheet reduced in its quiet gloss and having sufficient matte effect, further pref., an embossed sheet not bringing about directionality in its surface embossed shape. SOLUTION: Embossing processing is performed after a process (S2) forming a scalar field, a process (S3) forming mask images by binarizing the formed scalar field at every threshold values by using a plurality of threshold values and a process (S4) performing etching stepwise by using a plurality of the formed mask images to make an embossed sheet.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing various embossed sheets such as decorative paper used for building materials.
In particular, the present invention relates to a method of producing an embossed sheet having a low mattness and a sufficient matting effect, and an image processing apparatus therefor.

[0002]

2. Description of the Related Art Various decorative papers are used for wallpaper and the like of building material products. Such decorative paper is created by creating an image having a pattern obtained by generating a large number of symbols randomly or repeatedly by a computer, and printing this image. Also, in order to further improve the design, not only the pattern is printed,
Printed embossed sheets having embossed surfaces are preferably used as decorative paper.

[0003]

However, in the above-mentioned conventional decorative paper, the embossing is performed based on one mask image, so that the depth of the unevenness is constant. for that reason,
There is a problem that reflection of light is large and so-called bottom light is generated. Further, since the mask image is generated by performing random number processing on a computer, there is a problem that the shape to be embossed has a directionality.

[0004] In view of the above, the present invention provides an embossed sheet having a low shining level and a sufficient matting effect.
More preferably, an object of the present invention is to provide a method for producing an embossed sheet in which the unevenness of the surface has no directionality and an image processing apparatus for producing the embossed sheet.

[0005]

According to the first aspect of the present invention, a scalar field is generated by solving the above problem.
Generating a mask image obtained by binarizing the generated scalar field using a plurality of thresholds for each threshold, and creating an embossed sheet having a different depth using the generated plurality of mask images. And According to the first aspect of the present invention, a plurality of mask images are generated using the generated scalar field using a plurality of thresholds, and an emboss sheet having a different depth is created using the generated plurality of mask images. With this configuration, a plurality of steps are formed on the created embossed sheet, and the area for reflecting light is reduced, so that an embossed sheet having less bottoming and a sufficient matting effect is created.

According to a second aspect of the present invention, in the first aspect of the present invention, in generating the scalar field, a predetermined number of arbitrary scalar values are given, and a grid defined by a midpoint displacement method. The present invention is characterized in that the given scalar value is used as a fluctuation width when calculating a scalar value of a point. According to the second aspect of the present invention, a predetermined number of arbitrary scalar values are given, and this scalar value is used as a fluctuation width when calculating a scalar value of a grid point defined by the midpoint displacement method. Since a field is generated and an embossed sheet is created, an embossed sheet having no directionality in the surface irregularities is created.

According to a third aspect of the present invention, in the first aspect of the present invention, in generating the scalar field, a function representing a desired characteristic curve is provided, and the grid defined by the midpoint displacement method is provided. The fluctuation width when calculating the scalar value of a point is determined based on the function. According to the third aspect of the present invention, a function expressing a desired characteristic curve is provided, and this function is used as a fluctuation width when calculating a scalar value of a grid point defined by the midpoint displacement method. Is generated to create an embossed sheet, so that an embossed sheet with no directionality in the surface irregularities is created.

[0010] According to the present invention, the scalar field generating means and the mask image generating means for generating a mask image in which the generated scalar field is binarized for each threshold using a plurality of thresholds are provided. It is characterized by having. In the invention according to claim 4, a plurality of mask images are generated using a plurality of thresholds in the generated scalar field, so that an embossed sheet is created using the plurality of generated mask images. Thereby, a plurality of steps are attached to the created embossed sheet. Thereby, the area for reflecting light is reduced, so that an embossed sheet with less bottoming and a sufficient matting effect is produced.

