JP7065132B2 - Display medium - Google Patents

Description

The present invention relates to a display medium .

Display media that display images that differ from each other depending on the direction are used for posters, cards, etc. for advertisements because they attract the attention of the observer and are easily noticed. In general, special equipment and equipment are required to produce such a display medium.

For example, there is a display method in which a display device displays a pixel row for left side display and a pixel row for right side display side by side in the left-right direction, and the display device is provided with a parallax barrier in which a light-shielding member for blocking light is vertically arranged. Yes (see Patent Document 1). In Patent Document 1, the content composed of the pixel strings for left side display can be observed from the left side, and the contents composed of the pixel strings for right side display can be observed from the right side.

There is a display medium that displays different patterns by changing the angle at which two sheets printed with a universal pattern are overlapped (see Non-Patent Documents 1 to 3).

International Publication No. 2006/049213

SYLVAIN M. CHOSSON and ROGER D. HERSCH, "Beating Shapes Relying on Moire Level Lines", ACM Transactions on Graphics, Vol. 34, No. 1, Article 9, Publication date: December 2014. Thomas Walger and Roger David Hersch, "Hiding Information in Multiple Level-line Moires", DocEng '15 Proceedings of the 2015 ACM Symposium on Document Engineering, Pages 21-24 Roger David Hersch, Sylvain Chosson, "Band Moire Images", SIGGRAPH '04 ACM SIGGRAPH 2004 Papers, Pages 239-247

The display method described in Patent Document 1 requires a display device for displaying pixel rows for right-side display side by side in the left-right direction, and a parallax barrier in which a light-shielding member for blocking light is vertically arranged.

Further, in Non-Patent Documents 1 to 3, different patterns are displayed by changing the angle at which the two sheets are overlapped. Therefore, in order to display different patterns, there is a time difference for changing the angle at which the sheets overlap. Occurs. Non-Patent Documents 1 to 3 do not display different contents at the same time in a plurality of directions.

As described above, there is no disclosure of a technique for easily displaying different contents in a plurality of directions at the same time.

Therefore, an object of the present invention is to provide a technique for easily displaying different contents at the same time in a plurality of directions.

In order to solve the above problems, the first feature of the present invention relates to a display medium that displays different contents by light emitted in the first direction and light emitted in the second direction. The display medium according to the first feature of the present invention is formed of a sheet member that transmits light, is provided with a point cloud formed of one or more points, and includes a plurality of layers in which at least a part thereof overlaps. A plurality of contents corresponding to the first direction and the second direction, respectively, based on each portion of the light emitted in the first direction and the light emitted in the second direction passing through each of the plurality of layers. Is displayed.

Points may be discretely provided on each of the plurality of layers to form a point cloud.

The first direction and the second are due to the difference between the position and transmittance at which the light emitted in the first direction is attenuated by the point group and the position and transmittance at which the light emitted in the second direction is attenuated by the point group. A plurality of contents corresponding to each of the directions may be displayed.

The point cloud may be ink ejected by a printer.

The second feature of the present invention relates to a processing device for determining a position where a point cloud of the display medium is provided. The processing device according to the second feature is such that the difference between the first input image, which is the target image displayed in the first direction, and the first output image displayed in the first direction is small. In addition, a point cloud is set in each of the plurality of layers so that the difference between the second input image, which is the target image displayed in the second direction, and the second output image displayed in the second direction is small. It is provided with a point cloud determination unit that determines the position where the image is provided.

The point cloud determination unit is further provided with a point cloud based on the attenuation of the light by the point cloud and the shading in the output image caused by the attenuation of the light by the sheet member through which the light in the first direction and the light in the second direction pass. You may decide the position to be.

The point cloud is the ink ejected by the printer, and the point cloud determination unit divides each of the plurality of layers into virtual cells and determines the density in the cell that divides each of the plurality of layers. In the cell, the ink ejection position in the cell may be determined so as to have a determined density.

The color range of the first input image is changed so that the difference in density expressed by the display medium with respect to the predetermined density in the first input image is small, and the display medium with respect to the predetermined density in the second input image. A color range determining unit for changing the color range of the second input image is provided so that the difference in density expressed by is small, and the first input image and the second input image changed by the color range determining unit are provided. , The position of a new point group may be determined by the point group determination unit.

A third feature of the present invention relates to a processing program for determining a position where a point cloud of the display medium is provided. The processing program according to the third feature is such that the difference between the first input image displayed in the first direction and the first output image displayed in the first direction of the computer is small. , The position where the point cloud is provided in each of the plurality of layers so that the difference between the second input image displayed in the second direction and the second output image displayed in the second direction becomes small. It functions as a point cloud determination unit to determine.

