Image processing device, image processing method, and program

Abstract

To prevent a decrease in the forming height of an edge of a forming region that may occur when a foaming promotion component is applied to a recording medium including a foaming layer containing foamable particles to foam.SOLUTION: An image processing apparatus according to the present invention detects an edge pixel located inside a forming region at a border between the foaming region and a non-foaming region and increases an amount of application of the foaming promotion component, thereby being able to prevent a decrease in a forming height.SELECTED DRAWING: Figure 10

Description

Technical Field

[0001] The present invention relates to an image processing apparatus, an image processing method, and a program for recording an image on a recording medium.

Background Art

[0002] A recording medium having a foam layer that foams by heat is known, and a stereoscopic image forming system that forms a stereoscopic image by foaming a desired area is known.

[0003] The stereoscopic image forming system records a corresponding grayscale image on the back surface of the surface to be foamed in order to foam a desired area. The density of the grayscale image corresponds to the foam height, and the surface foam height is controlled by controlling the image density.

[0004] Patent Document 1 discloses adjusting the density of the edge of a grayscale image to control the edge of the surface foam to be steep.

[0005] Patent Document 2 discloses that the foaming of the foaming agent of a recording medium containing a vinyl chloride resin as a foaming agent is suppressed by imparting a foam suppressing component.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0007] When forming a foamed region on a recording medium, there is a problem in that the foaming height at the edges of the region to be foamed is low. For example, in a configuration in which a foamed region is formed by applying a foaming-promoting component to the surface of a recording medium having a foamed layer, the amount of foaming-promoting component spreading from the surroundings is small inside the edges of the foamed region. As a result, the foaming height at the edges of the foamed region will be lower than that of the central part of the region to which the foaming-promoting component has been applied. This may result in reduced visibility of the foamed region or a foaming height lower than that specified by the user.

[0008] To address these challenges, the present invention aims to control the foaming height at the edges of the foamed region so that it does not become too low. [Means for solving the problem]

[0009] The present invention A base material, and a component provided on the base material, which is heated foaming foam particles and binder resin and Recording medium having a foamed layer containing to, the aforementioned foaming of foam particles Lower the starting temperature. A means for imparting a foam-promoting component, and a means to impart a foam-promoting component to which the foam-promoting component has been imparted by the imparting means. The aforementioned recording media Heating Regarding the means and each pixel The aforementioned The system includes: an acquisition means for acquiring foaming data in which a grayscale value for imparting a foaming-promoting component is set; a detection means for detecting an inner edge pixel located inside the boundary between a foaming region where foaming particles are foamed and a non-foaming region where foaming particles are not foamed, based on the foaming data; and a generation means for generating a grayscale value for the inner edge pixel detected by the detection means such that it is greater than the amount of foaming-promoting component indicated by the foaming data acquired by the acquisition means. The foamed particles have a shell layer containing a thermoplastic resin and a volatile material enclosed within the shell layer, the binder resin contains a water-insoluble resin, the foaming-promoting component contains a compound that does not have a hydroxyl group, and the heating temperature by the heating means is above the foaming start temperature of the foamed particles treated with the foaming-promoting component, and below the boiling point of the compound. It is characterized by the following: [Effects of the Invention]

[0010] This invention makes it possible to form a three-dimensional image with an inner edge that suppresses the decrease in foam height in the foamed region, thereby suppressing the decrease in visibility of the foamed region. [Brief explanation of the drawing]

[0011] [Figure 1] Figure for explaining the recording device [Figure 2] Figure for explaining the recording system configuration [Figure 3] Figure for explaining the recording head configuration [Figure 4] Figure for explaining the recording medium [Figure 5] Figure for explaining the foam height control [Figure 6] Figure for explaining the processing of foam data [Figure 7] Figure for explaining edge detection [Figure 8] Figure for explaining dot overlap [Figure 9] Figure for explaining the processing of the color image resolution [Figure 10] Figure for explaining the flowchart of image processing [Figure 11] Figure for explaining edge detection [Figure 12] Figure for explaining dot overlap [Figure 13] Figure for explaining dot overlap

Embodiments for Carrying Out the Invention

[0012] (First Embodiment) Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Although a plurality of features are described in the following embodiments, not all of these plurality of features are essential to the present invention, and the plurality of features may be arbitrarily combined. Further, in the accompanying drawings, the same or similar configurations are denoted by the same reference numerals, and duplicate explanations are omitted.

[0013] <Overview of the recording device> FIG. 1 is a schematic diagram showing the configuration of a recording device 100 according to the present embodiment. The conveyance rollers 108, 109, 110, and 111 are each configured as a pair with conveyance rollers (not shown) that sandwich the recording medium 112, and convey the recording medium 112 in the Y direction shown in FIG. 1.

[0014] In this embodiment, the recording unit 101 records an image on the recording medium 112 by applying ink using an inkjet (IJ) recording method that ejects ink. The recording head 102 ejects foam-controlling ink (F) containing foam-controlling components. The recording head 103 ejects black ink (K). The recording head 104 ejects cyan ink (C). The recording head 105 ejects magenta ink (M). The recording head 106 ejects yellow ink (Y). The recording medium 112 is transported in the Y direction, and each recording head is equipped with multiple nozzles for ejecting ink in the X direction intersecting the Y direction. In this embodiment, the recording heads 102, 103, 104, 105, and 106 are arranged in the order of F, K, C, M, and Y in the Y direction in the figure, from upstream to downstream. Therefore, the inks are applied to the recording medium 112 in the order of F, K, C, M, and Y. Inks containing K, C, M, and Y colorants are collectively referred to as "color inks."

[0015] The heating unit 107 heats the recording medium 112 and the ink applied to the recording medium 112. As will be described in detail later, in this embodiment, a foaming accelerator containing a foaming-promoting component is used as the foaming control ink. If the recording medium 112 contains foaming particles that foam when heated, the area to which the foaming accelerator is applied will foam due to the heat from the heating unit 107. In addition, regardless of the type of recording medium 112, the water in the color ink applied to the recording medium 112 evaporates due to the heat provided by the heating unit 107 and the ink is fixed to the surface of the recording medium 112.

[0016] <Overview of the recording system configuration> Figure 2 is a block diagram showing the control configuration of a recording system consisting of the recording device 100 shown in Figure 1 and a host device connected to the recording device 100. As shown in Figure 2, this recording system consists of the recording device 100 shown in Figure 1 and a PC (personal computer) 200 as its host device.

[0017] The PC200 includes a CPU (201), RAM (202), HDD (203), data transfer interface (I / F) (204), keyboard / mouse interface (I / F) (205), and display interface (I / F) (206).

[0018] The CPU 201 executes processing according to the programs stored in the HDD 203 and RAM 202. RAM 202 is volatile storage and temporarily holds programs and data. HDD 203 is non-volatile storage and similarly holds programs and data. The data transfer interface 204 controls the transmission and reception of data between the PC and the recording device 100. This data transmission and reception method can be a wired connection such as USB, IEEE 1394, or LAN, or a wireless connection such as Bluetooth® or WiFi. The keyboard / mouse interface 205 controls the UI (user interface) such as a keyboard and mouse, and the user can input information to the PC 200 through it. The display interface 206 controls the display (not shown).

