Methods for creating print previews, print preview creation devices, and computer programs

Abstract

This invention provides a technology for providing a print preview of printed materials that use a translucent fabric as a printing medium, where the transparency changes within the surface due to the fineness of the threads or the coarseness of the weave. [Solution] The disclosed method includes (a) a step of acquiring an image color channel representing an image; (b) a step of acquiring media texture information including a media color channel representing the unevenness of the printing medium and a media alpha channel indicating the transparency of the printing medium; (c) a step of calculating albedo representing the reflectivity of the printed material using the image color channel and the media alpha channel; (d) a step of creating printed material color data representing the color of the printed material using the albedo and the media color channel; and (e) a step of creating a print preview by compositing a background onto the printed material color data using the media alpha channel without using the image alpha channel.

Description

Technical Field

[0001] The present disclosure relates to a method for creating a print preview, a print preview creation device, and a computer program.

Background Art

[0002] Patent Document 1 discloses a technique for realistically representing an object whose transparency changes depending on the positional relationship with a viewpoint.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the prior art, there has been a problem that a print preview cannot be provided for a printed matter using a see-through fabric whose transparency changes in-plane due to the fineness of the thread and the coarseness of the weave as a printing medium.

Means for Solving the Problems

[0005] A first embodiment of the present disclosure provides a method for creating a print preview of a printed material having an image printed on a print medium that is a translucent fabric. The method includes: (a) acquiring an image color channel representing the image; (b) acquiring media texture information including a media color channel representing the unevenness of the print medium and a media alpha channel indicating the transparency of the print medium; (c) calculating an albedo representing the reflectivity of the printed material using the image color channel and the media alpha channel; (d) creating printed material color data representing the color of the printed material using the albedo and the media color channel; and (e) creating the print preview by compositing a background onto the printed material color data using the media alpha channel without using the image alpha channel.

[0006] A second embodiment of the present disclosure provides a print preview creation device for creating a print preview of a printed material having an image printed on a print medium that is a translucent fabric. The print preview creation device comprises a memory and a processor. The processor is configured to perform the following: (a) a process of acquiring an image color channel representing the image and storing it in the memory; (b) a process of acquiring media texture information including a media color channel representing the unevenness of the print medium and a media alpha channel indicating the transparency of the print medium and storing it in the memory; (c) a process of calculating the albedo representing the reflectivity of the printed material using the image color channel and the media alpha channel; (d) a process of creating printed material color data representing the color of the printed material using the albedo and the media color channel; and (e) a process of creating the print preview by compositing a background onto the printed material color data using the media alpha channel without using the alpha channel of the image.

[0007] A third embodiment of the present disclosure provides a computer program for creating a print preview of a printed material having an image printed on a print medium that is a translucent fabric. The computer program causes the computer to perform the following steps: (a) a process of acquiring an image color channel representing the image; (b) a process of acquiring media texture information including a media color channel representing the unevenness of the print medium and a media alpha channel indicating the transparency of the print medium; (c) a process of calculating the albedo representing the reflectivity of the printed material using the image color channel and the media alpha channel; (d) a process of creating printed material color data representing the color of the printed material using the albedo and the media color channel; and (e) a process of creating the print preview by compositing a background onto the printed material color data using the media alpha channel without using the image alpha channel. [Brief explanation of the drawing]

[0008] [Figure 1] An explanatory diagram showing an example of printed material printed on a translucent fabric. [Figure 2] An explanatory diagram showing the process of creating a print preview. [Figure 3] An explanatory diagram showing an example of how pixels are handled according to the values ​​of the image's color channel and alpha channel. [Figure 4] A schematic diagram illustrating how printed materials are viewed in a virtual space. [Figure 5] A diagram illustrating the configuration of the printing system. [Figure 6] An explanatory diagram showing the configuration of an image processing device. [Figure 7] An explanatory diagram showing the configuration of the rendering unit. [Figure 8] A flowchart illustrating the rendering process. [Modes for carrying out the invention]

[0009] Figure 1 is an explanatory diagram showing the processing details of the embodiment. In this embodiment, a print preview of a printed material PT is created by printing an image IM on a transparent fabric printing medium PM. A typical image IM is a color image.

