JP6891917B2 - Stereoscopic image formation method, program and stereoscopic image formation system - Google Patents

Description

The present invention relates to a stereoscopic image forming method, a program and a stereoscopic image forming system .

As one of the modeling techniques, there is a stereoscopic image forming technique using a foamable sheet (thermally expandable sheet), and for example, the technique of Patent Document 1 is disclosed. The present technology forms a stereoscopic image through the following steps of printing and light irradiation. First, a shade image of black ink (carbon black) is printed on an effervescent sheet provided with a foam layer (the surface of the effervescent sheet) that expands by heating on a base material (the back surface of the effervescent sheet). Next, a color image is printed on the foamable sheet. Finally, the foamable sheet is irradiated with light, and the black ink absorbs the light and generates heat according to the shade of the shaded image, so that the foamed layer expands and rises to form a stereoscopic image.

The grayscale image is often printed on the back surface, which is the side with the base material, using black ink, but it is also possible to print on the front surface. By printing with color ink on top of black ink, it is possible to ensure the quality of appearance as a painting or a color image.
This technology is used not only to create three-dimensional paintings depicting animals and characters, but also to create three-dimensional images such as Braille, maps containing characters and lines for the visually impaired.

Japanese Unexamined Patent Publication No. 2001-150812

In a stereoscopic image such as a map, it is desirable that the heights of the characters and lines constituting the image are constant. However, even if a light and shade image is printed on a foamable sheet with a uniform black density and heated by irradiating with light, the foamed layer is excessive in the region near the intersection of the lines or in the region where the lines are dense, as compared with the other regions. There is a problem that the height of the stereoscopic image becomes uneven due to the expansion (raising).
An object of the present invention is to suppress uneven expansion at intersections of lines and regions where lines are densely packed.

In order to solve the above problem, the stereoscopic image forming method is a set of line images included in the shade image with respect to the print data for printing the shade image used when the desired region of the heat-expandable sheet is thermally expanded. A first specific step for specifying a center line for a figure or a character composed of, a second specific step for specifying an intersection of the center lines and an intersection area including the intersection, and a light print density for the intersection area. It is characterized by including an adjustment step for adjusting so as to be.

According to the present invention, it is possible to suppress non-uniform expansion at intersections of lines or in a region where lines are densely packed.

It is a figure which shows the whole structure of the stereoscopic image formation system which concerns on 1st Embodiment. It is a figure which shows the data structure of the stereoscopic image data which concerns on 1st Embodiment. It is sectional drawing which shows the structure of the foamable sheet on which the stereoscopic image which concerns on 1st Embodiment is formed. It is a flowchart which shows the whole process of forming a stereoscopic image in the stereoscopic image formation system which concerns on 1st Embodiment. It is a screen layout diagram which shows the structure of the image editing screen used for creating the image of the stereoscopic image which concerns on 1st Embodiment. It is a flowchart which shows the non-uniform expansion suppression processing which concerns on 1st Embodiment. It is a figure for demonstrating the processing content which specifies the high density area which concerns on 1st Embodiment. It is a figure for demonstrating the density | concentration adjustment which concerns on 1st Embodiment. It is a figure for demonstrating the density adjustment of a wide range which concerns on 1st Embodiment. It is a figure which shows the shading image after the non-uniform expansion suppression processing which concerns on 1st Embodiment. It is a perspective view which illustrates the stereoscopic image which expanded uniformly as a result of printing the mirror image of the shading image which concerns on 1st Embodiment on the back surface of the foamable sheet and irradiating with light. It is a figure for demonstrating the density adjustment of the shading image which concerns on 1st Embodiment for uniformly expanding the shading image of a cross. It is a perspective view which illustrates the stereoscopic image which expanded uniformly as a result of printing the mirror image of the shade image of the cross which concerns on 1st Embodiment on the back surface of the foamable sheet and irradiating with light. It is a figure for demonstrating the density adjustment of the shading image which concerns on 1st Embodiment for uniformly expanding the shading image of a thin line cross. It is a figure for demonstrating the non-uniform expansion suppression processing which concerns on 2nd Embodiment. It is a figure for demonstrating the process which specifies the high density area which concerns on 3rd Embodiment. It is a flowchart which shows the non-uniform expansion suppression processing which concerns on 4th Embodiment. It is a figure for demonstrating the density | concentration adjustment process which concerns on 4th Embodiment. It is a figure for demonstrating the problem of non-uniform expansion which occurs in the shading image of a cross. It is a figure for demonstrating the problem of non-uniform expansion which occurs in the shading image of a thin line cross. It is a figure for demonstrating the problem of non-uniform expansion which occurs in the Chinese character with a large number of strokes in bold.

≪Solid image height non-uniform expansion problem≫
Before explaining the first embodiment, with reference to FIGS. 19 to 21, there is a problem that the foamable sheet expands excessively in a region where lines and intersections are dense and the height of the stereoscopic image becomes non-uniform. explain.
FIG. 19 is a diagram for explaining the problem of non-uniform expansion that occurs in a shade image of a cross. FIG. 19A is a shade image 921 of a cross in which the problem of non-uniform expansion occurs. FIG. 19B is a perspective view schematically showing the vicinity of the intersection of the crosses of the stereoscopic image 922 which is unevenly expanded as a result of the mirror image of the shading image 921 printed on the back surface of the foamable sheet and irradiated with light. Is. FIG. 19 (c) is a graph 923 showing the height of the cross section of the foamed layer (see cross section 924 of FIG. 19 (b)) along the PP'line of the shading image 921.

The black density of the shade image 921 is uniform, but the region near the intersection in the center of the stereoscopic image 922 expands and protrudes from the region other than the intersection. As can be seen from the graph 923, the heights other than the vicinity of the intersection are uniform, but the vicinity of the intersection is excessively expanded and higher than the other regions, resulting in a non-uniform height as a stereoscopic image.

FIG. 20 is a diagram for explaining the problem of non-uniform expansion that occurs in the shading image of the thin line cross. FIG. 20A is a shade image 931 of a thin line cross in which the problem of non-uniform expansion occurs. In FIG. 20B, a mirror image of the shade image 931 is printed on the back surface of the foamable sheet, and as a result of being irradiated with light, the height of the cross section of the foamed layer by the SS'line of the foamable sheet that expands unevenly. It is a graph 932 which shows the above. Similar to Graph 923 (see FIG. 19C), the heights other than the vicinity of the intersection are uniform, but the height near the intersection is excessively expanded and higher than the other regions, and the height is uneven as a stereoscopic image. It has become.

