JP2019195961A - Image processing device, image processing method and program - Google Patents

Abstract

To determine a border in an image including a structure where an image region of one color tone parts an image region of another color tone according to a parting state, and to utilize it to suppress trouble that can occur in a border part of an image of printed matter.SOLUTION: The present invention relates to an image processing device which processes image data in a vector format, the image processing device comprising: first identification means which, when the image data includes a first image region formed with a first color tone and a second image region formed with a second color tone different from the first color tone, identifies a border region of the first image region that adjoins the second image region; second identification means which identifies a position where the first image regions are parted by the second image region in a vector direction of the first image region; and determining means which, among the border regions identified by the first identification means, determines a border region corresponding to the position identified by the second identification means as a first border region and other border regions as second border regions.SELECTED DRAWING: Figure 8

Description

  The present invention relates to an image processing apparatus, an image processing method, and a program.

  In an image forming apparatus such as an inkjet recording apparatus, when an image is formed using a plurality of types of ink, “bleeding” may occur between inks having different color materials. In general, “bleeding” (hereinafter referred to as bleeding phenomenon) occurs from an image side recorded using a low penetrability ink having low permeability to a recording medium to an image side recorded using a high penetrability ink having high penetrability to the recording medium. ) Occurs. As a result, the image quality is degraded.

  Conventionally, in order to suppress the bleed phenomenon, a technique for performing recording using a plurality of inks having different penetrability for the same color material has been proposed. For example, Patent Document 1 divides a black image into a black boundary area adjacent to the color image and a black non-boundary area not adjacent to the color image. Further, it is described that the black boundary region is recorded with the high penetration black ink and the black non-boundary region is recorded with the mixed color of the low penetration black ink and the high penetration black ink.

JP 2002-113850 A

  On the other hand, in an image in which a black image area and a color image area intersect, a processing method for reducing adverse effects that occur in an image in both cases where the black image area is not divided by an adjacent color image area and when the black image area is divided. There is no.

  Therefore, the present invention makes it possible to determine a boundary according to a divided state in an image including a configuration in which an image region of another hue is divided by an image region of a certain hue, and the adverse effect that occurs at the boundary portion in the image in the printed matter It aims at making it possible to use when performing the suppression.

  In order to solve the above problems, the present invention has the following configuration. That is, an image processing apparatus for processing image data in a vector format, wherein the image data includes a first image area formed with a first hue and a second hue different from the first hue. A first specifying means for specifying a boundary area adjacent to the second image area among the first image areas, A second specifying means for specifying a position at which the first image area is divided by the second image area in the vector direction of the first image area; A determining unit configured to determine a boundary region corresponding to the position specified by the second specifying unit among the boundary regions as a first boundary region and a boundary region other than the boundary region as a second boundary region;

  According to the present invention, in an image including a configuration in which an image area of another hue is divided by an image area of a certain hue, it is possible to perform boundary determination according to the divided state, and to suppress adverse effects that occur at the boundary portion in the image in the printed matter It is possible to make it available when performing.

The figure for demonstrating the process with respect to the evil which arises in an image. The figure for demonstrating the principal part of the recording device which concerns on this invention. FIG. 3 is a diagram schematically illustrating a recording control system of the recording apparatus according to the invention of the present application. FIG. 3 is a diagram showing a schematic configuration of image data processing according to the first embodiment. The flowchart of the boundary detection process which concerns on 1st Embodiment. The figure which shows typically the process at the time of performing a boundary detection process. The flowchart of the discrimination process of a black boundary area. Schematic of discrimination of black boundary area. The figure for demonstrating the process with respect to the bad effect which arises in the image which concerns on 2nd Embodiment. The flowchart of the extraction process which concerns on 2nd Embodiment. 10 is a flowchart of color boundary region discrimination processing according to the third embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Although the present embodiment describes an ink jet recording apparatus that uses ink as a recording agent for forming an image, the present invention is not limited to this. When the bleed phenomenon occurs due to the characteristics of the recording agent used for image formation, the recording apparatus using another method or another recording agent may be used.

[About harmful effects caused by images]
In the recording apparatus, color inks such as cyan (C), magenta (M), and yellow (Y) are preferably inks having relatively high permeability to the recording medium from the viewpoint of color uniformity. On the other hand, black (Bk) ink is preferably an ink having relatively low permeability to a recording medium from the viewpoint of color density and fine line quality. However, when an image recorded with low-penetration Bk ink is adjacent to an image recorded with high-penetration color ink, a bleed phenomenon in which Bk ink flows into the color image side occurs, resulting in a reduction in image quality.

  FIG. 1A shows a boundary processing area (hereinafter referred to as black) of a black image (monochromatic 100% duty) adjacent to a color image (monochromatic 100% duty) when low-penetration Bk ink and high-penetration Bk ink are used. An image diagram of the boundary area is shown. It should be noted that the single color 100% duty indicates a ratio of a single color in a certain image area.

  For example, in the method of Patent Document 1 described above, a black image region is divided into a black non-boundary region that is not adjacent to the color image, and black boundary regions 103 and 104 that are adjacent to the color image. Then, the black boundary regions 103 and 104 are recorded with only the high penetration Bk ink, and the black non-boundary region is recorded with a mixed color of the low penetration Bk ink and the high penetration Bk ink. Accordingly, since the high-penetration Bk ink and the high-penetration color ink are adjacent to each other in the black boundary regions 103 and 104, the bleeding phenomenon between the inks having different color materials (penetration) can be suppressed. However, since the black boundary regions 103 and 104 are recorded with only the high penetration Bk ink, the black color development in the boundary region is lowered as compared with the black non-boundary region. As a result, for example, when the black image adjacent to the color image is a black thin line, as shown in the areas 105 and 106 in FIG.

  On the other hand, there is also a method of recording the black boundary region with a mixed color of the high penetration Bk ink and the low penetration Bk ink. Accordingly, it is possible to suppress a decrease in black color development in the black boundary region as compared with the black non-boundary region, and recording can be performed without missing the black fine line adjacent to the color image. However, in this method, not only the high-penetration Bk ink but also the low-penetration Bk ink is used in the black boundary region, so a slight bleeding phenomenon that the low-penetration Bk ink flows into the color image side occurs. In particular, when the color image is a color fine line, as shown in the areas 107 and 108 in FIG.