According to the present invention, it is possible to provide a technique for easily displaying different contents at the same time in a plurality of directions.

It is a figure explaining the display medium which concerns on embodiment of this invention. It is a figure explaining the direction of the light which displays the content in the display medium. It is a figure which shows an example of the point cloud provided in each layer. It is a figure explaining an example of the image confirmed from each viewpoint. It is a figure explaining the path of light from the reflected light to a viewpoint. It is a figure explaining the hardware composition and the functional block of the processing apparatus which concerns on embodiment of this invention. This is an example of an input image referred to in the description of the color gamut determination unit. This is an example of a simulation image referred to in the explanation of the color gamut determination unit. It is a flowchart explaining the processing method which concerns on embodiment of this invention. This is an example of an input image to be displayed on the display medium according to the embodiment of the present invention. This is an example of an input image modified by the processing apparatus according to the embodiment of the present invention. It is an example of the point cloud of each layer calculated by the processing apparatus according to the embodiment of the present invention. This is an example of an output image displayed by a point cloud of each layer calculated by the processing apparatus according to the embodiment of the present invention. It is a figure explaining the process of calculating the transmittance of a sheet. It is a figure explaining the process of calculating the transmittance of ink.

Next, embodiments of the present invention will be described with reference to the drawings. In the description of the drawings below, the same or similar parts are designated by the same or similar reference numerals.

In the embodiment of the present invention, the plane of the sheet member forming the display medium 1 is referred to as an XY plane formed in the X direction and the Y direction. The thickness of the sheets, the direction in which the sheets are stacked, is referred to as the Z direction.

(Display medium)
The display medium 1 according to the embodiment of the present invention will be described with reference to FIG. The display medium 1 simultaneously displays different contents by the light emitted in the first direction and the light emitted in the second direction. In the embodiment of the present invention, the display medium 1 assumes that the light source exists in all directions. Even if the display medium 1 has a specific light source, it is sufficient that the light emitted from the display medium 1 can be visually recognized, and the display medium 1 does not have to have the specific light source. The first direction and the second direction in which the display medium 1 displays the content may be collectively referred to as a designated direction.

The display medium 1 includes a plurality of layers. Each layer is made of a thick, light-transmitting sheet member. A point cloud formed by one or more points is provided on the plane of the sheet member forming each layer. A point cloud is a set of one or more points. A pattern of one or more points provided in each layer is referred to as a point cloud. The points shield a part of the light and partially transmit the light.

Each layer is formed so that at least a part thereof overlaps. A point cloud is provided in each part where each layer overlaps. The case where the display medium 1 shown in FIG. 1 has a first layer L1 and a second layer L2 will be described, but the present invention is not limited to this. The display medium 1 may be formed by stacking two or more sheet members to form two or more layers.

In the display medium 1, points are discretely provided on each of the plurality of layers to form a point cloud. The points are formed discretely in each layer, partially centrally or dispersedly. In the embodiment of the present invention, it is not assumed that each layer is filled with dots.

The point cloud formed in each layer is, for example, ink ejected by a printer. One point forming the point cloud may be formed by the printer injecting ink once, or may be formed by injecting ink a predetermined number of times. The printer can print dots in parallel in a grid pattern by spraying the dots at a predetermined location one or more times. The point cloud is composed of points printed at predetermined positions among the points that can be printed in a grid pattern.

The display medium 1 has a first direction D1 and a second direction based on each portion of the light emitted in the first direction D1 and the light emitted in the second direction D2 passing through each of the plurality of layers. Display a plurality of contents corresponding to each of the directions D2 of. The display medium 1 displays the content depending on the presence or absence of a point on the line of sight when the observer observes the display medium 1. The display medium 1 is formed so that the presence or absence of a point on the line of sight differs depending on the direction in which the observer observes the display medium 1. Further, the display medium 1 expresses different densities (luminances) depending on the number of overlapping points on the line of sight. Further, the density of the display medium 1 is attenuated by the number of sheets superimposed on the points on the line of sight. Depending on the direction in which light is emitted from the display medium 1, the presence / absence of points and the attenuation of the density differ, and different contents are displayed.

