Image processing method, image processing device, printing system, and image processing program

Abstract

To provide a technique that enables a user to easily grasp each printing layer when a plurality of printing layers are formed.SOLUTION: An image processing method includes the steps of: (a) receiving the stacking order of printing medium and one or more printing layers; (b) displaying, on a display device, a preview image representing a state in which one or more virtual three-dimensional objects corresponding to one or more printing layers and the three-dimensional object corresponding to the printing medium are stacked and combined in the stacking order, the preview image corresponding to how the preview image appears in a three-dimensional virtual space; (c) displaying, on the display device, the preview image representing a state in which one or more three-dimensional objects corresponding to one or more printing layers and the three-dimensional object corresponding to the printing medium are stacked in the stacking order with intervals between them, the preview image corresponding to how the preview image appears in the virtual space; and (d) receiving an instruction to execute either the step (b) or the step (c), and executing the instructed step of the step (b) and the step (c).SELECTED DRAWING: Figure 19

Description

[Technical Field]

[0001] The present disclosure relates to an image processing method, an image processing device, a printing system, and an image processing program. [Background technology]

[0002] Patent Document 1 describes a technique for displaying preview images that simulate printed matter obtained as a result of printing on a transparent medium. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-159552 Summary of the Invention [Problem to be solved by the invention]

[0004] The technology described in Patent Document 1 displays a preview image in two-dimensional space, making it difficult to grasp non-printed areas, which are areas on a transparent medium where no image is formed. Furthermore, when multiple printed layers are formed, it is difficult to grasp each printed layer. For this reason, a technology that allows users to easily grasp each printed layer has been desired. [Means for solving the problem]

[0005] The present disclosure can be realized in the following forms. According to a first aspect of the present disclosure, there is provided an image processing method, including: (a) receiving one or more print layers to be stacked on a print medium by printing on the print medium and a stacking order of the print medium; (b) displaying, on a display device, a preview image representing one or more virtual three-dimensional objects corresponding to the one or more print layers and the three-dimensional objects corresponding to the print medium stacked and combined in the stacking order, the preview image corresponding to how they will appear in a three-dimensional virtual space; (c) displaying, on the display device, the preview image representing a state in which the one or more three-dimensional objects corresponding to the one or more print layers and the three-dimensional objects corresponding to the print medium are stacked with a gap between them in the stacking order, the preview image corresponding to how they will appear in the virtual space; and (d) receiving an instruction to execute either step (b) or step (c), and executing the instructed step of step (b) or step (c).

[0006] According to a second aspect of the present disclosure, there is provided an image processing device. The image processing device includes a print setting receiving unit that receives one or more print layers to be stacked on a print medium by printing on the print medium and a stacking order of the print medium, and a display processing unit that displays, on a display device, a preview image representing one or more virtual three-dimensional objects representing a printed matter, the preview image corresponding to how the objects will appear in a three-dimensional virtual space. In response to the received instruction regarding a display mode, the display processing unit displays, on the display device, the preview image representing a state in which one or more of the three-dimensional objects corresponding to the one or more print layers and the three-dimensional objects corresponding to the print medium are stacked and combined in the stacking order, the preview image corresponding to how the objects will appear in the virtual space, or displays, on the display device, the preview image representing a state in which one or more of the three-dimensional objects corresponding to the one or more print layers and the three-dimensional objects corresponding to the print medium are stacked with a gap between them in the stacking order, the preview image corresponding to how the objects will appear in the virtual space.

[0007] According to a third aspect of the present disclosure, there is provided a printing system. The printing system includes an image processing device, a printing device, and a display device. The image processing device includes a print setting receiving unit that receives one or more printing layers to be stacked on the printing medium by printing on the printing medium and a stacking order of the printing medium, and a display processing unit that displays, on the display device, a preview image representing one or more virtual three-dimensional objects representing a printed matter, the preview image corresponding to how the objects will appear in a three-dimensional virtual space. In response to the received instruction regarding the display mode, the display processing unit displays, on the display device, the preview image representing a state in which one or more of the three-dimensional objects corresponding to the one or more printing layers and the three-dimensional objects corresponding to the printing medium are stacked and combined in the stacking order, the preview image corresponding to how the objects will appear in the virtual space; or displays, on the display device, the preview image representing a state in which one or more of the three-dimensional objects corresponding to the one or more printing layers and the three-dimensional objects corresponding to the printing medium are stacked with a gap between them in the stacking order, the preview image corresponding to how the objects will appear in the virtual space.

[0008] According to a fourth aspect of the present disclosure, there is provided an image processing program that causes a computer to realize the following functions: (a) receiving one or more print layers to be stacked on a print medium by printing on the print medium and a stacking order of the print medium; (b) displaying, on a display device, a preview image representing one or more virtual three-dimensional objects corresponding to the one or more print layers and the three-dimensional objects corresponding to the print medium stacked and combined in the stacking order, the preview image corresponding to how they would appear in a three-dimensional virtual space; (c) displaying, on the display device, the preview image representing a state in which the one or more three-dimensional objects corresponding to the one or more print layers and the three-dimensional objects corresponding to the print medium are stacked with a gap between them in the stacking order, the preview image corresponding to how they would appear in the virtual space; and (d) receiving an instruction to execute either function (b) or function (c) and executing the instructed step of function (b) or function (c). [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a block diagram illustrating a schematic configuration of a printing system according to an embodiment. [Figure 2] FIG. 1 is an explanatory diagram showing an example of a printed matter in which an image is printed on a transparent printing medium. [Figure 3] FIG. 10 is an explanatory diagram showing another example of a printed matter in which an image is printed on a transparent printing medium. [Figure 4] FIG. 10 is an explanatory diagram of a printed matter PT3. [Figure 5] FIG. 10 is an explanatory diagram of a printed matter PT4. [Figure 6] FIG. 10 is an explanatory diagram of a printed matter PT5. [Figure 7] FIG. 10 is an explanatory diagram of a printed matter PT6. [Figure 8] FIG. 10 is an explanatory diagram of a printed matter PT7. [Figure 9] FIG. 1 is an explanatory diagram illustrating a configuration of an image processing device. [Figure 10] FIG. 10 is an explanatory diagram showing the processing contents of the CMS. [Figure 11] FIG. 10 is an explanatory diagram showing the flow of color conversion processing. [Figure 12] FIG. 2 is an explanatory diagram illustrating the configuration of a rendering unit. [Figure 13] 4 is a flowchart showing a printing process executed in the image processing apparatus. [Figure 14] FIG. 2 is an explanatory diagram showing an example of a user interface for inputting image data. [Figure 15] FIG. 10 is an explanatory diagram schematically showing how the surface of a printed matter expressed as a 3D object in a virtual space is observed. [Figure 16] FIG. 10 is an explanatory diagram schematically illustrating the state of observing the back side of a printed matter represented as a 3D object in a virtual space. [Figure 17] FIG. 10 is an explanatory diagram of a user interface on which a preview image is displayed. [Figure 18] 10 is a flowchart showing a preview image display switching process. [Figure 19] FIG. 10 is an explanatory diagram showing a user interface in a state in which a preview image showing an expanded printed matter is displayed in a display area. [Figure 20] FIG. 10 is an explanatory diagram showing an example of a display mode of a preview image according to the alternative first embodiment. [Figure 21] FIG. 10 is an explanatory diagram showing another example of a display mode of a preview image according to the alternative first embodiment. [Figure 22] FIG. 10 is an explanatory diagram of a user interface according to another embodiment 2. [Figure 23] FIG. 10 is an explanatory diagram of a user interface according to another embodiment 3. [Figure 24] FIG. 10 is an explanatory diagram of the operation of a user interface UI according to another fourth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] A. Implementation: 1 is a block diagram showing a schematic configuration of a printing system 10 according to this embodiment. The printing system 10 includes an image processing device 100, an input device 200, a display device 300, and at least one printing device 400. The printing system 10 functions as a printing device in the broad sense.