  Therefore, in the present invention, the black boundary region adjacent to the color image in the black image is distinguished from the black boundary region 103 that is not divided by the adjacent color image and the black boundary region 104 that is divided by the adjacent color image. Then, for each of the black boundary region 103 and the black boundary region 104, image formation is performed by switching the usage ratio of the high penetration Bk ink and the low penetration Bk ink. The ratio of the ink here is not particularly limited, but it is assumed that the inks are combined at a ratio that suppresses the above-described adverse effects.

  FIG. 1 (d) shows a case where the image shown in FIG. 1 (a) is recorded depending on how the black thin line and the color thin line overlap, and the usage ratio of the high penetration Bk ink and the low penetration Bk ink is switched. An example of In the black boundary area 103 where the solid thin line image 102 of the low penetrating Bk ink is not divided by the solid thin line image 101 of the high penetrating color ink, recording is performed with a mixed color of the low penetrating Bk ink and the high penetrating Bk ink. As a result, a bleed phenomenon of low penetrating Bk ink to the color fine line side occurs in the area 107, but the black color reduction in the black boundary area 103 can be reduced, and the main black fine line (solid fine line image 102) is not lost. Can record.

  On the other hand, in the black boundary region 104 where the solid thin line image 102 of the low penetrating Bk ink is divided by the solid thin line image 101 of the high penetrating color ink, recording is performed only with the high penetrating Bk ink. As a result, an area 106 in which the black color development of the black boundary area 104 decreases can be generated, but the main color thin line (solid thin line image 101) can be recorded without being lost. In the following embodiments, the black non-boundary region in the black image region will be described as using low penetrating Bk ink.

<First Embodiment>
[Device configuration]
FIG. 2 is a perspective view showing a schematic configuration of a serial type ink jet recording apparatus (hereinafter referred to as a recording apparatus) 200 according to the present embodiment. In the recording apparatus 200, only the part regarding the image forming part which performs image formation is schematically shown. The ink tanks 207 to 212 include 6 inks of high penetration Bk (Bk1) ink, low penetration Bk (Bk2a) ink, low penetration Bk (Bk2b) ink, yellow (Y) ink, magenta (M) ink, and cyan (C) ink. Each type contains ink. Each Bk ink is a similar color ink having substantially the same hue, and when formed on the recording medium P, it is visually recognized as the same hue. The high penetration Bk ink is an ink having a relatively low surface tension relative to the low penetration Bk ink. That is, the high-penetration Bk ink is an ink that has a relatively high permeability to the recording medium relative to the low-penetration Bk ink. The low penetration Bk (Bk2a) ink and the low penetration Bk (Bk2b) ink have the same or substantially the same permeability. The high penetration Bk (Bk1) ink and the color ink (yellow (Y), magenta (M), cyan (C)) will be described as having the same or substantially the same permeability. Here, inks of colors other than black are collectively referred to as color inks.

  These six types of ink can be supplied from the corresponding ink tanks 207 to 212 to the recording heads 201 to 206. The recording heads 201 to 206 are provided corresponding to six types of ink, and can eject ink supplied from the ink tanks 207 to 212. That is, in the present embodiment, for the same color ink, one recording head that ejects high-penetration Bk ink and two recording heads that eject low-penetration Bk ink are arranged in the main scanning direction X. Note that the form of the recording head is provided integrally with the same color ink so that one nozzle row for ejecting high penetration Bk ink and two nozzle rows for ejecting low penetration Bk ink are arranged in the main scanning direction. It may be a thing.

  In this embodiment, an example using six colors of ink has been described, but the present invention is not limited to this. For example, a configuration corresponding to a larger or smaller number of inks may be used as long as it has a different permeability and includes a plurality of inks of the same color. Further, the capacities of the ink tanks may all be the same, or may differ depending on the color and type of ink. Here, the recording medium will be described using an example in which standard plain paper 2 (manufactured by Canon Inc.) is used, but the present invention is not limited to this. Further, cut paper or roll paper may be used as the recording medium.

  In this embodiment, a combination of a high penetration Bk ink and a low penetration Bk ink will be described, but the present invention is not limited to this. For example, the present invention is applicable when color inks having the same hue and different permeability are used.

  The conveyance roller 220 rotates while sandwiching the recording medium P such as paper together with the auxiliary roller 221 to convey the recording medium P in the Y direction (sub-scanning direction) in FIG. 2 and hold the recording medium P. The carriage 222 can be mounted with ink tanks 207 to 212 and recording heads 201 to 206, and is configured to be able to reciprocate in the X direction (main scanning direction) in FIG. 2 by mounting these recording heads and ink tanks. ing. During the reciprocation of the carriage 222, ink is ejected from the recording head based on the image data, whereby an image is recorded on the recording medium P. During a non-recording operation such as a recovery operation of the recording head, the carriage 222 is controlled to stand by at a home position h indicated by a broken line in FIG.

  The carriage 222 waiting at the home position h records an image on the recording medium P by ejecting ink from the recording head while moving in the x direction in FIG. By one movement (scanning) of the carriage 222, recording is performed on an area having a width corresponding to the arrangement range of the ejection ports of the recording heads 201 to 206.

  When the printing accompanying one scanning in the main scanning direction (X positive direction) of the carriage 222 is completed, the carriage 222 moves toward the home position h and scans in the reverse direction of the main scanning direction (negative X direction). However, recording is performed. Before the next recording scan starts after the previous recording scan ends, the transport roller 220 rotates and the recording medium P is transported in the sub-scanning direction (Y direction) that intersects the main scanning direction. In this way, the image recording on the recording medium P is performed by repeating the recording scanning of the recording head and the conveyance of the recording medium. The recording operation for ejecting ink from the recording heads 201 to 206 is performed based on control by a control unit described later.