The presence or absence of a point at a position where the light emitted from the first direction D1 passes through each layer determines the shade and the position of the point when the observer observes the light emitted from the first direction D1. To. Similarly, depending on the presence or absence of a point at a position where the light emitted from the second direction D2 passes through each layer, the shading and the position of the point when the observer observes the light emitted from the second direction D2. Is determined. By providing points at predetermined positions in each of the plurality of layers, the positions of the points through which the light emitted in the first direction D1 passes and the positions of the points through which the light emitted in the second direction D2 passes can be determined. , Can be different. Therefore, the display medium 1 is formed so that the first output image displayed by the light emitted from the first direction D1 and the second output image displayed by the light emitted from the second direction D2 are different from each other. be able to.

The display medium 1 may have a plurality of layers formed on the base material B. The base material B is arbitrarily arranged in order to improve the visibility of the display medium 1 according to the surrounding conditions in which the display medium 1 is installed. When the observer observes the display medium 1, the base material B shields the background beyond the display medium 1 and improves the visibility of the image formed by the point cloud. It is preferable that the base material B avoids a color similar to the color of the point cloud and has a color in which the color of the point cloud is easy to understand. For example, when the dots are black, the base material B is white. The material of the base material B is not limited, but may be, for example, paper.

In the embodiment of the present invention, the direction in which the display medium 1 displays the content is, as shown in FIG. 2, a direction in which the display medium 1 is tilted more than the Z direction and has a predetermined elevation angle (<90 °) with respect to the XY plane. The first direction D1 is tilted to the left with respect to the Z direction, and the second direction D2 is tilted to the right.

The direction in which the content shown in FIG. 2 is displayed is an example, and is not limited to this. For example, the content may be displayed not only in the two directions shown in FIG. 2 but also in three or more directions. The display medium 1 may display the content in the Z direction, for example, or may display the content in the direction in which the elevation angle in the first direction D1 or the second direction is changed. The display medium 1 can display the content in any number of directions of two or more directions.

The mechanism of the display medium 1 will be described with reference to FIGS. 3 to 4.

As shown in FIGS. 3A and 3B, each layer is provided with one or more points. The first layer L1 is provided with points L1a and L1b separated from each other. The second layer L2 is provided with a point L2a. In a state where the first layer L1 and the second layer L2 are overlapped, the points L1a and the points L2a are formed at partially overlapping positions as shown in FIG. 3 (c).

When the first layer L1 and the second layer L2 are overlapped and observed in the first direction D1 shown in FIG. 2, the first output image T1 shown in FIG. 4A is observed. In the first output image T1, the point L1a of the first layer L1 and the point L2a of the second layer L2 appear to overlap. Therefore, two points are observed in the first output image T1. Further, since the point on the left side is formed by overlapping the two points L1a and L2a, it is observed to be darker than the point on the right side.

When the first layer L1 and the second layer L2 are overlapped and observed in the second direction D2 shown in FIG. 2, the second output image T2 shown in FIG. 4B is observed. In the second output image T2, the point L2a of the second layer L2 is observed between the points L1a and L1b of the first layer. Therefore, in the second output image T2, a rod shape in which three points are connected is observed. When the first layer L1 is formed on the second layer L2, the point L2a of the second layer L2 is affected by the attenuation by the sheet of the first layer L1. On the other hand, since the points L1a and L2b of the first layer L1 are provided on the upper surface of the uppermost sheet of the display medium 1, they are not affected by the attenuation due to the sheet. Therefore, even in the case of a rod in which a single point is connected as shown in FIG. 3B, the central point L2a is observed thinner than the left and right side points L1a and L1b.

As shown in FIG. 1, since the display medium 1 is observed at a predetermined elevation angle, the image observed from each viewpoint is formed into a trapezoid by the perspective method, but the figure shown in FIG. 4 is keystone-corrected. It was done.

As described above, the display medium 1 has a position and a transmittance at which the light emitted in the first direction D1 is attenuated by the point group and a position and a transmittance at which the light emitted in the second direction D2 is attenuated by the point group. Due to the difference, two contents corresponding to the first direction D1 and the second direction D2 are displayed. As shown in FIGS. 3 and 4, in the display medium 1, the position and transmittance at which the light emitted in the first direction D1 is attenuated by the point cloud and the light emitted in the second direction D2 are attenuated by the point cloud. It is different from the position and transmittance.

Here, the transmittance depends on the number of points through which the light passes. The greater the number of points through which light passes, the lower the transmittance. The smaller the number of points through which light passes, the higher the transmittance. The transmittance also depends on the number of sheets superimposed on the points on the line of sight. The greater the number of superimposed sheets, the lower the transmittance. The smaller the number of sheets to be superimposed, the higher the transmittance.