[0019] On the other hand, the recording device 100 includes a CPU 211, RAM 212, ROM 213, data transfer interface (I / F) 214, head controller 215, and image processing accelerator 216.

[0020] The CPU 211 executes the processing of each embodiment described later, according to the programs stored in the ROM 213 and RAM 212. RAM 212 is volatile storage and temporarily holds programs and data. ROM 213 is non-volatile storage and holds table data and programs used in the processing of each embodiment described later. The data transfer interface 214 controls the transmission and reception of data between the CPU and PC 200.

[0021] The head controller 215 controls the recording operation of each recording head 102 to 106 of the recording unit 101 based on the recording data. Specifically, the head controller 215 is configured to read control parameters and recording data from predetermined addresses in the RAM 212. In other words, when the CPU 211 writes the control parameters and recording data to predetermined addresses in the RAM 212, the head controller 215 starts processing and the recording operation of the recording head is performed.

[0022] The image processing accelerator 216 is hardware-based and performs image processing faster than the CPU 211. Specifically, the image processing accelerator 216 is configured to read the parameters and data necessary for image processing from a predetermined address in the RAM 212. When the CPU 211 writes the above parameters and data to the predetermined address in the RAM 212, the image processing accelerator 216 is activated and the predetermined image processing is performed.

[0023] Note that the image processing accelerator 216 is not necessarily a required component, and depending on the specifications of the recording device, the predetermined image processing may be performed solely by the CPU 211.

[0024] <Overview of Recording Head Configuration> Figure 3 is a schematic diagram showing the configuration of the recording head 102. The recording head 102 shown in Figure 3(a) comprises multiple recording chips 301, each recording chip 301 comprising multiple recording nozzles 302. Each recording chip 301 comprises a circuit for driving recording elements for ejecting ink from the recording nozzles 302. Examples of recording elements include heater elements and piezoelectric elements. The recording nozzles are arranged in a two-row configuration in the Y direction, and each row of recording nozzles is arranged in multiples in the X direction at a 600 dpi pitch. Furthermore, the two rows of recording nozzles are arranged with a 1200 dpi offset in the X direction. In addition, each recording chip 301 comprises three sets of two-row configurations in the Y direction (not shown).

[0025] Multiple recording chips 301 are arranged in the X direction, and the recording nozzles of two recording chips 301 and the same row between the recording chips 301 are arranged at 600 dpi intervals. Each row of nozzles arranged on the recording chip 301 has 600 recording nozzles 302 arranged in the X direction. In other words, one recording chip 301 has a recording width of 1 inch in the X direction. Foam-controlled ink ejected from each recording nozzle 302 using an inkjet method is applied to record an image on the recording medium 112. The recording head 102 of this embodiment has 13 recording chips 301 in the X direction and can record an image with a width of 13 inches, or approximately 330 mm, in the X direction. The recording resolution in the X direction is 1200 dpi. The recording resolution in the Y direction is also 1200 dpi. The ejection frequency, which is the number of times each recording head 102 can eject per second, is controlled to 10 kHz, and the recording medium 112 is transported in the Y direction at approximately 8.33 inches / second, so that the recording resolution in the Y direction is controlled to 1200 dpi. As mentioned above, each recording chip 301 is a set of two rows of recording nozzles 302 in the Y direction, and the two rows of recording nozzles are offset by 1200 dpi in the X direction. The recording nozzles in each row are arranged at intervals of 600 dpi in the X direction. By providing three sets of this set in the Y direction, it is possible to apply up to three ink droplets to the same pixel in the Y direction.

[0026] Recording heads 103, 104, 105, and 106 have the same configuration as recording head 102 in Figure 3(a) described above, so their description is omitted. F, C, M, Y, and K inks are applied to the recording medium 112 in sizes of 2 pl per drop. In addition, each of the F, C, M, Y, and K inks is adjusted to 2 ng per 2 pl. Since a maximum of 3 drops of each ink are applied to one pixel in a 1200 dpi square, a maximum of 6 pl, or 6 ng, can be applied.

[0027] Figure 3(b) shows another example of the recording head 102 configuration. The recording head 102 includes recording chips 303, 304, and 305, each of which has multiple recording nozzles 306. The recording nozzle rows are arranged in two rows in the Y direction, and multiple recording nozzles in each row are arranged in the X direction at 600 dpi intervals. The two rows of recording nozzles are offset by 1200 dpi in the X direction. The recording chips 303 to 305 are offset in the X and Y directions. Recording chips 303 and 304 are arranged so that the rightmost 2 pixels x 2 rows of recording chip 303 and the leftmost 2 pixels x 2 rows of recording chip 304 overlap in the X direction. Recording chip 304 is offset to the + side in the Y direction so that it does not physically overlap with recording chip 303. Similarly, recording chips 304 and 305 are arranged such that the rightmost 2 pixels x 2 rows of recording chip 304 and the leftmost 2 pixels x 2 rows of recording chip 305 overlap in the X direction. Recording chip 305 is positioned offset to the negative side in the Y direction so as not to physically overlap with recording chip 304. The arrangement shown in Figure 3(b) is a repetition of the arrangement of recording chip 304 relative to recording chip 305, similar to the arrangement of recording chip 304 relative to recording chip 303. The overlapping recording nozzles 306 distribute their ejection frequency at a predetermined rate so that ink is not applied to the same area on the recording medium 112.

[0028] In Figure 3(a), the recording nozzles 302 of each recording chip 301 do not overlap, but they may be configured to overlap. The overlapping recording nozzles 302 need to have their ejection frequencies distributed at a predetermined rate so that ink is not applied to the same area of ​​the recording medium 112.

[0029] <Recording medium comprising a foamed layer> Figure 4 is a schematic cross-sectional view showing a recording medium used for forming a three-dimensional image in this embodiment. The recording medium 400 has a base material 401 and a foamed layer 402 provided on the base material 401.

[0030] The base material 401 functions as a support for the foam layer 402. The type of base material 401 is not particularly limited. Examples of base material 401 include paper made from ordinary natural pulp, kenaf paper, and plastic film sheets such as polypropylene, polyethylene, and polyester. Other examples include so-called synthetic paper and nonwoven fabrics made by imiting synthetic fibers, synthetic pulp, or synthetic resin films.

[0031] The foamed layer 402 is provided on at least one surface of the substrate 401 and contains foamed particles 403 and a binder resin 404. The foamed particles 403 are heat-expandable microcapsules and consist of a capsule-shaped shell layer 405 containing a thermoplastic resin and a volatile material 406 enclosed within the shell layer 405. When heat is applied to the foamed particles 403, the thermoplastic resin constituting the shell layer 405 softens, and the volatile material 406 enclosed within the shell layer 405 vaporizes. This increase in volume of the foamed particles 403, causing them to become balloon-like, is called foaming.