[0011] The image processing device 100 uses physics-based rendering (hereinafter simply referred to as rendering) to generate a rendering image that corresponds to how a printed matter will appear in a three-dimensional virtual space. Before printing, the image processing device 100 displays the generated rendering image as a preview image on the display device 300. In this embodiment, the appearance of a printed matter in a three-dimensional virtual space is determined by the position and orientation of a three-dimensional object (hereinafter referred to as a 3D object) in the virtual space, or the user's viewpoint position and line of sight relative to the 3D object in the virtual space.

[0012] The printing device 400 is an inkjet printing device that prints an image directly onto a print medium. In this embodiment, the printing device 400 prints an image onto a transparent print medium. The print medium has a flat plate shape. The print medium can be a transparent film or sheet made of a material such as polypropylene (PP), polyethylene (PET), or polyvinyl chloride (PVC). Alternatively, the print medium can be a transparent plate made of a material such as acrylic or glass. However, the print medium may also be translucent. A transparent print medium may have, for example, an average visible light transmittance of 80% or more. Alternatively, a translucent print medium may have, for example, an average visible light transmittance of 30% or more but less than 80%. In this embodiment, processing when a transparent print medium is used will be described. Substantially the same processing can be applied whether a translucent print medium or an opaque print medium is used.

[0013] In addition to front printing, the printing device 400 can also perform reverse printing. Front printing refers to printing on the front side of a print medium. In this specification, the front side of a print medium refers to the side on which the printed matter is expected to be observed. The reverse side is the side opposite the front side. Reverse printing refers to printing an image on the reverse side of a transparent print medium with the image orientation and printing order reversed. The reverse-printed image can be seen through the transparent print medium. Reverse printing makes it possible to obtain printed matter with a transparent or glossy appearance. Below are some examples of front and reverse printing.

[0014] FIG. 2 is an explanatory diagram showing a printed matter PT1 in which an image is printed on a transparent printing medium. In the printed matter PT1, a color layer CL in which a front image SG is formed is formed on the surface of the transparent printing medium PM. The printed matter PT1 is printed by surface printing. The color layer CL is formed by printing plates of each process color. The color layer CL is formed by a collection of dots of process ink. The thickness of the layer is exaggerated for convenience of illustration. The printed matter PT1 is intended to be observed only from the front side, but when observed from the back side, a back image RG, which is a left-right inverted image of the front image SG, can be seen. A left-right inverted image is also called a mirror-inverted image.

[0015] 3 is an explanatory diagram showing another example of a printed matter in which an image is printed on a transparent printing medium, in which the thickness of layers is exaggerated for convenience of illustration.

[0016] In the printed matter PT2, a color layer CL that forms a back-side image RG is printed on the back side of a transparent printing medium PM. The printed matter PT2 is printed by reverse printing. Figure 3 shows the printed matter PT2 positioned so that the back side of the printing medium PM is facing up. Because the printing medium PM is transparent, when viewed from the front side, the front-side image SG, which is a left-right inverted image of the back-side image RG, can be seen through the printing medium PM.

[0017] Figure 4 is an explanatory diagram of a printed matter PT3 printed by surface printing on a transparent printing medium PM. Starting from the surface of the printing medium PM, a base layer WL formed with base ink and a color layer CL are layered on the surface of the printing medium PM in this order. The base layer WL is the base for the color layer CL. The color layer and base layer are collectively referred to as the printing layer. The printing layer is sometimes simply referred to as the layer. The printed matter PT3 is intended to be observed only from the front side. When observed from the front side, the front image SG is visible. When observed from the back side, the base region RWG is visible. The base region RWG formed by the base layer WL has a shape corresponding to a left-right reverse image of the front image SG.

[0018] Figure 5 is an explanatory diagram of a printed matter PT4 printed by reverse printing on a transparent printing medium PM. Starting from the side closest to the back surface of the printing medium PM, the color layer CL and the base layer WL are layered on the back surface of the printing medium PM in this order. The base layer WL is the base for the color layer CL. The printed matter PT4 is intended to be observed only from the front side. When observed from the front side, the front image SG is visible. When observed from the back side, the base region RWG is visible. The base region RWG formed by the base layer WL has a shape corresponding to a left-right inverted image of the front image SG.

[0019] FIG. 6 is an explanatory diagram of a printed matter PT5 in which images are printed on both sides of a transparent printing medium PM. Starting from the front side of the printing medium PM, a base layer WL1 and a color layer CL1 are layered on the front side of the printing medium PM in this order. The color layer CL1 and the base layer WL1 are formed by front-side printing. Starting from the back side of the printing medium PM, a color layer CL2 and a base layer WL2 are layered on the back side of the printing medium PM in this order. The color layer CL2 and the base layer WL2 are formed by back-side printing. The printed matter PT5 is intended to be observed only from the front side. When observed from the front side, the front image SG1 and the front image SG2 are visible. When observed from the back side, the base region RWG1 and the base region RWG2 are visible. When observed from the back side, the base region RWG1 formed by the base layer WL1 has a shape corresponding to a left-right mirror image of the front image SG1. The base region RWG2 formed by the base layer WL2 has a shape corresponding to a left-right mirror image of the front image SG2.

[0020] FIG. 7 is an explanatory diagram of a printed matter PT6 in which an image is printed on one side of a transparent printing medium PM. Starting from the surface of the printing medium PM, a color layer CL2, a base layer WL1, and a color layer CL1 are layered on the surface of the printing medium PM in this order. In the printed matter PT6, all layers are formed by front printing. The base layer WL1 is the base for the color layers CL1 and CL2. The base layer WL1 is formed in an elliptical shape that completely encompasses the front image SG1 formed by the color layer CL1 and the back image RG1 formed by the color layer CL2. The printed matter PT6 is intended to be viewed from both the front and back sides. When viewed from the front side, the front image SG1 and the base region SWG1 are visible. When viewed from the back side, the back image RG2 and the base region RWG1 are visible. The back image RG2 is not visible from the front side, and the front image SG1 is not visible from the back side.

[0021] FIG. 8 is an explanatory diagram of printed matter PT7. In printed matter PT6 shown in FIG. 7, all layers are formed on the front surface of the printing medium PM by front-side printing. In printed matter PT7 shown in FIG. 8, all layers are formed on the back surface of the printing medium PM by back-side printing. Starting from the back surface of the printing medium PM, color layer CL1, base layer WL1, and color layer CL2 are stacked in this order. The base layer WL1 is the base for color layers CL1 and CL2. The base layer WL1 is formed in an elliptical shape that completely encompasses the front image SG1 formed by color layer CL1 and the back image RG1 formed by color layer CL2. Printed matter PT7 is intended to be observed from both the front and back sides. When observed from the front side, the front image SG1 and base region SWG1 are visible. When observed from the back side, the back image RG2 and base region RWG1 are visible. Note that the back image RG2 is not visible from the front side, and the front image SG1 is not visible from the back side.

[0022] 7 and PT7 shown in Fig. 8 have in common that a front image SG1 representing a clownfish can be seen from the front side, and a back image RG2 representing a shark can be seen from the back side. However, because the printed layers of printed matter PT6 and printed matter PT7 are formed on different surfaces, in printed matter PT6 the back image RG2 representing a shark can be seen through the printing medium PT, whereas in printed matter PT7 the front image SG1 representing a clownfish can be seen through the printing medium PT.

[0023] As shown in FIG. 1, the image processing device 100 is a computer including a memory 101, an input / output interface 102, a processor 103, and an internal bus 104. The memory 101, the input / output interface 102, and the processor 103 are communicatively connected via the internal bus 104. The memory 101 stores various programs and data used for various processes executed by the image processing device 100. The memory 101 stores a program PG. An input device 200, a display device 300, and a printing device 400 are connected to the input / output interface 102 via wired or wireless communication. The processor 103 realizes various functions by executing the programs stored in the memory 101. The input device 200 is, for example, a keyboard or a mouse. The display device 300 is, for example, a liquid crystal display or an organic EL (Electro Luminescence) display. In this embodiment, the display device 300 further functions as a pointing device.

