JP4100959B2 - Image forming method, image forming program, and image forming control apparatus - Google Patents

Description

【００３８】
【数２】

これら数式を演算することにより、ＣＭＹ値が得られる。尚、Ｋ（ブラック）の信号値の決定方法としては様々な方法がある。例えば、上記行列式における最右辺を、そのベクトル要素のそれぞれからＫ値を引いたベクトル［Ｄｒ−Ｋ Ｄｇ−Ｋ Ｄｂ−Ｋ］ｔに置き換え、インク量に対応する各色信号値ＣＭＹが常に正または０であるという条件を利用してＫ値に拘束を加えつつ、試行鎖誤的にマスキングマトリクスを求めることにより、Ｋ値を決定することができる。尚、色分解処理部４０３は、ＬＵＴを使用して実現することももちろん可能である。
【００３９】
本実施形態ではメディアの種類により適正インク量が異なるため色分解テーブル部４０８に、メディア毎のＬＵＴとして複数の色分解テーブルを保持している。
【００４０】
４．出力ガンマ補正処理部
次に、プリンタ用補正処理部３０２内の出力ガンマ補正処理部４０４における処理について説明する。
【００４１】
出力ガンマ補正処理部４０４においては、入力画像の色信号をカラーマッチング処理部４０２及び色分解処理部４０３で順次変換して出力されたＣＭＹＫ各８ビットデータを、後段のハーフトーン処理部４０５において処理可能でデータへと変換し、Ｃ'Ｍ'Ｙ'Ｋ'各８ビットデータを出力する。ハーフトーン処理部４０５は、明度に対する非線形特性を補償すべく、インク別に一次元のＬＵＴを用いた調整を行う。
【００４２】
本実施形態では、メディアの種類により明度の非線形特性が異なるため、ガンマ補正テーブル部４０９にメディア毎のＬＵＴとして複数のガンマ補正テーブルを保持している。
【００４３】
５．ハーフトーン処理部
次に、プリンタ用補正処理部３０２内のハーフトーン処理部４０５における処理について説明する。
【００４４】
ハーフトーン処理部４０５においては、入力画像の色信号をカラーマッチング処理部４０２、色分解処理部４０３及び出力ガンマ補正処理部４０４で順次変換され出力されたＣ'Ｍ'Ｙ'Ｋ'各８ビットデータを、プリンタ１０８で印刷可能なＣ"Ｍ"Ｙ"Ｋ"各２ビットデータへと変換する。
【００４５】
このハーフトーン処理方法としては、入力されたＣ'Ｍ'Ｙ'Ｋ'の画像に、例えばベイヤー型の１６×１６のマトリクスをそれぞれあてがい、このマトリクスの要素よりも対応する画像上の画素値が大きい場合には１、画素値が前記マトリクスの要素以下の場合には０とすることによって実現される。また、別のハーフトーン処理方法として誤差拡散法などを用いることもできる。
【００４６】
このようにして得られたプリンタで印刷可能なＣ"Ｍ"Ｙ"Ｋ"各２ビットデータはプリンタ１０８に送られ、メディア上に画像形成される。
【００４７】
６．メディア別テーブル
メディアの種類別に用意されるテーブルは、マッチングテーブル部４０７、色分解テーブル部４０８及びガンマ補正テーブル部４０９にそれぞれ格納される。マッチングテーブル部４０７には、メディアの色再現空間（ガマット）の大きさや形状ごとにテーブルが用意される。また、色分解テーブル部４０８には、メディアのインク打込み量ごとにテーブルが用意される。そして、ガンマ補正テーブル部４０９には、メディアの特性ごとにテーブルが用意される。
【００４８】
これら複数のテーブルの中から、印刷時に指定されるメディアの種類に対応するテーブルが選択される。
【００４９】
７．対応メディアの追加
上述の画像形成システムにおいて、対応メディアを新規に追加するための処理について図７を用いて説明する。
【００５０】
ステップＳ７０１：画像形成に用いられる色材の記録媒体への定着状態を判断するためのテストパターンを発生し、テストパターンの複数を、それぞれ異なる量の色材を用いて録媒体上に形成させる。具体的には、インク打込み量判定テストパターン（図８）の画像データを、追加対象のメディア上に画像形成する。例えば、ＨＤＤ１０４に格納されているテストパターンの画像データを読み出し、読み出された画像データをプリンタドライバ２０８により画像処理し、対象メディアのセットされたプリンタ１０８によりテストパターンを画像形成する。
【００５１】
ステップＳ７０２：インク打込み量判定テストパターンの形成されたメディアを目視し、追加メディアの適正インク打込み量を判定する。なお、不図示の画像読取装置に当該メディアを設定して読み取り、読み取られたテストパターンと、予め設定された「にじみ」状態に関する画像データとを比較することにより、好適なインク打ち込み量をＣＰＵ１０１が判定してもよい。
【００５２】
ステップＳ７０３：色分解テーブル選択部４１０は、ステップＳ７０２で判定されたインク打込み量を、例えば、操作部１０７から入力する。入力されたインク打ち込み量に対応する色分解テーブルが色分解テーブル部４０８に存在すればステップＳ７０４に移行し、存在しなければステップＳ７０５に移行する。具体的には、各テーブルの識別情報と各テーブルのインク打ち込み量とを対応付けたデータベースを、ＲＡＭ１０２やＨＤＤ１０４に格納しておき、入力されたインク打ち込み量と一致するテーブルを色分解テーブル選択部４１０が検索処理により抽出してもよい。