[0032] Examples of thermoplastic resins that can be contained in the shell layer include: polystyrene, styrene-acrylic acid ester copolymer, polyamide resin, polyacrylic acid ester, polyvinylidene chloride, polyacrylonitrile, and polymethyl methacrylate. Other examples include vinylidene chloride-acrylonitrile, methacrylic acid ester-acrylic acid copolymer, vinylidene chloride-acrylic acid copolymer, and vinylidene chloride-acrylic acid ester copolymer.

[0033] Examples of volatile materials include: ethane, ethylene, propane, propene, n-butane, isobutane, n-pentane, isopentane, neopentane, n-hexane, heptane, petroleum ether, etc. Also, chlorofluorocarbons such as CCl3F, CCl2F2, CClF3, and CClF2-CClF2. Furthermore, tetraalkylsilanes such as tetramethylsilane, trimethylethylsilane, trimethylisopropylsilane, and trimethyl-n-propylsilane are also included. The volatile material is preferably a hydrocarbon with a molecular weight of 120 or less. There is no particular lower limit to the molecular weight of the volatile material, but for example, it is preferably 50 or more. The content of foamed particles in the foamed layer is preferably 5% by mass or more and 95% by mass or less, based on the total mass of the foamed layer.

[0034] The foamed layer 402 contains a binder resin 404 to enhance adhesion to the substrate 401. The binder resin is used to suppress the peeling of the foamed layer 402 from the substrate 401 when the foamed particles 403 in the foamed layer foam due to heat. A water-insoluble resin is used as the binder resin. Since the water-insoluble resin is not easily dissolved by the water in the foaming accelerator liquid used as a foaming control ink, it is possible to suppress the decrease in adhesion between the foamed layer and the substrate caused by the foaming accelerator liquid. Furthermore, even if an aqueous ink containing water is applied to the recording medium, for the same reason, it is possible to suppress the decrease in adhesion between the foamed layer 402 and the substrate 401.

[0035] A water-insoluble resin is defined as a resin that, when immersed in 80°C hot water for 2 hours, retains 95% by mass or more. The water-insoluble resin is preferably at least one selected from the group consisting of acrylic resins and urethane resins. Furthermore, it is even more preferable that the water-insoluble resin is at least one selected from the group consisting of acrylic resins without ester groups and urethane resins without ester groups. The water-insoluble resin is preferably a non-water-absorbing resin. The content of the water-insoluble resin in the foam layer 402 is preferably 10% by mass or more and 95% by mass or less, based on the total mass of the foam layer 402. The foam layer 402 may also contain a water-soluble resin, as long as the effects of the present invention are obtained within that range. The glass transition temperature of the binder resin is preferably -10°C or higher and 30°C or lower. By setting the glass transition temperature of the binder resin within the above range, it is possible to suppress the binder resin from hindering the foaming of the foam particles 403.

[0036] The mass ratio of foamed particles 403 to binder resin is preferably 5:95 to 90:10. By setting the mass ratio of foamed particles to binder resin within the above range, both the foaming properties of the foamed particles 403 and the binding properties of the binder resin to the substrate can be improved. The foamed layer 402 may further contain components such as pigments, antioxidants, dyes, and surfactants, as long as it does not impair the foaming properties.

[0037] <Foam-controlled ink> Next, the foaming accelerator used as a foaming control ink in this embodiment will be described in detail. The foaming accelerator contains a foaming-promoting component that lowers the foaming start temperature of the foaming particles 403. When the foaming accelerator is applied to the foaming layer 402 of the recording medium by ejection or coating using an inkjet method, it softens the thermoplastic resin contained in the shell layer 405 of the foaming particles 403. As a result, it is presumed that the foaming start temperature and the maximum foaming temperature of the foaming particles 403 will shift to the lower temperature side.

[0038] The foam-promoting component can be any compound that softens the thermoplastic resin contained in the shell layer 405 of the foam particles 403 and does not have hydroxyl groups. It can be appropriately selected and used depending on the type of thermoplastic resin. Examples of foam-promoting components include 2-pyrrolidone, dimethyl sulfoxide, N,N-dimethylformamide, and N-methyl-2-pyrrolidone. The boiling point of the hydroxyl-free compound, which is the foam-promoting component, is preferably higher than the temperature at which the foam layer 402 is heated. When the foam layer 402 is heated, if the boiling point of the compound is higher than the temperature at which the foam layer 402 is heated, it will not vaporize and can contribute to the softening of the thermoplastic resin in the shell layer 405 of the foam particles 403. The content of the hydroxyl-free compound, which is the foam-promoting component, is preferably 10% by mass or more and 70% by mass or less, based on the total mass of the foam-promoting liquid.

[0039] The absolute difference (|SP1-SP2|) between the solubility parameter (SP1) of the thermoplastic resin forming the shell layer 405 of the microcapsule foam particles 403 and the solubility parameter (SP2) of the foam-promoting component is preferably 3.5 or less. By having the absolute difference of the solubility parameters within the above numerical range, the foaming properties of the region in the foam layer 402 to which the foam-promoting liquid containing the foam-promoting component is applied can be further improved.

[0040] Furthermore, it is preferable that the absolute value of the difference between the Hansen solubility parameter (HSP1) of the thermoplastic resin forming the shell layer 405 of the foamed particles 403 and the solubility parameter (HSP2) of the foaming-promoting component (|HSP1-HSP2|) is 20 or less. By having the absolute value of the difference in Hansen solubility parameters within the above numerical range, the foaming properties of the region in the foamed layer 402 to which the foaming-promoting liquid containing the foaming-promoting component is applied can be further improved.

[0041] The solubility parameters (SP values) of the thermoplastic resin and foam-promoting component forming the shell layer 405 are both calculated values. Furthermore, the Hansen solubility parameters (HSP values) of the thermoplastic resin and foam-promoting component forming the shell layer are both measured and calculated values ​​obtained by dynamic light scattering.

[0042] If the foam-promoting component is liquid at room temperature (25°C), the foam-promoting component itself may be used as the foam-promoting solution. Furthermore, the foam-promoting solution may contain other components besides the foam-promoting component. For example, to improve the discharge stability of the foam-promoting solution, liquid components such as solvents may be added. As solvents, water and various water-soluble organic solvents can be used. Deionized water (ion-exchanged water) is preferred as the water. Examples of water-soluble organic solvents include alcohols, glycols, glycol ethers, and nitrogen-containing compounds.

[0043] Other components besides the liquid component include water-soluble organic compounds that are solid at 25°C, such as urea and its derivatives, trimethylolpropane, and trimethylolethane. Furthermore, various additives such as pH adjusters, defoamers, rust inhibitors, preservatives, fungicides, antioxidants, reduction inhibitors, and chelating agents may be included in the foaming accelerator as needed.