[0024] 9 is an explanatory diagram showing the configuration of the image processing device 100. The image processing device 100 includes an image data acquisition unit 110, a profile acquisition unit 120, a printing condition acquisition unit 130, a parameter acquisition unit 140, a preprocessing unit 150, a rendering unit 160, an update reception unit 165, and a print data generation unit 170. The functions of these units are realized by the processor 103 executing the program PG stored in the memory 101 shown in FIG. 1. The rendering unit 160 is also called a "display processing unit."

[0025] The image data acquisition unit 110 acquires image data selected by a user via a user interface UI (described later). The selected image data is referred to as input image data IMi. The input image data IMi represents an image to be formed on a print medium. The input image data IMi is sent to the pre-processing unit 150.

[0026] The profile acquisition unit 120 acquires an input profile IPF, a media profile MPF, and a common color space profile CPF that are stored in advance in the memory 101. Note that the input profile IPF, media profile MPF, and common color space profile CPF are not shown in FIG. 1. The input profile IPF, media profile MPF, and common color space profile CPF are used for color conversion by a color management system 151 of a pre-processing unit 150, which will be described later. Details of each profile will be described later. The acquired profiles are sent to the pre-processing unit 150. Note that the profile acquisition unit 120 may acquire each profile from an external server via a network (not shown).

[0027] The printing condition acquisition unit 130 acquires printing conditions. The printing conditions include the type of printing medium, the type of printing, the layering order indicating the order in which the printing medium and one or more printing layers are layered, the type of ink for the printing layers, the printing resolution, the type of printing device, and so on. If the printing medium has a flat shape, the layering order indicates the order in which the printing medium and one or more printing layers are layered with the surface of the printing medium facing up. The printing conditions acquired by the printing condition acquisition unit 130 are sent to the profile acquisition unit 120, the preprocessing unit 150, and the parameter acquisition unit 140. The printing condition acquisition unit 130 is also referred to as the "print setting acceptance unit."

[0028] The parameter acquisition unit 140 acquires various parameters used for rendering from the memory 101. The various parameters are stored in advance in the memory 101. The various parameters used for rendering include, for example, 3D object information (hereinafter referred to as 3D object information), camera information, lighting information, and medium parameters. The 3D object information is a parameter related to the shape of the print medium as a 3D object placed in virtual space. The camera information is a parameter related to the position and orientation of the camera placed in virtual space. The lighting information is a parameter related to the type, position, orientation, color, and luminous intensity (amount of light) of the light source placed in virtual space. The types of light source include, for example, fluorescent lamps and incandescent lamps.

[0029] The medium parameters are parameters related to the texture of the print medium. In this embodiment, the medium parameters include a texture parameter that represents the texture of the print medium and a translucency parameter that represents the translucency of the print medium. The texture parameters include, for example, a base color (Base Color) related to the background color of the print medium, smoothness (Smoothness) that represents the smoothness of the print medium, metallicity (Metallic) that represents the metallicity of the print medium, a normal map (Normal Map), and a height map (Height Map). High metallicity increases the likelihood that the surrounding scenery will be reflected in the print medium. Instead of smoothness, the texture parameters may also include roughness (Roughness) that represents the roughness of the print medium. The normal map and height map are used to represent minute irregularities in the print medium that affect light reflection. The normal map is a texture that represents the distribution of normal vectors of minutely irregular surfaces. The height map is a texture that represents the distribution of heights of minutely irregular surfaces. Reducing the size of the polygons that make up a 3D object to represent minute irregularities results in an enormous number of polygons, increasing the computational load of rendering. Using normal maps and height maps makes it possible to represent the effect of minute irregularities on light reflection without reducing the size of polygons. Translucency parameters include media transmittance, which represents the light transmittance (transparency) of the printing medium. Translucency parameters may also include media opacity, which represents the light opacity (opacity) of the printing medium.

[0030] The various parameters acquired by the parameter acquisition unit 140 are transmitted to the rendering unit 160. The parameter acquisition unit 140 may acquire the various parameters from an external server via a network (not shown).

[0031] The preprocessing unit 150 includes a color management system 151, a spot color setting unit 152, and a medium color calculation unit 153. Hereinafter, the color management system 151 may be simply referred to as the CMS 151.

[0032] 10 is an explanatory diagram showing the processing content of the CMS 151. The CMS 151 uses each profile acquired by the profile acquisition unit 120 to execute various color conversion processes.

[0033] The input profile IPF is an ICC (International Color Consortium) profile used for color conversion from the color space of image data (input color space) to a device-independent color space. The input color space is, for example, the RGB color space. The device-independent color space is, for example, the CIE-L*a*b* color space. The media profile MPF is an ICC profile used for color conversion from the device-independent color space to a device-dependent color space for the printing device 400. The device-dependent color space for the printing device 400 is, for example, the CMYK color space. Colors in the device-dependent color space for the printing device 400 are also called device colors. The common color space profile is an ICC profile used for color conversion from the device-independent color space to a color space for rendering. The color space for rendering is, for example, sRGB, AdobeRGB, or Display-P3.

[0034] An example of color conversion processing executed by the CMS 151 is as follows: The CMS 151 executes the following color conversion processing in order on the input image data IMi. (1) A first color transformation CC1 from the input color space to a device-independent space using the input profile IPF. (2) A second color transformation CC2 from the device independent color space to the device dependent color space for the printing device 400 using the media profile MPF. (3) A third color transformation CC3 from a device-dependent color space to a device-independent color space for the printing device 400 using the media profile MPF. (4) A fourth color transformation CC4 from a device-independent color space to a rendering color space using the common color space profile CPF.

[0035] The first color conversion CC1 and the second color conversion CC2 convert the color values ​​of the image data into a range that can be represented by printing. In other words, the first color conversion CC1 and the second color conversion CC2 convert the color values ​​of the image data into color values ​​in a color space that depends on the printing device and the printing medium. The image data that has undergone the first color conversion CC1 and the second color conversion CC2 is called device color image data IMd. The device color image data IMd is sent to the print data generation unit 170 (see FIG. 9). Note that, for example, multiple input image data IMi may be input because images are printed on both sides of the printing medium PM. In this case, multiple device color image data IMd are obtained by performing color conversion on each input image data IMi.

[0036] As shown in FIG. 10, the third color conversion CC3 and the fourth color conversion CC4 convert the color values ​​of the image data into a range that can be represented by rendering. By applying the first color conversion CC1 to the fourth color conversion CC4, the color values ​​of the image data are converted into color values ​​in the rendering color space. The image data converted into color values ​​in the rendering color space is called rendering image data IMm. The rendering image data IMm is used as a texture to be added to the polygon representing the color layer CL in rendering. The RGBA values ​​of the base color of the color layer CL are set to (1,1,1,1). The rendering image data IMm is sent to the rendering unit 160. Furthermore, for example, multiple input image data IMi may be input because images are printed on both sides of the printing medium PM. In this case, multiple pieces of rendering image data IMm are obtained by performing color conversion processing on each piece of input image data IMi.

[0037] 11 is an explanatory diagram showing the flow of color conversion processing. For the sake of convenience, multiple CMSs 151 are shown in FIG.

[0038] The spot color setting unit 152 generates spot color image data IMt and spot color image data for rendering IMmt. The spot color image data IMt is image data for printing the base layer WL. The spot color image data for rendering IMmt is image data obtained by converting the spot color image data IMt into color values ​​in the rendering color space. Note that, as shown in FIGS. 2 and 3, if the base layer WL is not formed, it is not necessary to generate the spot color image data IMt and the spot color image data for rendering IMmt.