In this way, in the image that can be confirmed from the viewpoint, the desired image can be displayed because the attenuation rate differs depending on the position. As a result, the display medium 1 can display different images from different viewpoints.

An image formed by light emitted from a predetermined direction will be described with reference to FIG. The display medium 1 shown in FIG. 5 is stacked in the order of the first layer L1, the second layer L2, and the third layer L3 from the top. A point L1a is provided on the first layer L1. A point L2a is provided on the second layer L2. A point L3a is provided on the third layer L3. The point L1a of the first layer L1 and the point L2a of the second layer L2 overlap in the Z direction. The point L3a of the third layer L3 does not overlap the point L1a of the first layer L1 and the point L2a of the second layer L2 in the Z direction.

The line of sight shown in FIG. 5 passes through the point L1a of the first layer L1 and the point L3a of the third layer L3. The light entering the viewpoint shown in FIG. 5 is attenuated by the point L1a of the first layer L1 and the point L3a of the third layer L3.

The light entering the viewpoint is attenuated by other than the point cloud. For example, the light entering the viewpoint is attenuated by the sheets constituting each layer. The light entering the viewpoint shown in FIG. 5 is attenuated by the sheets constituting the first layer L1, the second layer L2, and the third layer L3. In addition, the transparent sheet for printing that constitutes the layer is surface-processed so that ink can easily get on it, and has translucent. Therefore, the light incident on the viewpoint is due to the translucency of the sheet. It is reflected on the surface of the surface and further attenuated.

As described above, the display medium 1 causes a phenomenon called moire due to the appearance of coarseness and density of the point cloud different from the point cloud position of each layer due to the overlap of the point cloud of each layer. Since the display medium 1 has different density of points depending on the viewing direction, it displays different densities depending on the viewing direction and causes different moire. As a result, the display medium 1 can display different images depending on the viewing direction.

(Solution of the position of the point cloud)
Here, a method of calculating the position of the point cloud of each layer for displaying a desired image on the display medium 1 described with reference to FIG. 1 and the like will be described.

In the embodiment of the present invention, the input image is a target image to be displayed on the display medium 1. The output image is an image displayed by the display medium 1. The input images are prepared in advance according to the number of directions assumed by the display medium 1. For example, when displaying different contents from two directions as shown in FIG. 1, two input images are prepared. When two input images are prepared, the display medium 1 also displays two output images.

The point cloud provided in each layer is defined by the presence or absence of grid-shaped points so that the positions of the points can be specified in the image. When dots are formed by the injection of ink from the printer, the position of the dots depends on the accuracy of the printer.

The input image is expressed by the equation (1).

At this time, a point cloud of each layer is formed so as to satisfy the equation (2).

As shown in the equation (2), the display medium 1 forms y'close to (1) y, and satisfies the condition that the color gamut of y is contained in the color gamut of (2) y', and the display medium 1 is of each layer. It is necessary to optimize the position of the point cloud. In order to solve this optimization problem, the range of the output image y'is set to 0 to 1. The brightness of the area corresponding to one cell is mapped to a value from 0 to 1 by normalization.

Since a point cloud is formed on each sheet of the display medium 1, the portion where the point is not provided is blank. Therefore, in the embodiment of the present invention, when light is incident on such a blank portion, reflection of the sheet itself occurs, and it is necessary to design a rendering model in consideration of the influence. In the case where the ink is applied to one surface, the influence of the reflection of the sheet is small, but since the ink is printed discretely on the display medium 1 and the blank portion is large, it is preferable to consider the influence of the reflection of the sheet itself.

A rendering model that simulates the output image y'will be described. Here, as shown in FIG. 5, the first layer L1 is referred to as a 0th sheet, the second layer L2 is referred to as a first sheet, and the third layer L3 is referred to as a second sheet. Although not shown in FIG. 5, a base material B made of a white reflective material is provided on the bottom surface (nth from 0) of the sheet.

The point cloud printed on the sheet is shown in the formula (3).

The vector indicating the presence or absence of the point cloud of the i-th sheet is shown in Eq. (4). The maximum number z of points provided in each layer is larger than the number of cells m of the input image, and the resolution of each layer is higher than that of the input image. The maximum number z of points provided in each layer corresponds to the number of positions where the printer can inject ink into each layer.

In embodiments of the invention, the transmittance of light by the points formed by the ink is defined by q. q differs depending on the path length of light, depending on the model of Kubelkamunck. The path length of light in the ink is expressed by the equation (5).

The transmittance q is a value obtained by multiplying the transmittance of light in the direction perpendicular to the sheet by 1 / sin (α).