[0044] <Controlling foaming height> Figure 5 shows the relationship between the amount of foaming accelerator applied to a recording medium 400 equipped with a foaming layer 402, the grayscale value controlling the application amount, and the foaming height. Figure 5(a) shows the relationship between the amount of foaming accelerator applied to a recording medium 400 equipped with a foaming layer 402 and the grayscale value corresponding to the foaming height. In this figure, the horizontal axis is the grayscale value corresponding to the amount of foaming accelerator applied, and is the grayscale value per pixel in a 1200 dpi square. The vertical axis is the foaming height of one pixel in a 1200 dpi square when heated by the heating unit 107 at a heating temperature of 95°C and a heating time of 15 seconds. The foaming height of the foaming layer 402 can be controlled according to the grayscale value corresponding to the foaming accelerator.

[0045] <Foaming Data Processing> Figure 6 is a block diagram illustrating the foaming data processing when a foaming accelerator is applied to a recording medium 400 equipped with a foaming layer 402. The foaming data processing in this figure is performed on the PC 200.

[0046] The foam data height setting unit 601 sets the number of gradation values ​​corresponding to the desired foam height. Foam data is input as 8-bit alpha channel data with a resolution of 1200 dpi, separate from the 8-bit RGB data for each color of the color image described later. This data is called alpha data. The desired foam height is set by operating the keyboard and mouse connected to the keyboard and mouse interface 205 via a UI displayed on a display (not shown) connected to the display interface 206. For example, the UI accepts the maximum value of the foam height desired by the user.

[0047] The foam data height setting unit 601 sets the grayscale value corresponding to the maximum foam height desired by the user, based on the graph in Figure 5(a). Here, we will explain using the case where a foam height of 0.4 mm is set from the UI as an example. By referring to the graph in Figure 5(a), it can be deduced that the grayscale value corresponding to a foam height of 0.4 mm is 200. The foam data height setting unit 601 detects the maximum value in the acquired α data. Then, it sets the detected maximum value to 200, which is the grayscale value corresponding to the maximum foam height set by the UI. The input α data is then converted to α' data based on (Equation 1). α' = α × desired height gradation value ÷ detected maximum value ... (Equation 1) For example, if the maximum value detected within the alpha data was 150, the alpha data would be replaced with the value transformed by (Equation 1') below. α'=α×200÷150...(Formula 1') If the maximum value detected within the alpha data is 255, the alpha data is replaced with the value transformed by (Equation 1'') below. α'=α×200÷255...(Formula 1'') In this embodiment, the decimal part is rounded to an integer during the conversion. However, the handling of the decimal part is not limited to this; truncation or rounding up may also be used.

[0048] Returning to Figure 6, the foam data edge detection unit 602 detects the edges of the α' data. Figure 7 is a diagram illustrating the edge detection performed by the foam data edge detection unit 602. Figure 7(a) shows a portion of the α' data, which is an area of ​​9 pixels in the x direction and 18 pixels in the y direction. In this figure, the area of ​​3 pixels in the x direction and 12 pixels in the y direction enclosed by the thick black line is the "foamed area," and the grayscale value of each pixel is 200. The area outside the foamed area enclosed by the thick black line, where the grayscale value of each pixel is 0, is the "non-foamed area." In this embodiment, an edge refers to the boundary between the foamed area and the non-foamed area, and corresponds to the thick black line in the figure.

[0049] Figure 7(b) shows the result of performing edge detection processing on Figure 7(a), and Figure 7(c) shows a 3x3 Laplacian filter used for edge detection processing. The edge detection processing is described below. The center pixel of the Laplacian filter in Figure 7(c) is associated with the pixel of interest in Figure 7(a). The eight surrounding pixels adjacent to the pixel of interest in Figure 7(a) are associated with the eight pixels of the Laplacian filter in Figure 7(c), excluding the center pixel. The product of each pixel value in Figure 7(a) and each pixel value (coefficient) of the Laplacian filter in Figure 7(c) is taken. The sum of the nine resulting numbers is calculated, and the single resulting number is taken as the value of the pixel of interest in Figure 7(b) that corresponds to the pixel of interest in Figure 7(a).

[0050] In Figure 7(b), within the foaming region enclosed by the thick black line, pixels adjacent to and inside the thick black line are called inner edge pixels, and pixels adjacent to and outside the thick black line are called outer edge pixels. The value of an inner edge pixel is negative, and the value of an outer edge pixel is positive. In other words, if the sign of the value calculated in the edge detection process is negative, it can be determined to be an inner edge pixel, and if the sign is positive, it can be determined to be an outer edge pixel. In this embodiment, since the foaming accelerator is used for recording, inner edge pixels are detected as edge pixels. In this embodiment, one pixel inside the edge is defined as an inner edge pixel, but two or more pixels may be defined as inner edge pixels.

[0051] Returning to Figure 6, the foaming data pixel value adjustment unit 603 adjusts the gradation value of the edge pixels. Figure 8 shows the overlap of dots when foaming accelerator liquid is applied to the recording medium. Figure 8(a) shows the overlap of dots of foaming accelerator liquid applied to two adjacent pixels. The area where the two dots indicated by the shaded area in Figure 8(a) overlap one another is calculated by the following (Equation 3). r: radius of the dot d: pixel side length θ: Angle between the line connecting the center point of one dot and the intersection point of two dots, and the line connecting the center points of two pixels. S: Area where two dots overlap one another. θ = cos - 1(d / 2r) ... (Equation 2) S=((πr2×θ / 360)-(d×r×sinθ / 4))×2...(Formula 3) Figure 8(b) shows a portion of 7 pixels in the y-direction where dots overlap when foam-promoting liquid is applied to 3 consecutive pixels in the x-direction and 3 consecutive pixels in the y-direction. The 7 pixels aligned in the y-direction are called a column, and in the figure, columns 1 to 7 are defined from left to right in the x-direction.

[0052] Each pixel in column 4 is covered not only by the foaming accelerator dots applied to that pixel, but also by the foaming accelerator dots applied to adjacent pixels in column 3 and adjacent pixels in column 5. On the other hand, each pixel in column 3 is covered by foaming accelerator dots from adjacent pixels in column 4, and each pixel in column 5 is covered by dots from adjacent pixels in column 4. In other words, the amount of foaming accelerator on each pixel in columns 3 and 5 is less than the amount of foaming accelerator on each pixel in column 4 by an amount corresponding to the overlapping area S of the dots in Figure 8(a). Therefore, in this embodiment, the amount of foaming accelerator applied to each pixel in columns 3 and 5 corresponding to the detected inner edge pixels is increased to reduce the difference with the amount of foaming accelerator corresponding to the area S. For the sake of simplicity, let's assume that the applied foaming accelerator is uniformly spread over the area πr2 of one dot. Let Vng be the amount of foaming accelerator applied to one dot. Then, the amount of ink ΔVng to supplement the pixels in column 3 and column 5 is calculated by the following (Equation 4). ΔV=V×(S / (πr2)) (Formula 4) In this embodiment, binary data is generated indicating either dot formation or no dot formation. When dot formation occurs, the amount of foaming accelerator applied is Vng, and when no dot formation occurs, the amount of foaming accelerator applied is 0ng. Therefore, for the pixel group in column 3 and the pixel group in column 5, the amount of foaming accelerator applied to some pixels and not to others is controlled, and an average amount of foaming accelerator of V × (S / (πr²))ng is added per pixel. Depending on the grayscale value of each pixel, the quantization unit shown in Figure 10, described later, generates the aforementioned binary data indicating whether or not to apply the foaming accelerator.