FIG. 21 is a diagram for explaining the problem of non-uniform expansion that occurs in Chinese characters having a large number of strokes in bold. FIG. 21A is a shade image 941 in bold characters in which the problem of non-uniform expansion occurs. In FIG. 21B, a mirror image of the shade image 941 is printed on the back surface of the foamable sheet, and as a result of irradiation with light, the height of the cross section of the foamed layer by the QQ'line of the foamable sheet that expands unevenly. It is a graph 942 showing. Slightly below the center of the character, the four lines intersect and the lines are denser than the other areas, near the intersection of Graph 923 (see FIG. 19 (c)) and Graph 932 (see FIG. 20 (b)). A region wider than the region expands and an inclination toward the center occurs, resulting in a non-uniform height as a stereoscopic image.

A first embodiment (embodiment) of the present invention that solves the problem of non-uniform expansion of a stereoscopic image described above will be described in detail with reference to the drawings. It should be noted that each figure is merely schematically shown to the extent that the present invention can be fully understood, and the present invention is not limited to the illustrated examples. Further, even if the same element is shown in different figures, the same reference numerals may be given to omit the duplicated description.

≪Overall composition≫
FIG. 1 is a diagram showing the overall configuration of the stereoscopic image forming system 1 according to the first embodiment. The stereoscopic image forming system 1 includes a stereoscopic image data editing device 5, an image printing device 6, and a foaming device 7.

The stereoscopic image forming system 1 can create and edit stereoscopic image data 4 by user operation on the stereoscopic image data editing device 5. The created stereoscopic image data 4 (see FIG. 2 to be described later) is formed on a foamable sheet 2 (see FIG. 3 to be described later) by the stereoscopic image data editing device 5 operating the image printing device 6 to form a shade image (back surface). Printed as a color image (front side). After that, the stereoscopic image data editing device 5 operates the foaming device 7 to irradiate the light and shade image (back surface) of the foamable sheet 2 with light, so that the foamable sheet 2 expands to form a stereoscopic image (three-dimensional structure). Will be done.

The image printing device 6 is a printer that prints a shade image of black ink on the back surface of the foamable sheet 2 and prints a color image on the front surface. The foaming device 7 is a device that irradiates light while transporting the foamable sheet 2 to generate heat in a shade image with black ink to foam the foamable sheet 2 and expand (raise) it.

The stereoscopic image data editing device 5 edits an image and controls the image printing device 6 and the foaming device 7. The stereoscopic image data editing device 5 includes a CPU (CentralProcessingUnit) 51, a storage unit 52, an input / output unit 53, and a touch panel (touch panel display) 55. The stereoscopic image data editing device 5 may include a display, a keyboard, and a mouse instead of the touch panel 55.
The CPU 51 makes the stereoscopic image data editing device 5 function by executing the OS (Operating System) 521 and the stereoscopic image data editing program 522 stored in the storage unit 52.

The storage unit 52 is embodied by semiconductor elements such as a RAM (RandomAccessMemory), an HDD (HardDiskDrive), and a flash memory, and stores the OS 521 of the stereoscopic image data editing device 5, the stereoscopic image data editing program 522, and the stereoscopic image data 4.
The input / output unit 53 is embodied by a communication device such as NIC (NetworkInterfaceCard), UIC (USBInterfaceCard), PPC (ParallelPortCard), and transmits image data to the image printing device 6 and the foaming device 7, or prints an image. Send and receive control data for light irradiation.

FIG. 2 is a diagram showing a data structure of the stereoscopic image data 4 according to the first embodiment. The stereoscopic image data 4 is configured to include the shading print data 41 and the color print data 42. The shading print data 41 is shading image data expressing the height of a three-dimensional image composed of characters, braille, straight lines, ellipses, and squares. In the shade image, the higher the height of the foam of characters, Braille, straight lines, ellipses or squares, the higher the density, and the lower the height, the lower the density. The color print data 42 is color image data including color information (picture) of the stereoscopic image.

FIG. 3 is a cross-sectional view showing the structure of the foamable sheet (thermally expandable sheet) 2 on which the stereoscopic image according to the first embodiment is formed. FIG. 3A is a cross-sectional view of the foamable sheet 2 before being irradiated with light to expand it, and FIG. 3B is a cross-sectional view of the foamable sheet 2a after being irradiated with light to be heated and expanded and raised. It is a sectional view.
The foamable sheet 2 has a structure in which the base material 21, the foam layer 22, and the ink receiving layer 23 are laminated in this order.

The base material 21 is a base layer of the foamable sheet 2, and paper on a flat surface, cloth such as a campus area, a plastic panel material, or the like can be used.
The foamed layer 22 is a layer provided on the surface side (upper side of FIG. 3) of the base material 21, contains heat-expandable microcapsules, and is formed to have a uniform thickness using a thermoplastic resin as a binder. It is a layer. Although it depends on the type of microcapsules and binders, when the foam layer 22 is heated to about 80 ° C. or higher, it foams and expands, and rises on the surface side of the foamable sheet 2 on the opposite side of the base material 21.

The ink receiving layer 23 is a layer formed so as to cover the entire surface of the foamed layer 22. The ink receiving layer 23 is made of a material suitable for receiving color ink used in an inkjet printer, toner used in a laser beam printer, ink of a ballpoint pen, and the like and fixing them on the surface of the foamable sheet 2.

The shading image 25 is formed by printing on the back surface (lower side of FIG. 3) of the foamable sheet 2 with black ink containing carbon black. Printing is performed by the stereoscopic image data editing device 5 operating the image printing device 6. In the foamable sheet 2, the heat generation temperature when irradiated with light changes according to the degree of shading (concentration) of the image, that is, the amount of carbon black attached per area. In response to this temperature, heat propagates through the base material 21 to the foam layer 22, and the foam layer 22 is heated, expands, and rises toward the surface side.