According to a fifth aspect of the present invention, in the image processing apparatus according to the fourth aspect, the scalar field generating means generates a grid point based on a midpoint displacement method, and a grid point generating section. A scalar value calculation unit that uses an input scalar value as a fluctuation width when calculating a scalar value of a grid point generated by the above method. According to the fifth aspect of the present invention, a predetermined number of arbitrary scalar values are given, and the scalar value is used as a fluctuation width when calculating a scalar value of a grid point defined by the midpoint displacement method. A field is generated, and a mask image is generated based on the generated scalar field.By creating an emboss sheet using this mask image,
An embossed sheet with no directionality in the surface irregularities is created.

According to a sixth aspect of the present invention, in the image processing apparatus according to the fourth aspect, the scalar field generating means generates a grid point based on a midpoint displacement method, and a grid point generating section. A scalar value calculator for calculating a fluctuation width in calculating a scalar value of a grid point generated by the above based on an input function. In the invention according to claim 6, a grid point generating unit that generates grid points based on the midpoint displacement method, and a fluctuation width when calculating a scalar value of a grid point generated by the grid point generating unit,
A scalar field is generated by obtaining the scalar field based on the input function, and a mask image is generated based on the generated scalar field. An embossed sheet with no direction is created.

[0011]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a flowchart of the embossed sheet producing method of the present invention, and FIG. 2 is a sectional view showing each process of producing an embossed plate for producing an embossed sheet. First, step S1 in FIG.
In, parameters are input. There are three types of parameters: the size of the created pattern, the power spectrum of the scalar field, and the threshold for the binarization process. The size of the creation pattern is a size for generating a scalar field, that is, the size of an image for creating an embossing plate, and is usually designated by a two-dimensional value of X and Y. The power spectrum of a scalar field is a rule for generating a scalar field, and is usually input by a mathematical formula. A plurality of threshold values for the binarization process are used to generate a mask image from the generated scalar field. As many as specified,
A mask image will be generated.

Next, in step S2, a two-dimensional scalar field is generated. A two-dimensional scalar field is defined by defining grid points on a certain plane and defining a scalar value for each grid point. For how to generate a scalar field,
There are several methods, and specific methods will be described later. FIG. 2A is a cross-sectional view of the scalar field generated in step S2. Assuming that the scalar field is defined on the XY plane, the horizontal axis indicates the X axis, the axis perpendicular to the drawing indicates the Y axis, and the vertical direction in the drawing indicates the direction of the scalar value.

Subsequently, in step S3, a mask image is generated. This is performed by binarizing the scalar value in the scalar field generated in step S2 with the threshold value input in step S1. FIG.
Three straight lines shown in (b) each indicate a threshold. Here, it is shown that three thresholds A, B, and C have been input in step S1. The mask image A generated by the threshold value A is “1” between a1 and a2 and between a3 and a4 in FIG. In the subsequent etching step, the areas of “1” in the mask image are “exposure” and “0”.
Indicates that the region is “non-exposed”. Similarly, mask images B and C are generated using thresholds B and C.

In step S4, the cylinder is etched using the generated mask images A, B, and C. First, using the mask image C having the minimum threshold value, the cylinder coated with the resist is exposed and etched. Since a known method is used for the etching, a detailed description will not be given here. By performing the etching using the mask image C, the hatched portions shown in FIG. 2C are removed from the flat cylinder surface. Etching is further performed on the removed cylinder surface using the mask image B. Then, newly, FIG.
The hatched portion shown in FIG. Similarly, etching is performed on the cylinder surface using the mask image C. Then, the hatched portion shown in FIG. 2E is removed. Actually, the corners are not completely removed at each etching, and roundness remains.
As shown in FIG. Due to the roundness, the area for directly reflecting light decreases as the number of etchings increases. For this reason, bottoming is reduced. 2 (c) to 2 (f) show sectional views of the cylinder surface, and the lower side of the solid line is the cylinder body.

After the embossing plate is created in the etching step in step S4, in step S5, the embossing is performed by using the created embossing plate to transfer the unevenness of the embossing plate to the sheet. create.