  In the above example, the configuration in which the ink tanks 207 to 212 and the recording heads 201 to 206 are detachably mounted on the carriage 222 is shown. However, a configuration in which a cartridge in which the ink tanks 207 to 212 and the recording heads 201 to 206 are integrated is mounted on the carriage may be employed. Further, a form in which a multi-color integrated head capable of ejecting a plurality of colors of ink from one recording head is mounted on the carriage 222 may be employed. Further, the head is not limited to the serial head in which the main scanning direction of the carriage 222 is the X direction, and may be a line type head in which the main scanning direction of the carriage 222 is the conveyance direction (Y direction) of the recording medium P. In the case of a line type head, recording elements are arranged along the X direction by the recording width. A plurality of line-type heads corresponding to the respective colors are arranged along the transport direction (Y direction in FIG. 2).

[Ink composition]
Next, the ink used in this embodiment will be described. Hereinafter, “parts” and “%” are based on mass unless otherwise specified. The composition shown below is an example, and the composition is not limited to this composition as long as the relationship between the inks is the same.

-Preparation of highly penetrating Bk ink (Bk1) (1) Preparation of dispersion First, anionic polymer P-1 [styrene / butyl acrylate / acrylic acid copolymer (polymerization ratio (weight ratio) = 30/40/30) ) Acid value 202, weight average molecular weight 6500]. This is neutralized with an aqueous potassium hydroxide solution and diluted with ion-exchanged water to produce a homogeneous 10% by mass polymer aqueous solution.

  Then, 200 g of the polymer solution, 100 g of carbon black, and 300 g of ion-exchanged water are mixed and mechanically stirred for a predetermined time. Then, the non-dispersed material including coarse particles is removed by centrifugal treatment to obtain a black dispersion liquid. To do. The resulting black dispersion had a pigment concentration of 10% by mass.

(2) Preparation of ink Ink preparation uses the above black dispersion. The following components are added to the above black dispersion, and after sufficiently mixing and stirring, pressure filtration is performed with a microfilter (manufactured by Fuji Film) having a pore size of 2.5 μm to prepare a pigment ink having a pigment concentration of 5 mass%. Thus, the high penetration black ink used by this invention was produced. The surface tension at this time was 28.8 mN / m.
Black dispersion 50 parts Glycerin 10 parts Triethylene glycol 10 parts Acetylene glycol EO adduct (manufactured by Kawaken Fine Chemical Co., Ltd.) 1.0 part Ion-exchanged water balance

-Preparation of low penetration Bk ink (Bk2a and Bk2b) The above black dispersion prepared with high penetration Bk ink is used. The following components are added to the above black dispersion, and after sufficiently mixing and stirring, pressure filtration is performed with a microfilter (manufactured by Fuji Film) having a bore size of 2.5 μm to prepare a pigment ink having a pigment concentration of 3 mass%. Thus, the low penetration Bk ink used by this invention was produced. The surface tension at this time was 39.4 mN / m.
Black dispersion 30 parts Glycerin 10 parts Triethylene glycol 10 parts 2-Pyrrolidone 5 parts Acetylene glycol EO adduct (manufactured by Kawaken Fine Chemical Co., Ltd.) 0.1 part Ion-exchanged water balance

-Preparation of cyan ink (C) (1) Preparation of dispersion First, an AB type block polymer having an acid value of 250 and a number average molecular weight of 3000 is prepared from benzyl acrylate and methacrylic acid as raw materials by using potassium hydroxide. Neutralize with an aqueous solution and dilute with ion exchange water to make a homogeneous 50% by weight polymer aqueous solution.

  200 g of the polymer solution, C.I. I. 100 g of Pigment Blue 15: 3 and 700 g of ion-exchanged water are mixed and mechanically stirred for a predetermined time, and then a non-dispersed material including coarse particles is removed by a centrifugal separation process to obtain a cyan dispersion. The obtained cyan dispersion had a pigment concentration of 10% by mass.

(2) Preparation of ink For the preparation of ink, the above cyan dispersion is used. The following components are added to the above-mentioned cyan dispersion, and after sufficiently mixing and stirring, pressure filtration is performed with a micro filter (manufactured by Fuji Film) having a pore size of 2.5 μm to prepare a pigment ink having a pigment concentration of 2 mass%. Thus, the cyan ink used in this embodiment was produced. The surface tension at this time was 28.5 mN / m.
Cyan dispersion 20 parts Glycerin 10 parts Diethylene glycol 10 parts 2-Pyrrolidone 5 parts Acetylene glycol EO adduct (manufactured by Kawaken Fine Chemical Co., Ltd.) 1.0 part Ion-exchanged water remainder

-Preparation of magenta ink (M) (1) Preparation of dispersion First, an AB type block polymer having an acid value of 300 and a number average molecular weight of 2500 is prepared from benzyl acrylate and methacrylic acid as raw materials, and potassium hydroxide is prepared. Neutralize with an aqueous solution and dilute with ion exchange water to make a homogeneous 50% by weight polymer aqueous solution.

  100 g of the polymer solution, C.I. I. 100 g of CI Pigment Red 122 and 800 g of ion-exchanged water are mixed, mechanically stirred for a predetermined time, and then a non-dispersed material containing coarse particles is removed by centrifugation to obtain a magenta dispersion. The obtained magenta dispersion had a pigment concentration of 10% by mass.

(2) Preparation of ink The ink is prepared using the magenta dispersion. The following components are added to the above magenta dispersion, and after sufficiently mixing and stirring, pressure filtration is performed with a microfilter (manufactured by Fuji Film) having a pore size of 2.5 μm to prepare a pigment ink having a pigment concentration of 4% by mass. Thus, the magenta ink used in this embodiment was produced. The surface tension at this time was 28.3 mN / m.
Magenta dispersion 40 parts Glycerin 10 parts Diethylene glycol 10 parts 2-Pyrrolidone 5 parts Acetylene glycol EO adduct (manufactured by Kawaken Fine Chemicals Co., Ltd.) 1.0 part Ion-exchanged water remainder

Preparation of yellow ink (Y) (1) Preparation of dispersion First, the anionic polymer P-1 was neutralized with an aqueous potassium hydroxide solution and diluted with ion-exchanged water to obtain a homogeneous 10% by mass polymer aqueous solution. Is made.

