JP2018008508A - Image processing apparatus, image processing method, and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image processing apparatus for obtaining a printed matter having anisotropy more easily than a conventional technique.SOLUTION: An image processing apparatus which generates data for forming an uneven layer in which a plurality of unit regions having protrusions are arrayed on a recording medium includes: first acquisition means which acquires the first brightness information on the brightness in a prescribed region of an object in the first observation direction and the brightness in the prescribed region of the object in the second observation direction being the direction having the different elevation angle from the first observation direction; and first generation means which generates the first recording amount data expressing the recording amount of the recording material for forming the uneven layer in which at least one of the width of the unit region and the height of the protrusion is changed on the basis of the first brightness information on the recording medium.SELECTED DRAWING: Figure 7

Description

  The present invention relates to an image processing technique for outputting a printed matter whose brightness changes when an observation angle is changed.

  Fabrics such as satin fabrics and embroidery, and metal surfaces that have been hairlined have anisotropy that changes their appearance greatly when the angle of observation is changed due to the complex fine shape of the surface. . An example of a printed material that reproduces this anisotropy is one using a lenticular lens. Patent Document 1 discloses a technique that can simultaneously form an image and a lenticular lens superimposed on the image by using a UV curable ink jet printer capable of forming arbitrary irregularities with an ink containing a photocurable resin.

Japanese Patent No. 3555420

  However, in the method using a lenticular lens as in Patent Document 1, it is necessary to print an image with high resolution in order to smoothly change brightness and color when the observation angle is changed. In addition, it is difficult to accurately form the curved surface shape of the lens with high resolution using an inkjet printer.

  An object of this invention is to provide the image processing for obtaining the printed matter which has anisotropy more easily than before.

  In order to solve the above problems, an image processing apparatus according to the present invention is an image processing apparatus that generates data for forming a concavo-convex layer in which a plurality of unit regions having convex portions are arranged side by side on a recording medium. First brightness information relating to the brightness of a predetermined region of the object in the first observation direction and the brightness of the predetermined region of the object in a second observation direction that is a direction having an elevation angle different from the first observation direction is obtained. Recording amount of a recording material for forming on the recording medium, the uneven layer in which at least one of the width of the unit region and the height of the convex portion changes based on the first brightness information And first generation means for generating first recording amount data to be expressed.

  According to the present invention, a printed matter having anisotropy can be obtained more easily than in the past.

The block diagram showing the hardware structural example of the image processing apparatus 1 A block diagram showing a configuration example of the printer 12 Schematic diagram for explaining the operation of the printer 12 to form the concave and convex layers and the image layer. Schematic diagram for explaining the uneven layer Schematic diagram showing the cross-sectional structure of ink amount data Schematic diagram showing the cross-sectional structure of the formed printed matter Schematic diagram for explaining the mechanism by which the elevation anisotropy is expressed by the formed printed matter The block diagram showing the functional composition of image processing device 1 Schematic diagram showing the structure of image data Schematic diagram showing how the object to be reproduced was imaged under different geometric conditions The figure showing the example of the LUT to refer The figure explaining the relationship between w / d and the shape of an unevenness | corrugation The figure showing the example of CL ink amount data A flowchart showing the operation of the image processing apparatus 1 Schematic diagram for explaining the rotation process Schematic diagram for explaining the mechanism by which azimuthal anisotropy is manifested by the printed matter formed The figure for demonstrating the change of the shadow area according to the change of the height of the formed convex part

[Example 1]
In this embodiment, image data having color information representing the color of the image and brightness change amount information when the observation angle is changed in the elevation direction is acquired. Then, based on the acquired image data, colored ink amount data (colored ink recording amount data) and CL ink amount data (CL ink recording amount data) are generated.

  FIG. 1 is a block diagram illustrating a hardware configuration example of the image processing apparatus 1. In FIG. 1, an image processing apparatus 1 is, for example, a computer, and includes a microprocessor (CPU) 101 and a memory 102 such as a random access memory. The CPU 101 executes an operating system (OS) and various programs stored in a hard disk drive (HDD) 103 using the memory 102 as a work memory. Then, each component is controlled via the system bus 106. The general-purpose interface (I / F) 104 is connected to an input device 11 such as a mouse and a keyboard and a printer 12. A monitor 13 is connected to the video interface (I / F) 105. The CPU 101 displays a user interface (UI) screen provided by the program on the monitor 13 and accepts a user instruction via the input device 11.

  FIG. 2 is a configuration diagram of the printer 12. The printer 12 is assumed to be an ink jet printer that uses ink to form irregularities and record colors. The head cartridge 801 has a recording head composed of a plurality of ejection openings, an ink tank that supplies ink to the recording head, and a connector for receiving a signal for driving each ejection opening of the recording head. Is provided. Hereinafter, the unevenness and the color layer formed by the ink are referred to as an unevenness layer and an image layer, respectively. The ink tank includes clear (CL) ink for forming an uneven layer and colored inks of cyan (C), magenta (M), yellow (Y), and black (K) for forming an image layer. A total of five types of ink are provided independently. These inks are UV curable inks that are cured by irradiation with ultraviolet rays. The head cartridge 801 is mounted on the carriage 802 in a replaceable manner, and the carriage 802 is provided with a connector holder for transmitting a drive signal and the like to the head cartridge 801 via a connector. In addition, an ultraviolet (UV) irradiation device 815 is mounted on the carriage 802 and is controlled to cure the ejected ink and fix it on the recording medium. The carriage 802 can reciprocate along the guide shaft 803. Specifically, the carriage 802 is driven through a driving mechanism such as a motor pulley 805, a driven pulley 806, and a timing belt 807 using the main scanning motor 804 as a driving source, and its position and movement are controlled. In this embodiment, the movement of the carriage 802 along the guide shaft 803 is referred to as “main scanning”, and the movement direction is referred to as “main scanning direction”. A recording medium 808 such as print paper is placed on an auto sheet feeder (ASF) 810. During image formation, the pickup roller 812 rotates through a gear by driving the paper feed motor 811, and the recording medium 808 is separated one by one from the ASF 810 and fed. Further, the recording medium 808 is conveyed to a recording start position facing the ejection port surface of the head cartridge 801 on the carriage 802 by the rotation of the conveying roller 809. The conveyance roller 809 is driven via a gear using a line feed (LF) motor 813 as a drive source. The determination as to whether or not the recording medium 808 has been fed and the determination of the feeding position are performed when the recording medium 808 passes the paper end sensor 814. The head cartridge 801 mounted on the carriage 802 is held so that the ejection port surface protrudes downward from the carriage 802 and is parallel to the recording medium 808. The control unit 820 includes a CPU, a storage unit, and the like, and controls the operation of each part of the printer 12.