The transparent sheet for printing is surface-treated so that ink can easily get on it. Therefore, the sheet has translucency. In rendering, this translucency is treated as a reflection of light on the surface of the seat. Let r be the reflected light on the surface of each sheet. It is assumed that the light source exists in all directions and the reflected light is isotropically diffused in all directions. Therefore, the position of the light source is not considered.

Let r _i be the amount of reflected light in the specified direction on the i-th sheet surface. Focusing only on the reflected light on the surface of the i-th sheet, the light passing in the specified direction passes through the point cloud on the 0th sheet from the i-th sheet. The reflected light passes through the i-1 sheet. Due to the reflection of the printed surface, the light is attenuated as it passes. The image when r _i reaches the viewpoint is expressed by Eq. (6).

The reflected light of the base material B provided on the bottom surface (nth from 0) of the sheet is treated in the same manner as the reflected light of the sheet. Also, d _n is all 1. The reflected light of all the sheets is additively combined, and the image y'' of the point cloud D in the specified direction is defined by the equation (7).

The image in the designated direction can be obtained by the equation (8).

When the equation (8) is substituted into the equations (6) and (7) and arranged, the output image y'in the designated direction is represented by the equation (9).

Here, the point cloud D of each layer is calculated by the equation (10). The input image y, the designated direction a, the sheet transmittance b, the ink transmittance q, the number of sheets n, the projection function p, and the matrix f are given in advance. Further, a is a set of designated directions, and y is a set of input images corresponding to each designated direction. The predetermined designated direction and the input image corresponding to the designated direction are specified by k.

(Processing device)
The processing apparatus 2 according to the embodiment of the present invention will be described with reference to FIG. The processing device 2 determines the position where the point cloud of the display medium 1 is provided. The processing device 2 calculates the position of the point cloud of each layer for displaying a desired input image, and outputs the position of the point cloud of each layer to a printer or the like. The printer prints the point cloud according to the position of the point cloud of each layer input from the processing device 2. By stacking the sheets on which the point cloud is printed by the printer, the display medium 1 described with reference to FIG. 1 and the like is formed.

The processing device 2 is a general computer including a processing control device 20, a storage device 10, and an input / output interface 30. The function shown in FIG. 6 is realized by executing a processing program by a general computer.

The processing control device 20 is a CPU (Central Processing Unit) and executes processing in the processing device 2. The storage device 10 is a ROM (Read Only Memory), a RAM (Random access memory), a hard disk, an SSD, or the like, and various data such as input data, output data, and intermediate data for the processing control device 20 to execute processing. Remember. The input / output interface 30 is an interface for the processing control device 20 to send and receive data to and from an external device. External devices include input devices such as mice and keyboards, display devices, output devices such as printers, and computer-readable recording media.

The processing program may be stored in a computer-readable recording medium such as a hard disk, SSD (Solid State Drive), USB (Universal Serial Bus) memory, CD (Compact Disc), DVD (Digital Versatile Disc), or a network. It may be delivered via.

The storage device 10 stores the input image group data 11, the parameter data 12, and the point cloud data 13.

The input image group data 11 is a set data of input images corresponding to each designated direction. The input image is a target image to be displayed on the display medium 1.

The parameter data 12 is specific data of the sheet used by the processing device 2 to determine the position of the point cloud of each sheet. The parameter data 12 is the value of the parameter required for simulating the output image based on the above equation (10). Specifically, the parameters are a designated direction a, a sheet transmittance b, an ink transmittance q, a maximum number z of points provided on one layer, a number n of sheets, a projection function p, and a matrix f. The parameter data 12 is stored in the storage device 10 before the process of determining the position of the point cloud.

The point cloud data 13 is data for specifying the position of the point cloud of each sheet calculated by the processing control device 20. The point cloud data 13 is data that is input to the printer and prints points at a desired position.

The processing control device 20 includes a point cloud determination unit 21, a color gamut determination unit 22, and an output unit 23.

The point cloud determination unit 21 makes the difference between the first input image, which is the target image to be displayed in the first direction, and the first output image displayed in the first direction small, and is the first. A point cloud is provided in each of the plurality of layers so that the difference between the second input image, which is the target image displayed in the two directions, and the second output image displayed in the second direction is small. Determine the position. The point cloud determination unit 21 simulates the output image in each designated direction and optimizes the point cloud so as to be closest to the input image. The first input image and the second input image are images that the display medium 1 wants to display in each direction. The processing device 2 calculates the position of the point cloud of the display medium 1 so that the display medium 1 can display the first input image and the second input image. The first output image and the second output image are images that the display medium 1 formed according to the position of the point cloud calculated by the processing device 2 displays in each direction.