[0053] Figure 5(b) is a graph showing the increment in grayscale value with respect to the amount of foaming accelerator added. Based on this graph, the increment in grayscale value is determined from the amount of foaming accelerator added. The foaming data pixel value adjustment unit 603 adds the determined additional grayscale value to the grayscale value of each pixel in column 3 and column 5. Here, the adjusted grayscale value is called α'' data.

[0054] Based on the α'' data generated by the above process, the pixels to which the foaming accelerator is applied are determined by the quantization process described later. By using the adjusted α'' data, the amount of foaming accelerator applied to each pixel in column 3 and column 5, which are the inner edge pixels of the foaming region, is increased compared to when quantization is performed using the unadjusted α data. As a result, the foaming height of the inner edge pixels based on the α'' data can be made higher than the foaming height of the inner edge pixels based on the α data.

[0055] Furthermore, since the applied foaming accelerator may not be evenly distributed across the dot area, the amount of foaming accelerator to be added may be determined experimentally rather than by the calculation method described above. For example, one method is to experimentally determine in advance the amount of foaming accelerator to be added to the inner edge pixels for each pre-adjustment grayscale value and create a table. The amount of foaming accelerator to be added is determined by referring to the pre-prepared table based on the pre-adjustment grayscale value of the inner edge pixels. Then, the increment of the grayscale value is determined from the amount of foaming accelerator added in Figure 5(b), and the grayscale value of the inner edge pixels is adjusted.

[0056] Furthermore, increasing the number of foam-promoting liquid dots in each pixel of column 3 or column 5 in Figure 8(b), which correspond to the inner edge pixels, increases the amount of foam-promoting liquid in each pixel of column 4 by an area S. The difference between the amount of foam-promoting liquid in column 3 or column 5 and the amount of foam-promoting liquid in column 4 does not become smaller than desired. Therefore, the increment of the grayscale value on the vertical axis in Figure 5(b) may be changed, or the increment of the grayscale value may be set to be larger. The increment of the grayscale value may be experimentally determined to suppress the decrease in visibility of the foamed area, and the graph in Figure 5(b) may be prepared in advance.

[0057] Furthermore, depending on the value indicating the foam height set by the user UI, the α' data may be converted to 255 in the foam data height setting unit 601. Since 255 is the maximum value for 8 bits, the foam data pixel value adjustment unit 603 cannot set the gradation value of the inner edge pixels to a value greater than 255. Therefore, it is advisable to restrict the α' data so that it is less than 255. For example, the upper limit of the foam height that can be set in the UI can be set to 0.51 mm or less, which corresponds to a gradation value of 255 in Figure 5(a). This allows the foam height set in the UI to be restricted so that even when the increment of the gradation value of the inner edge pixels is added, it remains within 255.

[0058] <Image processing of color images recorded by a recording device> Figure 9 is a block diagram illustrating the image processing of a color image in this embodiment. The image processing shown in this figure is performed in the recording device 100 shown in Figure 2. The data received by the input color conversion unit 901 is multi-level data with 8 bits each for RGB and a resolution of 1200 dpi. The input color conversion unit 901 generates multi-level data with 8 bits each for R'G'B' by converting the RGB data to the color reproduction range of the recording device 100.

[0059] This data conversion is performed using known methods such as matrix operations and three-dimensional lookup table (3DLUT) processing. Here, a 3DLUT is a table that stores combinations of input RGB data and converted R'G'B' data. For example, if the table is stored in 16 steps (0, 17, 34, ..., 221, 238, 255) from the range of 0 to 255 for each of the R, G, and B colors, then it will consist of 16 × 16 × 16 = 4096 combinations. If a value that satisfies a combination, i.e., RGB data of a grid point, is input, the corresponding R'G'B' data from the table is output. If a value that does not satisfy a combination in the table, i.e., RGB data that is not a grid point, is input, the R'G'B' data is calculated using known operations such as tetrahedral interpolation with the four nearest combinations.

[0060] The color separation processing unit 902 generates multi-level data consisting of 8 bits each of CMYK, which are the color inks of the recording device 100, by performing color separation processing on the R'G'B' data. This color separation processing can be carried out using known methods such as matrix arithmetic processing or 3DLUT processing.

[0061] The gamma correction unit 903 generates multi-level data with 12 bits each of C'M'Y'K' by correcting the CMYK data so that the brightness of the recorded image on the recording medium 112 of the recording device 100 changes linearly. This correction process can be performed using a one-dimensional lookup table (1DLUT).

[0062] The quantization unit 904 generates quantized data by quantizing the C'M'Y'K' data. The quantization process can be performed using known dithering or error diffusion methods. In this embodiment, the generated quantized data is quadrivalent data with 2 bits per pixel at 1200 dpi for each ink color C, M, Y, and K. In the quantized data for each color, a value of 0 indicates that no ink droplets will be ejected. On the other hand, a value of 1 indicates that one ink droplet will be ejected, a value of 2 indicates that two ink droplets will be ejected, and a value of 3 indicates that three ink droplets will be ejected.

[0063] Furthermore, the foaming accelerator data generated by the foaming data pixel value adjustment unit 603 is also quantized by the quantization unit 904 into quadrivalent data with 2 bits per pixel at 1200 dpi. The correspondence between the quantized data values ​​and the number of foaming accelerators dispensed is the same as that for color inks.

[0064] Figure 10 is a flowchart illustrating the image processing and recording processes of this embodiment. In this embodiment, steps S1001 to S1006 are performed by the PC 200, and steps S1007 onward are performed by the recording device 200. Alternatively, all processing may be performed by the recording device 200, or some processing may be shared between the recording device 100 and the PC 200.

[0065] In step S1001, when this flow starts, in step S1002, foam data and color image data are input to PC200. In step S1003, it is determined whether the acquired data is foam data. This determination is made by the CPU201 executing a program stored in HDD203. Whether it is foam data can be determined by whether it is alpha data of the alpha channel. If the result of the determination is foam data, the process proceeds to step S1004. If it is not foam data, it is determined to be a color image with RGB data, and the process proceeds to step S1007.

[0066] In this embodiment, in step S1003, it is simultaneously determined whether the resolution of the α data, which is the foaming data, is 1200 dpi. If it is not 1200 dpi, it is converted to a resolution of 1200 dpi using the nearest neighbor method. Bilinear and bicubic methods may be used for the resolution conversion process, but in this embodiment, the nearest neighbor method is used in order to maintain the sharpness of the edges of the foaming regions in the α data.

[0067] Similarly, in step S1003, even if the resolution of the RGB data, which is color image data, is not 1200 dpi, the resolution is converted using known resizing methods such as the nearest neighbor method, bilinear method, or bicubic method. It is preferable to convert the resolution using the bicubic method in order to suppress the occurrence of jagged edges and the reduction in sharpness.