  300 g of the polymer solution, C.I. I. 100 g of Pigment Yellow 74 and 600 g of ion-exchanged water are mixed and mechanically stirred for a predetermined time, and then a non-dispersed material containing coarse particles is removed by a centrifugal separation process to obtain a yellow dispersion. The resulting yellow dispersion had a pigment concentration of 10% by mass.

(2) Preparation of ink The following components are mixed, sufficiently stirred, dissolved and dispersed, and then filtered under pressure with a micro filter (manufactured by Fuji Film) having a pore size of 1.0 μm, and a pigment having a pigment concentration of 4% by mass. Prepare ink. Thus, the yellow ink used in this embodiment was produced. The surface tension at this time was 28.6 mN / m.
Yellow dispersion 40 parts Glycerin 9 parts Ethylene glycol 10 parts 2-Pyrrolidone 5 parts Acetylene glycol EO adduct (manufactured by Kawaken Fine Chemicals Co., Ltd.) 1.0 part Ion-exchanged water remainder

  The recording apparatus 200 uses two types of inks of different colors (Bk ink) that have different penetrability into the recording medium P when they land on the recording medium P. The high penetration Bk ink (Bk1) is adjusted so that the permeability to the recording medium P is relatively higher than the low penetration Bk ink (Bk2a and Bk2b).

  Control of the permeation speed of the ink used in this embodiment with respect to the recording medium can be performed using the surface tension of the ink as an index. The smaller the surface tension of the ink, the higher the permeation speed with respect to the recording medium, and the larger the surface tension of the ink, the lower the permeation speed with respect to the recording medium. The surface tension can be controlled by adding a penetrating material such as a surfactant or a penetrating solvent. In particular, the surface tension of the high permeability ink is preferably 20 to 35 mN / m, and the surface tension of the low permeability ink is preferably 35 to 50 mN / m. More preferably, the surface tension of the high permeability ink is 25 to 30 mN / m, and the surface tension of the low permeability ink is 35 to 40 mN / m. Therefore, among the inks described above, the highly permeable Bk ink is a highly permeable ink, and the other inks are low permeable inks. If the surface tension of the low penetrating ink is less than 20 mN / m, wetting may occur in the vicinity of the nozzles of the recording head, which may cause problems such as non-ejection of ink and deflection of the ejection direction.

  The “surface tension” described in this specification may be either static surface tension or dynamic surface tension. The static surface tension of the ink is measured using an automatic surface tension meter CBVP-Z (manufactured by Kyowa Interface Science Co., Ltd.) after adjusting the ink temperature to 25 ° C. The dynamic surface tension can be measured by adopting a maximum bubble pressure method in which an air bubble is formed in a liquid and an internal pressure change is measured. As a commercially available measuring device, BBUS-made Bubble Pressure Tesiometer Model: BP2 and the like can be mentioned. In addition, the dynamic surface tension generally stabilizes to the value of the static surface tension while gradually decreasing as the interface formation time (elapsed time from the moment when ink has landed on the recording medium) elapses. Go. According to the study of the present inventor, particularly when the recording medium is plain paper, it has been found that the value of the dynamic surface tension when the interface formation time is about 10 msec affects the image adverse effect such as the bleeding phenomenon.

[Configuration of recording system control system]
FIG. 3 is a diagram showing a schematic configuration of the recording control system of the recording apparatus 200 shown in FIG. The recording apparatus 200 is connected to a data supply apparatus such as a host computer (hereinafter referred to as host PC) 1201 via an interface 1200. The connection method here is not particularly limited, and may be connected to a plurality of external devices via a network (not shown). Various data transmitted from the data supply device, control signals related to recording, and the like are input to the recording control unit 300 of the recording device 200.

  The recording control unit 300 performs processing of image data input via the interface 1200 and processing of a signal input from the head type signal generation circuit 306. The transport motor 301 is a motor for rotating the transport roller 220 for transporting the recording medium P. The carriage motor 302 is a motor for reciprocating the carriage 222 on which the recording heads 201 to 206 are mounted. Motor drivers 303 and 304 are motor drivers for driving the conveyance motor 301 and the carriage motor 302, respectively. The head driver 305 is a head driver that drives the recording heads 201 to 206, and a plurality of head drivers 305 are provided according to the number of recording heads. Therefore, in this embodiment, six head drivers 305 are provided. The head type signal generation circuit 306 supplies a signal indicating the type and number of the recording heads 201 to 206 mounted on the carriage 222 to the recording control unit 300.

[Image processing]
FIG. 4 is a functional block diagram showing a schematic configuration for image data processing in an image processing system including the recording apparatus 200 and the host PC 1201 described above. The recording control unit 300 of the recording apparatus 200 performs data processing transferred from the host PC 1201 in which a printer driver (not shown) is installed via the interface 1200. In the present embodiment, a drawing including vector information having line attribute information, such as a CAD drawing, will be described as an example of a target image for image formation. The resolution of the image shown below is an example, and the present invention is not limited to this.

  As shown in FIG. 4A, the host PC 1201 performs rendering processing 401 at a resolution of 1200 dpi using vector format input image data 400 from an application (not shown). Thereby, the input image data 400 in the vector format is converted into the image data in the bitmap format, and the recording multi-value RGB data 402 is generated. In this embodiment, 256-value bitmap format data recording multi-value RGB data 402 is generated from input image data 400 that is 8-bit RGB data in vector format. The generated multi-value RGB data for recording 402 is transferred to the recording control unit 300 of the recording apparatus 200 via the interface 1200.