[0039] For example, as shown in FIG. 4, if the base area formed by the base layer WL has the same shape as the image formed by the color layer CL, the spot color setting unit 152 first determines the area occupied by the image, which is the area printed with process ink, from the values ​​of each pixel of the input image data IMi. The area occupied by the image to be printed refers to the area composed of pixels having a substantial color, i.e., pixels where R=G=B=1. The spot color setting unit 152 generates spot color image data IMt by performing an expansion process on the surface image SG. The spot color image data IMt indicates the area where the base ink is printed to form the base layer WL. The spot color image data IMt is used to create a spot color plate to be used to print the base ink. The color space of the spot color image data IMt is a device-dependent color space for the printing device 400. The spot color image data IMt is a grayscale image of a single color, white. The spot color image data IMt is sent to the print data generation unit 170. Furthermore, as shown in FIG. 4, when the base layer WL is formed over almost the entire back surface of the printing medium PM, the spot color setting unit 152 generates spot color image data IMt representing that the base layer WL is formed over the entire back surface.

[0040] The spot color setting unit 152 also generates spot color image data for rendering IMmt by converting the spot color image data IMt into an image for rendering. The spot color image data for rendering IMmt is used as a texture to be added to the polygons representing the base layer WL during rendering. In this embodiment, since white ink is used to print the base layer WL, the spot color setting unit 152 sets, for example, (1,1,1,1) as the RGBA values ​​of the base color of the base layer WL. The spot color image data for rendering IMmt is sent to the rendering unit 160.

[0041] As shown in FIG. 11, the medium color calculation unit 153 obtains YXZ values ​​representing the color of the print medium PM from the media profile MPF. The media profile MPF pre-stores XYZ values ​​representing the color of the print medium PM. The CMS 151 converts the XYZ values ​​Clx representing the color of the print medium PM into RGB values ​​using the common color space profile CPF. The medium color calculation unit 153 also obtains a medium transmittance α representing the light transmittance (transparency) of the print medium. The medium transmittance is included in the medium parameters obtained by the parameter acquisition unit 140. The medium color calculation unit 153 combines the RGB values ​​obtained by converting the XYZ values ​​Clx representing the color of the print medium PM with the medium transmittance α, and outputs the combined values ​​to the rendering unit 160 as an RGBA value representing the rendering medium color Clp.

[0042] 9, the rendering unit 160 generates a rendering image that represents how a print medium with an image printed thereon will appear in a virtual space. In the rendering, the printed matter is represented as a 3D object in the virtual space. Furthermore, as will be described in more detail below, upon receiving a user operation instruction, the rendering unit 160 updates the display of the rendering image displayed on the user interface UI.

[0043] 12 is an explanatory diagram showing the configuration of the rendering unit 160. The rendering unit 160 employs a pipeline configuration including a vertex pipeline VPL, a rasterizer RRZ, a pixel pipeline PPL, and a post-processing unit. The vertex pipeline VPL includes a vertex shader VS and a geometry shader GS. The pixel pipeline PPL includes a pixel shader PS and a render backend RBE.

[0044] The vertex shader VS uses 3D object information, camera information, and lighting information to perform processing related to the polygons that make up the 3D object. This processing includes coordinate transformation of the vertices of each polygon that makes up the 3D object, calculation of the normal vectors of each polygon, shading, and calculation of texture mapping coordinates (UV coordinates). Coordinate transformations include model transformation, which is a coordinate transformation from the 3D object's local coordinate system to the world coordinate system, view transformation, which is a coordinate transformation from the world coordinate system to the view coordinate system, and projection transformation, which is a coordinate transformation from the view coordinate system to the screen coordinate system. Some of the above coordinate transformations may be performed by the geometry shader GS. The processing results of the vertex shader VS are sent to the geometry shader GS.

[0045] The geometry shader GS processes a set of vertices of a 3D object. The geometry shader GS can convert polygons into points and lines, and convert points or lines into polygons, by increasing or decreasing the number of vertices. The processing results of the geometry shader GS are sent to the rasterizer RRZ. Note that the rendering unit 160 does not necessarily need to be provided with a geometry shader GS. In this case, the processing results of the vertex shader VS are sent to the rasterizer RRZ.

[0046] The rasterizer RRZ performs rasterization processing to generate drawing information for each pixel from the processing results of the vertex pipeline VPL. The processing results of the rasterizer RRZ are sent to the pixel shader PS.

[0047] The pixel shader PS performs lighting processing using the rasterized 3D object, image data, and material parameters to calculate the colors of the front and back polygons corresponding to each pixel. The Disney principle BRDF (Bidirectional Reflectance Distribution Function) can be used as a function to calculate the reflection of light during lighting processing. The processing results of the pixel shader PS are sent to the render backend RBE.

[0048] The render backend RBE determines whether to write pixel data generated by the pixel shader PS to the display area of ​​the memory 101. If the render backend RBE determines to write to the memory 101, the pixel data is saved as a drawing target. If the render backend RBE does not determine to write to the memory 101, the pixel data is not saved as a drawing target. The determination of whether to write is made using, for example, an alpha test, a depth test, or a stencil test. In this embodiment, the pixel data includes color information of front-facing polygons and color information of back-facing polygons. The render backend RBE writes the colors of polygon objects from the farthest side to the camera, for example, using a depth sorting method. After writing the color of the farthest polygon object, when writing the color of the nearer polygon, the render backend RBE combines the color of the farther polygon with the color of the nearer polygon, for example, using alpha blending, depending on the transparency of the nearer polygon. If the transparency is zero, the color of the polygon in the foreground is overwritten by the color of the polygon in the background when the color of the polygon in the foreground is written. This process of writing to the display area is also called the "drawing process." Pipeline processing ends when the pixel data is written to memory 101.

[0049] The post-processing unit PST performs post-processing such as anti-aliasing, ambient occlusion, screen space reflection, and depth of field processing on the rendered image made up of pixel data stored in the memory 101. Post-processing improves the appearance of the rendered image.

[0050] 9, the update receiving unit 165 receives an instruction to update the display of a rendering image that represents a printed matter expressed as a 3D object in a virtual space. Specifically, the update receiving unit 165 receives a change instruction to change the appearance of the 3D object in the rendering image as a preview image displayed on a user interface UI, which will be described later. The update receiving unit 165 outputs the received change instruction to the rendering unit 160.

[0051] The print data generation unit 170 generates print data to be supplied to the printing device 400. The print data generation unit 170 includes a setting unit 171, a plate separation unit 173, and a halftone processing unit 175.

[0052] The setting unit 171 determines whether or not left-right flipping of the image to be printed is necessary depending on the printing conditions. Specifically, when "reverse printing" is selected as the type of printing, the setting unit 171 determines that left-right flipping of the image to be printed is necessary. When "front printing" is selected as the type of printing, the setting unit 171 determines that left-right flipping of the image to be printed is not necessary.

[0053] If left-right reversal processing is required, that is, if reverse printing is specified, the setting unit 171 performs left-right reversal processing of the device color image data IMd obtained by the color conversion processing of the CMS 151. On the other hand, if front printing is specified, reversal processing is not performed.

[0054] The setting unit 171 also determines the order in which the printing layers are stacked. Specifically, depending on the printing conditions, the placement position (placement surface) at which the printing layer is placed on the printing medium and the stacking order in which the multiple printing layers are stacked when there are multiple printing layers are determined. If the base layer is selected as "yes," there will be two printing layers: a color layer and a base layer. If the base layer is selected as "no," there will be one printing layer: a color layer. If "reverse printing" is selected as the printing type, each layer will be placed on the reverse side of the printing medium. If "front printing" is selected as the printing type, each layer will be placed on the front side of the printing medium.

[0055] For example, if "reverse printing" is selected as the type of printing and "yes" as the base layer, it is determined that a color layer and a base layer will be overlaid in this order on the back side of the print medium. Also, if "front printing" is selected as the type of printing and "yes" as the base layer, it is determined that a base layer and a color layer will be overlaid in this order on the front side of the print medium.