  Hereinafter, the formation operation of the uneven layer and the image layer in the printer 12 will be described. First, when the recording medium 808 is conveyed to the recording start position in order to form the uneven layer, the carriage 802 moves on the recording medium 808 along the guide shaft 803, and the ejection port of the recording head is moved during the movement. More ink is ejected. The ultraviolet irradiation device 815 irradiates ultraviolet rays in accordance with the movement of the recording head, cures the ejected CL ink, and fixes it on the recording medium. When the carriage 802 moves to one end of the guide shaft 803, the conveyance roller 809 conveys the recording medium 808 by a predetermined amount in a direction perpendicular to the scanning direction of the carriage 802. In this embodiment, the conveyance of the recording medium 808 is referred to as “paper feeding” or “sub-scanning”, and the conveyance direction is referred to as “paper feeding direction” or “sub-scanning direction”. When the conveyance of the recording medium 808 by a predetermined amount is completed, the carriage 802 moves again along the guide shaft 803. In this way, an uneven layer is formed on the entire recording medium 808 by repeating scanning with the carriage 802 of the recording head and paper feeding. After the concavo-convex layer is formed, the conveyance roller 809 returns the recording medium 808 to the recording start position, and discharges cyan, magenta, yellow, and black colored inks on the concavo-convex layer in the same process as the concavo-convex layer formation, An image layer is formed.

  In order to simplify the description, the recording head in this embodiment is expressed by binary control of whether or not to eject ink droplets. The same applies to CL ink and colored ink. In this embodiment, whether or not to eject ink droplets for each pixel defined by the printer resolution of the printer 12 is controlled, and a state where it is decided to eject ink droplets to all pixels in a unit area is the ink amount (recording). Amount) shall be handled as 100%. A recording head capable of modulating the ink ejection amount is generally used. However, the above-described binarization process can be applied to a multi-level multi-level process that can be modulated. It is not limited to the value.

  In the formation of the concavo-convex layer of this embodiment, the height is controlled for each position using the above-described concept of the ink amount. When a substantially uniform layer is formed with an ink amount of 100% in the formation of the concavo-convex layer, the layer has a certain thickness (height) according to the volume of the ejected ink. For example, when a layer formed with an ink amount of 100% has a thickness of 15 μm, in order to reproduce a thickness of 75 μm, the layers may be stacked five times. That is, the amount of ink to be ejected to a position where a height of 75 μm is required is 500%.

  FIG. 3 is a diagram for explaining the operation of forming the concavo-convex layer and the image layer by the recording head scanning over the recording medium 808. A layer is formed by the width L of the recording head in the main scanning by the carriage 802, and the recording medium 808 is conveyed by a distance L in the sub-scanning direction every time one line recording is completed. Here, one line is an area where printing is performed by one scan. In order to simplify the explanation, it is assumed that the printer 12 in the present embodiment can only eject ink up to 100% of ink in a single scan. In the case of layer formation exceeding the ink amount of 100%, no conveyance is performed. The same area is scanned multiple times. For example, when the ink amount to be applied is 500% at the maximum, the same line is scanned five times. Referring to FIG. 3, after the area A is scanned five times by the recording head (FIG. 3A), the recording medium 808 is conveyed in the sub-scanning direction, and the main scanning of the area B is repeated five times (FIG. 3). (B))

  In order to suppress image quality deterioration such as periodic unevenness due to drive accuracy of the recording head, so-called multi-pass printing may be performed in which scanning is performed a plurality of times even when the ink amount is 100% or less. FIGS. 3C to 3E show examples of 2-pass printing. In this example, an image is formed by the width L of the recording head in the main scanning by the carriage 802, and the recording medium 808 is conveyed by a distance L / 2 in the sub-scanning direction every time one line recording is completed. Area A is recorded by the m-th main scan (FIG. 3C) and m + 1-th main scan (FIG. 3D) of the recording head, and area B is m + 1-th main scan (FIG. 3 (FIG. 3)). d)) and m + 2 main scanning (FIG. 3E). Here, the operation of two-pass printing has been described, but how many passes are recorded can be changed according to the desired accuracy. When n-pass printing is performed, for example, the recording medium 808 is conveyed by a distance L / n in the sub-scanning direction every time one line of printing is completed. In this case, even if the ink amount is 100% or less, the printing layer is divided into a plurality of printing patterns, and the recording head performs n main scanning on the same line of the recording medium, thereby forming the uneven layer and the image layer. In this embodiment, in order to prevent confusion between the above-described scanning by multi-pass printing and scanning for ejecting 100% or more of ink, multi-pass printing is not performed, and a plurality of scans are performed to stack layers. It will be described as. The recording medium is not particularly limited, and various materials such as paper and plastic film can be used as long as the recording medium can cope with image formation.