The color image 26 is composed of general printing cyan (C), magenta (M), and yellow (Y) color inks, and the image is transferred to the surface of the foamable sheet 2 (upper side in FIG. 3) by, for example, an inkjet method. It is formed by being printed. Printing is performed by the stereoscopic image data editing device 5 operating the image printing device 6. The black color in the color image 26 is represented by a mixture of the three color inks, and the black ink containing carbon black is not used.

When the stereoscopic image data editing device 5 operates the foaming device 7, light is irradiated from the back surface of the foamable sheet 2 (lower side of FIG. 3) to heat the foamed sheet 2, and a shade image printed on the back surface of the foamable sheet 2. The region of the foam layer 22a on the surface side corresponding to 25 expands and rises. Through such a process, a three-dimensional image of characters and figures with unevenness is formed on the surface of the foamable sheet 2.

In FIG. 3, the shade image 25 is printed only on the back surface of the foamable sheet 2, but the present invention is not limited to this example. For example, it is possible to print only on the front surface of the foamable sheet 2 or to print on both the back surface and the front surface. When printing a light and shade image on the surface, the light and shade image is printed before printing the color image, and the color image is printed on the surface so that the color image can be seen on the surface.

When a light and shade image is printed on the surface of the foamable sheet 2, heat is directly transferred to the foam layer 22 without passing through the base material 21, so that a three-dimensional image having finer irregularities can be formed. However, since color printing is performed on the carbon black shade image with color ink, the hue may be inferior to that in the case of printing the shade image on the back surface.

As described above, the stereoscopic image data 4 is composed of the shading print data 41 and the color printing data 42, and the shading image may be printed on the front surface and the back surface of the foamable sheet 2. In the first embodiment, as shown in FIG. 3, the shade image 25 is printed only on the back surface by using the image printing device 6.

≪Overall processing≫
FIG. 4 is a flowchart showing the entire process of forming a stereoscopic image in the stereoscopic image forming system 1 according to the first embodiment.
As a first step, the user of the stereoscopic image forming system 1 edits the stereoscopic image, and the CPU 51 generates the stereoscopic image data 4 (step S21). Using the image editing screen 3 as shown in FIG. 5 (described later), the stereoscopic image data 4 desired by the user of the stereoscopic image forming system 1 is created. The user creates the three-dimensional image data 4 while designating the position and color of straight lines and characters stored as the color print data 42 and the height of the foam stored as the shade print data 41.

The image editing screen 3 is controlled by the CPU 51, and the CPU 51 stores the created stereoscopic image data 4 in the storage unit 52. The shading image at the time of storage is a shading image having a density corresponding to the foaming height specified by the user (shading image 921 in FIG. 19A, shading image 931 in FIG. 20A, and FIG. 21A). It is a shading image 941), and there is a possibility that non-uniform expansion may occur due to the tendency of the density distribution.

After the CPU 51 stores the stereoscopic image data 4, the CPU 51 changes the density (shade of black) of the shading print data 41 included in the stereoscopic image data 4 in order to suppress the height non-uniformity after foaming. The expansion suppression process is executed (step S22). The non-uniform expansion suppression process includes a high density area identification process for specifying a region where lines and intersections are dense, and a density adjustment process for changing the density of a shading image. The non-uniform expansion suppression process changes the density of the light and shade image generated in step S21 to suppress non-uniform expansion (the light and shade image 711 of FIG. 12 (b) and the light and shade image of FIG. 14 (b) described later). 731, a process for generating the shade image 741) of FIG. 10, which will be described in detail later with reference to FIGS. 6 to 10.

Next, the image printing device 6 prints a shading image after the non-uniform expansion suppression process of step S22 is performed on the back surface of the foamable sheet 2 (step S23). When the user sets the foamable sheet 2 in the image printing device 6 and instructs the stereoscopic image data editing device 5 to print, the CPU 51 is subjected to the non-uniform expansion suppression process by the image printing device 6 via the input / output unit 53. Send the mirror image data of the grayscale image and instruct printing. The image printing device 6 that has received the instruction prints a mirror image of the received light and shade image on the back surface of the foamable sheet 2. When the printing is completed, the image printing device 6 notifies the CPU 51 that the printing is completed via the input / output unit 53.

Subsequently, the image printing device 6 prints a color image on the surface of the foamable sheet 2 (step S24). In step S23, when the CPU 51 receives the print end notification of the shading image, it transmits color print data to the image printing device 6 via the input / output unit 53 to instruct printing. Upon receiving the instruction, the image printing device 6 prints the color image on the surface of the foamable sheet 2. When the printing is completed, the image printing device 6 discharges the foamable sheet 2 on which the grayscale image and the color image have been printed to the outside of the device, and notifies the CPU 51 that the printing is completed via the input / output unit 53. At this point, a mirror image of a shading image that has been subjected to a non-uniform expansion suppression treatment is printed on the back surface of the foamable sheet 2, and a color image is printed on the front surface.

Finally, the foaming device 7 foams the printed foamable sheet 2 (step S25). When the user sets the foamable sheet 2 discharged from the image printing device 6 in the foaming device 7 and instructs the stereoscopic image data editing device 5 to foam in step S24, the CPU 51 causes the foaming device via the input / output unit 53. Instruct 7 to foam. Upon receiving the instruction, the foaming device 7 takes in the foamable sheet 2 set by the user, irradiates light from the back surface side to foam (expand) the foamed layer 22 of the foamable sheet 2, and foams (expands) the foamable sheet 2. Is discharged, and the CPU 51 is notified via the input / output unit 53 that the foaming is completed. As a result, a stereoscopic image having a uniform height without uneven expansion (three-dimensional image 721 of FIG. 13 and stereoscopic image 751 of FIG. 11 described later) can be obtained.

≪Image editing≫
FIG. 5 is a screen layout diagram showing a configuration of an image editing screen 3 used for creating an image of a stereoscopic image according to the first embodiment. The CPU 51, which functions as an image editing means, processes an instruction given by the user to the image editing screen 3 and controls the display. An image display area 301 for displaying the image being edited is arranged on the left side of the screen, and buttons, pull-down menus, and the like (311 to 313, 321 to 326, 331) used for editing are arranged on the right side of the screen.