[0010] "Transparent fabric" refers to a fabric that is somewhat see-through. Examples of transparent fabrics include chiffon, tulle, organza, georgette, lace, mesh, lawn, and gauze. These transparent fabrics have the characteristic that their transparency changes within a surface due to the fineness of the threads and the coarseness of the weave. Printed materials (PT) on transparent fabrics are also called "transparent printed fabrics." Transparent printed fabrics are, for example, printed materials on transparent fabrics using a textile printing machine.

[0011] Figure 2 is an explanatory diagram illustrating the process of creating a print preview. In this embodiment, the following resources are primarily used. (1) 3D object OBJ (3-Dimensional Object) A 3D object (OBJ) is a polygon object used to render print materials (PT) and create a print preview (previewColor) as a 3D preview (3-Dimensional Preview). However, it is also possible to create a print preview (previewColor) as a 2D preview (2-Dimensional Preview) without using a 3D object (OBJ). This will be explained later. (2) Main Texture Information mainTI The main texture information, mainTI, includes an image color channel, mainTex_rgb, which represents the color of each pixel of the image IM, and an image alpha channel, mainTex_a, which indicates the transparency of each pixel of the image IM. (3) Media texture information meditTI The media texture information mediaTI includes a media color channel mediaTex_rgb representing the pixel-level topography of the print medium PM, a media alpha channel mediaTex_a indicating the transparency of each pixel, and the base color baseColor of the print medium PM. The media color channel mediaTex_rgb represents the topography of the print medium PM and is an RGB image in image format, but the RGB values ​​do not represent colors, but rather the normal direction of the topography. (4) Background backGround The background (backGround) is the background image used when creating the print preview (previewColor).

[0012] Preferably, the size of the image area of ​​the media texture information meditTI is the same as the size of the image area of ​​the main texture information mainTI. However, it is also possible that the image area of ​​the media texture information meditTI is smaller than the image area of ​​the main texture information mainTI. In this case, it is preferable to place the media texture information meditTI in an area that encompasses the image area of ​​the main texture information mainTI by arranging multiple identical media texture information meditTI in a tiled pattern without gaps. In this way, the same media texture information meditTI can be applied to a main texture information mainTI of any size without enlarging the image area of ​​the media texture information meditTI.

[0013] The color channels mainTex_rgb and mediaTex_rgb, and the base color baseColor are preferably represented in a rendering color space. For example, sRGB is used as the rendering color space. The value α of the alpha channels mainTex_a and mediaTex_a has a value in the range of 0 to 1. α=1 means completely opaque, and α=0 means completely transparent. Note that the value of α between 0 and 1 is a semantic number and is a real number.

[0014] Pixels with the value (R, G, B) of the image color channel mainTex_rgb being (255, 255, 255) are either white areas where white ink is applied or non-printing areas where no ink is applied. Note that the RGB values are in decimal notation of 8-bit data. Whether it is a white area or a non-printing area is determined according to the base color of the printing medium PM and the value of the image alpha channel mainTex_a.

[0015] Figure 3 is an explanatory diagram showing examples of pixel handling according to the values of the image color channel mainTex_rgb and the image alpha channel mainTex_a. Table 1 in Figure 3 shows the case where the base color of the printing medium PM is other than white, and Table 2 shows the case where the base color of the printing medium PM is white. Table 1 is also applicable when the printing medium PM is transparent.

[0016] When the base color of the printing medium PM is other than white, as shown in cases #11 and #12 of Table 1, pixels with the value of the image color channel mainTex_rgb being (255, 255, 255) are treated as white areas where white ink is applied when 0 < α, and are treated as non-printing areas where no ink is applied when α = 0. By doing so, the case where the image color channel mainTex_rgb represents the application of white ink can be correctly reproduced. Also, as shown in cases #13 and #14, pixels with the value of the image color channel mainTex_rgb not being (255, 255, 255) are treated as color printing areas where ink is applied when 0 < α, and are treated as non-printing areas where no ink is applied when α = 0.

[0017] When the base color of the printing medium PM is white, as shown in cases #21 and #22 of Table 2, pixels with the value of the image color channel mainTex_rgb being (255, 255, 255) are treated as non-printing areas where no ink is applied regardless of the value α of the image alpha channel mainTex_a. Cases #23 and #24 in Table 2 are the same as cases #13 and #14 in Table 1.