Here, the point cloud determination unit 21 may determine the position where the point cloud is provided from the shading in the output image caused by the attenuation of the light by the point cloud. The point cloud determination unit 21 further determines the position where the point cloud is provided in consideration of the light and shade generated in the output image due to the attenuation of the light by the sheet member through which the light in the first direction and the light in the second direction pass. You may. Here, the output image in each designated direction is simulated by the equation (10).

The point cloud determination unit 21 determines the position where the point cloud is provided, for example, in a full search. At this time, the point cloud determination unit 21 divides each of the plurality of layers into virtual cells, determines the density in the cell that divides each of the plurality of layers, and makes the determined density in the cell. , Determines the ink ejection position in the cell.

The point cloud determination unit 21 searches for all possible combinations based on the number z of the maximum points provided on one sheet. If all the pixels of the input image are solved at the same time, the search space is too large. Therefore, the point cloud determination unit 21 evaluates the point cloud corresponding to the pixel for each pixel of the input image. For example, when the size of the cell on the sheet corresponding to the input pixel is 3 * 3, z = 3 * 3 * m (m: the number of pixels of the input image). When the number of sheets n = 2, the combination of the presence or absence of points corresponding to one pixel of the input image is a combination of 3 * 3 * 2 = 18 patterns, so the number searched by the point cloud determination unit is 2. 18th power = 262144 times. The point cloud determination unit 21 calculates the luminance in each of the designated directions in all of these combinations, and uses the calculated luminance value to calculate D in which the equation (10) is satisfied.

In the embodiment of the present invention, the point cloud determination unit 21 has described the case of determining the position where the point cloud is provided in the full search, but the present invention is not limited to this. The point cloud determination unit 21 may determine the position where the point cloud is provided by using an optimization algorithm such as a genetic algorithm.

The color gamut determination unit 22 changes the color gamut of each input image so that the color gamut of the density accuracy searched for when calculating the position of the point group includes the color gamut of the input image. Specifically, the color gamut determination unit 22 changes the color gamut of the first input image so that the difference in the density expressed by the display medium 1 with respect to the predetermined density in the first input image becomes small, and the second The color gamut of the second input image is changed so that the difference in the density expressed by the display medium 1 with respect to the predetermined density in the input image of 2 becomes small.

The color gamut that can be expressed by the full search in the point cloud determination unit 21 depends on the accuracy of the density searched by the full search. Therefore, the color gamut determination unit 22 changes the color gamut of the input image so as to match the color gamut searched by the point cloud determination unit 21.

For example, an 8-bit image can express a density of 256 gradations. That is, the input image can specify the density from 0 to 255. The density is black when it is 0 and white when it is 255. For example, assume that the display medium 1 has two layers and has two input images.

As shown in FIGS. 7A and 7B, it is assumed that there is a first input image N1 and a second input image N2. The positions of the pixels N1a and N1b of the first input image N1 correspond to the positions of the pixels N2a and N2b of the second input image.

8 (a) and 8 (b) are a first simulation image P1 and a second simulation image P2 simulated based on the point cloud position determined by the point cloud determination unit 21. The positions of the pixels P1a and P1b of the first simulation image P1 correspond to the positions of the pixels P2a and P2b of the second simulation image P2. Further, the positions of the pixels N1a and N1b of the first input image N1 correspond to the positions of the pixels P1a and P1b of the first simulation image P1. The positions of the pixels N2a and N2b of the second input image N2 correspond to the positions of the pixels P2a and P2b of the second simulation image P2. The point cloud determination unit 21 determines the density of the cell on the display medium 1 corresponding to the predetermined pixel so as to satisfy the density set in the first simulation image P1 and the second simulation image P2. decide.

When each density of N1a = 0 and N2a = 255 is specified in the input image, the point cloud determination unit 21 calculates each density of P1a = 100 and P2a = 200 by the simulation of the equation (9), and calculates this density. As expressed, it is assumed that the cell concentration 200 corresponding to N1a, N2a, P1a and P2a on the display medium 1 is calculated. Further, each density of N1b = 255 and N2b = 255 is specified in the input image, and the point cloud determination unit 21 calculates each density of P1b = 255 and P2b = 255 by the simulation of the equation (9), and expresses this density. As such, it is assumed that the cell concentration 255 corresponding to N1b, N2b, P1b and P2b on the display medium 1 is calculated.