The two buttons 311 at the top right of the screen are a new button and a save button. The new creation button is a button that is pressed when the user of the stereoscopic image forming system 1 newly starts editing the stereoscopic image data. When the new creation button is pressed, the CPU 51 clears the image display area 301 in preparation for editing the new stereoscopic image data.

The save button is a button pressed when the user stores the stereoscopic image data 4 of the stereoscopic image displayed in the image display area 301 in the storage unit 52. When the save button is pressed, the CPU 51 inquires of the user for the file name, and saves the stereoscopic image data 4 in the file with the file name stored in the storage unit 52.

The file name display area 312 is an area for displaying the name (title of the stereoscopic image) of the file in which the stereoscopic image data 4 is stored.
The five buttons 313 arranged below the file name display area 312 are buttons that are pressed when the type of input data is selected, and input of straight lines, ellipses, squares, characters, and Braille is selected in order from the left. Button.

The straight line button is a button that is pressed when the user inputs a straight line. When the straight line button is pressed and the positions of the start point and the end point of the straight line are instructed in the image display area 301, the CPU 51 displays the straight line at the position.

The ellipse button is a button that is pressed when the user inputs an ellipse. When the ellipse button is pressed and the positions of the start point and the end point of the diagonal line of the ellipse area are instructed in the image display area 301, the CPU 51 displays the ellipse at the position.

The square button is a button that is pressed when the user inputs a square. When the square button is pressed and the positions of the start point and the end point of the diagonal line of the square are instructed in the image display area 301, the CPU 51 displays the square at the position.

The character button is a button that is pressed when the user inputs a character string. When the character button is pressed, the start position of the character string is instructed in the image display area 301, and the character string is input to the text input area 321 described later, the CPU 51 displays the character string at the position.

The Braille button is a button that is pressed when the user inputs Braille. When the braille button is pressed, the start position of the braille is specified in the image display area 301, and the reading of the braille is input, the CPU 51 displays the line of the braille at the position.

FIG. 5 is a diagram of the screen layout when the character button (second from the right of the five buttons 313) is pressed, and the buttons and pull-down menus (321 to 326) related to the editing of the character string are displayed. .. When another button is pressed, a button or pull-down menu corresponding to that button is displayed.

The text input area 321 is an area (text box) in which an input character string is input.
The font pull-down menu 322 is a menu used when the user specifies a font for a character string. When the target character string is selected in the image display area 301 and the font is specified in the font pull-down menu 322, the CPU 51 changes the character string to the selected font and displays it in the image display area 301.

The character color pull-down menu 323 is a pull-down menu used when the user specifies a character color. When the target character string is selected in the image display area 301 and the character color is specified in the character color pull-down menu 323, the CPU 51 changes the character string to the selected character color and displays it in the image display area 301. ..

The two buttons 324 of the character size "large" and "small" are buttons that are pressed when the user changes the character size of the character string. When the target character string is selected in the image display area 301 and the "large" button is pressed, the CPU 51 changes the character string by one step and displays it in the image display area 301. The same is true when the "small" button is pressed. The current font size is displayed small to the right of the button.

The four foam height buttons 325 are buttons that are pressed when the user specifies the height of the character string after foaming, and the four buttons "None", "Low", "Medium", and "High" are is there. The current ratio of foam height to maximum height is displayed to the right of the High button.

The two direction buttons 326 are buttons that are pressed when the user specifies the direction of the character string, and there are two buttons, horizontal writing and vertical writing. When the target character string is selected in the image display area 301 and the horizontal writing button is pressed, the CPU 51 writes the character string horizontally and displays it in the image display area 301. The same applies when the vertical writing button is pressed.

The three image enlargement ratio buttons 331 arranged at the bottom right of the screen are buttons that are pressed when the user specifies the enlargement ratio of the image displayed in the image display area 301. There are three types: reduction and enlargement. When the same size button is pressed, the CPU 51 displays the image at the same size, the reduction button reduces the image by one step, and the enlarge button enlarges the image by one step to display the image. The current magnification is displayed to the left of the 1x button.

In the first embodiment, a black shade image is printed on the back surface and a color image is printed on the front surface. Therefore, the stereoscopic image data 4 is composed of two image data, the shade print data 41 and the color print data 42. Further, the shade print data 41 stored in the storage unit 52 by the CPU 51 is an image shaded according to the foam height specified by the foam height button 325, and the higher the foam height, the darker the black image. Become. The foam height button 325 on the image editing screen 3 was a button for selecting the foam height of the character string, but there are similar buttons for straight lines and ellipses, and the foam height can be selected. ..

≪Non-uniform expansion suppression processing≫
The non-uniform expansion suppression process of step S22 (see FIG. 4) executed by the CPU 51 according to the first embodiment will be described in detail with reference to FIGS. 6 to 10. FIG. 6 is a flowchart showing the non-uniform expansion suppression process according to the first embodiment. FIG. 7 is a diagram for explaining the processing content for specifying the high density region according to the first embodiment. FIG. 8 is a diagram for explaining the concentration adjustment according to the first embodiment. FIG. 9 is a diagram for explaining a wide range of concentration adjustment according to the first embodiment. FIG. 10 is a diagram showing a shade image 741 after the non-uniform expansion suppression process according to the first embodiment.

The CPU 51 divides the entire shaded image into division areas of a predetermined size (step S31). FIG. 7A is an example of division when the light and shade image 761 of characters is regarded as the entire light and shade image, and is divided into 7 × 7 = 49 division areas.
Next, the CPU 51 calculates the density of each divided region (step S32). When calculating the density of the divided region, the density of the shading image in the divided region is taken into consideration. In addition to the method of calculating the ratio of the area of the region higher than the predetermined concentration in the divided region as the density, there is a method of calculating by weighting the concentration (calculating the average value of the concentrations).

Subsequently, the CPU 51 connects the divided regions having a density higher than a predetermined value to specify the dense density region (step S33). That is, if the divided regions having a density higher than a predetermined value are adjacent to each other, the CPU 51 connects the divided regions to form a high density region. Some shade images have a plurality of high density regions, and some shade images have zero density.