[0018] As shown in Figure 2, the print preview previewColor is created by the following processes P1 to P3. <Processing P1> In process P1, the printAlbedo, which represents the reflectivity of the printed material PT, is calculated using the image color channel mainTex_rgb, the image alpha channel mainTex_a, and the media alpha channel mediaTex_a. Since the printAlbedo has the data format of an RGB image, it can also be considered to represent the color of the printed material PT. If the base color baseColor of the printing medium PM is specified, the base color baseColor is also used in the calculation of the printAlbedo. The method for calculating the printAlbedo will be described later.

[0019] <Processing P2> In process P2, the albedo printAlbedo and mediaTex_rgb color channel are used to create print color data printingColor, which represents the color of the printed PT. The method for calculating print color data printingColor will be described later.

[0020] <Processing P3> In process P3, the print preview (previewColor) is created by compositing the background (backGround) with the print color data (printingColor) using the media alpha channel (mediaTex_a). Note that the image alpha channel (mainTex_a) is not used in process P3. The method for calculating the print preview (previewColor) will be described later.

[0021] The print preview previewColor created by these processes P1-P3 reproduces a state in which the print medium PM is not completely obscured by ink even in areas with high density in the image IM, and the print medium PM remains semi-transparent. The reason why the print medium PM is not completely obscured by ink even in areas with high density in the image IM is that the print medium PM is a translucent fabric such as a thin cloth or mesh, and there are gaps where ink does not adhere or areas where ink adheres poorly. As will be explained below, the method of this embodiment makes it possible to create a print preview previewColor that can successfully reproduce the semi-transparent print medium PM even in areas with high density in the image IM for printed materials PT using a translucent fabric as the print medium PM.

[0022] Figure 4 is a schematic diagram illustrating how to observe a printed document (PT) in a virtual space. The printed document (PT) is represented using a 3D object (OBJ). The 3D object (OBJ) may consist of a single polygon or multiple small polygons (micropolygons). By composing the 3D object with multiple micropolygons, it is possible to easily generate not only rendering images of flat printed documents but also rendering images of curved printed documents.

[0023] Figure 4 shows the coordinate systems used in the rendering process: the local coordinate system Σm (also called the model coordinate system), which is the 3D Cartesian coordinate system of the 3D object OBJ; the world coordinate system Σg (also called the global coordinate system), which is the 3D Cartesian coordinate system of the virtual space; and the view coordinate system Σc (also called the camera coordinate system), which is the 3D Cartesian coordinate system of the camera CM placed in the virtual space. Other coordinate systems, such as the 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 in Figure 3. In the rendering process, the image of the 3D object OBJ observed through the camera CM is generated as the rendered image, i.e., the print preview previewColor.

[0024] Figure 5 is an explanatory diagram showing the configuration of a printing system 500 equipped with an image processing device 100 according to an embodiment. The printing system 500 comprises an image processing device 100, an input device 200, a display device 300, and a printing device 400. The image processing device 100 generates a print preview previewColor, which is a rendered image representing a printed document PT placed in a virtual space, by physically based rendering (hereinafter simply referred to as rendering), and displays the print preview previewColor on the display device 300. The print preview previewColor can be displayed before printing the printed document PT.

[0025] The image processing device 100 comprises a processor 101, memory 102, input / output interface 103, and internal bus 104. The processor 101, memory 102, and input / output interface 103 are connected bidirectionally via the internal bus 104. The memory 102 includes volatile memory, such as main memory and video memory, and non-volatile memory, such as a hard disk or SSD (Solid State Drive). The input device 200, display device 300, and printing device 400 are connected to the input / output interface 103 of the image processing device 100 by wired or wireless communication. The input device 200 is, for example, a keyboard or mouse, and the display device 300 is, for example, a liquid crystal display. The input device 200 and the display device 300 may be integrated as a touch panel. The printing device 400 is, for example, an inkjet printer that prints images on a printing medium using multiple types of ink.