In such a situation, in the second input image N2, the densities of the pixels N2a and N2b are both set to 255, whereas the densities expressed by the display medium 1 are 200 and 255, so that a difference occurs. .. This difference causes ghosting. Therefore, the color gamut determination unit 22 reduces the color gamut of each input image and reduces the image contrast so that the difference in the density expressed by the display medium 1 with respect to the predetermined density in each input image becomes small.

For the first input image and the second input image changed by the color gamut determination unit 22, the position of the new point cloud is determined by the point cloud determination unit 21. The processing device 2 repeats the process of further determining the point cloud by the point cloud determining unit 21 using the input image whose color gamut has been changed until a predetermined condition is satisfied. The predetermined conditions are the number of times, time, and the like specified by the user.

When the processing of the color gamut determination unit 22 and the point cloud determination unit 21 is repeated until the predetermined condition is satisfied, the output unit 23 specifies the position of the point cloud of each sheet determined by the point cloud determination unit 21. Data 13 is generated and output. The point cloud data 13 is input to the printer, and a sheet in which points are printed at desired positions is formed.

A processing method by the processing apparatus 2 will be described with reference to FIG.

First, the processes of steps S1 and S2 are repeated until a predetermined end condition is satisfied. In step S1, the processing device 2 determines the position of the point cloud of each layer by the point cloud determination unit 21. In step S2, the processing device 2 changes the color gamut of the input image group by the color gamut determination unit 22 based on the position of the point cloud determined by the point cloud determination unit 21 set in step S1. The first process of step S1 is performed according to the input image group data 11 given in advance, and the second and subsequent processes are performed according to the data of the input image group after being changed by the process of step S2.

When the end condition is satisfied, in step S3, the processing device 2 determines the position of the point cloud of each layer according to the data of the input image group finally obtained and changed.

In step S4, the processing device 2 inputs the position of the point cloud of each layer determined in step S3 to the printer by the output unit 23, and causes the printer to print the position of the point cloud of each layer.

(Concrete example)
A specific description will be given with reference to FIGS. 10 to 13. Here, a case where the display medium 1 is formed of two layers and displays three contents in three designated directions will be described.

Here, one cell is composed of 3 * 3 points. In the predetermined direction, the elevation angles are set to −45 degrees, 0 degrees and 45 degrees (normal direction is 0 degrees). It should be noted that each of the predetermined directions is set on the predetermined XZ plane at an azimuth angle of 0 degrees in each predetermined direction. Further, as the parameters, those specified by the following equations (14) and (17) are used.

10 (a), (b) and (c) are input images, respectively. The input image shown in FIG. 10 is composed of white and black, and has a large difference in density, that is, a difference in luminance.

Each input image shown in FIG. 10 is finally changed to the input image shown in FIGS. 11A, 11B, and 11C by the processing device 2. The input image after the change has a smaller difference in density, that is, a difference in luminance than the input image before the change. This is a result of the color gamut being narrowed by the color gamut determination unit 22.

The processing device 2 calculates the point cloud shown in FIGS. 12 (a) and 12 (b) in order to display the input image shown in each figure of FIG. 11. FIG. 12A shows a point cloud of the first layer L1, and FIG. 12B shows a point cloud of the second layer L2.

The display medium 1 formed by stacking the sheets on which the points shown in FIG. 12 are printed displays the images shown in FIGS. 13 (a), 13 (b) and 13 (c). Each image shown in FIG. 13 is a simulation result, which is originally formed into a trapezoid by the perspective method, but is a trapezoid-corrected image. Each image shown in FIGS. 13A, 13B and 13C corresponds to each image shown in FIGS. 10A, 10B and 10C, respectively.

The display medium 1 according to the embodiment of the present invention can easily display different contents in a plurality of directions by printing and superimposing a point cloud on each of a plurality of sheets.

Further, the processing device 2 calculates the position of the point cloud in consideration of not only the output image displayed by the display medium 1 comes close to the input image but also the attenuation due to the sheet and the attenuation of the ink constituting the point cloud. As a result, the display medium 1 can display fine contents.

Further, the processing device 2 changes the color gamut of each input image so that the color gamut of the density obtained when calculating the position of the point cloud includes the color gamut of the input image. As a result, the display medium 1 can display an output image in which ghosting is unlikely to occur.

(Calculation method of sheet parameters)
In the embodiment of the invention, a method of calculating the light transmittance b by the sheet and the light transmittance q of the ink from the material of the sheet and the ink will be described.