  FIG. 4 is a schematic diagram for explaining an uneven layer and an image layer formed by the printer 12. FIG. 4A shows CL ink amount data. Unit areas represented by broken lines are periodically arranged, and each unit area is composed of a convex portion (region that ejects CL ink) and a concave portion (region that does not eject CL ink). The unit areas can be periodically arranged in the same way as a general halftone screen, and can take an arbitrary angle other than those shown in the figure. Moreover, the height of a convex part can take a different value for every place.

  FIG. 5 is a schematic diagram showing a cross-sectional structure of the CL ink amount data and the colored ink amount data. In this embodiment, the printer resolution is 600 dpi, and the width of one dot is 40 μm. Since the unit area of 8 dot width is repeatedly arranged, one structure is about 320 μm. Further, the thickness of one layer in this embodiment is 15 μm, and the height of the convex portion is controlled by changing the number of dots stacked. An image layer is formed on the surface of the concavo-convex layer. In this embodiment, the thickness of the image layer is ignored for the sake of simplicity. Such minute concavo-convex layers and image layers are almost invisible to the observer, and look like a flat printed matter such as paper or cloth.

  FIG. 6 is a schematic diagram illustrating an example of a cross-sectional structure of a printed matter output by the printer 12 based on the ink amount data illustrated in FIG. In the formation process of the concavo-convex layer by the printer 12, the ejected CL ink wets and spreads in the surface direction of the recording medium from landing to curing by UV irradiation. Therefore, the unevenness finally formed has a smooth shape as shown in FIG. Note that the uneven shape shown in FIG. 6 is an example. For example, an uneven shape close to that shown in FIG. 5 can be formed by using a high-viscosity ink that hardly wets and spreads.

  FIG. 7 is a schematic diagram for explaining a mechanism in which anisotropy is exhibited by the printed material formed according to this example. Illumination and observation angles can be expressed by azimuth angle θ and elevation angle φ. In the present embodiment, the direction parallel to the x-axis in FIG. 7 will be described as the azimuth angle θ = 0 °. FIG. 7A is a schematic diagram for explaining shadows that occur when the elevation angle φ of the illumination position changes. The height h of the convex portion shown in FIG. 7A is ½ of the width ws of the unit region. When the elevation angle φ of the illumination position is 0 °, no light is generated because light strikes both the convex portion and the concave portion in the unit region. When the elevation angle φ of the illumination position exceeds 0 °, shade is generated, and when φ exceeds 45 °, all the concave portions are shaded. This change in shade area is perceived as elevation anisotropy. Therefore, in this embodiment, the elevation angle anisotropy of the printed matter is controlled by controlling the height h of the convex portion in the unit region. FIG. 17 is a diagram for explaining a change in the shadow area according to a change in the height of the convex portion formed in the present embodiment. FIG. 17A is a diagram when the height of the convex portion is 2 dots (30 μm), and FIG. 17B is a diagram when the height of the convex portion is 4 dots (60 μm). As shown in the figure, since the shaded area generated by the change in the height of the convex portion changes, the elevation angle anisotropy can be controlled by controlling the height of the convex portion.

  FIG. 8 is a block diagram illustrating a functional configuration of the image processing apparatus 1 in the present embodiment. The acquisition unit 701 acquires image data including color information representing the color of the image and brightness change amount information when the observation angle is changed in the azimuth direction as anisotropic information. FIG. 9 is a schematic diagram illustrating a configuration of image data acquired by the acquisition unit 701. The image data has an arbitrary resolution, and each information is recorded in four different channels. RGB values representing the color information of the object to be reproduced are stored in channels 1 to 3. Here, the RGB values are defined by the standard sRGB. In addition, RGB values defined by AdobeRGB, L * a * b * values defined by CIELAB, and the like can be used. The fourth channel stores a brightness change amount ΔL when the object to be reproduced is observed under different geometric conditions.

Here, an example of image data generation will be described. FIG. 10 is a schematic diagram showing a state in which an object to be reproduced is imaged under a plurality of different geometric conditions. First, the RGB values of the first imaging data obtained by imaging under the geometric condition 1 with the observation angle φ = 0 ° and the illumination angle φ = 60 ° are stored in channels 1 to 3 of the image data acquired by the acquisition unit 701. Can be used as RGB values. Subsequently, as geometric condition 2, only the illumination angle is changed to φ = 20 °, and the object to be reproduced is imaged to obtain second imaging data. The second imaging data can acquire brightness change amount information by taking a difference in brightness from the first imaging data in each pixel. In this embodiment, as the brightness, the RGB value of the imaging data is converted into an L * a * b * value defined in the CIELAB space, and the L * value is the brightness L _{φ = 60 ° of} the first imaging data _{. ,} the brightness L φ _{= 20 °.} The brightness change amount ΔL, which is the difference between the brightness L _{φ = 60 °} and L _{φ = 20 °} , calculated as shown in Expression (1), is stored in the fourth channel of the image data.

ΔL = L _{φ = 60 °} −L _{φ = 20 °} Formula (1)
In this embodiment, the brightness change amount ΔL as described above is used. However, the brightness ratio L _{φ = 60 °} / L _{φ = 20 °} , the change amount of the RGB average value represented by the equation (2), and the like. It is also possible to use.

ここで、ＲＧＢ上部の横棒状の記号バーはＲＧＢ値の平均を表す。また、取得するデータを第１撮像データ及び第２撮像データとし、装置内部の上記方法を用いた演算により明るさ変化量ΔＬに変換する方法も考えられる。

Here, a horizontal bar symbol bar above RGB represents the average of RGB values. Further, a method of converting the acquired data into the first imaging data and the second imaging data and converting the data to the brightness change amount ΔL by the calculation using the above method inside the apparatus is also conceivable.