[0068] In step S1003, if the input data is determined to be foam data, in step S1004, the foam data height setting unit 601 generates α' data based on the input α data using the method described above. In this embodiment, we will explain assuming that the foam height set by the user via the UI is 0.4 mm. From Figure 5(a), 200 is calculated as the gradation value corresponding to a foam height of 0.4 mm. Based on the maximum gradation value in the α data and (Equation 1), the gradation value of the foam area in a 3 × 12 region is converted as shown in Figure 7(a). In this embodiment, the maximum gradation value of the α data is 255, and the foam height set by the user is 0.4 mm, so the maximum value of the converted α' data is 200.

[0069] In step S1005, the foaming data edge detection unit 602 detects edges within the α' data. The edge detection process is performed using the Laplacian filter shown in Figure 7(c), and the result of the edge detection process is shown in Figure 7(b). In this embodiment, since a foaming-promoting component is used as the foaming control ink, inner edge pixels are detected as edge pixels.

[0070] In step S1006, the foaming data pixel value adjustment unit 603 adjusts the gradation value for each pixel of the inner edge pixels in the foaming region, and the adjusted set value is set. The adjustment of the gradation value is performed for the purpose of adding foaming accelerator liquid, as explained with reference to Figures 5 and 8. In this embodiment, r=15um, d=21.167μm, and V=2ng. ​​Based on (Equation 2) and (Equation 3), S=64.705μm² is calculated, and based on (Equation 4), ΔV=0.183ng is calculated for the inner edge pixels. From Figure 5(b), 7.7775 is calculated as the increment of gradation value to add foaming accelerator liquid to the inner edge pixels.

[0071] In the α' data, the grayscale value of the inner edge pixel, 200, is added to the grayscale value of the increment, 7.7775, to calculate 207.7775. Here, it is converted to a 12-bit integer value in preparation for quantization. 207.7775 × 16 = 3324.44 is calculated. Rounding to the nearest whole number, 3324 is calculated as the 12-bit α'' data. The grayscale value of each pixel in column 4 of the foamed region, 200, is converted to 200 × 16 = 3200, and 3200 is calculated as the 12-bit α'' data.

[0072] Meanwhile, in step S1007, the input color conversion unit 901 converts the 8-bit RGB data into 8-bit R'G'B' data. In step S1008, the color separation processing unit 902 converts the 8-bit R'G'B' data into 8-bit CMYK data. In step S1009, the gamma correction unit 903 corrects the 8-bit CMYK data into 12-bit C'M'Y'K' data.

[0073] In step S1010, quantization processing is performed by the quantization unit 904. 12-bit α'' data at 1200 dpi and 12-bit C'M'Y'K' data at 1200 dpi are input. The quantization unit 904 generates 2-bit 4-value quantized data corresponding to the foaming control ink (F ink), which is the foaming accelerator. The ΔV value calculated in step S1006 is ΔV = 0.183 ng, and V = 2 ng. Therefore, compared to not adjusting the gradation value of the inner edge pixels, the number of additional foaming accelerator dots is 0.183 ng ÷ 2 ng = 0.0915. In other words, an average of 0.0915 dots are added per pixel to the inner edge pixels. In addition, 2-bit 4-value quantized data corresponding to each CMYK ink is generated as a color image.

[0074] In step S1011, each ink is applied to the recording medium 112 from the recording unit 101 according to the quantization data. If the quantization data for each ink color is 0, 0 ink pulses are applied; if it is 1, 1 ink pulse is applied; if it is 2, 2 ink pulses are applied; and if it is 3, 3 ink pulses are applied. A maximum of 3 ink pulses are applied to one 1200 dpi pixel.

[0075] In step S1012, the heating unit 107 heats the recording medium 112 to which the ink has been applied. Compared to when the gradation value of the inner edge pixels is not adjusted, the amount of foam control ink (F) applied to the inner edge pixels increases by an average of 0.0915 times per pixel, and therefore the foam height of the inner edge pixels also increases. The CMYK color inks are fixed onto the recording medium 112 by heating.

[0076] In step S1013, this process is completed.

[0077] As described above, this embodiment controls the amount of foam control ink applied to the edges of the foamed region, which is the area that foams to form a three-dimensional image, so that the foam height does not decrease. This makes it possible to suppress the foam height at the edges from being lower than that at the center of the foamed region. Furthermore, it is possible to suppress the foam height from being lower than the foam height desired by the user, thereby suppressing a decrease in the visibility of the foamed region.

[0078] (Second embodiment) In the first embodiment, an example was described in which a foam-promoting liquid containing a foam-promoting component is used as the foam-controlling ink. In this embodiment, however, a case in which a foam-inhibiting liquid containing a foam-suppressing component is used will be described.

[0079] As mentioned above, Patent Document 2 discloses a configuration in which, when a foaming-inhibiting component is applied to a recording medium containing polyvinyl chloride resin as foaming particles, and then heated and dried, foaming of the foaming agent in the areas to which the foaming-inhibiting component has been applied is suppressed. The amount of foaming-inhibiting component applied is controlled to lower the foaming height in the areas to which it has been applied and to increase the foaming height in the areas to which it has not been applied.

[0080] In this embodiment, a recording medium coated with polyvinyl chloride resin as a foaming agent is used as the recording medium 112. In addition, an ink containing a foaming inhibitor component that suppresses foaming of the polyvinyl chloride resin is used as the foaming control ink (F ink). The foaming inhibitor liquid is applied to the recording medium 112 from the recording head 102. The recording method is the same as the method already described with reference to Figures 1, 2, and 3.

[0081] Figure 11 illustrates the edge detection process when using an ink containing a foam-suppressing component as a foam control ink. Figure 11(a) shows α' data, where the area enclosed by the thick black line is the foaming area. Since the F ink in this embodiment contains a foam-suppressing component, the amount of F ink applied to the foaming area is relatively small, and the amount of F ink applied outside the foaming area is relatively large. Therefore, in the α' data generated based on the α data, the gradation values ​​of pixels within the foaming area are converted to relatively small values, which in this embodiment is 0. On the other hand, the gradation values ​​of pixels outside the foaming area are converted to relatively large gradation values, which in this embodiment is 200. The conversion to α' data is performed in step S1004 of Figure 10 by the foaming data height setting unit 601 in Figure 6. Figure 11(b) shows the edge detection process of the α' data, and Figure 11(c) shows the Laplacian filter used for edge detection. The edge detection process is the same as the method described using Figure 7.

[0082] The Laplacian filter shown in Figure 11(c) is applied to the α' data in Figure 11(a) to obtain the edge detection result in Figure 11(b). Inner edge pixels have positive values, and outer edge pixels have negative values. In other words, if the sign is positive, it is determined to be an inner edge pixel, and if the sign is negative, it is determined to be an outer edge pixel. The relationship between the sign and whether the edge is inside or outside in Figure 11(b) is the opposite of the relationship between the sign and whether the edge is inside or outside in Figure 7(b). In the first embodiment, inner edge pixels were detected as edge pixels, but in this embodiment, since foam suppression liquid is used, outer edge pixels are detected as edge pixels. The above edge detection processing of α' data is performed by the foam data edge detection unit 602 in step S1005 of Figure 10.