  The recording control unit 300 performs color conversion processing 403 for converting the recording multi-value RGB data 402 into multi-value (256 values) KCMY data 404. Next, the multi-value KCMY data 404 is quantized (binarized) by a quantization process 405 (for example, error diffusion process). As a result, binary KCMY data 406 with a resolution of 1200 dpi is generated. By performing boundary processing X407 on the binary K data in the generated KCMY data 406, the black boundary area 103 and the black boundary area 104 as shown in FIG. ) Here, the K data corresponds to the recording data of the high penetrating Bk ink and the low penetrating Bk ink, and the CMY data corresponds to the recording data of the CMY inks (low penetrating ink).

  On the other hand, as shown in FIG. 4B, the host PC 1201 performs specific RGB value image data extraction processing 408 from the input image data 400 on an application (not shown), and extracts specific RGB value image data. Next, the host PC 1201 performs boundary processing Y409 (details will be described later) on the extracted specific RGB value image data. In the present embodiment, as specific RGB value image data extraction processing 408, pure black attribute data is extracted by extracting image data having RGB (0, 0, 0) values from the input image data 400. When the boundary processing Y409 is performed on the pure black attribute data, it is possible to extract pure black attribute data that includes the black boundary region 103 illustrated in FIG. 1A but does not include the black boundary region 104. Next, the quantization process 405 is performed from the rendering process 401 to the multi-value data generated in the boundary process Y409, as in FIG. As a result, binary K data that includes the black boundary region 103 but not the black boundary region 104 is generated in the present embodiment.

  In the present embodiment, the case where RGB (0, 0, 0) is extracted in the specific RGB value image data extraction processing 408 is taken as an example, but the processing is omitted depending on the data format or the like. It may be a configuration. For example, if the input image data 400 is vector format image data having line attribute information, the subsequent boundary processing Y409 is performed without extracting only the data having pure black attribute information and including the color thin line data. Also good. This is because the binary K data subjected to the boundary processing X407 generated in the sequence shown in FIG. 4A is limited to binary data of image data having a pure black attribute, and therefore specific RGB value image data. Even if the extraction process 408 is omitted, the result is the same.

[Processing flow]
The boundary processing according to the present embodiment will be described in detail below.

(Boundary processing X)
FIG. 5 is a flowchart of the boundary detection process of the boundary process X407 according to the present embodiment. FIG. 6 is a diagram schematically showing a process when the boundary processing X407 shown in FIG. 5 is performed on a certain black image (black image region) adjacent to the color image (color image region). This process is executed by the recording control unit 300 of the recording apparatus 200.

  In S501, the recording control unit 300 reads dot recording data. Specifically, binary KCMY data 406 obtained as a result of the quantization process 405 shown in FIG.

  In S502, the recording control unit 300 determines whether black dots and color dots are adjacent in the read dot recording data. In this determination, an area having a predetermined size may be set as the predetermined area, and the entire dot recording data may be sequentially determined for each size. In this case, when it is determined that there is an area where the black dot and the color dot are adjacent to any part of the entire dot recording data, it is determined that they are adjacent. If it is determined that the black dots and the color dots are adjacent (YES in S502), the process proceeds to S503, and if it is determined that they are not adjacent (NO in S502), the process flow ends.

  In S503, the recording control unit 300 extracts black data corresponding to the black ink and color data corresponding to the color ink (CMY inks) from the dot recording data. FIG. 6A is a diagram schematically illustrating an example of the dot recording data of the black ink and the color ink extracted in S503. Here, a case is shown in which a color dot region constituting a color image is formed adjacent to a black dot region constituting a black image.

  In S504, the recording control unit 300 performs a bold process on the color data. Thereby, color bold data (hereinafter referred to as discrimination data) is generated. Here, the bold process is a process of shifting the address of specific data (here, the position of a dot (pixel)) by a predetermined amount in a predetermined direction, and ORing (OR) the specific data before the shift and the specific data after the shift. This is a process of expanding the range of specific data by performing the above. In the present embodiment, as an example of the bold process, a process of shifting the color data by two pixels in the X direction is performed to generate color bold data. Note that the shifting direction differs depending on the adjacent direction of the color data and the black data.

  FIG. 6B is a diagram schematically showing color bold data (discrimination data) generated by executing bold processing on the color data shown in FIG. As can be seen from FIG. 6B, the color bold data (discrimination data) is data in which the color dot portion is expanded by two pixels in the X direction as compared with the color data shown in FIG. . In FIG. 6, since the black area is adjacent to the left side of the color area, the bold process is performed so as to expand (expand) the color area in the left direction. On the other hand, when the adjacent relationship between the black area and the color area is opposite, the bold process is performed so that the color area extends rightward.

  In S505, the recording control unit 300 performs a logical product (AND) process of the black data acquired in S503 and the color bold data generated in S504, and generates black dot boundary area data (black boundary area data). To do.

  FIG. 6C is a diagram schematically showing black boundary region data obtained by performing a logical product process of the dot recording data shown in FIG. 6A and the color bold data shown in FIG. 6B. is there. In the dot recording data, a pixel array of black dots other than the black boundary region is defined as a “black non-boundary region” as shown in FIG.

  In S506, the recording control unit 300 stores the position of the black boundary area specified from the black boundary area data generated in S505.

  In step S507, the recording control unit 300 stores the positions of black dots other than the black boundary region specified from the black boundary region data generated in step S505 as black non-boundary regions. Then, this processing flow ends.

  In this embodiment, when it is determined in S502 that the black dots and the color dots are not adjacent, the boundary processing is not performed on the recording data. In the present embodiment, the case where the bold processing of the color data in S504 is expanded by 2 pixels in the X direction is described, but it may be expanded by 4 pixels in the X direction, and the number of pixels to be expanded is not limited to this. . However, the larger the number of pixels to be expanded, the larger the black boundary region 104 shown in FIG. For this reason, the image adverse effect area as shown in the area 106 in FIG. 1D as a recording product tends to be conspicuous. Therefore, it is preferable to fit within four pixels in the X direction.