  The conversion unit 702 performs resolution conversion processing on R, G, B, and ΔL stored in each pixel of the image data acquired by the acquisition unit 701, and converts the image data to the same resolution as the printer resolution of the printer 12. The R, G, B, and ΔL after the resolution conversion process are set as R ′, G ′, B ′, and ΔL ′, respectively. For the resolution conversion process, a method such as a known nearest neighbor method or a bilinear method can be used.

  The first generation unit 703 generates colored ink amount data representing CMYK ink amounts used for printing from the R′G′B ′ value after resolution conversion. For conversion from RGB values to CMYK values, a known conversion method using an LUT (look-up table) can be used.

The second generation unit 704 generates CL ink amount data representing the CL ink amount for forming the convex portion in the unit region using the ΔL ′ value after resolution conversion. As described above, in this embodiment, the printer resolution is 600 dpi, and the width of one dot is 40 μm. In this embodiment, the description will be made assuming that the depth ds and the width ws of the unit area are 8 dots, respectively. This corresponds to a halftone dot having a screen angle of 0 ° and a screen line number of 75 lpi. The convex portion in the unit area in this embodiment is a rectangular parallelepiped having a width w of 4 dots, a depth d of 8 dots, and a height h. The second generation unit 704 calculates an average value ΔL _ave of ΔL ′ for each unit region, and uses the LUT illustrated in FIG. 11A to calculate the height h of the convex portion and the width ws of the unit region with respect to each other. A length ratio (hereinafter referred to as a height / width ratio) is calculated. In the LUT of FIG. 11A, the CL ink amount is determined from the height / width ratio and the width and depth of the convex portion, and a plurality of convex portions having different height / width ratios are formed on the recording medium in advance. It can be created by measuring the brightness.

  The formation control unit 705 causes the printer 12 to form an uneven layer and an image layer based on the color ink amount data and the CL ink amount data.

  FIG. 13 is an example of a unit region in the CL ink amount data generated based on the height / width ratio calculated using the LUT illustrated in FIG. FIG. 13A shows an example when the height / width ratio is 1: 8, and FIG. 13B shows an example when the height / width ratio is 1: 4. In the example in FIG. 13, the uneven protrusions are left-justified in the unit area, but may be right-justified or centered. The CL ink amount data in this embodiment is generated based on the height / width ratio. However, the CL ink amount data may be acquired by storing in advance in a storage device such as the HDD 103 and associating it with the height / width ratio. good. The formation control unit 705 causes the printer 12 to form a concavo-convex layer using CL ink based on the CL ink amount data received from the second generation unit 704. In addition, the formation control unit 705 performs known pass separation processing and halftone processing based on the color ink amount data received from the first generation unit 703, and uses the color ink on the previously formed uneven layer. Thus, the image layer is formed on the printer 12.

  FIG. 14A is a flowchart showing a process flow of the image processing apparatus 1 in the present embodiment. Hereinafter, each step (process) is represented by adding S before the reference numeral.

  In S201, the acquisition unit 701 acquires image data in which the color information R, G, B of the reproduction object and the brightness change amount information ΔL indicating the elevation angle anisotropy are stored in each pixel, and R, G, B, The ΔL value is output to the conversion unit 702. In S202, the conversion unit 702 performs resolution conversion processing on the R, G, B, and ΔL values, calculates R ′, G ′, B ′, and ΔL ′, and sets the R ′, G ′, and B ′ values as the first values. The ΔL ′ value is output to the generation unit 703 and the second generation unit 704.

In step S <b> 203, the first generation unit 703 generates colored ink amount data representing the CMYK ink amounts from the R ′, G ′, and B ′ values, and outputs them to the printer 12. In S204, the second generation unit 704 calculates ΔL ′ _ave by averaging ΔL ′ for each unit region, and calculates the height / width ratio h / ws in the unit region from the ΔL ′ _ave value. Further, the second generation unit 704 generates CL ink amount data representing the CL ink amount of the CL ink for forming the uneven layer based on the calculated h / ws, and outputs the CL ink amount data to the printer 12.

  In step S205, the formation control unit 705 causes the printer 12 to form a concavo-convex layer using CL ink based on the CL ink amount data. In step S206, the formation control unit 705 causes the printer 12 to form an image layer using colored ink on the uneven layer formed in step S205 based on the color ink amount data.

  As described above, it is possible to form a printed matter in which a plurality of the unit regions are arranged side by side so that the height of the convex portions and the arrangement period of the unit regions having the convex portions change according to the brightness change amount. Anisotropy of Further, since the shape of the structure is controlled using only the height / width ratio h / ws, there is an advantage that the calculation is easy and the uneven shape can be flexibly formed even with an arbitrary number of screen lines.

  Further, as an example of the printer 12, a UV curable ink jet method has been described as an example. However, a method such as an electrophotographic method may be used as long as an uneven layer and an image layer can be formed according to the generated ink amount data.

  In this embodiment, image data having color information and brightness change amount information when the observation angle is changed is acquired as the image data to be acquired, but is not limited to the above example. First image data representing color information under a certain geometric condition (for example, illumination angle φ = 60 °) and color information under a geometric condition (for example, illumination angle φ = 20 °) different from the first image data The second image data may be acquired separately, and the brightness change amount when the geometric condition changes may be calculated. Based on the calculated brightness change amount, CL ink amount data is generated. In this case, the image data used to generate the color ink amount data may be selected from the first image data or the second image data, or may be calculated using an average value of the two image data. Can also be used.

  In this embodiment, the L * value calculated from the RGB value is used as the brightness. However, the reflection intensity (reflectance) with respect to the incident light obtained by the spectral radiance measuring device may be used.