[0083] Figure 12 illustrates the overlap of ink dots in the foam-suppressing solution. In the x-direction, pixels in columns 14, 15, and 16 are foamed regions, while pixels in the other columns are non-foamed regions. Although not shown, non-foamed regions are also continuous in the -x direction for column 11 and in the +x direction for column 19.

[0084] When using a foam-suppressing component, a large amount of the foam-suppressing liquid, F ink, is applied to the pixels in the non-foaming region. Therefore, Figure 12 shows an example where dots are formed only in the non-foaming region. Each pixel in column 13 is superimposed with dots only from the pixels of column 12. Similarly, each pixel in column 17 is superimposed with dots only from the pixels of column 18. Pixels in columns other than columns 13 and 17 in the non-foaming region are superimposed with dots from the pixels of two adjacent columns. Consequently, the foam-suppressing function for columns 13 and 17 is weaker than the foam-suppressing function for the other columns in the non-foaming region, resulting in a higher foam height. As a result, the difference in foam height between column 15 and the non-foaming region becomes smaller, reducing the visibility of the foamed region.

[0085] Therefore, in this embodiment, control is performed to increase the amount of foam suppression liquid applied to each pixel in column 13 and column 17. The amount of foam suppression liquid in columns 13 and 17 is increased in such a way that it compensates for the smaller ink overlap in columns 13 and 17 compared to the ink dot overlap in columns 12 and 18. Using Figure 5(b), the increment in the gradation value for the amount of foam suppression liquid added can be calculated. The calculated increment in the gradation value is added to the gradation value of each pixel in columns 13 and 17 of the α' data to generate α'' data. Each pixel in columns 13 and 17 that is the target of increasing the gradation value is detected as an outer edge pixel by the foam data edge detection unit 602. The above conversion to α'' data is performed by the foam data pixel value adjustment unit in step S1006 of Figure 10. Similar to the first embodiment, the α'' data is 12 bits.

[0086] Returning to Figure 10, in step S1010, quantization processing is performed on the α'' data, and quantized data is generated. For the outer edge pixels, the quantization result is such that the amount of foam control liquid increases compared to when the α data is quantized. In step S1012, the heating unit 107 heats the recording medium 112 to which the ink has been applied. Compared to when the grayscale value of the outer edge pixels is not adjusted, the amount of foam suppression liquid applied to the outer edge pixels increases, thus suppressing foaming at the outer edge pixels. In step S1013, this flow ends. The other steps in Figure 10 that were not described in this embodiment are the same as in the first embodiment, so their description is omitted.

[0087] With the configuration described above, when using a foaming suppression component, it is possible to suppress the decrease in foaming height at the edges of the foaming region in pixels outside the foaming region.

[0088] (Third embodiment) In the first embodiment, the grayscale value of the inner edge pixels was increased in order to add foam-promoting liquid to the inner edge pixels of the foaming region. In the second embodiment, the grayscale value of the outer edge pixels was increased in order to add foam-suppressing liquid to the outer edge pixels of the foaming region. In contrast, in this embodiment, the grayscale value of the pixels excluding the inner and outer edge pixels within the foaming region is reduced in order to thin out the foaming control ink in those pixels.

[0089] If the pixels in the foaming region within the black frame of the α' data in Figure 7(a) are set to the maximum value of 255, it is not possible to increase the gradation value of the inner edge pixels. In this case, the gradation value of pixels excluding the inner edge pixels within the foaming region is reduced. The gradation value is reduced in such a way that it is equivalent to thinning out the amount of foaming accelerator liquid corresponding to the area S. For example, in this embodiment, the horizontal axis of Figure 5(b) represents the amount of ink to be thinned out, and the vertical axis of Figure 5(b) represents the reduction in gradation value. Then, the reduction in gradation value can be calculated from the amount of foaming accelerator liquid corresponding to the area S to be thinned out. The calculated reduction in gradation value is subtracted from the gradation value of pixels excluding the inner edge pixels within the foaming region and converted to α'' data. As a result, a three-dimensional image with an inner edge that suppresses the relative decrease in foaming acceleration can be formed in the foaming region, thus suppressing the decrease in visibility of the foaming region. In this embodiment, the explanation was given assuming that the pixels in the foaming region within the black frame of the α' data are set to the maximum value of 255, but it is not limited to this. When a grayscale value smaller than the maximum value is set, the above-described decimation may be performed to form a three-dimensional image with an inner edge in the foaming region, suppressing the relative decrease in foaming promotion.

[0090] Furthermore, if the maximum value of 255 is set for pixels outside the foaming region within the black frame of the α' data in Figure 7(b), the gradation value of the outer edge pixels cannot be increased. In this case, the gradation value of pixels excluding the outer edge pixels is reduced outside the foaming region. The gradation value is reduced by thinning out the amount of foam suppression liquid corresponding to the area S. For example, in this embodiment, the horizontal axis of Figure 5(b) represents the amount of ink to be thinned out, and the vertical axis of Figure 5(b) represents the reduction in gradation value. Then, the reduction in gradation value can be calculated from the amount of foam suppression liquid corresponding to the area S to be thinned out. The calculated reduction in gradation value is subtracted from the gradation value of pixels excluding the outer edge pixels outside the foaming region, and converted to α'' data.

[0091] As a result, a stereoscopic image with an outer edge that suppresses the relative decrease in foam suppression can be formed outside the foam region, thereby suppressing the decrease in visibility of the foam region. In this embodiment, the maximum value of 255 was set for pixels outside the foam region within the black frame of the α' data, but this is not the only case. If a grayscale value smaller than the maximum value is set, a stereoscopic image with an outer edge that suppresses the relative decrease in foam suppression can be formed outside the foam region by performing the above decimation process.

[0092] (Other embodiments) Figure 13 illustrates the overlapping ink dots in foam regions with different pixel counts in the x-direction (x-width or short-side pixel width). Columns 21-23 in this figure represent foam regions with a width of 3 pixels in the x-direction. Columns 25-26 in this figure represent foam regions with an x-width of 2, and when the Laplacian filter shown in Figure 7(c) is applied, columns 25 and 26 are detected as inner edge pixels. The gradation values ​​incremented by columns 21 and 23, which are inner edge pixels with a width of 3 pixels in the x-direction, are added to the gradation values ​​of columns 25 and 26, which are inner edge pixels with a width of 2 pixels in the x-direction. As a result, foam regions with a width of 2 pixels in the x-direction can form an edge shape equivalent to that of foam regions with a width of 3 pixels.