(Boundary processing Y)
FIG. 7 is a flowchart of the boundary detection process of the boundary process Y409 according to the present embodiment. This processing is processing relating to determination of how the black image and the color image overlap when the input image data 400 is in the vector format and the line attribute information is included in the black thin line image. With this process, in the black boundary region, the black boundary region 103 that is not divided by the adjacent color image and the black boundary region 104 that is divided by the adjacent color image can be distinguished. This process is realized by the CPU (not shown) of the host PC 1201 reading and executing a program stored in a storage unit such as a memory (not shown).

  In step S <b> 701, the host PC 1201 performs line width compression processing on vector-format multi-value input image data 400 having line attribute information. The line width compression process here is not particularly limited as long as the vector direction (stretching direction) of the line can be specified. For example, the compression ratio may be defined corresponding to the number of pixels expanded by the bold processing in S504 of FIG.

  In step S702, the host PC 1201 performs inversion processing on the multivalued image data that has been subjected to the line width compression processing in step S701.

  In step S <b> 703, the host PC 1201 performs a logical product (AND) process on the multi-value image data obtained in step S <b> 702 and the input image data 400, and extracts an edge region in the vector direction from the input image data 400. . Here, the vector direction indicates the extending direction of the line.

  In step S704, the host PC 1201 performs rendering processing on the extracted edge area, and generates binary data of the edge area in the vector direction.

  In step S <b> 705, the host PC 1201 acquires black boundary area data stored in the recording control unit 300 of the recording apparatus 200. The black boundary area data is generated by the process of FIG. 5 and includes both the black boundary area 103 and the black boundary area 104 shown in FIG. Although acquisition of black area data here is not shown in FIG. 4B, it is assumed that the host PC 1201 can acquire it from the recording control unit 300 of the recording apparatus 200.

  In step S <b> 706, the host PC 1201 performs a logical product (AND) process on the binary data generated in step S <b> 704 and the black boundary region data acquired in step S <b> 705, and extracts only the region corresponding to the black boundary region 103. Specifically, as a result of performing the logical product process, among the black boundary areas acquired in S705, the black boundary areas in which all pixels (dots) match the value of the binary black data generated in S704 are: An area corresponding to the black boundary area 103 is extracted. In other words, among the black boundary areas included in the black boundary area data, the black image is divided by the color image in the black boundary areas where some of the pixels (dots) do not match the value of the binary black data generated in S704. This is a black boundary region at the position where the position is set.

  In S707, the host PC 1201 extracts data other than the area extracted in S706 from the black boundary area data acquired in S705 as an area corresponding to the black boundary area 104. Then, this processing flow ends.

  With this processing, it is possible to distinguish between the black boundary region 103 and the black boundary region 104 in the black boundary region.

  The processing in FIG. 7 will be described in more detail with reference to FIG. Here, vector-type multi-valued input image data 400 having line attribute information will be described by limiting it to black thin lines. In this embodiment, in FIG. 7, the input image data 400 includes multi-value image data having line attribute information as input values, and color thin line data is included without extracting only data having pure black attribute information. He said that it could be left alone. However, the present invention is not limited to this configuration, and only black thin lines having line attribute information in the input image data 400 may be limited as processing targets. In this case, since the other input value to be subjected to the logical product (AND) processing in S706 is limited to the black image, the input image data 400 may not be limited to the black thin line. Further, as in the present embodiment, there is no problem as multi-value image data having line attribute information including color fine lines and black fine lines.

  FIG. 8A shows an example of multi-value input image data 400. Here, one horizontal line composed of multi-value black data and two vertical lines composed of multi-value color data are included. The straight line made of black data is arranged so as to divide the straight line made of left color data, and is arranged so as to be divided from the straight line made of right color data.

  FIG. 8B shows a state in which multi-value black data (multi-value black thin line image) extracted from the input image data 400 is extracted. When the line width compression processing in S701 of FIG. 7 is performed on this multi-value black thin line image, the state shown in FIG. 8C is obtained. Furthermore, when the inversion process in S702 of FIG. 7 is performed, black multi-value data shown in FIG. 8D is obtained.

  When the logical product (AND) processing of the multi-value black thin line image shown in FIG. 8B and the black multi-value data shown in FIG. 8D is performed, the information shown in FIG. 8E is obtained. . That is, information on the edge region (end portion in the longitudinal direction of the line) of the multi-value black thin line is obtained. Further, by binarizing the data of FIG. 8E, binary data of black thin lines is obtained as shown in FIG. 8F.

  On the other hand, by performing the boundary processing X407 shown in FIG. 5 from the input image data 400, black boundary region data shown in FIG. 8G is obtained. As described above, in the black boundary region data shown in FIG. 8G, the black boundary region 103 and the black boundary region 104 are not distinguished in the black boundary region.

  Then, the information shown in FIG. 8H is obtained by performing AND processing (S706 in FIG. 7) on the data shown in FIG. 8F and the data shown in FIG. 8G. Specifically, among the black boundary areas, a black boundary area that includes both “0” and “1” as a result of the AND process can be identified as an area corresponding to the black boundary area 104. Therefore, it is possible to acquire information on an area corresponding to the black boundary area 103 among the black boundary areas. This makes it possible to distinguish between the black boundary region 103 that is not divided by the adjacent color region and the black boundary region 104 that is divided by the adjacent color region.

  Using the above identification result, in this embodiment, the area corresponding to the black boundary area 103 is recorded as a mixed color of the low penetration Bk ink and the high penetration Bk ink. As a result, the black color reduction in the black boundary region 103 can be reduced, and the main black thin line (solid thin line image 102) can be recorded without being lost. On the other hand, the black boundary area 104 is recorded only with the high penetration Bk ink. As a result, recording can be performed without any loss of main color fine lines.

  As described above, according to the present invention, in an image including a configuration in which an image area of another hue is divided by an image area of a certain hue, boundary determination according to the division state can be performed. By using this determination result, it is possible to suppress adverse effects that occur at the boundary portion in the image in the printed matter.

<Second Embodiment>
In the first embodiment, the standard plain paper 2 (manufactured by Canon Inc.) is used as a recording medium, and the input image data is vector format data, that is, the black thin line image includes line attribute information. The method was described. In the second embodiment, extraction of a color boundary area adjacent to the black boundary area 103 among the color boundary areas on the color image side that is more effective when using plain paper with low permeability will be described. Note that a description of the same parts as those in the first embodiment will be omitted.