  In the present embodiment, the difference in brightness is used as the brightness change amount, but the present invention is not limited to the above example. For example, a brightness ratio may be used as the brightness change amount.

  In this embodiment, in order to acquire the height / width ratio, the LUT in which the average value of the brightness change amount is associated with the height / width ratio is used. However, the present invention is not limited to the above example. Information regarding brightness (brightness information) in a plurality of different geometric conditions may be associated with the height / width ratio. For example, the LUT in which the brightness under the first geometric condition (illumination angle φ = 60 °), the brightness under the second geometric condition (illumination angle φ = 20 °), and the height / width ratio are associated with each other. It may be used.

  In this embodiment, the color ink and the CL ink are used as the recording material to be recorded on the recording medium. However, the present invention is not limited to the above example. As a substitute for the colored ink, a colored material such as a colored toner can be used. Also, a recording material such as achromatic white ink or CL toner can be used in place of the CL ink.

  In this embodiment, the height / width ratio h / ws is used to determine the shape of the convex portion. However, either value is fixed and the height h of the convex portion or the width ws of the unit area is fixed. In either case, the shape of the convex portion or the period for forming the convex portion may be determined.

[Example 2]
In the first embodiment, an example has been described in which image data has a difference in brightness due to a change in elevation angle with reference to observation at an azimuth angle θ = 0 °. In the present embodiment, a method for controlling the anisotropy of the elevation angle at a desired angle by using image data in which the observation angle in the azimuth angle direction is stored in each pixel will be described. Note that the configuration and operation of the image processing apparatus 1 in the present embodiment are the same as those shown in the first embodiment unless otherwise specified, and thus are omitted.

  A processing flow of the image processing apparatus 1 in the present embodiment will be described with reference to FIG.

  In S201, the acquisition unit 701 displays the color information R, G, and B of the reproduction object and the azimuth angle θ of the position that appears brightest when observed, and the elevation angle that represents the change in brightness between the position that appears brightest and the position that appears darkest. Image data in which the brightness change amount ΔL in the direction is stored in each pixel is acquired. In image data, R, G, B, θ, and ΔL values are recorded in five different channels. Further, the R, G, B, ΔL, and θ values are output to the conversion unit 702. As for the azimuth angle θ, it is only necessary to image the object to be reproduced under a plurality of geometric conditions with the azimuth angle changed by 15 ° and store the azimuth angle under the condition that the brightness L is maximum in each pixel.

  In step S202, the conversion unit 702 performs resolution conversion processing on the R, G, B, θ, and ΔL values, and calculates R ′, G ′, B ′, θ ′, and ΔL ′. R ′, G ′, and B ′ are output to the first generation unit 703, and θ ′ and ΔL ′ are output to the second generation unit 704. When converting a plurality of observation directions φ having a high resolution to a low resolution by resolution conversion, an average of angles in each direction may be simply obtained. Conversely, when converting from a low resolution to a high resolution, a known nearest neighbor method or the like may be used.

In step S <b> 203, the first generation unit 703 generates colored ink amount data representing the CMYK ink amounts from R ′, G ′, and B ′, and outputs the data to the printer 12. In S204, the second generation unit 704 calculates ΔL ′ _ave and θ ′ _ave by averaging ΔL ′ and θ for each unit region, and calculates the height / width ratio h / ws from ΔL ′ _ave . Further, the second generation unit 704 generates CL ink amount data representing the CL ink amount for forming the uneven layer based on the calculated θ ′ _ave and the calculated h / ws, and outputs the CL ink amount data to the printer 12. FIG. 15 is a schematic diagram illustrating CL ink amount data generated based on θ ′ _ave and h / ws. A plurality of patterns corresponding to h / ws and θ ′ _ave are created in advance and stored in the memory. FIG. 15 shows a pattern group corresponding to h / ws = 1/8. Further, each pattern group, 'a plurality of patterns corresponding to the _ave, calculated theta' theta CL ink amount data corresponding an _ave is selected.

  In step S <b> 205, the formation control unit 705 causes the printer 12 to perform printing with CL ink based on the CL ink amount data, thereby forming an uneven layer. In step S206, the formation control unit 705 causes the printer 12 to form an image layer using colored ink on the formed uneven layer based on the color ink amount data.

  As described above, the image processing apparatus 1 according to the present embodiment acquires an observation direction as image data to be acquired, and controls anisotropy at a desired angle by controlling the direction of the convex portion in the unit region. A printed matter can be obtained.

[Example 3]
In the above-described embodiments, the method for forming a printed material with controlled elevation angle anisotropy has been described. In this example, a method for forming a printed material in which the azimuth anisotropy is also controlled will be described. Note that the configuration and operation of the image processing apparatus 1 in the present embodiment are the same as those shown in the first embodiment unless otherwise specified, and thus are omitted.

  FIG. 16 is a schematic diagram for explaining a mechanism in which the azimuthal anisotropy of the printed material formed according to this example is developed. FIG. 16A shows an example of a pattern having an uneven shape when the printed material is observed from directly above (position at an elevation angle of 90 °). FIG. 16B and FIG. ) Is a schematic diagram for explaining the appearance when the pattern is observed from a position at an elevation angle of 45 °. Assuming that the azimuth angle θ = 0 ° in the x direction of the printed material, FIG. 16B shows a case where the pattern of FIG. 16A is observed from a direction parallel to the x axis, that is, an azimuth angle θ = 0 °. FIG. On the other hand, FIG. 16C is a diagram when observed from an azimuth angle θ = 90 °. When the illumination angle and the observation angle are in a relation of regular reflection with respect to the recording medium surface, the position of FIG. 16C is compared with FIG. The amount of light observed is small and looks dark. In this embodiment, this mechanism is used to control the azimuthal anisotropy of the printed material.