[0026] Figure 6 is an explanatory diagram showing the configuration of the image processing device 100. The image processing device 100 includes a resource data acquisition unit 110, a print condition acquisition unit 120, a parameter acquisition unit 130, and a rendering unit 140. The functions of each of these units are realized in software by the processor 101 executing an image processing program PG that is pre-stored in memory 102. However, some of the functions of each unit may be realized by hardware circuits.

[0027] The resource data acquisition unit 110 acquires the main texture information mainTI, media texture information mediaTI, and background background shown in Figure 2. This resource data may be stored in the memory 102 of the image processing device 100, or it may be acquired from an external device via a network. The resource data acquired by the resource data acquisition unit 110 is transmitted to the rendering unit 140.

[0028] The print condition acquisition unit 120 acquires print conditions, including the image IM to be used for printing and the type and size of the printing medium PM. Preferably, the print conditions also include other conditions such as the base color of the printing medium PM and the printing resolution. The print conditions acquired by the print condition acquisition unit 120 are transmitted to the resource data acquisition unit 110 and the parameter acquisition unit 130. The resource data acquisition unit 110 and the parameter acquisition unit 130 acquire resource data and parameters according to the print conditions, respectively.

[0029] The parameter acquisition unit 130 acquires various parameters used for rendering. These parameters include, for example, 3D object information, camera information, and lighting information. 3D object information refers to parameters related to 3D objects (OBJ) placed in the virtual space. Camera information refers to parameters related to the position and orientation of cameras (CM) placed in the virtual space. Lighting information refers to parameters related to the type, position, orientation, color, and luminous intensity (light quantity) of light sources (LS) placed in the virtual space. Examples of light source types (LS) include fluorescent lamps and incandescent light bulbs. The parameters acquired by the parameter acquisition unit 130 are transmitted to the rendering unit 140.

[0030] Figure 7 is an explanatory diagram showing the configuration of the rendering unit 140. The rendering unit 140 comprises a vertex pipeline VPL, a rasterizer RRZ, a pixel pipeline PPL, and a post-processing unit PST. In this embodiment, the vertex pipeline VPL comprises a vertex shader VS and a geometry shader GS, and the pixel pipeline PPL comprises a pixel shader PS and a render backend RBE.

[0031] The vertex shader VS uses 3D object information OBI, camera information CMI, and lighting information LTI to perform processing on the polygons that make up the 3D object OBJ. This processing includes coordinate transformations of the vertices of each polygon that makes up the 3D object OBJ, calculation of the normal vector of each polygon, shading, and calculation of texture mapping coordinates (UV coordinates). Coordinate transformations include model transformation, which is a coordinate transformation from the local coordinate system Σm of the 3D object OBJ to the world coordinate system Σg; view transformation, which is a coordinate transformation from the world coordinate system Σg to the view coordinate system Σc; and projection transformation, which is a coordinate transformation from the view coordinate system Σc to the screen coordinate system. The processing results of the vertex shader VS are sent to the geometry shader GS.

[0032] The geometry shader GS processes the set of vertices in a 3D object (OBJ). By increasing or decreasing the number of vertices, the geometry shader GS can convert polygons to points or lines, and vice versa. The processing results of the geometry shader GS are sent to the rasterizer RRZ.

[0033] The rasterizer RRZ generates pixel-specific drawing information from the processing results of the vertex pipeline VPL by performing a rasterization process. The processing results of the rasterizer RRZ are sent to the pixel shader PS.

[0034] The pixel shader PS determines the pixel color of the 3D object OBJ corresponding to each pixel by performing lighting processing using the rasterized 3D object OBJ, the main texture information mainTI, and the media texture information mediaTI. The data representing the pixel color of the 3D object OBJ corresponds to the print color data printingColor explained in Figure 2.

[0035] In this embodiment, the pixel shader PS includes an albedo calculation unit PS1 and a printed color calculation unit PS2.

[0036] The albedo calculation unit PS1 executes the process P1 described in Figure 2. Specifically, the albedo calculation unit PS1 uses the image color channel mainTex_rgb, the image alpha channel mainTex_a, the media alpha channel mediaTex_a, and the base color baseColor to calculate the printAlbedo, which represents the reflectivity of the printed material PT. In particular, the printAlbedo is calculated by the following formula. printAlbedo = ( mainTex_rgb × mainTex_a + baseColor × (1 - mainTex_a) ) × mediaTex_a …(q1) Furthermore, if the base color (baseColor) is not specified, it is preferable to substitute baseColor = 1 in equation (q1). This is because white fabric is often used as a translucent fabric. The base color (baseColor) of white fabric is RGB = (1,1,1).