FIG. 3 shows a functional block diagram of an embossed sheet forming apparatus for executing the embossed sheet forming method in steps S1 to S5. The embossed sheet creating apparatus of the present embodiment includes an input unit 1, a scalar field generating unit 2, a mask image generating unit 3, a printing plate unit 4, and an embossing unit 5. The input means 1 is for inputting data necessary for the parameter input operation in step S1 of FIG. 1 and the scalar field generation processing in step S2, and a keyboard, a mouse, and the like are actually used. The scalar field generation means 2 and the mask image generation means 3 perform the scalar field generation processing of step S2 in FIG. 1 and the mask image generation processing of step S3, respectively. Actually, a dedicated program is installed in the computer. Things. The scalar field generation unit 2 includes a memory unit 21, a grid point generation unit 22, a random number generation unit 23, and a scalar value calculation unit 2.
4, which will be described later. The printing plate means 4 performs the etching process in step S4 in FIG. 1, and a normal printing plate device is used. The embossing means 5 performs the embossing in step S5 in FIG. 1, and a normal embossing device is used.

(Generation of Scalar Field) Here, a method of generating a scalar field in the scalar field generation step of step S2 by the scalar field generation means 2 will be described in detail.
The present invention is characterized in that a scalar field is used to generate a mask image for creating an embossed sheet. This scalar field generation method includes a known fractal two-dimensional scalar field generation method. There is a method for generating a non-fractal two-dimensional scalar field according to the present invention.

(Generation of a fractal scalar field)
A method of generating a fractal two-dimensional scalar field (two-dimensional fractal lattice) by a known midpoint displacement method as a method of generating a scalar field will be described. To generate a two-dimensional fractal grid, which is a two-dimensional scalar field, use FIG.
As shown in the figure, grid points A, B, C, D
(Indicated by a double circle in the figure), and scalar values a, b, c, and d are defined for these grid points A, B, C, and D, respectively. The four grid points A, B,
C and D are lattice points at an initial stage (hereinafter referred to as a 0th stage), and scalar values a, b, c, and d are set to these four lattice points A, B, C, and D, so to speak. This is the initial condition.
Here, the size of this square is the size of the finally generated two-dimensional fractal lattice.

Next, as shown in FIG. 5, between grid points AB,
The grid points E, F, G, and H of the first stage are defined at the middle points between BC, CD, and DA, and at the intersections of the diagonal lines of the four grid points A, B, C, and D, Another first
A step lattice point I is defined. At this time, this grid point E,
Scalar values e, f, g, h, and also for F, G, H, and I
i will be defined, and the scalar values e, f,
g, h, and i are defined by predetermined calculations based on the scalar values ea, b, c, and d. FIG. 5 shows grid points E, F,
This shows a state where the scalar values e, f, g, h, and i of G, H, and I have not yet been determined. Note that, here, a grid point in a state where a scalar value is undefined is indicated by a single circle, and a grid point in a state where a scalar value is defined is indicated by a double circle. Hereinafter, the same applies. And grid points E, F, G,
The scalar values e, f, g, h, and i of H and I are calculated by the following equations.

E = (a + b) / 2 + T · RND (1) f = (b + c) / 2 + T · RND (2) g = (c + d) / 2 + T · RND (3) h = (d + a) / 2 + T · RND (4) i = (a + b + c + d) / 4 + T · RND (5) where a, b, c, and d are lattices Scalar values defined for points A, B, C, and D, T is the maximum half-amplitude value of fluctuation, and RND is a random number. As this random number, a random number in the range of −1 ≦ RND ≦ + 1 is usually used.

As described above, random numbers are used in the definition of the scalar value, and an accidental element influences the random number. However, for example, in the case of the above formula (1), a scalar value e is not necessarily defined as a completely slammed value, and the scalar values a and b of the adjacent grid points A and B and the maximum half-amplitude value T
And will be limited by That is, as shown in the above equation (1), a value obtained by adding an arbitrary value (determined by a random number) in the range of −T to + T to the average value of the scalar values a and b is a scalar value. e. Therefore, the maximum half-amplitude value T is a parameter that limits the degree of fluctuation that deviates from the average value.