FIG. 7B is a diagram showing a high density region 762 of the shade image 761. The high density region 762 is a region in which 16 division regions having a density higher than a predetermined value are connected among the 49 division regions.
The CPU 51 executes the density adjustment processing of steps S35 to S37 for each of the high density regions specified in step S33 (step S34).
As the first step of the density adjustment process, the CPU 51 identifies the center of gravity of the high density region (step S35). FIG. 7C is a diagram showing the center of gravity 764 of the high density region 762.

Next, the CPU 51 changes the density of the shading image 761 in the vicinity of the high density area 762 (the high density area and its surroundings) so that the density gradually decreases toward the center of gravity (step S36). FIG. 8 (a) is a shade image 761 before changing the density, which is the same image as in FIG. 7 (a), and is shown for comparison with FIG. 8 (b). FIG. 8B is a shade image 771 as a result of changing the density in a concentric circle centered on the center of gravity 764 so that the density gradually decreases toward the center. FIG. 8C is a graph 773 showing the density of the U-U'line of the shading image 771 after the density change.

The densities at both ends of the U-U'line shown by the dotted line 774 are the densities of the original shading image 761, and the densities are changed so that the densities gradually decrease from this density toward the center. The density step is many steps (gradation) such as high gradation used for printing, for example, 256 gradation, but may be 3 or 4 steps. Hereinafter, the density of the shading image 761 before the density change is also referred to as a basic density. The basic density is determined by the foaming height set by the foaming height button 325 on the image editing screen 3 (see FIG. 5).

FIG. 9A shows the shading of the result of changing the density in a concentric circle centered on the center of gravity 764 of the high density region 762 so that the density gradually decreases toward the center in a wider range than that of FIG. Image 776. FIG. 9B is a graph 778 showing the density of the T-T'line of the shading image 776 after the density change. In the density change in FIG. 8, the CPU 51 gradually lowers the density from the basic density at both ends of the U-U'line toward the center. In the density change shown in FIG. 9, the CPU 51 lowers the density in a wider range, lowers the density over the entire TT'line, and also lowers the density than the basic density at both ends. The density is changed in the entire shade image 761 of.

The region where the density is changed may be widened according to the size of the high density region, or may be widened as the basic concentration is higher. Further, the region where the density is changed may be widened according to the integrated value of the density in the high density region (sum of the densities of the pixels in the high density region) and the average density.

At the end of the density adjustment process, the CPU 51 returns the density of the contour having a predetermined width of the shading image 761 to the basic density before the density change (step S37). The result of executing the process of step S37 on the shade image 771 (see FIG. 8 (b)) in which the density is changed is the shade image 741 (see FIG. 10).
As described above, the density of the center is concentrically low centering on the point where the lines are dense and the density of the character image is high (center of gravity 764 of the high density region 762), and the density is gradually decreased toward the outside. The density of black is increased, and the density is changed so that the contour remains the basic density. The reason why the contour remains at the basic density is to prevent the contour of the expanded portion from becoming dull and blurring the stereoscopic image as a result of reducing the density of the contour. The process of recognizing the contour of the original shading image 761 and returning it to the basic density can be realized by using an existing image processing technique such as boundary tracing.

When the CPU 51 executes the density adjustment processing of steps S35 to S37 for all the high density regions specified in step S33, the entire processing of FIG. 6 is completed (step S38).

FIG. 11 is a perspective view illustrating a stereoscopic image 751 in which a mirror image of the shading image 741 according to the first embodiment is printed on the back surface of the foamable sheet 2 and uniformly expanded as a result of being irradiated with light. A stereoscopic image 751 having no inclination as shown in Graph 942 (see FIG. 21B) and having a uniform height can be obtained.

Next, in the non-uniform expansion suppression process (step S22 of FIG. 4) executed by the CPU 51 for the light and shade image 921 of the cross (see FIG. 19 (a)) and the light and shade image 931 of the thin line cross (see FIG. 20 (a)). (Steps S35 to S37 in FIG. 6) will be described.
FIG. 12 is a diagram for explaining the density adjustment of the shade image according to the first embodiment in order to uniformly expand the shade image 921 of the cross. FIG. 12 (a) is a shade image 921 before changing the density, which is the same image as in FIG. 19 (a), and is shown for comparison with FIG. 12 (b). FIG. 12B is a shade image 711 after the density adjustment process of the shade image 921. FIG. 12 (c) is a graph 714 showing the density of the shading image 711 on the YY'line. FIG. 12 (d) is a graph 715 showing the density of the shading image 711 on the ZZ'line.

In the density adjustment shown in the shading image 711, the density of the center is concentrically low around the intersection of the crosses, which is the center of gravity of the high density region, and the density of black is gradually increased toward the outside. The concentration has been changed so that it remains at the basic concentration. As shown in Graph 714, the density is from the low density in the center to the density at both ends of the YY'line, from the base density shown by the dotted line 716, to the density from the center to both ends through many steps inside the shade image of the cross. The concentration has been changed to increase.

Concentration changes are not always continuous. As shown in the graph 715 showing the density of the ZZ'line, the density is gradually increased from the center of the intersection to the outside, and the density is changed so as to be the basic density shown by the dotted line 717 discontinuously in the contour portion. In some cases.

FIG. 13 is a perspective view illustrating a stereoscopic image 721 in which a mirror image of the cross shade image 711 according to the first embodiment is printed on the back surface of the foamable sheet 2 and uniformly expanded as a result of irradiation with light. .. A stereoscopic cross image having a uniform height can be obtained without a protruding region as in the stereoscopic image 922 (see FIG. 19B).

FIG. 14 is a diagram for explaining the non-uniform expansion suppression process according to the first embodiment for uniformly expanding the shade image 931 (see FIG. 20A) of the thin line cross. FIG. 14 (a) is a shade image 931 before changing the density, which is the same image as in FIG. 20 (a), and is shown for comparison with FIG. 14 (b). FIG. 14B is a shading image 731 after the density adjustment processing of the shading image 931. FIG. 14 (c) is a graph 735 showing the density of the shading image 731 on the XX'line. FIG. 14D shows the height of the cross section of the foamed layer of the foamable sheet 2 uniformly expanded as a result of the mirror image of the shading image 731 printed on the back surface of the foamable sheet 2 and being irradiated with light by the XX'line. It is a graph 737 showing the above.