  When recording a CAD drawing, which is a target image for image formation, plain paper that is inexpensive, does not contain divalent metals, and has low permeability may be used. In the present embodiment, an example in which IJM021 (Oce plain paper) is used as a recording medium will be described.

  FIG. 9A shows an example of image data according to the present embodiment. Here, one solid thin line image 102 (single color 100% Duty) in the horizontal direction composed of a solid image with low penetrating Bk ink and two solid thin line images 101 (single color 100 in the vertical direction composed of a solid image with high penetrating color ink). % Duty). The solid thin line image 102 by the low penetration Bk ink is arranged so as to separate the left color solid thin line image, and is arranged so as to be separated from the right color solid thin line image. FIGS. 9B and 9C show a state in which the phenomenon described with reference to FIGS. 1B and 1C in the first embodiment is shown in the image of FIG. 9A.

  FIG. 9D shows the use ratio of the high penetration Bk ink and the low penetration Bk ink in the boundary area of the solid penetration line image 102 of the low penetration Bk ink adjacent to the solid fine line image 101 of the high penetration color ink in this embodiment. It is an image figure at the time of switching and recording. In the black boundary region 103, recording with a mixed color of the low-permeability Bk ink and the high-permeability Bk ink may cause a bleeding phenomenon (region 107) of the low-permeability Bk ink to the color thin line side. However, the black color reduction in the black boundary region 103 can be reduced, and the main black fine line in contact with the fine color line can be recorded without being lost. However, on plain paper with low permeability such as IJM021, the mixed color of the low penetration Bk ink and the high penetration Bk ink recorded in the black boundary region 103 is difficult to be absorbed by the recording medium. Therefore, due to the occurrence of the bleed phenomenon (region 107), the main black thin line in contact with the color thin line becomes too thick.

  Therefore, in the present embodiment, as shown in FIG. 9E, among the color boundary areas 109 and 110 adjacent to the black image, the dots of the color boundary area 109 adjacent to the black boundary area 103 are thinned out, and the black boundary The area 103 is recorded only with the low penetration Bk ink. Thereby, there is no fear that the bleed phenomenon occurs in the region 107. As a result, as shown in FIG. 9G, the color solid thin line image 101 lacks only the color boundary region 109, but the main black solid thin line image 102 in contact with the color solid thin line image 101 is missing. Things will disappear. Therefore, the black thin line can be recorded without becoming too thick.

  On the other hand, the black boundary area 104 is recorded only with the high penetration Bk ink. As a result, as shown in FIG. 9G, the black color development in the black boundary region 104 can be reduced in the region 106, but the main color fine line in contact with the black fine line can be recorded without being lost. At this time, the thinning process is not performed on the color boundary region 110 adjacent to the black boundary region 104 among the color boundary regions 109 and 110 adjacent to the black image.

[Extraction process]
FIG. 10 is a flowchart showing an area extraction process corresponding to the color boundary area 109 according to this embodiment. This process is realized by the CPU (not shown) of the host PC 1201 reading and executing a program stored in a storage unit such as a memory (not shown).

  In step S1001, the host PC 1201 acquires information on an area corresponding to the black boundary area 103 obtained in step S706 of FIG. 7 described in the first embodiment. This corresponds to the information shown in FIG.

  In S1002, the host PC 1201 performs bold processing on the area acquired in S1001. The bold processing method here is the same as S504 in FIG. 5 described in the first embodiment. In the case of the example in FIG. 9, the bold process is performed so that the black boundary region expands in the vertical direction.

  In step S <b> 1003, the host PC 1201 performs a logical product (AND) process on the data processed in step S <b> 1002 and the binary color data generated by the recording control unit 300 of the recording apparatus 200. Thereby, only the information of the color boundary area 109 adjacent to the area corresponding to the black boundary area 103 is generated. Then, this processing flow ends.

  It is possible to generate image data as shown in FIG. 9F by performing the thinning process on the color solid thin line image 101 using the information of the color boundary region 109 obtained by the above processing flow. Become. In this case, the region corresponding to the black boundary region 103 can be handled as not being a boundary region.

  In this embodiment, using the above results, image formation is performed using different inks for each region.

  As described above, according to the present embodiment, even when plain paper with low penetrability is used, it is possible to suppress adverse effects that occur during image formation.

<Third Embodiment>
In the third embodiment, a mode for discriminating between the color boundary area 109 and the color boundary area 110 among the color boundary areas on the color image side as shown in FIG. 9E will be described. Note that description of the same parts as those in the first and second embodiments is omitted.

[Distinction process]
FIG. 11 is a flowchart showing the color boundary region discrimination processing according to the present embodiment. The same reference numerals are assigned to the same steps as the processing of FIG. 7 described in the first embodiment. This process is realized by the CPU (not shown) of the host PC 1201 reading and executing a program stored in a storage unit such as a memory (not shown).

  In step S1101, the host PC 1201 reads dot recording data corresponding to the input image data 400. Specifically, binary KCMY data 406 obtained as a result of the quantization process 405 shown in FIG. Further, the host PC 1201 determines whether or not the black image and the color image are adjacent to each other in a predetermined area. The determination here may use the processing result by the processing of FIG. 5 described in the first embodiment. When the black image and the color image are adjacent to each other, the host PC 1201 extracts black data and color data based on the dot recording data.

  In step S1102, the host PC 1201 performs bold processing on the binary black data. Thereby, black bold data (discrimination data) is generated. The bold processing method here is the same as S504 in FIG. 5 described in the first embodiment.

  In step S1103, the host PC 1201 performs a logical product (AND) process on the color data acquired in step S1101 and the black bold data generated in step S1102, and generates color dot boundary area data (color boundary area data). The color boundary area data generated here corresponds to data including the color boundary area 109 and the color boundary area 110.