[0056] The plate separating unit 173 converts the output value of each pixel of the device color image data IMd, which may or may not have been subjected to left-right flipping, into density values ​​of multiple color materials of the printing device 400. In this embodiment, the plate separating unit 173 converts the CMYK output value of each pixel of the device color image data IMd into density values ​​of each color of process ink. Each plate of CMYKLcLm is generated by the processing of the plate separating unit 173. Note that when printing is performed on both sides of the printing medium PM, the plate separating unit 173 generates each plate of CMYKLcLm for each of the front and back surfaces of the printing medium PM.

[0057] The halftone processing unit 175 generates print data by performing halftone processing using the density values ​​of each pixel after color separation. The printing device 400 receives the print data sent from the halftone processing unit 175 and executes printing based on the printing conditions included in the received print data. Note that when printing is performed on both sides of the print medium PM, the halftone processing unit 175 generates print data for both the front and back sides of the print medium PM.

[0058] 13 is a flowchart showing a printing process executed in the image processing device 100. The process in FIG. 13 starts when an operation instruction is received via the input device 200 from the user, for example.

[0059] In step S10, input image data IMi and printing conditions are acquired. Specifically, first, a user interface UI is displayed on the display device 300. Then, image data (input image data IMi) specified by a user through input via the user interface UI is acquired. Then, information indicating the printing conditions input by the user through the user interface UI is acquired. The processing of step S10 is executed by the processor 103 functioning as the image data acquisition unit 110 and the printing condition acquisition unit 130.

[0060] 14 is an explanatory diagram showing an example of a user interface UI for inputting image data. The user interface UI is displayed on the display device 300 under the control of the processor 103. Here, an example will be described in which an acrylic plate is used as the printing medium PM.

[0061] The user interface UI has a display area FM that displays the type of printing medium PM, a button BT1 for adding a printing layer to be overlaid on the front surface of the printing medium PM, a button BT2 for adding a printing layer to be overlaid on the back surface of the printing medium PM, a display area FV1 that displays an image selected by the user, a display area FV2 that displays a preview image, and a print button BTP that instructs the start of printing.

[0062] When the user taps button BT1, input form IF1 is displayed. Input form IF1 is used to add a printing layer to be placed on the surface of the acrylic plate used as the printing medium PM. In input form IF1, a color layer and a base layer can be selected. The user can add the desired printing layer by tapping button BT3.

[0063] When the user taps button BT2, input form IF2 is displayed. Input form IF2 is used to add a printing layer to be placed on the back side of the acrylic plate as the printing medium PM. In input form IF2, a color layer and a base layer can be selected. The user can add the desired printing layer by tapping button BT3.

[0064] As shown in FIG. 13, in step S20, preprocessing is performed by each unit of the preprocessing unit 150. The contents of the preprocessing are as shown in FIG. 11. As a result of the preprocessing, device color image data IMd, spot color image data IMt, rendering image data IMm, rendering spot color image data IMmt, and rendering medium color Clp are generated. The device color image data IMd and spot color image data IMt are sent to the print data generation unit 170. The rendering image data IMm, rendering spot color image data IMmt, and rendering medium color Clp are sent to the rendering unit 160. Note that if a base layer has not been added in the user interface UI, spot color image data IMt and rendering spot color image data IMmt are not generated.

[0065] In step S30, the rendering image generated by the rendering unit 160 is displayed as a preview image on the display device 300. The processing of the rendering unit 160 is as shown in FIG.

[0066] In step S40, print data is generated by the print data generation unit 170. If reverse printing is specified, the setting unit 171 performs left-right flipping of the image. Here, if the device color image data IMd and the spot color image data IMt are supplied from the preprocessing unit 150, the setting unit 171 performs left-right flipping of each of the device color image data IMd and the spot color image data IMt. If only the device color image data IMd is supplied from the preprocessing unit 150, the setting unit 171 performs left-right flipping of the device color image data IMd. In the case of reverse printing and if it is specified that multiple print layers are to be superimposed, the setting unit 171 changes the layering order. In the case of front printing, a base layer and a color layer are layered in this order on the front surface of the print medium. In the case of reverse printing, a color layer and a base layer are layered in this order on the back surface of the print medium.

[0067] The plate separating unit 173 creates each of the CMYKLcLm plates, and spot color plates if necessary. The halftone processing unit 175 performs halftone processing to generate print data. In step S50, the print data is sent to the printing device 400. The above is a series of processes related to printing executed in the image processing device 100.

[0068] In this embodiment, the image processing device 100 displays a rendering image as a preview image. FIG. 15 is an explanatory diagram that shows a schematic view of the front side of a printed matter represented as a 3D object in a virtual space. FIG. 16 is an explanatory diagram that shows a schematic view of the back side of a printed matter represented as a 3D object in a virtual space. Here, as shown in FIG. 2, an example of a printed matter printed on the front side of a printing medium PM by front printing is shown. The printed matter is represented as a 3D object OBJ (3-dimensional object). The 3D object OBJ includes a polygon object POa for rendering the printing medium PM and a polygon object POb for rendering the printing layer.

[0069] Two polygon objects POa and POb are arranged parallel to each other. The normal vector Np of polygon object POa faces the surface of 3D object OBJ. 3D object OBJ is illuminated by light source LS. In FIGS. 15 and 16, the line of sight of camera CM is indicated by a dashed arrow. In rendering processing, 3D object OBJ is treated as a transparent object. For convenience, the distance between the two polygon objects POa and POb is depicted as large in FIGS. 15 and 16. However, in reality, the distance between polygon objects POa and POb in virtual space is very short so that Z-fighting does not occur. Furthermore, in virtual space, the thickness of polygon object POa representing printing medium PM reflects the thickness of printing medium PM, while the thickness of polygon object POb representing the printing layer is almost zero.

[0070] 15 and 16 depict, as coordinate systems used in the rendering process, a local coordinate system Σm (also called a model coordinate system), which is a three-dimensional Cartesian coordinate system of the 3D object OBJ, a world coordinate system Σg (also called a global coordinate system), which is a three-dimensional Cartesian coordinate system of the virtual space, and a view coordinate system Σc (also called a camera coordinate system), which is a three-dimensional Cartesian coordinate system of the camera CM placed in the virtual space. Other coordinate systems, such as a screen coordinate system, which is the coordinate system of the screen onto which the scene viewed from the camera CM is projected, are also used in the rendering process, but are omitted from FIGS. 15 and 16.

[0071] As shown in FIG. 15, when the front side of the 3D object OBJ faces the line of sight of the camera CM, a front side view of the front side of the 3D object OBJ observed through the camera CM is generated as a rendering image.

[0072] As shown in FIG. 16, when the line of sight of the camera CM is directed toward the back side of the 3D object OBJ, a back side view of the back side of the 3D object OBJ observed through the camera CM is generated as a rendering image.

[0073] The polygon objects POa and POb may each be composed of a single polygon. Alternatively, the polygon objects POa and POb may each be composed of multiple small polygons. If the polygon objects are composed of multiple polygons, it is possible to easily generate rendering images of not only flat printed matter but also curved printed matter.

[0074] FIG. 17 is an explanatory diagram of the user interface UI displaying a preview image. FIG. 17 shows the user interface UI after the user selects image data and adds a color layer and a base layer. In the illustrated example, the image represented by the selected image data is displayed in the display area FV1. The color layer and base layer have also been added to the surface of an acrylic plate serving as the printing medium PM.

[0075] The user interface UI displays a button BT4 for deleting each color layer added by the user. The user can delete an added color layer or base layer by tapping the button BT4.

[0076] A preview image is displayed in the display area FV2. A rendering image showing one or more virtual 3D objects corresponding to one or more printing layers and a virtual 3D object corresponding to the printing medium superimposed in a specified stacking order is displayed in the display area FV2 as a preview image. In this embodiment, the preview image displayed in the display area FV2 is the image of the printed matter viewed from a predetermined position in a predetermined line of sight.