The high density region of the shade image 931 is the intersection (intersection region) of the cross.
The density of the shading image 731 in the intersection region is the same as the density (basic density) of the shading image 931 before the density adjustment, but the density is different in the intersection region. The intersection area is divided into two areas by one rectangle inside, the inner rectangular area 732, the intersection area 733 excluding the inner rectangular area 732, and the image area 734 outside the intersection area outside the intersection area 733, in that order. The concentration is changed so that the concentration increases step by step.

As shown in Graph 735, assuming that the maximum density is 100%, the density of the inner rectangular region 732 is 0%, the density of the intersection region 733 excluding the inner rectangular region 732 is 25%, and the density of the image region 734 outside the intersection region is 25%. The concentration (basic concentration indicated by the dotted line 736) is set to 50%, but the concentration is not limited to these values.

The shading image 731 is divided into three regions (732-734) and changed to three levels of density including 0%, but it is not limited to three areas and three levels of density. Absent. The intersection region may be divided into more regions, and the density may be changed so that the density of black increases in order from the center of the intersection region to the outside.

A rectangle is used to divide the intersection area, but the present invention is not limited to this. If the lines do not go perpendicular, intersect diagonally, and the intersection region becomes a parallelogram, it may be divided into parallelogram regions. Alternatively, the intersection region may be divided into a circle or polygonal region.
When a mirror image of the shading image 731 is printed on the back surface of the foamable sheet 2 and irradiated with light, the foamable sheet 2 becomes a three-dimensional image having a uniform height, similar to the three-dimensional image 721 of the cross (see FIG. 13). It expands into a cross image.
As shown in the shade image 711 (see FIG. 12 (b)) and the shade image 731 (see FIG. 14 (b)), the density is changed so that the density of black at the center of the intersection is low and the density is high toward the outside. By doing so, the non-uniform expansion of the foam layer at the intersection is suppressed, and a stereoscopic image having a uniform height can be obtained.

<< Modified example of non-uniform expansion suppression processing >>
The contents of the non-uniform expansion suppression treatment in the second embodiment of the present invention are shown below. FIG. 15 is a diagram for explaining the non-uniform expansion suppression process according to the second embodiment. FIG. 15A is a diagram for explaining the identification of the high density region in the present embodiment, and the entire density image is divided into rectangles (mass). FIG. 15B is a diagram showing a high density region 825 and a center of gravity 826 thereof in the present embodiment. FIG. 15C is a diagram showing a shade image 828 after the non-uniform expansion suppression process in the present embodiment.

The processing content of the CPU 51 that scans the grayscale image 821 using the scanning window 823 will be described. The scanning window 823 is an area composed of 2 × 2 squares, and moves vertically and horizontally in units of 1 square. The scanning window 823 moves vertically and horizontally by a distance of 1 square while overlapping half the areas (2 squares) before and after the movement. As a result, the scanning window passes through one cell four times.

The high density region 825 in the second embodiment is a region connecting the scanning windows 823 when the region having a density higher than a predetermined value occupies 3/4 or more of the scanning windows 823.
The density adjustment process after the high density region is specified is the same as that of the first embodiment, and a shade image 828 is obtained.

A third embodiment of the present invention is shown below. FIG. 16 is a diagram for explaining a process for specifying a high density region according to the third embodiment. FIG. 16A is a diagram showing a shading image 831 to be scanned and a scanning window 833. FIG. 16B is a diagram showing a scanning window during scanning. FIG. 16C is a diagram showing a high density region.
The procedure in which the CPU 51 scans the grayscale image 831 through the scanning window 833 will be described. The shade image 831 consists of two cross images. The scanning window 833 is a cross-shaped scanning window 833 composed of five squares, and moves vertically and horizontally in units of one square.

The area ratio of the region where the density is higher than the predetermined value at the position of the scanning window 834 is 100%, and 80% at the position of the scanning window 835. The high density region in the third embodiment is a region in which one square in the middle of the scanning window in which the area ratio of the region having a concentration higher than a predetermined value is 90% or more is connected, and two high density regions ( 837 and 838). The concentration adjustment process of steps S35 to S37 of FIG. 6 is performed twice.

The divided regions of the first embodiment and the scanning windows (scanning window 823 of FIG. 15A and scanning window 833 of FIG. 16A) in the second and third embodiments are rectangular or cross-shaped. However, it may be circular or other shape / size. Further, the high density region is not limited to the divided region where the area ratio and the average density of the region whose density is higher than the predetermined value satisfy the predetermined conditions and the region where the scanning windows are connected, but also the internal region of the scanning window (partial region). May be a concatenated area. As an example of the internal region of the scanning window, there is one square in the middle of the cross-shaped scanning window 833.

The high density region in the non-uniform expansion suppression process of the above embodiment is a divided region satisfying a predetermined condition and a region in which scanning windows are connected. As another embodiment, there is a mode in which the density adjustment process is performed by setting a region where characters, straight lines, and elliptical lines intersect (hereinafter, also referred to as an intersection region) as a high density region. A fourth embodiment for identifying a high density region and adjusting the concentration by searching for an intersection will be described in detail with reference to FIGS. 17 and 18.

FIG. 17 is a flowchart showing the non-uniform expansion suppression process according to the fourth embodiment. FIG. 18 is a diagram for explaining the concentration adjusting process according to the fourth embodiment.

The CPU 51 regards the figures and characters included in the shade image as a set of line images having a predetermined width, and specifies the center line of the line images constituting each figure and character (step S51). FIG. 18A is a diagram showing a shade image 851 of characters and a center line thereof, and the specified center line is shown by a solid white line. The center line consists of five connected components, and the center line 852 is the longest center line among the connected components. This process of identifying the center line can be realized by using thinning and other existing image processing techniques.

Next, the CPU 51 identifies the intersection of the center lines obtained in step S51 (step S52).
Subsequently, the CPU 51 specifies an intersection region including the intersection specified in step S52 (step S53).
Next, the CPU 51 executes the density adjustment processing of steps S55 and S56 for each of the intersection regions specified in step S53 (step S54).