As a preparation, the printer settings are specified as CMYK so that all image processing inside the printer does not work. The point cloud is printed with K (Key-Plate). A sheet printed with predetermined points under these conditions is placed on the base material B and photographed with a digital camera. The brightness obtained by shooting is treated as a measured value. The light source is in a state of being uniformly around the display medium 1 as in the environment for observing the display medium 1.

First, the transmittance b of the sheet is estimated. As shown in FIG. 14, the two transparent sheets are partially staggered and stacked, and placed on the base material B. The reflected light on each sheet surface shall be the same, and the transmittance of each shall be the same. Then, from the rendering equation of equation (9), the following equation (11) with r and b as unknown variables is derived.

By substituting x ₂ for x ₀ and x ₁ and rearranging for r, equation (12) can be obtained from equation (11).

By substituting r in the equation (12) and rearranging it, the equation (13) is obtained.

Equation (13) is a quadratic equation for b, and this solution is obtained by equation (14). The transmittance b of the sheet is calculated by the formula (14).

Next, the transmittance b of the ink is estimated. As shown in FIG. 15, a printed sheet is placed on the base material B, and an image is taken under the same conditions as in FIG. As a result, equation (15) holds.

By rearranging the equation (15) with respect to q, the equation (16) is obtained. The transmittance q of the ink is calculated by the equation (16).

From the above, the parameters are calculated, for example, as in equation (17).

(Other embodiments)
As mentioned above, although described by embodiments of the invention, the statements and drawings that form part of this disclosure should not be understood to limit the invention. This disclosure reveals to those skilled in the art various alternative embodiments, examples and operational techniques.

For example, the processing apparatus described in the embodiment of the present invention may be configured on one hardware as shown in FIG. 6, or may be configured on a plurality of hardware according to its function and the number of processes. May be. It may also be realized on a computer that realizes other functions.

It goes without saying that the present invention includes various embodiments not described here. Therefore, the technical scope of the present invention is defined only by the matters specifying the invention relating to the reasonable claims from the above description.

1 Display medium 2 Processing device 10 Storage device 11 Input image group data 12 Parameter data 13 Point cloud data 20 Processing control device 21 Point cloud determination unit 22 Color gamut determination unit 23 Output unit 30 Input / output interface

Claims (2)

It is a display medium that displays different contents by the light emitted in the first direction and the light emitted in the second direction.
A point cloud formed of a sheet member that transmits light and formed by one or more points is provided, and includes a plurality of layers in which at least a part thereof overlaps.
Each of the light emitted in the first direction and the light emitted in the second direction is in the first direction and the second direction based on each portion passing through each of the plurality of layers. Display the corresponding first and second contents, respectively.
So that the position of the points in the first content, the position where the points overlap, and the shading of each position are different from the position of the points in the second content, the position where the points overlap, and the shading of each position. The plurality of layers are formed,
The plurality of layers are formed in consideration of the attenuation of light by the layer closer to the viewpoint than the layer provided with the points .
The shade caused by the attenuation of light by the layer closer to the viewpoint than the layer provided with the point makes the first content closer to the target image to be displayed in the first direction, and the second content is the second. A display medium characterized in that the plurality of layers are formed so as to be close to a target image to be displayed in a direction . It is a display medium that displays different contents by the light emitted in the first direction and the light emitted in the second direction.
A point cloud formed of a sheet member that transmits light and formed by one or more points is provided, and includes a plurality of layers in which at least a part thereof overlaps.
Each of the light emitted in the first direction and the light emitted in the second direction is in the first direction and the second direction based on each portion passing through each of the plurality of layers. Display the corresponding first and second contents, respectively.
The first is based on the presence or absence of points in each portion where the light emitted in the first direction passes through each of the plurality of layers and the presence or absence of overlapping points in the direction in which the light emitted in the first direction passes. The position and transmittance at which the light emitted in the direction of 1 is attenuated,
The first is based on the presence or absence of points in each portion where the light emitted in the second direction passes through each of the plurality of layers and the presence or absence of overlapping points in the direction in which the light emitted in the second direction passes. Unlike the position and transmittance at which the light emitted in the second direction is attenuated,
The position of the point is determined in consideration of the attenuation of light by the layer closer to the viewpoint than the layer on which the point is provided .
The shade caused by the attenuation of light by the layer closer to the viewpoint than the layer provided with the point makes the first content closer to the target image to be displayed in the first direction, and the second content is the second. A display medium characterized in that the position of the point is determined so as to be close to the target image to be displayed in the direction .

Images