[0037] The print color calculation unit PS2 executes the process P2 described in Figure 2. Specifically, the print color calculation unit PS2 uses the albedo printAlbedo and the media color channel mediaTex_rgb to create print color data printingColor, which represents the color of the print PT. In particular, the print color data printingColor is calculated by the following formula. printingColor = LightingFunction( albedo, mediaTex_rgb, light ) …(q2) Here, LightingFunction is the light reflection function, and light is information about light such as its color and direction.

[0038] For the light reflection function, a Bidirectional Reflectance Distribution Function can be used. Typically, the Disney Principled BRDF is used. The processing results of the pixel shader PS are sent to the render backend RBE.

[0039] The render backend RBE uses the print color data printingColor generated by the pixel shader PS to perform the process P3 described in Figure 2. Specifically, the render backend RBE creates the print preview previewColor by compositing the background background with the print color data printingColor using the media alpha channel mediaTex_a. In particular, the print preview previewColor is calculated by the following formula. previewColor = printingColor + backGround × (1 - mediaTex_a) …(q3)

[0040] As can be understood from equation (q3), in this embodiment, a print preview previewColor can be created by compositing the background using the media alpha channel (mediaTex_a) instead of the image alpha channel (mainTex_a). As explained in Figure 2, since the image alpha channel (mainTex_a) is not used in process P3, it is possible to create a print preview previewColor that can successfully reproduce the semi-transparent printing medium PM even in areas with high density of the image IM for printed material PT using a translucent fabric as the printing medium PM.

[0041] The post-processing unit (PST) improves the appearance of the print preview (previewColor) stored in memory 102 by performing post-processing such as anti-aliasing, ambient occlusion, screen-space reflection, and depth-of-field processing.

[0042] Figure 8 is a flowchart showing the processing of the rendering unit 140. In step S10, the vertex pipeline VPL performs processing on the polygon objects that make up the 3D object OBJ.

[0043] In step S20, the pixel shader PS acquires resource data. The resource data includes the main texture information (mainTI), media texture information (mediaTI), and background (backGround), as shown in Figure 2, depending on the print conditions specified by the user. The acquired resource data is stored in memory 102.

[0044] If the image alpha channel mainTex_a is not specified by the user, the image alpha channel mainTex_a may be created according to the value of the image color channel mainTex_rgb. In this case, for example, if the value of the image color channel mainTex_rgb is (255,255,255), α may be set to 0, and if it is anything other than (255,255,255), α may be set to 1.

[0045] In step S30, the albedo calculation unit PS1 of the pixel shader PS calculates the albedo printAlbedo by executing the process P1 shown in Figure 2 using the resource data acquired in step S20.

[0046] In step S40, the print color calculation unit PS2 of the pixel shader PS calculates the print color data printingColor by executing the process P2 shown in Figure 2.

[0047] In step S50, the render backend RBE calculates the print preview previewColor by performing the process P3 shown in Figure 2.

[0048] In step S60, a rendering image represented by print preview previewColor is displayed on the display device 300.

[0049] According to the embodiments described above, a print preview previewColor can be created for a printed material PT using a translucent fabric as the printing medium PM, where the transparency changes within the surface due to the fineness of the threads and the coarseness of the weave. Furthermore, since the print preview previewColor is created without using the image alpha channel mainTex_a, it is possible to create a print preview previewColor that can accurately reproduce the semi-transparent printing medium PM even in areas with high density in the image IM.

[0050] In the embodiment described above, the calculation of the albedo printAlbedo by process P1 in Figure 2 is performed by the pixel shader PS, but process P1 may also be performed as a preprocessing step prior to the rendering process by the rendering unit 140.

[0051] Furthermore, this disclosure is also applicable when creating a print preview previewColor as a 2D preview rather than a 3D preview. A 2D preview can be created, for example, by one of the following methods:

[0052] <How to create a 2D preview M1> In method M1, the direction of light, represented by "light" in equation (q2) above, is fixed, and the print color data printingColor is calculated. The rest of the process is almost the same as the process for creating a 3D preview.