  In step S1104, the host PC 1201 performs a logical product (AND) process on the color boundary area data obtained in step S1103 and the binary data generated in step S704, so that the color boundary area 109 adjacent to the black boundary area 109 is processed. Only the corresponding area is extracted. In this step, the extraction process shown in FIG. 10 of the second embodiment may be performed to generate only the color boundary region 109.

  In step S1105, the host PC 1201 extracts data other than the region extracted in step S1104 from the color boundary region data acquired in step S1103 as a region corresponding to the color boundary region 110. Then, this processing flow ends.

  With this processing, it is possible to distinguish the color boundary area 110 from the area corresponding to the color boundary area 109 in the color boundary area.

  Based on the above results, it is possible to suppress the adverse effects that occur during image formation by switching the ink when performing image formation for each color region, or by thinning out the images in the color region.

<Other embodiments>
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 But it is feasible. It can also be realized by a circuit (for example, ASIC) that realizes one or more functions.

DESCRIPTION OF SYMBOLS 200 ... Image forming apparatus, 201-206 ... Recording head, 207-212 ... Ink tank, 222 ... Carriage, 300 ... Recording control part, 301 ... Conveyance motor, 302 ... Carriage driver, 303-304 ... Motor driver, 305 ... Head Driver, 306 ... Head type signal generation circuit, 1200 ... Interface, 1201 ... Host PC

Claims (15)

An image processing apparatus for processing image data in a vector format,
The image data includes a first image area formed with a first hue and a second image area formed with a second hue different from the first hue. A first specifying means for specifying a boundary area adjacent to the second image area in the first image area;
Second specifying means for specifying a position at which the first image area is divided by the second image area in the vector direction of the first image area;
Of the boundary areas specified by the first specifying means, the boundary area corresponding to the position specified by the second specifying means is the first boundary area, and the other boundary areas are the second boundary areas. An image processing apparatus comprising: determination means for determining as a boundary region. The first specifying means includes:
Extracting binary data of the first image area and binary data of the second image area from binary data obtained by binarizing the image data in the vector format,
The second image area is expanded by performing a bold process on the binary data of the second image area,
The boundary area of the first image area is specified by performing a logical product process on the binary data of the first image area and the binary data of the expanded second image area. The image processing apparatus according to claim 1. The second specifying means includes:
Binary data of an image obtained by performing a line width compression process on the first image area and further performing an inversion process, and 2 of the first image area not subjected to the line width compression process and the inversion process. By performing AND processing with value data, the edge region of the first image region is specified,
Using the boundary area of the first image area specified by the first specifying means and the edge area of the first image area, the first image area is changed by the second image area. The image processing apparatus according to claim 2, wherein adjacent positions are identified without being divided. A first recording agent for forming an image of the first hue and a second recording agent for forming an image of the first hue having a lower permeability to a recording medium than the first recording agent. Recording agent, and
The ratio of the first recording agent to the second recording agent in the case of forming the first boundary region is greater in the ratio of the first recording agent than in the case of forming the second boundary region. The image processing apparatus according to claim 1, wherein the image processing apparatus is processed so as to increase the number of the image processing apparatus.   The image processing apparatus according to claim 4, wherein an area other than the first boundary area in the first image area is processed so as to be formed by the second recording agent. . A third specifying means for specifying, as a third boundary area, an area adjacent to the second boundary area in the second image area;
4. The image processing apparatus according to claim 1, wherein the image processing apparatus performs processing so as to form an image by thinning out the image of the third boundary area from the second image area. 5. A first recording agent for forming an image of the first hue and a second recording agent for forming an image of the first hue having a lower permeability to a recording medium than the first recording agent. Recording agent, and
When the first boundary region is formed, the ratio of the first recording agent to the second recording agent forms a region other than the first boundary region in the first image region. The image processing apparatus according to claim 6, wherein the processing is performed so that the amount of the first recording agent is larger than that of the case.   The determination unit further sets a region adjacent to the first boundary region in the second image region as a fourth boundary region, and a region adjacent to the second boundary region in the second image region. The image processing apparatus according to claim 1, wherein the image processing device is determined as a third boundary region. The first hue is black;
The image processing apparatus according to claim 1, wherein the second hue is a color other than black.   An image forming apparatus comprising the image processing apparatus according to claim 1. The image forming apparatus includes an image forming unit capable of forming an image using a plurality of recording agents corresponding to the first hue and at least one recording agent corresponding to the second hue,
The image forming apparatus according to claim 10, wherein the plurality of recording agents corresponding to the first hue have different penetrability with respect to a recording medium. The image forming apparatus is an ink jet recording apparatus that uses ink as a recording agent,
The first ink of the plurality of inks corresponding to the first hue and the at least one ink corresponding to the second hue are the second of the plurality of inks corresponding to the first hue. The image forming apparatus according to claim 10, wherein the image forming apparatus has higher permeability to a recording medium than ink. The penetrability of the ink into the recording medium is controlled by the surface tension of the ink,
The surface tension of the first ink and at least one ink corresponding to the second hue is 20 to 35 mN / m,
The image forming apparatus according to claim 12, wherein the surface tension of the second ink is controlled to be 35 to 40 mN / m. An image processing method for processing image data in a vector format,
The image data includes a first image area formed with a first hue and a second image area formed with a second hue different from the first hue. A first specifying step of specifying a boundary region adjacent to the second image region out of the first image region;
A second specifying step of specifying a position at which the first image region is divided by the second image region in the vector direction of the first image region;
Of the boundary regions specified in the first specifying step, the boundary region corresponding to the position specified in the second specifying step is the first boundary region, and the other boundary regions are the second And a determination step of determining the boundary region. On the computer,
The image data in vector format includes a first image area formed with a first hue and a second image area formed with a second hue different from the first hue. A first specifying step of specifying a boundary region adjacent to the second image region out of the first image region,
A second specifying step of specifying a position at which the first image region is divided by the second image region in the vector direction of the first image region;
Of the boundary regions specified in the first specifying step, the boundary region corresponding to the position specified in the second specifying step is the first boundary region, and the other boundary regions are the second The program for performing the determination process determined as a boundary area.

Images