[0077] In response to a user's instruction, the image processing device 100 of this embodiment can display a preview image on the display device 300, in which 3D objects corresponding to the elements constituting the printed material are separated. As described above, the display device 300 has a function as a pointing device. The user can instruct the display of the preview image to be switched by performing a touch operation on the image displayed on the display device 300. An instruction to switch the display of the preview image is also referred to as an "instruction regarding the display mode."

[0078] FIG. 18 is a flowchart showing the display switching process of a preview image. FIG. 19 is an explanatory diagram showing a user interface UI. The process shown in FIG. 18 is executed by the processor 103 functioning as the preprocessing unit 150, the rendering unit 160, and the update receiving unit 165. In step S501, it is determined whether or not a touch operation instructing display switching has been performed. The touch operation instructing display switching refers to the operation of touching button BT6 when the user interface UI shown in FIG. 17 is displayed. The touch operation refers to the operation of touching button BT7 when the user interface UI shown in FIG. 19 is displayed. Details of FIG. 19 will be described later.

[0079] In step S502 shown in FIG. 18, it is determined whether the preview image displayed on the user interface UI represents a state in which the layers are combined. A combined state refers to a state in which the 3D object corresponding to the print medium and the 3D objects corresponding to each print layer are combined. The preview image shown in FIG. 17 represents a state in which the layers are combined. If it is determined that the layers are combined (step S502; YES), it is determined in step S503 that each layer is to be expanded. When the preview image shown in FIG. 17 is displayed, the user taps button BT6 located at the top of display area FV2 to instruct the expansion of each layer constituting the virtual printed material displayed in display area FV2. Button BT6 is used by the user to instruct the expansion of the 3D object representing the printed material.

[0080] As shown in FIG. 18, if it is determined in step S502 that the layers are not combined, i.e., that the layers are in an expanded state (step S502; NO), it is determined in step S504 that the layers are to be combined. The expanded state refers to a state in which the 3D object corresponding to the print medium and the 3D objects corresponding to each print layer are stacked in stacking order with a gap between them. The preview image shown in FIG. 19 shows the state in which the layers are expanded. When the preview image shown in FIG. 19 is displayed, the user taps button BT7 located at the top of display area FV2 to instruct the user to combine the layers that make up the virtual printed material displayed in display area FV2. Button BT7 is used by the user to instruct the user to combine the 3D objects representing the layers.

[0081] In step S505, the rendering process is executed again. If it is determined in step S503 that each layer is to be developed, in step S505, the positions of the 3D objects corresponding to the print medium and the 3D objects corresponding to each print layer are changed so that the mutual intervals between the 3D objects are determined to be a predetermined distance. As a result, a rendering image is generated that represents the state in which the 3D object corresponding to the print medium and the 3D objects corresponding to each print layer are stacked in stacking order with a mutual interval between them. The generated rendering image represents the developed state of the print medium and each print layer.

[0082] If it is determined in step S504 that the layers are to be combined, in step S505, the positions of the 3D objects corresponding to the printing medium and the 3D objects corresponding to the printing layers are changed so that the distance between them is zero or close to zero. As a result, a rendering image is generated that represents the state in which the 3D object corresponding to the printing medium and the 3D objects corresponding to the printing layers are stacked in stacking order and combined with each other.

[0083] In step S506, the newly generated rendering image is displayed as a preview image in the display area FV2 of the user interface UI. If it is determined in step S503 that each layer is to be expanded, a preview image such as that shown in Fig. 19 is displayed in the display area FV2. If it is determined in step S504 that each layer is to be combined, a preview image such as that shown in Fig. 17 is displayed in the display area FV2.

[0084] In step S507, it is determined whether or not to end the process. For example, if the print button BTP is pressed on the user interface UI, it is determined that the process should be ended. If it is determined that the process should be ended (step S507; YES), the process shown in FIG. 18 is ended. If it is determined that the process should be continued (step S507; NO), the process of step S501 is executed again. The processes of steps S501 to S507 are repeatedly executed until the print button BTP is pressed.

[0085] As described above, in this embodiment, the preview image of the developed printed matter shows the print medium and 3D objects representing each print layer stacked at intervals. Therefore, when multiple print layers are formed, the user can easily understand each print layer. Furthermore, the user can easily understand the effect of overlapping print layers. For example, the user can check how a color layer appears when a base layer is overlapped and how a color layer appears when the base layer is not overlapped, without having to configure settings to add or remove print layers.

[0086] Furthermore, by switching between the preview image showing the combined print and the preview image showing the unfolded print according to the user's instructions, the user can check each printed layer in detail or the entire print, making it easy to check the finished state of the print before printing.

[0087] B. Other Embodiments: B1. Alternative Embodiment 1: The user may be able to adjust the spacing between the unfolded printed materials as desired. Fig. 20 is an explanatory diagram showing an example of a display mode of a preview image according to Alternative Embodiment 1. In the illustrated example, only the display area FV2 of the user interface UI is shown.

[0088] When the developed printed material is displayed, a slider bar SB1 is displayed in the display area FV2 along with the preview image. The slider bar SB1 is used by the user to instruct adjustment of the spacing between layers. The user can instruct to increase the spacing between layers by moving the knob KN1 upward. The user can also instruct to decrease the spacing between layers by moving the knob KN1 downward. In response to an instruction to operate the knob KN1, the image processing device 100 executes the rendering process again and updates the display of the preview image. At this time, the spacing between layers is adjusted according to the position of the knob KN1. This allows the user to check any printed layer in detail. By adjusting the spacing between layers, the user can easily check each layer and the layer overlap effect.

[0089] Furthermore, when the knob KN1 is moved to the bottom, the image processing device 100 may display a preview image of the printed matter in the combined state.

[0090] Although FIG. 20 shows an example in which the layers are spaced equally apart, the layers may be spaced unequal. FIG. 21 is an explanatory diagram showing another example of the display mode of a preview image according to another embodiment 1. For example, if the user drags only a desired layer, the position of only that layer may be changed. In response to this operation instruction, the image processing device 100 executes the rendering process again and updates the display of the preview image. FIG. 21 shows an example in which the position of the base layer is changed by the user dragging the base layer. The user can change the position of the desired layer and check any printed layer in detail.

[0091] B2. Alternative Embodiment 2: FIG. 22 is an explanatory diagram of the operation of the user interface UI according to another embodiment 2. As shown in the upper part of FIG. 22, the user can highlight and display the desired printing layer in the preview image by tapping the desired printing layer in the user interface UI. In response to the above operation instruction, the image processing device 100 executes the rendering process again and updates the display of the preview image. The instruction by tapping the printing layer to highlight and display the desired printing layer is also called a "highlighting instruction." The lower part of FIG. 22 shows the user interface UI in which the selected base layer is highlighted. When multiple printing layers are overlaid, the user can easily identify the printing layer of interest.

[0092] In addition, the user can return the highlighted print layer to its normal display (unhighlighted display) by tapping the selected print layer again in the user interface UI. In response to the above operation instruction, the image processing device 100 executes the rendering process again and updates the display of the preview image.

[0093] B3. Alternative Embodiment 3: FIG. 23 is an explanatory diagram of the operation of the user interface UI according to another embodiment 3. In the illustrated example, the user interface UI displays a display switching icon IC1 or icon IC2 corresponding to each layer. As shown in the upper part of FIG. 23 , the user can hide the desired printing layer in the preview image by tapping the display switching icon IC1 for the desired printing layer in the user interface UI. In response to the above operation instruction, the image processing device 100 executes the rendering process again and updates the display of the preview image. The instruction given by tapping the display switching icon IC1 is also referred to as a “hide instruction.” The lower part of FIG. 23 shows the user interface UI in which the selected color layer is not displayed. Furthermore, an icon IC2 indicating that the color layer is hidden is displayed. Since the desired printing layer can be hidden, for example, the user can easily check other printing layers arranged below the hidden printing layer.