The CPU 51 changes the density of the intersection region specified in step S53 so that the density gradually decreases from the periphery toward the center (step S55). FIG. 18B is a diagram showing a shade image 861 in the vicinity of the intersection region including the intersection 853 after the density is changed. Similar to the shade image 731 (see FIG. 14B), the intersection region is divided into two by one rectangle, and the region sandwiched between the intersection region and the rectangle is divided from the basic density of 864 outside the intersection region (see FIG. 14B). The densities are changed to 863 (inner and outer regions of the intersection region) and 862 of the rectangular region (inner and inner regions of the intersection region) so that the densities decrease toward the inside. In this density change, the intersection area is divided into two areas by one rectangle and three levels of concentration are used, but the area is further divided into more areas and the concentration is gradually lowered from the outside to the inside. May be changed.

Subsequently, when the contour of the intersection region is the contour of the shading image 851 before the density change, the CPU 51 changes the contour of a predetermined width to the basic density before the density change (step S55) (the density of 864 outside the intersection region). ) (Step S56). FIG. 18C is a diagram showing a shade image 865 near the intersection region after the density of the intersection region including the intersection 853 is changed and the density of the contour is returned. Compared with the shading image 861 after the density change, the right side (contour portion) 866 of the outer contour of the inner / outer region 863 of the intersection region has returned to the basic density.

FIG. 18D is a graph showing the density of the WW'line of the shading image 865. From left to right, the densities of the outer 864 of the intersection region, the inner and outer regions of the intersection region 863, the inner and inner regions of the intersection region 862, the inner and outer regions of the intersection region 863, and the contour portion 866 change.
When the CPU 51 executes the processes of steps S55 and S56 for all the intersection regions specified in step S53, the entire process of FIG. 17 is completed (step S57).

FIG. 18E is a diagram showing a shade image 867 in the vicinity of the intersection region when the inner region 862 in the intersection region is wide in the density change (step S55) and the width of the contour processed in step S56 is wide. The right side of the inner / outer region 863 of the intersection region is missing. The CPU 51 may adjust the density in this way.

FIG. 18 (f) is a shade image 871 as a result of completing the non-uniform expansion suppression process of the shade image 851. The area 872 surrounded by the broken line corresponds to the shade image 865. The region 873 surrounded by another broken line has a plurality of intersections, and the plurality of intersection regions overlap. When a plurality of intersection areas overlap, the CPU 51 does not repeatedly execute the density adjustment processing (steps S55 and S56) in each intersection area, but collectively considers the plurality of intersection areas as one intersection area. And execute the density adjustment process. The intersection area in the area 873 surrounded by the broken line is a hexagon, and the intersection area is divided into two by a circle, and the outside of the intersection area is 876, the inside and outside area of the intersection area is 875, and the intersection area. The concentration is changed so that the concentration decreases in the order of the inner and inner regions 874.

In FIG. 18, the shading image is regarded as a set of line images constituting the characters, and the density adjustment is described with the intersection region as the high density region. The same processing can be performed not only for characters but also for lines of figures such as straight lines and ellipses. In addition, lines such as straight lines and ellipses overlap with characters, and the same processing can be performed for intersections of lines of straight lines and ellipses and lines of characters.
The line image is an image generated by the CPU 51 converting straight lines and ellipses input by the user into shading print data 41. Instead of specifying the center line from the image and obtaining the intersection, the intersection may be obtained from the coordinate information of the straight line or the ellipse in the stereoscopic image data 4. It has the effect of being able to process at a higher speed than identifying the intersection from the image.

≪Other variants≫
In steps S37 and S56, the contour density is the basic density, but it may be higher than the basic density. Further, the CPU 51 may set not only the outline of the region where the density is changed but also the entire outline of the image such as characters, straight lines, and ellipses to have a density higher than the density inside the image. By increasing the density of the contour, the contour of the expanded portion is emphasized, and a conspicuous effect can be expected.

In image 771 (see FIG. 8 (b)) and image 776 (see FIG. 9 (a)), the densities were changed using concentric multi-gradation density steps (gradation), but the densities were not limited to circles but rectangular. The concentration may be changed using other shapes.
The processing target of the CPU 51 does not have to be limited to the shade image generated by the CPU 51. The non-uniform expansion suppression process may be applied to an image created outside the stereoscopic image forming system 1.

In steps S23 to S25 of FIG. 4, the user has set the foamable sheet 2 in the image printing device 6 and the foaming device 7, but both devices may be integrated or an automatic sheet supply mechanism may be provided. The user may not intervene.
In the above embodiments, the figures are straight lines, ellipses, and squares, but the present invention is not limited to these, and other figures such as triangles and free curves may be used. Further, the CPU 51 may execute the non-uniform expansion suppression process on the area specified by the user in the image, or conversely, exclude the specified area and execute the non-uniform expansion suppression process. May be good.

In the above embodiment, the shading image to be treated for the non-uniform expansion suppression treatment is a shading image printed on the back surface of the foamable sheet 2, but it may be a shading image on the front surface side.
Further, the above-mentioned non-uniform expansion suppression treatment can be applied to a region where lines with different foaming heights (basic concentrations) are densely packed (intersected). In this case, the CPU 51 processes the contour according to the basic density of each line (step S37 and step S56). Further, it may be applied to a region where lines (lines drawn overlapping the region) within a region having a constant density are densely (intersected).

≪Effect≫
As described above, in the stereoscopic image forming system 1, in a stereoscopic image composed of characters and lines formed on the foamable sheet (thermally expandable sheet) 2, the intersections of lines, areas where lines are dense, and the number of strokes are set. It is possible to suppress excessive expansion in a large number of complicated characters and achieve a uniform foam height. As a result, it is possible to edit the stereoscopic image data and form a stereoscopic image without worrying about design restrictions and failure of uneven foaming height.

Specifically, in a region where the foamable sheet is irradiated with light and heated to foam and raise the foam layer, or in a shade image that contributes to the amount of heating, in a region where lines intersect, intricate characters, and regions where lines are densely packed. By identifying a certain high-density region and gradually reducing the density of the grayscale image from the peripheral portion to the central portion of the region, the amount of heat is reduced and non-uniform expansion is suppressed.
Further, by not reducing the density of the outline of the shaded image of characters and lines, it is possible to prevent the outline of the stereoscopic image of lines and characters from becoming dull.