  A processing flow of the image processing apparatus 1 in the present embodiment will be described with reference to FIG.

In S201, the acquisition unit 701 acquires image data in which the color information R, G, B of the reproduction object, the brightness change information ΔLφ of the elevation angle, and the brightness change information ΔLθ of the azimuth are stored in each pixel, and R , G, B, ΔLφ, ΔLθ values are output to the conversion unit 702. The brightness change amount of the azimuth is acquired as in the first embodiment. The brightness change amount ΔLφ of the elevation angle can be acquired by performing imaging while changing the position of the illumination in the elevation angle direction, as represented by the geometric conditions 3 and 4 in FIG. As the brightness change amount of the elevation angle in this embodiment, the azimuth angle of the illumination position is fixed at θ = 0 °, and the brightness Lφ ₁ when the elevation angle changes from φ ₁ = 60 ° to φ ₂ = 20 ° use the difference between the Lφ _2.

  In S202, the conversion unit 702 performs resolution conversion processing on the R, G, B, ΔLθ, and ΔLφ values, and calculates R ′, G ′, B ′, ΔLθ ′, and ΔLφ ′. R ′, G ′, and B ′ are output to the first generation unit 703, and ΔLθ ′ and ΔLφ ′ are output to the second generation unit 704.

  In step S <b> 203, the first generation unit 703 generates colored ink amount data representing CMYK ink amounts from R ′, G ′, and B ′, and outputs the data to the printer 12.

In S204, the second generation unit 704 calculates ΔLθ ′ _ave by averaging ΔLθ ′ for each unit region, and uses the LUT shown in FIG. 11B to calculate the convex portion in the unit region from ΔLθ ′ _ave. The width / depth ratio (aspect ratio) w / d is calculated.

Here, the relationship between ΔL ′ _ave and the shape of the convex portion will be described. FIG. 12A is a schematic diagram showing the relationship between the brightness change amount ΔLθ ′ _ave representing the degree of anisotropy and the width / depth ratio of the convex portion in the unit area in the present embodiment. As described with reference to FIG. 16, the anisotropy appears due to variations in reflection direction and changes in shadow due to unevenness when the observation angle changes. When the pattern shown in the center of FIG. 12A is repeatedly arranged, the unevenness observed at the azimuth angles θ = 0 ° and θ = 90 ° is the same, so there is no anisotropy. That is, when ΔL is 0, it is appropriate to use this pattern. On the other hand, the pattern shown at the left end of FIG. 12A has many irregularities when observed at an azimuth angle θ = 0 ° and is small at θ = 90 °. That is, the brightness is _{Lθ = 90 °} > _{Lθ = 0 °} , and it is appropriate to use a pattern closer to the left end as ΔL is positive and the value is larger. Conversely, it is appropriate to use the pattern shown at the right end of FIG. 12A when the value of ΔL is negative and large.

Further, the second generation unit 704 calculates ΔLφ ′ _ave by averaging ΔLφ ′ for each position region, and calculates the height of the convex portion from the relationship between ΔLφ ′ _ave and the shadow area ratio A that changes due to the elevation angle change. The length h is calculated. Specifically, A is the area ratio of the shaded area to the shaded area in the unit area, and can be expressed by the following equation (3).

ここで、分母は単位領域一つの面積、分子は仰角変化による陰の面積の変化である。ΔＬφ’と面積比率Ａとの関係は予め測定するなどして保持しておけばよい。図１１（ｂ）は、ΔＬφ’_ａｖｅと陰の面積比率Ａとの関係を表すＬＵＴの一例である。実施例１では、凸部の幅ｗと奥行きｄが固定で合ったため、ΔＬφ’から高さｈを簡易に変換することができた。しかし、本実施例では凸部のｗおよびｄが可変であるため、ＬＵＴ中でｈ／ｗｓとして扱っていた値を、変化する陰の面積比率Ａに置き換えて高さｈを算出する。単位領域内の凸部の高さｈは、図１１（ｂ）に例示するＬＵＴと式（４）に表す面積比率Ａとｈとの関係から算出する。

Here, the denominator is the area of one unit region, and the numerator is the change of the shadow area due to the elevation angle change. The relationship between ΔLφ ′ and the area ratio A may be held by measuring in advance. FIG. 11B is an example of an LUT representing the relationship between ΔLφ ′ _ave and the shadow area ratio A. In Example 1, since the width w and depth d of the protrusions were fixed and matched, the height h could be easily converted from ΔLφ ′. However, since the w and d of the convex portions are variable in the present embodiment, the height h is calculated by replacing the value treated as h / ws in the LUT with the changing shadow area ratio A. The height h of the convex portion in the unit region is calculated from the relationship between the LUT exemplified in FIG. 11B and the area ratios A and h expressed in the equation (4).

そして、第２生成部７０４は、算出したｗ／ｄ及びｈから、凹凸層を形成するためのＣＬインク量を表すＣＬインク量データを生成し、プリンタ１２へ出力する。

Then, the second generation unit 704 generates CL ink amount data representing the CL ink amount for forming the uneven layer from the calculated w / d and h, and outputs the CL ink amount data to the printer 12.

  In step S <b> 205, the formation control unit 705 causes the printer 12 to perform printing with CL ink based on the CL ink amount data, thereby forming an uneven layer. In step S206, the formation control unit 705 causes the printer 12 to form an image layer using colored ink on the formed uneven layer based on the color ink amount data.

  As described above, the image processing apparatus 1 according to the present exemplary embodiment acquires image data in which the brightness change amount of the azimuth angle is stored in each pixel, and further controls the width and depth of the convex portion in the unit area. Further, it is possible to obtain a printed matter in which the azimuth anisotropy is controlled in addition to the elevation anisotropy.