[0094] In addition, the user can display the selected print layer again by tapping the icon IC2 for switching the display of the selected print layer in the user interface UI. In response to the above operation instruction, the image processing device 100 executes the rendering process again and updates the display of the preview image.

[0095] Furthermore, the user can perform a pinch-out operation on a 3D object representing a desired print layer in the user interface UI to enlarge and display the 3D object in the preview image. In response to the above operation instruction, the image processing device 100 executes the rendering process again and updates the display of the preview image. In addition, the user can perform a pinch-in operation on a 3D object representing a desired print layer in the user interface UI to reduce and display the 3D object in the preview image. An instruction via a pinch-out operation is also referred to as an "instruction regarding enlargement display." An instruction via a pinch-in operation is also referred to as an "instruction regarding reduction display." In response to the above operation instruction, the image processing device 100 executes the rendering process again and updates the display of the preview image. By enlarging and displaying some print layers, the user can check the desired print layer in detail.

[0096] B4. Alternative Embodiment 4: FIG. 24 is an explanatory diagram of the operation of the user interface UI according to the fourth alternative embodiment. An auxiliary line L1 may be displayed in the preview image displayed in the display area FV2 of the user interface UI. In the illustrated example, a straight line passing through part of the outline of the color layer and perpendicular to the color layer is displayed as the auxiliary line L1. Note that in the preview image, the 3D object representing the color layer and the 3D object representing the base layer are parallel. It is desirable to display two or more auxiliary lines L1. To prevent the base layer from overflowing due to misalignment or bleeding during printing, the range of the base layer may be narrower than the range of the color layer. Displaying two or more auxiliary lines L1 in the preview image allows the user to easily check the degree of overlap between the color layer and the base layer. The color layer is also referred to as the "first printed layer." The base layer is also referred to as the "second printed layer." The image formed by the color layer is also referred to as the "first image." The base formed by the base layer is also referred to as the "second image."

[0097] C. Other forms: The present disclosure is not limited to the above-described embodiments and can be realized in various configurations without departing from the spirit thereof. For example, the technical features in the embodiments corresponding to the technical features in each aspect described in the Summary of the Invention section can be appropriately replaced or combined to solve some or all of the above-described problems or achieve some or all of the above-described effects. Furthermore, if a technical feature is not described as essential in this specification, it can be deleted as appropriate.

[0098] (1) According to a first aspect of the present disclosure, there is provided an image processing method including: (a) receiving one or more print layers to be stacked on a print medium by printing on the print medium and a stacking order of the print medium; (b) displaying, on a display device, a preview image representing one or more virtual three-dimensional objects corresponding to the one or more print layers and the three-dimensional objects corresponding to the print medium stacked and combined in the stacking order, the preview image corresponding to how they will appear in a three-dimensional virtual space; (c) displaying, on the display device, the preview image representing a state in which the one or more three-dimensional objects corresponding to the one or more print layers and the three-dimensional objects corresponding to the print medium are stacked with a gap between them in the stacking order, the preview image corresponding to how they will appear in the virtual space; and (d) receiving an instruction to execute either step (b) or step (c), and executing the instructed step of step (b) or step (c). According to the above embodiment, a preview image of the printed matter is displayed in a state in which the print medium and three-dimensional objects representing each print layer are stacked at intervals. Therefore, when multiple print layers are formed, the user can easily understand each print layer. (2) The image processing method of the above aspect may further include a step of: (e) when a change instruction to change the spacing is received while the preview image is being displayed by executing step (c), displaying on the display device the preview image representing the state in which the spacing between one or more of the three-dimensional objects corresponding to the one or more printing layers and the three-dimensional object corresponding to the printing medium has been changed in accordance with the change instruction. According to the above aspect, when a plurality of printed layers are superimposed, the user can check any printed layer in detail. (3) In the image processing method of the above aspect, when the preview image is displayed by executing step (c), upon receiving a highlighting instruction to highlight a selected printing layer, the preview image in which the three-dimensional object corresponding to the selected printing layer is highlighted may be displayed on the display device. According to the above aspect, when a plurality of printed layers are superimposed, the user can easily recognize the printed layer of interest. (4) In the image processing method of the above form, (g) when the one or more printing layers include a first printing layer and a second printing layer overlaid on the first printing layer, and the first image formed by the first printing layer encompasses the second image formed by the second printing layer, the method may further include a step of projecting at least a portion of the contour of the first image onto the second printing layer by displaying an auxiliary line that is a straight line passing through at least a portion of the contour of the first image and is perpendicular to the first printing layer within at least a portion of the range. (5) In the image processing method of the above aspect, (h) when the preview image is displayed by executing step (c), upon receiving a hide instruction to hide the selected printing layer, the preview image in which the three-dimensional object corresponding to the selected printing layer is hidden may be displayed on the display device. According to the above embodiment, when multiple printed layers are stacked, by hiding some of the printed layers, it becomes easier to check, for example, other printed layers that are placed below the hidden printed layers. (6) In the image processing method of the above aspect, (i) when the preview image is displayed by executing step (c), upon receiving an instruction regarding an enlarged or reduced display of a selected printing layer, the preview image in which the three-dimensional object corresponding to the selected printing layer is enlarged or reduced may be displayed on the display device. According to the above aspect, by enlarging and displaying some of the printed layers, the user can check the desired printed layer in detail. (7) According to a second aspect of the present disclosure, there is provided an image processing device. The image processing device includes: a print setting receiving unit that receives one or more print layers to be stacked on a print medium by printing on the print medium and a stacking order of the print medium; and a display processing unit that displays, on a display device, a preview image representing one or more virtual three-dimensional objects representing a printed matter, the preview image corresponding to how the objects will appear in a three-dimensional virtual space. In response to the received instruction regarding the display mode, the display processing unit displays, on the display device, the preview image representing a state in which one or more of the three-dimensional objects corresponding to the one or more print layers and the three-dimensional objects corresponding to the print medium are stacked and combined in the stacking order, the preview image corresponding to how the objects will appear in the virtual space; or displays, on the display device, the preview image representing a state in which one or more of the three-dimensional objects corresponding to the one or more print layers and the three-dimensional objects corresponding to the print medium are stacked with a gap between them in the stacking order, the preview image corresponding to how the objects will appear in the virtual space. According to the above embodiment, a preview image of the printed matter is displayed in a state in which the print medium and three-dimensional objects representing each print layer are stacked at intervals. Therefore, when multiple print layers are formed, the user can easily understand each print layer. (8) According to a third aspect of the present disclosure, a printing system is provided. The printing system includes an image processing device, a printing device, and a display device. The image processing device includes a print setting receiving unit that receives one or more printing layers to be stacked on a printing medium by printing on the printing medium and a stacking order of the printing medium, and a display processing unit that displays, on the display device, a preview image representing one or more virtual three-dimensional objects representing a printed matter, the preview image corresponding to how the objects will appear in a three-dimensional virtual space. In response to the received instruction regarding the display mode, the display processing unit displays, on the display device, the preview image representing a state in which one or more of the three-dimensional objects corresponding to the one or more printing layers and the three-dimensional objects corresponding to the printing medium are stacked and combined in the stacking order, the preview image corresponding to how the objects will appear in the virtual space; or displays, on the display device, the preview image representing a state in which one or more of the three-dimensional objects corresponding to the one or more printing layers and the three-dimensional objects corresponding to the printing medium are stacked with a gap between them in the stacking order, the preview image corresponding to how the objects will appear in the virtual space. According to the above embodiment, a preview image of the printed matter is displayed in a state in which the print medium and three-dimensional objects representing each print layer are stacked at intervals. Therefore, when multiple print layers are formed, the user can easily understand each print layer. (9) According to a fourth aspect of the present disclosure, there is provided an image processing program that causes a computer to realize: (a) a function for receiving one or more print layers to be stacked on a print medium by printing on the print medium and a stacking order of the print medium; (b) a function for displaying, on a display device, a preview image representing one or more virtual three-dimensional objects corresponding to the one or more print layers and the three-dimensional objects corresponding to the print medium stacked and combined in the stacking order, the preview image corresponding to how they would appear in a three-dimensional virtual space; (c) a function for displaying, on the display device, a preview image representing a state in which the one or more three-dimensional objects corresponding to the one or more print layers and the three-dimensional objects corresponding to the print medium are stacked with a gap between them in the stacking order, the preview image corresponding to how they would appear in the virtual space; and (d) a function for receiving an instruction to execute either function (b) or function (c) and executing the instructed step of function (b) or function (c). According to the above embodiment, a preview image of the printed matter is displayed in a state in which the print medium and three-dimensional objects representing each print layer are stacked at intervals. Therefore, when multiple print layers are formed, the user can easily understand each print layer. [Explanation of symbols]