Thus, the first stage grid points E, F, G,
After the scalar values e, f, g, h, and i for H and I have been defined, subsequently, as shown in FIG. 6, the middle point of each adjacent grid point and the intersection of the diagonal lines of the four grid points are respectively set. The grid points J, K, L, M, N... Of the second stage are defined. In FIG. 6, grid point names are displayed only for grid points J, K, L, M, and N in order to avoid complication.
Then, scalar values j, k, l, m, n,... Are defined for each of these grid points, which are calculated by the following equations. Here, only equations for j to n are shown.

J = (a + e) / 2 + (１ ／) · T · RND (6) k = (e + i) / 2 + (１ ／) · T · RND (7) ) L = (i + h) / 2 + (1/2) · T · RND (8) m = (h + a) / 2 + (1/2) · T · RND (9) n = (A + e + i + h) / 4 + (1/2) T RND (10) As described above, T is the maximum half-amplitude value of fluctuation, R
ND is a random number. Equations (6) to (10) are obtained from Equations (1) to
Very similar to (5), but with a maximum half-amplitude value T of (1 /
2) is different.

Hereinafter, similarly, the third stage, the fourth stage,.
If the processing of the n-th stage is repeatedly executed, scalar values are defined for a large number of grid points arranged on a two-dimensional plane.

The above processing will be described in general terms. First, in the 0th stage, four grid points are defined at four corner positions of a rectangle of a desired size, and a predetermined scalar value is defined at each grid point. I do. Then, the following processes may be sequentially executed as the process at the i-th stage.
That is, first, the smallest rectangle at the current stage that does not include the lattice points defined up to the (i-1) th stage is recognized.
For example, in the case of the first stage where i = 1, the rectangle A shown in FIG.
BCD is a minimum rectangle (a rectangle not including the grid points A, B, C, and D defined up to the 0th stage), and i = 2
In the case of the second stage, four rectangular AEIHs shown in FIG.
EBFI, HIGHD, and IFCG are the minimum rectangles (rectangles that do not include any of the lattice points A to I defined up to the first stage).

Then, a lattice point to be defined in the i-th stage is generated at the midpoint of each side of the minimum rectangle and the center point of the minimum rectangle. For example, in the case of the first stage where i = 1, FIG.
, The midpoints E, F,
Grid points to be defined are generated at G, H and the center point I. Further, among these lattice points, the lattice point generated at the midpoint of each side is defined as the scalar value of the two lattice points defined by the (i-1) th stage existing at the end point of the side. Gives a scalar value obtained by applying a random number. For example, for a grid point E shown in FIG. 5, a scalar value e obtained by applying a random number RND to scalar values a and b of two grid points A and B
Is given. In general, a scalar value s ₁ for a grid point defined as the midpoint of adjacent grid points in the n-th stage is given by the following equation.

S ₁ = (α + β) / 2 + (1/2 ⁿ⁻¹ ) · T · RND (11) where α and β are scalar values of grid points on both sides of the grid point. (Calculated in the (n-1) th step).

On the other hand, with respect to the grid point generated at the center point of the minimum rectangle, the (i)
-1) A scalar value obtained by applying random numbers to the scalar values of the four grid points defined up to the stage is provided. For example, for the lattice point I shown in FIG.
The scalar values a, b, and 4 of the four grid points A, B, C, and D
A scalar value i obtained by applying a random number RND to c and d is given. In general, a scalar value s ₂ for a grid point defined as the center point of the minimum rectangle in the n-th stage is given by the following equation.

S ₂ = (α + β + γ + σ) / 4 + (1/2 ⁿ⁻¹ ) · T · RND (12) where α, β, γ, and σ are the four corners of the minimum rectangle. Is a scalar value (calculated in the (n-1) -th step) of the grid point located at the point (a).

The two-dimensional fractal lattice generated by such a method eventually gives a scalar field spread in a two-dimensional plane.

The method for generating a two-dimensional fractal lattice has been described above.
It is known that n-dimensional fractal lattices can be generated. For example, Toshiya Okada, "Texture Representation of Heterogeneous Materials Using Three-Dimensional Random Fractals" (Information Processing Society of Japan Nov.1987 Vol.29 No.11 No.11
46 pages or less) is famous.