The inventions described in the claims originally attached to the application of this application are added below. The claim numbers given in the appendix are the scope of the claims originally attached to the application for this application.
≪Additional notes≫
<< Claim 1 >>
A region in which the density pattern included in the shade image has a density higher than a predetermined value with respect to the print data for printing the shade image used for thermally expanding the desired region of the heat-expandable sheet. High density area identification means for identifying the high density area, and
A density adjusting means for adjusting the density of the grayscale image so that the expansion height of the high density region becomes a desired height, and
A stereoscopic image forming system characterized by having.
<< Claim 2 >>
The stereoscopic image forming system according to claim 1, wherein the density pattern is a figure or a character composed of a set of line images.
<< Claim 3 >>
The high density region is a region in which divided regions having an image having a density higher than a predetermined density having an area ratio higher than a predetermined ratio are connected, or a division having an average density higher than a predetermined density. The stereoscopic image forming system according to claim 1, wherein the regions are connected regions.
<< Claim 4 >>
The high density region is a region in which the internal regions of the partial regions having a density higher than the predetermined density and the area ratio of the image having a density higher than the predetermined density are connected to each other in the partial regions having a predetermined shape of the grayscale image, or The stereoscopic image forming system according to claim 1, wherein the internal regions of partial regions having an average density higher than a predetermined density are connected to each other.
<< Claim 5 >>
The stereoscopic image forming system according to any one of claims 1 to 4, wherein the density adjusting means lowers the density in the central portion of the high density region and changes the density of the grayscale image.
<< Claim 6 >>
The three-dimensional object according to claim 5, wherein the density adjusting means changes the density of the grayscale image by using the size of the high density region, the average density, or the gradation of a circle corresponding to the density integrated value. Image formation system.
<< Claim 7 >>
The stereoscopic image forming system according to claim 5 or 6, wherein the density adjusting means does not change the density of the contour included in the shading image.
<< Claim 8 >>
Computer of stereoscopic image forming device,
A region in which the density pattern included in the shade image has a density higher than a predetermined value with respect to the print data for printing the shade image used for thermally expanding the desired region of the heat-expandable sheet. High density area identification means for identifying a high density area,
A density adjusting means for adjusting the density of the grayscale image so that the expansion height of the high density region becomes a desired height.
A program to function as.
<< Claim 9 >>
It is a three-dimensional structure formed on a heat-expandable sheet on which a grayscale image is printed.
A solid characterized in that the density of the grayscale image printed in the high density region, which is a region where the lines of the solid are dense or intersect in the three-dimensional structure, is low in the central portion of the high density region. Structure.

1 Solid image forming system 2 Foamable sheet 21 Base material 22 Foam layer 23 Ink receiving layer 25 Dark and light image 26 Color image 3 Image editing screen 4 Solid image data 41 Dark and light print data 42 Color print data 5 Solid image data editing device 51 CPU
52 Storage unit 521 OS
522 Stereoscopic image data editing program 53 Input / output unit 55 Touch panel 6 Image printing device 7 Foaming device 711 Non-uniform expansion suppression of grayscale image 921 (density adjustment) Darkness image after processing 731 Nonuniform expansion suppression of grayscale image 931 (density adjustment) Light and shade image after processing 741 Light and shade image 941 Non-uniform expansion suppression (concentration adjustment) Light and light image after processing 921 Light and shade image of cross with non-uniform expansion problem 931 Light and light image of thin line cross with non-uniform expansion problem 941 Non Bold shade image with uniform expansion problem

Claims (11)

For print data for printing a shade image used for thermally expanding a desired region of a heat-expandable sheet, a center line is specified for a figure or character composed of a set of line images included in the shade image. The first specific step and
A second specific step of identifying the intersection of the center lines and the intersection region including the intersection, and
An adjustment step for adjusting the print density with respect to the intersection region so as to be lighter, and
A stereoscopic image forming method comprising. The stereoscopic image forming method according to claim 1, wherein in the adjustment step, the print density of the intersection region is adjusted so as to gradually become thinner toward the center of the intersection region. A division step for dividing the intersection region into a plurality of regions is further included.
The solid according to claim 1 or 2, wherein the adjustment step is adjusted so that the print density of the region located at the center of the intersection region among the regions divided by the division step is low. Image formation method. In the adjustment step, when the contour of the intersection region corresponds to the contour of the grayscale image, the print density of the intersection region in a region having a predetermined width from the contour of the grayscale image is adjusted in the adjustment step. The stereoscopic image forming method according to any one of claims 1 to 3, wherein the density is set to the previous level. One of claims 1 to 4, wherein the adjustment step adjusts the print density by using the overlapping area as one intersection area when there is an overlapping area where a plurality of the intersection areas overlap. The stereoscopic image forming method according to the section. Computer of stereoscopic image forming device,
For print data for printing a shade image used for thermally expanding a desired region of a heat-expandable sheet, a center line is specified for a figure or character composed of a set of line images included in the shade image. First specific means,
A second specifying means for specifying the intersection of the center lines and the intersection region including the intersection,
An adjusting means for adjusting the print density with respect to the intersection region so as to be lighter.
A program to function as. The program according to claim 6, wherein the adjusting means adjusts the print density of the intersection region so as to gradually become thinner toward the center of the intersection region. It functions as a dividing means for dividing the intersection region into a plurality of regions.
The program according to claim 6 or 7, wherein the adjusting means adjusts the area divided by the dividing means so that the print density of the area located at the center of the intersection area becomes low. .. When the contour of the intersection region corresponds to the contour of the shading image, the adjusting means adjusts the print density of the intersection region in a region having a predetermined width from the contour of the shading image by the adjusting means. The program according to any one of claims 6 to 8, wherein the concentration is set to the previous concentration. Any one of claims 6 to 9, wherein the adjusting means adjusts the print density by using the overlapping area as one intersection area when there is an overlapping area where a plurality of the intersection areas overlap. The program described in the section. For print data for printing a shade image used for thermally expanding a desired region of a heat-expandable sheet, a center line is specified for a figure or character composed of a set of line images included in the shade image. The first specific means and
A second specifying means for specifying the intersection of the center lines and the intersection region including the intersection, and
An adjustment means for adjusting the print density with respect to the intersection region so as to be lighter, and
A stereoscopic image forming system characterized by having.

Images