[0053] <How to create a 2D preview M2> In method M2, the print color data printingColor is calculated in process P2 of Figure 2 using a method different from that of equation (q2) above. For example, the print color data printingColor may be created by applying a texture assignment process to the albedo printAlbedo, which assigns the media color channel mediaTex_rgb as a texture. As the texture assignment process, for example, a process similar to the one disclosed in Japanese Patent Application Publication No. 06-86045 can be used. Specifically, a value obtained by multiplying the difference between the average value of the texture values ​​and the individual texture values ​​by a gain may be added to the pixel values ​​of the albedo printAlbedo. Alternatively, the media color channel mediaTex_rgb may be assigned as a texture according to other known methods.

[0054] Other forms: This disclosure is not limited to the embodiments described above, and can be implemented in various forms without departing from its spirit. For example, this disclosure can also be implemented in the following forms. The technical features in the embodiments described below that correspond to the technical features in each of the forms described below can be replaced or combined as appropriate in order to solve some or all of the problems of this disclosure, or to achieve some or all of the effects of this disclosure. Furthermore, if such technical features are not described as essential in this specification, they can be deleted as appropriate.

[0055] (1) According to a first embodiment of the present disclosure, a method is provided for creating a print preview of a printed material having an image printed on a print medium which is a translucent fabric. The method includes (a) a step of acquiring an image color channel representing the image; (b) a step of acquiring media texture information including a media color channel representing the unevenness of the print medium and a media alpha channel indicating the transparency of the print medium; (c) a step of calculating an albedo representing the reflectivity of the printed material using the image color channel and the media alpha channel; (d) a step of creating printed material color data representing the color of the printed material using the albedo and the media color channel; and (e) a step of creating the print preview by compositing a background onto the printed material color data using the media alpha channel without using the alpha channel of the image. This method allows for the creation of print previews for printed materials using translucent fabrics, where transparency varies within a surface due to thread thickness and weave coarseness. Furthermore, because the print preview is created without using the image's alpha channel, it is possible to create a print preview that accurately reproduces the semi-transparent print medium even in areas with high image density.

[0056] (2) In the above method, when the media alpha channel is set to mediaTex_a, the background to backGround, the print color data to printingColor, and the print preview to previewColor, step (e) is: previewColor = printingColor + backGround × (1 - mediaTex_a) This may be defined as a step in calculating the print preview according to the above procedure. This method allows you to create a print preview that composites the background using the media's alpha channel, without using the image's alpha channel.

[0057] (3) In the above method, step (d) may be a step of creating the printed color data by applying a bidirectional reflectance distribution function to the albedo and the medium color channel. This method allows for the creation of a good 3D preview that takes into account the direction of the light source.

[0058] (4) In the above method, when the media texture information includes the base color of the printing medium, the image color channel is set to mainTex_rgb, the alpha channel of the image is set to mainTex_a, the media alpha channel is set to mediaTex_a, the base color is set to baseColor, and the albedo is set to printAlbedo, then step (c) is: printAlbedo = ( mainTex_rgb × mainTex_a + baseColor × (1 - mainTex_a) ) × mediaTex_a The process may be defined as the step of calculating the albedo according to the formula. This method allows for the calculation of albedo using the image's color channels, alpha channel, and media alpha channel.

[0059] (5) According to a second embodiment of the present disclosure, a print preview creation device is provided for creating a print preview of a printed material having an image printed on a print medium which is a transparent fabric. The print preview creation device comprises a memory and a processor. The processor is configured to perform the following: (a) a process of acquiring an image color channel representing the image and storing it in the memory; (b) a process of acquiring media texture information including a media color channel representing the unevenness of the print medium and a media alpha channel indicating the transparency of the print medium and storing it in the memory; (c) a process of calculating an albedo representing the reflectivity of the printed material using the image color channel and the media alpha channel; (d) a process of creating printed material color data representing the color of the printed material using the albedo and the media color channel; and (e) a process of creating the print preview by compositing a background onto the printed material color data using the media alpha channel without using the alpha channel of the image.