  In this embodiment, the shape of the convex portion in the unit region is a rectangular parallelepiped, but a solid shape such as a quadrangle whose bottom surface can be defined by a width w and a depth d, such as a quadrangular pyramid, a roof shape, a kamaboko shape, etc. Shapes can also be used. If the width and depth are considered to be the base and height of the triangle, respectively, the shape of the convex portion can be a triangular pyramid or a triangular prism.

  Further, as in the pattern shown in the center of FIG. 12B, an example in which a convex portion is not formed when anisotropic reproduction is not necessary is also conceivable.

  Further, when the unevenness can be formed with higher resolution, it is possible to use a cylinder, a cone, a hemisphere, or the like whose bottom is circular or elliptical as illustrated in FIG. In this case, the width / depth ratio w / d can be used, or the roundness or the like can be used as an alternative.

  In this embodiment, the width / depth ratio w / d is used to determine the shape of the convex portion. However, either value is fixed and the convex portion is either the width w or the depth d. The shape may be determined.

[Example 4]
In Example 3, the method for forming a printed matter that was controlled so that the anisotropy of the azimuth angle was developed in addition to the elevation angle was described. In this example, a method for forming a printed matter in which the elevation angle anisotropy related to color is also controlled will be described. Note that the configuration and operation of the image processing apparatus 1 in the present embodiment are the same as those shown in the third embodiment unless otherwise specified, and are omitted.

  FIG. 16B is a schematic diagram for explaining the printed matter formed according to the present embodiment. In this embodiment, by applying different RGB values to the convex image layer and the concave image layer in the unit area, the image formed on the recording medium in accordance with the change in the elevation angle direction of the observation angle φ. Forms a printed matter that changes color.

  FIG. 14B is a flowchart showing the flow of processing of the image processing apparatus 1 in the present embodiment.

  In S301, the acquisition unit 701 obtains the color information R1, G1, B1 at the first observation angle φ1 in the elevation direction of the reproduction object and the color information R2, G2, B2 at the second observation angle φ2 in the elevation direction and the brightness of the azimuth angle. Image data in which the change amount ΔLθ is stored in each pixel is acquired. Then, the R1, G1, B1, R2, G2, B2, and ΔLθ values are output to the conversion unit 702. In this embodiment, the R1G1B1 value of imaging data (captured image 1) obtained by imaging at an elevation angle of φ1 = 45 ° and the R2G2B2 value of imaging data (captured image 2) obtained by imaging at φ2 = 0 ° are used. Shall.

In S <b> 302, the conversion unit 702 performs resolution conversion processing on the values R ₁ , G ₁ , B ₁ , R ₂ , G ₂ , B ₂ , ΔLθ, and R ₁ ′, G ₁ ′, B ₁ ′, R ₂ ′. , G ₂ ′, B ₂ ′, ΔLθ ′. Then, R ₁ ′, G ₁ ′, B ₁ ′, R ₂ ′, G ₂ ′, B ₂ ′ are sent to the first generation unit 703, R ₁ ′, G ₁ ′, B ₁ ′, R ₂ ′, G ₂ ′, B ₂ ′, ΔLθ ′ are output to the second generation unit 704. In step S303, the first generation unit 703 generates first color ink amount data representing the ink value C ₁ M ₁ Y ₁ K ₁ from R ₁ ′, G ₁ ′, B ₁ ′, and R ₂ ′, G _2. Second color ink amount data representing the ink value C ₂ M ₂ Y ₂ K ₂ is generated from “, B ₂ ” and output to the printer 12.

In S <b> 304, the second generation unit 704 calculates ΔLθ ′ _ave by averaging ΔLθ ′ within the unit region, and calculates the width / depth ratio w / d of the convex portion within the unit region from ΔLθ ′ _ave . In S <b> 305, the second generation unit 704 determines the brightness of the elevation angle by the method described above from R ₁ ′, G ₁ ′, B ₁ of the captured image ₁ and R ₂ ′, G ₂ ′, B ₂ ′ of the captured image 2. A change amount ΔLφ ′ is calculated.

  In S306, the second generation unit 704 calculates the height h of the convex portion in the unit region from ΔLφ ′, as in S204 of the third embodiment. Based on w / d and h, CL ink amount data is generated and output to the printer 12. The second generation unit 704 generates mask data for determining whether the predetermined area in the unit area is a convex area or a concave area based on the CL ink amount data, and outputs the mask data to the printer 12. In step S <b> 307, the formation control unit 705 causes the printer 12 to perform printing with CL ink based on the CL ink amount data, thereby forming an uneven layer.

  In step S <b> 308, the formation control unit 705 forms an image layer on the printer 12 on an area corresponding to the convex portion of the uneven layer based on the mask data and the second color ink amount data input from the second generation unit 704. Further, based on the mask data and the second color ink amount data input from the second generation unit 704, an image layer is formed on a region corresponding to the concave portion of the concave / convex layer.

  As described above, in the formed printed matter, the visible area of the image formed in the concave portion changes according to the elevation angle to be observed. Thereby, since the color of the captured image 1 and the color of the captured image 2 are mixed at a ratio corresponding to the angle in the elevation angle direction, the elevation angle anisotropy of the color in addition to the brightness can be controlled.

[Other Examples]
The present invention supplies a program that realizes one or more functions of the above-described embodiments to a system or apparatus via a network or a storage medium, and one or more processors in a computer of the system or apparatus read and execute the program This process can be realized. It can also be realized by a circuit (for example, ASIC) that realizes one or more functions.