[0093] Column 28 in this figure represents a foamed region with a width of 1 pixel in the x-direction. When the Laplacian filter shown in Figure 7(c) is applied, column 28 is detected as an inner edge pixel. By adding the gradation values ​​incremented in columns 21 and 23, which are inner edge pixels with a width of 3 pixels in the x-direction, to the gradation values ​​of column 28, which is an inner edge pixel with a width of 1 pixel in the x-direction, a foamed region with a width of 1 pixel in the x-direction can form an edge shape equivalent to that of a foamed region with a width of 3 pixels in the x-direction. For foamed regions with a width of 4 pixels or more in the x-direction (not shown), when the Laplacian filter shown in Figure 7(c) is applied, the columns at both ends of the foamed region are detected as inner edge pixels. The gradation values ​​incremented in columns 21 and 23, which are inner edge pixels with a width of 3 pixels in the x-direction, are added to the gradation values ​​of the columns at both ends, which are inner edge pixels with a width of 4 pixels or more in the x-direction. As a result, foamed regions with a width of 4 pixels or more in the x-direction can form an edge shape equivalent to that of a foamed region with a width of 3 pixels in the x-direction.

[0094] The Laplacian filters in Figures 7(c) and 11(c) can detect edges in the x and y directions. Therefore, using the methods described in the first and second embodiments, the gradation values ​​of the edge pixels in the x and y directions can be adjusted and converted into α'' data.

[0095] In the above-described embodiment, the PC200 performs the processing of the foam data and the recording device 100 performs the image processing of the color image, but this is not limited to this. The recording device 100 may perform the processing of the foam data, and the PC200 may perform the image processing of the color image. It is sufficient that the quantized data from step S1010 in Figure 10 is present in the recording device 100.

[0096] Furthermore, as shown in Figure 8(b), the configuration of the first embodiment may be adopted when there is a difference between the amount of ink dot overlap of the inner edge pixels within the foamed region and the amount of ink dot overlap of the other pixels within the foamed region. If there is no difference, it is not necessary to adjust the gradation value of the inner edge pixels. A threshold value for the gradation value that determines whether or not there is a difference is determined experimentally in advance. In the foamed data pixel value adjustment unit 603, the gradation value of the α' data is compared with the threshold value. If the gradation value of the α' data is greater than or equal to the threshold value, the gradation value of the inner edge pixels is adjusted as described in the first embodiment. As shown in Figure 12, the configuration of the second embodiment may be adopted when there is a difference between the amount of dot overlap of the outer edge pixels and the amount of dot overlap of the other pixels outside the foamed region. If there is no difference, it is not necessary to adjust the gradation value of the outer edge pixels. A threshold value for the gradation value that determines whether or not there is a difference is determined experimentally in advance. In the foamed data pixel value adjustment unit 603, if the gradation value of the α' data is greater than or equal to the threshold value, the gradation value of the outer edge pixels is adjusted as described in the second embodiment.

[0097] Furthermore, while the first embodiment described a configuration in which foamed particles are foamed by heating, the foaming method is not limited to heating, as long as the foamed particles are foamed by means of adding thermal energy or by irradiating them with electromagnetic waves. [Explanation of symbols]

[0098] 100 Recording device 102 Recording head 200 PC 211 CPU 216 Image Processing Accelerators 302 Recording Nozzle

Claims

1. A means for applying a foaming promoting component to a recording medium having a base material and a foamed layer provided on the base material containing foamed particles that foam when heated and a binder resin, which lowers the foaming start temperature of the foamed particles, A heating means for heating the recording medium to which the foaming promoting component has been applied by the aforementioned application means, Acquisition means for acquiring foaming data in which a grayscale value for imparting the foaming promoting component is set for each pixel, A detection means for detecting an inner edge pixel located inside the boundary between a foaming region where foaming particles are produced and a non-foaming region where foaming particles are not produced, based on the foaming data, A generation means generates grayscale values ​​for the inner edge pixels detected by the detection means such that the grayscale values ​​increase to the amount of foam-promoting component indicated by the foam data acquired by the acquisition means, Equipped with, The foamed particles have a shell layer containing a thermoplastic resin and a volatile material enclosed within the shell layer. The binder resin comprises a water-insoluble resin. The foam-promoting component includes a compound that does not have a hydroxyl group. The image processing apparatus is characterized in that the heating temperature by the heating means is equal to or greater than the foaming start temperature of the foaming particles treated with the foaming promoting component, and is lower than the boiling point of the compound.

2. The image processing apparatus according to claim 1, characterized in that the foamed particles are foamed when the thermoplastic resin softens and the volatile material vaporizes upon heating.

3. The system further includes means for receiving a value indicating the height of foaming, The image processing apparatus according to claim 1, characterized in that the generating means generates the grayscale value based on a value indicating the height of the foam.

4. The image processing apparatus according to claim 1, characterized in that the detection means detects one pixel located inside the boundary as an inner edge pixel.

5. The image processing apparatus according to claim 1, characterized in that the generation means generates a grayscale value such that, when the foaming data acquired by the acquisition means is above a predetermined threshold, the value increases to a level greater than the amount of foaming promoting component indicated by the foaming data.

6. A transport means for transporting the recording medium, A color ink applying means for applying color ink containing a colorant, located downstream of the applying means in the direction of transport by the transport means, Furthermore, The image processing apparatus according to claim 1, characterized in that the color ink is applied by the color ink application means onto the recording medium onto which the foam-promoting component has been applied by the application means.

7. The image processing apparatus according to claim 6, characterized in that the heating means is located downstream of the color ink application means in the direction of transport by the transport means.

8. The image processing apparatus according to claim 1, characterized in that the content of the foam particles in the foam layer is 5% by mass or more and 95% by mass or less, based on the total mass of the foam layer.

9. The image processing apparatus according to claim 1, characterized in that the volatile material is a hydrocarbon with a molecular weight of 120 or less.

10. The image processing apparatus according to claim 1, characterized in that the water-insoluble resin is a non-water-absorbing resin.

11. The image processing apparatus according to claim 3, characterized in that the means for receiving a value indicating the foam height is a UI for receiving a desired foam height setting from a user.

12. The image processing apparatus according to claim 1, wherein, when the gradation value of the foam region in the foam data is the maximum value, the gradation value of pixels in the foam region excluding the inner edge pixels is made smaller than the gradation value of the inner edge pixels.

13. A recording medium comprising a base material and a foamed layer provided on the base material containing foamed particles that foam upon heat and a binder resin, comprising: a means for applying a foaming promoting component that lowers the foaming start temperature of the foamed particles; and a heating means for heating the recording medium to which the foaming promoting component has been applied by the applying means, wherein the foamed particles have a shell layer containing a thermoplastic resin and a volatile material enclosed within the shell layer, and the binder resin contains a water-insoluble resin. The foam-promoting component comprises a compound that does not have a hydroxyl group, and the heating temperature by the heating means is equal to or greater than the foaming start temperature of the foam particles treated with the foam-promoting component, and lower than the boiling point of the compound, in an image processing method for an image processing apparatus, A step of acquiring foaming data in which a grayscale value for imparting the foaming promoting component to each pixel is set, Based on the foaming data, the process involves detecting an inner edge pixel located inside the boundary between the foaming region where foaming particles are produced and the non-foaming region where foaming particles are not produced. A step of generating grayscale values ​​for the detected inner edge pixels such that they are greater than the amount of foam-promoting component indicated by the acquired foam data, An image processing method characterized by comprising:

14. A program for causing a computer to perform each of the steps described in the image processing method of claim 13.

Images