(Generation of Non-Fractal Scalar Field) Next, a non-fractal two-dimensional scalar field (two-dimensional fractal lattice) is applied by a unique method according to the present invention which applies the above-mentioned midpoint displacement method as a method of generating a scalar field. ) Will be described. First, the fluctuation width Z is defined. Here, a coefficient to which a random number is applied when determining a scalar value to be given to each grid point by the midpoint displacement method is defined as a fluctuation width Z. For example, as shown in the above equation (11), when a two-dimensional fractal scalar field is generated by the midpoint displacement method, the scalar value s ₁ of the grid point at the n-th stage is s ₁ = (α + β) / 2 + ( (1/2 ^n-1 ) · T · RND (11) where the coefficient “(1/2 ⁿ⁻¹ ) · T” on which the random number RND is applied is defined as the fluctuation width It is. Therefore, in the following description, when generating a two-dimensional scalar field, the scalar s ₁ values of the grid points of the n stages is generally expressed by the following equation.

S ₁ = (α + β) / 2 + Z · RND (13) where α and β are scalar values calculated for the lattice points defined in the (n−1) th step Of course.

A specific method of generating a two-dimensional scalar field according to the present invention will be described below. First, a sequence of fluctuation width Z consisting of the following scalar values is given. Z ₀ , Z ₁ , Z ₂ , Z ₃ , Z ₄ ,..., Z _m (14) Here, the value of each fluctuation width can be arbitrarily determined.
This sequence is a scalar value given to a grid point defined in the 0th stage, a scalar value which is a fluctuation width used when calculating a scalar value given to a grid point defined in the 1st stage, and a scalar value defined in the nth stage. This is a sequence of scalar values that are the fluctuation widths used when calculating the scalar value given to the grid point to be performed.

Accordingly, assuming that grid points A, B, C, and D are defined at the four vertices of the square at the 0th stage as shown in FIG. 4, for example, the grid point A has the scalar value Z of the first term of the above-mentioned sequence.
0, grid point B is given the scalar value Z1 of the second term of the sequence, grid point C is given the scalar value Z2 of the third term of the sequence, and grid point D is the fourth scalar value of the sequence. The scalar value Z3 of the term is provided.

Next, as a first stage, as shown in FIG.
Grid points E, F, G, and H are defined at intermediate points between grid points AB, BC, CD, and DA, and another first stage is formed at the intersection of the diagonal lines of the four grid points ABCD. Is defined, and scalar values are calculated for these grid points E to I. In this case, the scalar values of the fifth to ninth terms of the above sequence are given as fluctuation widths. Is calculated by the following equation.

E = (Z ₀ + Z ₁ ) / 2 + Z ₄ · RND (15) f = (Z ₁ + Z ₂ ) / 2 + Z ₅ · RND (16) g = (Z ₂ + Z ₃ ) / 2 + Z ₆ .RND (17) h = (Z ₃ + Z ₀ ) / 2 + Z ₇ .RND (18) i = (Z ₀ + Z ₁ + Z ₂ + Z ₃ ) / 4 + Z ₈ · RND (19) Here, RND is a random number. A random number having an appropriate distribution may be used.

Hereinafter, if the calculations are similarly performed from the second stage to the n-th stage, a non-fractal two-dimensional scalar field having desired characteristics can be generated. In addition,
Naturally, the scalar value of each term in the above-mentioned sequence is a value that can obtain a scalar field having desired characteristics.

Also, as is apparent from the above description, when a plurality of grid points are defined at a certain stage, the scalar values of the number sequence are changed by the number of grid points defined at that stage. Will be used as a width,
The order in which these scalar values correspond to which grid points may be arbitrarily determined in advance.

As described above, in the conventionally used midpoint displacement method, the fluctuation width when calculating the scalar values of the grid points defined after the first stage is automatically determined by the maximum half amplitude value T. On the other hand, according to the method for generating a nonfractal scalar field, the fluctuation width when calculating the scalar value of each grid point defined after the first stage can be arbitrarily determined. A non-fractal scalar field with the desired properties can be generated.