DESCRIPTION OF SYMBOLS 1 Image processing apparatus 701 Acquisition part 704 2nd production | generation part

Claims (19)

An image processing apparatus for generating data for forming a concavo-convex layer in which a plurality of unit regions having convex portions are arranged on a recording medium,
First brightness information relating to the brightness of a predetermined region of the object in the first observation direction and the brightness of the predetermined region of the object in a second observation direction that is a direction having an elevation angle different from the first observation direction is obtained. 1 acquisition means;
A first recording amount representing a recording amount of a recording material for forming the uneven layer on the recording medium in which at least one of the width of the unit area and the height of the convex portion changes based on the first brightness information. First generation means for generating data;
An image processing apparatus comprising:   The first brightness information is a difference between brightness of a predetermined area of the object in the first observation direction and brightness of the predetermined area of the object in the second observation direction. An image processing apparatus according to 1.   The first brightness information is brightness of a predetermined area of the object in the first observation direction and brightness of the predetermined area of the object in the second observation direction. Image processing apparatus. The first acquisition means is configured to determine the predetermined area of the object in the second observation direction that is brighter than the brightness of the predetermined area of the object in the first observation direction and the brightness of the predetermined area of the object in the first observation direction. Obtaining means for obtaining the first brightness information relating to the brightness of a region,
Based on the first brightness information, the first generation means has a higher brightness when the uneven layer is observed from the second observation direction than when the uneven layer is observed from the first observation direction. Generating first recording amount data representing a recording amount of a recording material for forming the uneven layer on the recording medium so that at least one of the width of the unit region and the height of the convex portion changes. The image processing apparatus according to any one of claims 1 to 3, wherein the image processing apparatus is characterized.   The first acquisition means includes the predetermined brightness of the predetermined region of the object in the first observation direction and the predetermined of the object in the second observation direction in which the elevation angle is different from the first observation direction and the azimuth angle is equal. 5. The image processing apparatus according to claim 1, wherein the first brightness information relating to the brightness of a region is acquired.   The first generation means represents the recording amount of the recording material for forming the concavo-convex layer on the recording medium in which the ratio of the width of the unit region having the convex portion to the height of the convex portion changes. 6. The image processing apparatus according to claim 1, wherein the first recording amount data is generated.   The image processing apparatus according to claim 1, wherein a bottom surface of the convex portion is any one of a square, a triangle, a circle, and an ellipse.   The said convex part is any one of a rectangular parallelepiped, a quadrangular pyramid, a roof type, a semi-cylindrical type, a triangular prism, a triangular pyramid, a cylinder, a cone, and a hemisphere. An image processing apparatus according to 1.   The image processing apparatus according to claim 1, wherein the brightness is a reflection intensity or a reflectance with respect to light incident on the object. The second brightness related to the brightness of the predetermined area of the object in the third observation direction and the brightness of the predetermined area of the object in the fourth observation direction, the azimuth angle is different from the third observation direction and the elevation angle is the same. A second acquisition means for acquiring the information,
10. The first recording unit according to claim 1, wherein the first generation unit further generates the first recording amount data representing a recording amount of the recording material based on the second brightness information. The image processing apparatus according to one item. Third acquisition means for acquiring an azimuth angle in the second observation direction in which the brightness of the predetermined area of the object is greater than the brightness of the predetermined area of the object in the first observation direction;
The first recording amount data representing the recording amount of the recording material so as to form the concavo-convex layer by rotating the direction of the convex portion by the azimuth angle of the second observation direction. The image processing apparatus according to claim 1, wherein the image processing apparatus generates an image.   2. The apparatus according to claim 1, further comprising first forming means for forming an uneven layer on the recording medium using the recording material based on the first recording amount data representing a recording amount of the recording material. The image processing apparatus according to claim 11.   The image processing apparatus according to claim 1, wherein the recording material is a recording material that is cured by irradiation with ultraviolet rays. Fourth acquisition means for acquiring color information representing the color of the predetermined region of the object in the first observation direction or the second observation direction;
Second generation means for generating second recording amount data representing the recording amount of the color material based on the color information;
Second forming means for forming an image on the concavo-convex layer on the recording medium using the colored color material based on the second recording amount data representing the recorded amount of the colored color material; The image processing apparatus according to claim 12, wherein the image processing apparatus is an image processing apparatus.   The image processing apparatus according to claim 14, wherein the colored color material is a color material that is cured when irradiated with ultraviolet rays.   The said 2nd formation means forms the said image on the said uneven | corrugated layer after the said 1st formation means forms the said uneven | corrugated layer on the said recording medium, The Claim 14 or Claim 15 characterized by the above-mentioned. The image processing apparatus described. Fifth acquisition means for acquiring first color information representing the color of the predetermined area of the object in the first observation direction and second color information representing the color of the predetermined area of the object in the second observation direction. When,
Third generation means for generating mask data for determining whether or not the predetermined region in the concavo-convex layer is a convex portion based on the shape of the convex portion;
First forming means for forming a concavo-convex layer on the recording medium using the recording material based on the first recording amount data;
Based on the first color information and the mask data, a first image representing a color represented by the first color information is formed on the convex portion using a colored material, and the second color information and the mask data are formed. Second forming means for forming a second image representing a color represented by the second color information using the colored color material in an area that is not the convex portion based on mask data;
The image processing apparatus according to claim 1, further comprising: An image processing method of an image processing apparatus for generating data for forming a concavo-convex layer in which a plurality of unit regions having convex portions are arranged on a recording medium,
An acquisition step of acquiring brightness information relating to brightness of a predetermined area of the object in the first observation direction and brightness of the predetermined area of the object in a second observation direction that is a direction having an elevation angle different from that of the first observation direction; ,
Based on the brightness information, recording amount data representing a recording amount of a recording material for forming the concavo-convex layer on the recording medium in which at least one of the width of the unit region and the height of the convex portion changes is generated. Generation step;
An image processing method comprising:   A program for causing a computer to function as each unit of the image processing apparatus according to any one of claims 1 to 17.

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