[0060] (6) According to a third embodiment of the present disclosure, a computer program is provided for creating a print preview of a printed material having an image printed on a print medium which is a translucent fabric. The computer program causes the computer to perform the following: (a) a process of acquiring an image color channel representing the image; (b) a process of acquiring media texture information including a media color channel representing the unevenness of the print medium and a media alpha channel indicating the transparency of the print medium; (c) a process of calculating the albedo representing the reflectivity of the printed material using the image color channel and the media alpha channel; (d) a process of creating printed material color data representing the color of the printed material using the albedo and the media color channel; and (e) a process of creating the print preview by compositing a background onto the printed material color data using the media alpha channel without using the alpha channel of the image.

[0061] This disclosure can also be implemented in various forms other than a method for creating a print preview, a device for creating a print preview, and a computer program. For example, it can be implemented in the form of an image processing method or a non-transitory storage medium on which a computer program is recorded. [Explanation of symbols]

[0062] 100…Image processing device, 101…Processor, 102…Memory, 103…Input / Output interface, 104…Internal bus, 110…Resource data acquisition unit, 120…Print condition acquisition unit, 130…Parameter acquisition unit, 140…Rendering unit, 200…Input device, 300…Display device, 400…Printing device, 500…Printing system

Claims

1. A method for creating a print preview of a printed material in which an image is printed on a print medium that is a translucent fabric, (a) A step of acquiring an image color channel representing the image, (b) A step of acquiring media texture information including a media color channel representing the unevenness of the printing medium and a media alpha channel representing the transparency of the printing medium, (c) A step of calculating the albedo, which represents the reflectivity of the printed material, using the image color channel and the medium alpha channel, (d) A step of creating print color data that represents the color of the print using the albedo and the media color channels, (e) A step of creating the print preview by compositing the background onto the print color data using the media alpha channel without using the alpha channel of the image, A method that includes this.

2. The method according to claim 1, When the alpha channel of the media is set to mediaTex_a, the background to backGround, the print color data to printingColor, and the print preview to previewColor, The aforementioned step (e) is, previewColor = printingColor + backGround × (1 - mediaTex_a) A method comprising the step of calculating the print preview according to the above.

3. The method according to claim 1, The method, wherein step (d) is the step of creating the print color data by applying a bidirectional reflectance distribution function to the albedo and the medium color channels.

4. The method according to claim 1, The media texture information includes the base color of the print medium, When the image color channel is defined as mainTex_rgb, the image alpha channel as mainTex_a, the media alpha channel as mediaTex_a, the base color as baseColor, and the albedo as printAlbedo, The aforementioned step (c) is, printAlbedo = ( mainTex_rgb × mainTex_a + baseColor × (1 - mainTex_a) ) × mediaTex_a A method comprising the step of calculating the albedo according to the above.

5. A print preview creation device that creates a print preview of a printed material in which an image is printed on a print medium that is a transparent fabric, Equipped with memory and a processor, The aforementioned processor, (a) A process of obtaining the image color channels representing the image and storing them in the memory, (b) A process of acquiring media texture information including a media color channel representing the unevenness of the printing medium and a media alpha channel representing the transparency of the printing medium and storing it in the memory, (c) A process of calculating the albedo, which represents the reflectivity of the printed material, using the image color channel and the medium alpha channel, (d) A process of creating print color data that represents the color of the print using the albedo and the media color channels, (e) A process to create the print preview by compositing the background onto the print color data using the media alpha channel, without using the alpha channel of the image, A print preview creation device configured to perform the following actions.

6. A computer program that creates a print preview of a printed material in which an image is printed on a print medium that is a translucent fabric, (a) A process to obtain the image color channels representing the image, (b) A process for obtaining media texture information including a media color channel representing the unevenness of the printing medium and a media alpha channel representing the transparency of the printing medium, (c) A process of calculating the albedo, which represents the reflectivity of the printed material, using the image color channel and the medium alpha channel, (d) A process of creating print color data that represents the color of the print using the albedo and the media color channels, (e) A process to create the print preview by compositing the background onto the print color data using the media alpha channel, without using the alpha channel of the image, A computer program that causes a computer to execute a command.

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