[0099] IC1, IC2...icon, 10...printing system, 100...image processing device, 101...memory, 102...input / output interface, 103...processor, 104...internal bus, 110...image data acquisition unit, 120...profile acquisition unit, 130...printing condition acquisition unit, 140...parameter acquisition unit, 150...preprocessing unit, 151...color management system, 152...spot color setting unit, 153...medium color calculation unit, 160...rendering unit, 165...update reception unit, 170...print data generation unit, 171...setting unit, 173...plate separation unit, 175...half Tone processing unit, 200...input device, 300...display device, 400...printing device, BT1...button, BT2...button, BT3...button, BT4...button, BT6...button, BT7...button, BTP...print button, CC1...first color conversion, CC2...second color conversion, CC3...third color conversion, CC4...fourth color conversion, CL, CL1, CL2...color layers, CM...camera, CMYK...output value, CPF...common color space profile, Clp...rendering medium color, Clx...XYZ value, EL...organic, FM...display area, FV1...display area, FV2...display area, GS... Geometry shader, IF1...input form, IF2...input form, IMd...device color image data, IMi...input image data, IMm...image data for rendering, IMmt...spot color image data for rendering, IMt...spot color image data, IPF...input profile, L1...auxiliary line, LS...light source, MPF...media profile, Np...normal vector, OBJ...3D object, PG...program, PM...printing medium, POa...polygon object, POb...polygon object, PPL...pixel pipeline, P S...pixel shader, PST...post-processing unit, PT...printing medium, PT1~PT7...printed material, RBE...render backend, RG,RG1,RG2...backside image, RRZ...rasterizer, RWG,RWG1,RWG2...base area, SB1...slider bar, SG...front image, SG1...front image, SG2...front image, SWG1...base area, UI...user interface, VPL...vertex pipeline, VS...vertex shader, WL,WL1,WL2...base layer, Σc...view coordinate system, Σg...world coordinate system, Σm...local coordinate system

Claims

1. 1. An image processing method, comprising: (a) receiving one or more printing layers to be printed on a print medium and a stacking order of the print medium; (b) displaying on a display device a preview image representing a state in which one or more virtual three-dimensional objects corresponding to the one or more printing layers and the three-dimensional object corresponding to the printing medium are stacked and combined in the stacking order, the preview image corresponding to how they will appear in a three-dimensional virtual space; (c) displaying on the display device a preview image representing a state in which the one or more three-dimensional objects corresponding to the one or more printing layers and the three-dimensional object corresponding to the printing medium are stacked in the stacking order with a gap between them, the preview image corresponding to how they will appear in the virtual space; (d) receiving an instruction to execute either the step (b) or the step (c), and executing the instructed step of the step (b) or the step (c); An image processing method comprising:

2. 2. The image processing method according to claim 1, (e) when the preview image is displayed by executing the step (c), when receiving a change instruction to change the spacing, displaying on the display device the preview image that represents a state in which the spacing between the one or more three-dimensional objects corresponding to the one or more print layers and the three-dimensional object corresponding to the print medium has been changed in accordance with the change instruction; further comprising: Image processing methods.

3. 2. The image processing method according to claim 1, (f) when the preview image is displayed by executing the step (c), a step of displaying, upon receiving a highlighting instruction for instructing highlighting of a selected printing layer, the preview image in which the three-dimensional object corresponding to the selected printing layer is displayed in a highlighted manner on the display device; further comprising: Image processing methods.

4. 2. The image processing method according to claim 1, (g) When the one or more printing layers include a first printing layer and a second printing layer superimposed on the first printing layer, and a first image formed by the first printing layer encompasses a second image formed by the second printing layer, a step of projecting at least a portion of the contour of the first image onto the second printing layer by displaying an auxiliary line that is a straight line passing through at least a portion of the contour of the first image and is perpendicular to the first printing layer within the range of at least the portion; further comprising: Image processing methods.

5. 2. The image processing method according to claim 1, (h) when the preview image is displayed by executing the step (c), a step of displaying, on the display device, the preview image in which the three-dimensional object corresponding to the selected printing layer is not displayed, when a non-display instruction for instructing not to display the selected printing layer is received; further comprising: Image processing methods.

6. 6. The image processing method according to claim 1, further comprising: (i) when the preview image is displayed by executing the step (c), and further comprising a step of displaying, on the display device, the preview image in which the three-dimensional object corresponding to the selected printing layer is displayed in an enlarged or reduced form when an instruction regarding enlarged or reduced display of the selected printing layer is received. Image processing methods.

7. An image processing device, a print setting receiving unit that receives one or more print layers to be laminated on the print medium by printing on the print medium and a lamination order of the print medium; a display processing unit that displays, on a display device, a preview image representing one or more virtual three-dimensional objects representing the printed matter, the preview image corresponding to how the objects would appear in the three-dimensional virtual space; Equipped with The display processing unit In response to the received instructions regarding the display mode, displaying, on the display device, a preview image representing a state in which the one or more three-dimensional objects corresponding to the one or more printing layers and the three-dimensional object corresponding to the printing medium are stacked and combined in the stacking order, the preview image corresponding to how they will appear in the virtual space; or a preview image representing a state in which the one or more three-dimensional objects corresponding to the one or more printing layers and the three-dimensional object corresponding to the printing medium are stacked in the stacking order with a gap between them, the preview image corresponding to how they will appear in the virtual space being displayed on the display device; Image processing device.

8. 1. A printing system comprising: An image processing device, a printing device, and a display device, Equipped with The image processing device includes: a print setting receiving unit that receives one or more print layers to be laminated on the print medium by printing on the print medium and a lamination order of the print medium; a display processing unit that displays, on the display device, a preview image representing one or more virtual three-dimensional objects representing the printed matter, the preview image corresponding to how the objects would appear in a three-dimensional virtual space; Equipped with The display processing unit In response to the received instructions regarding the display mode, displaying, on the display device, a preview image representing a state in which the one or more three-dimensional objects corresponding to the one or more printing layers and the three-dimensional object corresponding to the printing medium are stacked and combined in the stacking order, the preview image corresponding to how they will appear in the virtual space; or a preview image representing a state in which the one or more three-dimensional objects corresponding to the one or more printing layers and the three-dimensional object corresponding to the printing medium are stacked in the stacking order with a gap between them, the preview image corresponding to how they will appear in the virtual space being displayed on the display device; Printing system.

9. An image processing program, (a) receiving one or more printing layers to be printed on a print medium and a stacking order of the print medium; (b) a function of displaying, on a display device, a preview image representing a state in which one or more virtual three-dimensional objects corresponding to the one or more printing layers and the three-dimensional object corresponding to the printing medium are stacked and combined in the stacking order, the preview image corresponding to how they will appear in a three-dimensional virtual space; and (c) a function of displaying, on the display device, a preview image representing a state in which the one or more three-dimensional objects corresponding to the one or more printing layers and the three-dimensional object corresponding to the printing medium are stacked in the stacking order with a gap between them, the preview image corresponding to how they will appear in the virtual space; and (d) a function of receiving an instruction to execute either the function (b) or the function (c) and executing the instructed step of the function (b) or the function (c); An image processing program to make it happen on a computer.

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