For example, it is assumed that an appropriate scalar value is given to a grid point defined first in the 0th stage, and a scalar value serving as a fluctuation width used in calculating a scalar value given to a grid point defined in the 1st stage , An arbitrary value α is given, α / 3 is given as a scalar value which is a fluctuation width used when calculating a scalar value given to a grid point defined in the second stage, and a grid defined in the third stage is given. When the scalar value which is a fluctuation range used for calculating the scalar value given to the point to allow of providing alpha / n ^n, the scalar field of characteristic power decreases rapidly fluctuations with increasing spatial frequency Can be generated.

Further, the fluctuation width used when calculating the scalar value given to the grid points defined in the first to i-th stages is set to 0, and the scalar value given to the grid points defined in the (i + 1) -th and subsequent stages is set. If an appropriate value other than 0 is given as the fluctuation width used in calculating the value, the power of the fluctuation is "0" up to a certain spatial frequency, has a value at a predetermined spatial frequency, and the power of the fluctuation decreases from there. A scalar field having such characteristics can be generated.

Next, another embodiment of a method for generating a non-fractal scalar field will be described. In this embodiment, first, a desired characteristic curve, that is, a fluctuation power spectrum is given as a function of a spatial frequency.
As a fluctuation width used in calculating a scalar value given to a grid point defined in a certain stage, a function value obtained when a value of a spatial frequency corresponding to the stage is substituted into this function is used. For example, assuming that a desired characteristic curve is given by a function F (f) and a spatial frequency corresponding to a certain stage is f _i, it is used when calculating a scalar value to be given to a grid point defined at that stage. The fluctuation width is F (f _i ). In this case, an arbitrary scalar value may be given to the grid point defined in the 0th stage. Obviously, this method can be applied when generating an arbitrary n-dimensional scalar field.

The scalar field generation step of step S2 has been described above. Next, an embodiment of the scalar field generation means 2 for generating the scalar field will be described with reference to FIG. In the scalar field generating means 2 of FIG.
1 is a memory unit, 22 is a grid point generator, 23 is a random number generator, and 24 is a scalar value calculator.

First, a case will be described in which a sequence as given by equation (14) is given, and a scalar value of a grid point at each stage is obtained based on the sequence. In this case, the operator first sets the size of the two-dimensional scalar field generated from the input means 1 and the number of stages for which the calculation is performed, and further obtains a two-dimensional scalar field having desired characteristics. A sequence of scalar values of fluctuation width is input to instruct the generation of a scalar field.

When these are input, the input values are temporarily stored in a predetermined area of the memory unit 21. When the execution of the operation is instructed, first, the grid point generation unit 2
2 generates a grid point of the 0th stage. When the grid point of the 0th stage is generated, the scalar value calculation unit 24 is activated, and the values of the first to fourth terms are fetched from the sequence stored in the memory unit 21 and are respectively stored in the grid points of the 0th stage. assign.

When the scalar value of the grid point at the 0th stage is determined in this way, the grid point generator 22 generates the grid point at the first stage. When the grid point generating unit 22 generates the first-stage grid points, the scalar value calculating unit 24
A value determined as the fluctuation width of the grid point at the first stage is taken in from the sequence stored in 1 and a random number is generated by the random number generation unit 23 to take in the value.
The scalar value for the grid point at the first stage is calculated by the above equations (15) to (19).

The above processing is performed up to the designated stage. As a result, a non-fractal two-dimensional scalar field having desired characteristics can be generated.

Next, a description will be given of the operation in the case where a desired characteristic curve, that is, the power spectrum of fluctuation is given as a function of the spatial frequency as a mathematical expression, and the scalar value of the lattice point at each stage is obtained based on the function. In this case, the operator sets the size of the two-dimensional scalar field generated from the input device, the number of grid points to be calculated, and further inputs the scalar value corresponding to the grid point defined in the 0th step. At the same time, a function of a spatial frequency representing a two-dimensional scalar field having desired characteristics is input to instruct execution of generation of the scalar field.

When these are input, the input values and functions are temporarily stored in a predetermined area of the memory unit 21. Then, when the calculation instruction is executed, first, the grid point generating unit 22 generates a grid point of the 0th stage. When the grid point of the 0th stage is generated, the scalar value calculation unit 24 is started, and the scalar value of the 0th stage stored in the memory unit 21 is fetched and assigned to the grid point of the 0th stage.

When the scalar value of the grid point at the 0th stage is determined in this way, the grid point generating section 22 next generates the grid point at the first stage. When the grid point generating unit 22 generates the first-stage grid points, the scalar value calculating unit 24
1, the function value is substituted for the value of the spatial frequency corresponding to the first step, the function value is obtained, and the fluctuation value of the lattice point at the first step is used. , A random number is generated, the value is taken in, and a scalar value for the first-stage grid point is calculated by the above equations (15) to (19). The above processing is performed up to the designated stage. As a result, a non-fractal two-dimensional scalar field having desired characteristics can be generated.

[0052]

As described above, according to the present invention,
A scalar field is generated, a mask image is generated by binarizing the generated scalar field for each threshold using a plurality of thresholds, and an emboss sheet having a different depth is generated using the generated mask images. Is formed, a plurality of steps are formed on the created embossed sheet, and the area for reflecting light is reduced. Therefore, an embossed sheet having less bottoming and a sufficient matting effect is created. further,
In the generation of a scalar field, a given number of arbitrary scalar values or a function expressing a desired characteristic curve is given, and given as a fluctuation width when calculating a scalar value of a grid point defined by the midpoint displacement method. Since the determined scalar value or function is used, an embossed sheet having no directivity in the surface unevenness is created.

[Brief description of the drawings]

FIG. 1 is a flowchart of an embossed sheet producing method of the present invention.

FIG. 2 is a diagram illustrating a relationship between a generated scalar field and a surface of an embossing plate.

FIG. 3 is a block diagram of the embossed sheet producing apparatus of the present invention.

FIG. 4 is a diagram illustrating a 0th case of generating a two-dimensional fractal lattice.
It is a figure showing a state of a stage.

FIG. 5 shows a first case of generating a two-dimensional fractal lattice.
It is a figure showing a state of a stage.

FIG. 6 shows a second case of generating a two-dimensional fractal lattice.
It is a figure showing a state of a stage.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 input means 2 scalar field generating means 3 mask image generating means 4 printing plate means 5 embossing means 21 memory unit 22 lattice point generating unit 23: random number generator 24: scalar value calculator

Claims (6)

[Claims] 1. A step of generating a scalar field, a step of generating a mask image obtained by binarizing the generated scalar field using a plurality of thresholds for each threshold, and Producing an embossed sheet having different depths by using the embossed sheet. 2. The method according to claim 1, wherein the step of generating the scalar field includes a step of calculating a scalar value of a grid point defined by a midpoint displacement method, given a predetermined number of arbitrary scalar values. The method according to claim 1, wherein a given scalar value is used. 3. The step of generating the scalar field is provided with a function representing a desired characteristic curve, and the fluctuation width when calculating a scalar value of a grid point defined by a midpoint displacement method is as follows: The method according to claim 1, wherein the embossing sheet is determined based on a function. 4. An image, comprising: scalar field generating means; and mask image generating means for generating a mask image obtained by binarizing the generated scalar field using a plurality of threshold values for each threshold value. Processing equipment. 5. A scalar field generating means, comprising: a grid point generating section for generating grid points based on a midpoint displacement method; and a fluctuation width for calculating a scalar value of the grid points generated by the grid point generating section. The image processing apparatus according to claim 4, further comprising: a scalar value calculation unit that uses an input scalar value. 6. A scalar field generating means, comprising: a grid point generating section for generating grid points based on a midpoint displacement method; and a fluctuation width for calculating a scalar value of the grid points generated by the grid point generating section. The image processing apparatus according to claim 4, further comprising a scalar value calculation unit that obtains based on an input function.