【００５３】
ステップＳ７０４：色分解テーブル選択部４１０により選択された色分解テーブルを、追加メディアの色分解テーブルとして新たに色分解テーブル部４０８に登録する。
【００５４】
ステップＳ７０５：テーブル作成部４１１は、ステップＳ７０２で判定されたインク打込み量に前後する色分解テーブルを２つ選択し、２つの色分解テーブルを補間演算することにより該当インク打込み量の色分解テーブルを生成し、追加メディア用の色分解テーブルとして新たに色分解テーブル部４０８に登録する。
【００５５】
ステップＳ７０６：ガマット判定部４１２は、ステップＳ７０４もしくはステップＳ７０５で新たに登録された色分解テーブルにおける追加メディアの色再現空間（プリンタガマット）の大きさを判定する。
【００５６】
ステップＳ７０７：マッチングテーブル選択部４１３は、ステップＳ７０６で判定された追加メディアの色再現空間の大きさに対応するマッチングテーブルを、マッチングテーブル部４０７から選択し、追加メディアのマッチングテーブルとして新たにマッチングテーブル部４０７に登録する。
【００５７】
以上のステップにより新規の対応メディアの追加作業が行われる。
【００５８】
８．インク打込み量判定テストパターン
インク打込み量判定テストパターンは、単色面、背景及び文字などの細線を組み合わせたものからなり、特定のガンマ補正テーブル下で、所定のインク打込み量となるよう調整されたＣＭＹＫの画像データである。この画像データは、特定のガンマ補正テーブルを設定された出力ガンマ補正処理部４０４に入力することにより印字出力される。
【００５９】
テストパターンの単色面を用いて、メディアのインク吸収限界を判定することができる。例えば、インク打ち込み量がメディアの吸収限界を超えると、一様な単色面が「むら」となる。従って、この「むら」が単色面に存在すると、インクの打ち込み量が多すぎると判定できる。テストパターンの背景と文字などの細線を用いれば、インクの「にじみ」状態を判定することができる。例えば、細線がぼやけていたりすれば、インクが滲んでいることになろう。背景と文字の色の組み合わせとしては、ＲＧＢなどの２次色や、さらにＫを加えた３次色を用い、それぞれが隣接するように配置すればよい。これにより、隣接する色の境界での「にじみ」を目視確認し判定する。
【００６０】
図８は、テストパターンが表面に画像形成されたメディアの一例である。この例では、テストパターンの横に、各種打込み量（１５０％，１７５％，２００％，２２５％，２５０％）をも画像形成している。このように、一枚のメディアに、それぞれ打ち込み量の異なる複数のテストパターンを形成しているので、メディアの適正インク打込み量を容易に目視で判断できよう。
【００６１】
（他の実施形態）
上述の実施形態では、色材としてインクを用いる場合を例に説明したが、トナーなど他の色材についても同様に本願発明を適用できることはいうまでもない。
【００６２】
前述した実施形態の各機能を実現するソフトウエアのプログラムコードを記録した記憶媒体を、システムあるいは装置に供給し、そのシステムあるいは装置のコンピュータ（またはＣＰＵやＭＰＵ）が記憶媒体に格納されたプログラムコードを読み出して実行することによっても、本願発明の目的が達成されることは言うまでもない。この場合、記憶媒体から読み出されたプログラムコード自体が本願発明の新規な機能を実現することになり、そのプログラムコードを記憶した記憶媒体は本願発明を構成することになる。
【００６３】
プログラムコードを供給するための記憶媒体としては、例えば、フレキシブルディスク、ハードディスク、光ディスク、光磁気ディスク、ＣＤ−ＲＯＭ，ＣＤ−Ｒ、磁気テープ、不揮発性のメモリカード、ＲＯＭなどを用いることができる。
【００６４】
また、コンピュータが読み出したプログラムコードを実行することによって、前述した実施形態の機能が実現される他、そのプログラムコードの指示に基づき、コンピュータ上で稼動しているＯＳなどが実際の処理の一部または全部を行い、その処理によっても前述した実施形態の機能が実現され得る。
【００６５】
さらに、記憶媒体から読み出されたプログラムコードが、コンピュータに挿入された機能拡張ボードやコンピュータに接続された機能拡張ユニットに備わるメモリに書き込まれた後、そのプログラムコードの指示に基づき、その機能拡張ボードや機能拡張ユニットに備わるＣＰＵなどが実際の処理の一部または全部を行い、その処理によっても前述した実施形態の機能が実現され得る。
【００６６】
なお、本願発明は、前述した実施形態の機能を実現するソフトウエアのプログラムコードを記録した記憶媒体から、そのプログラムをパソコン通信など通信回線を介して要求者にそのプログラムを配信する場合にも適用できることは言うまでもない。
【発明の効果】
本発明によれば、専用の画像処理テーブルもしくは専用の画像処理装置を用意していない想定外の任意メディアに対しても、そのメディアのインク打込み量を判定することができ、適切なインク打込み量となる画像処理テーブルを選択できる。その結果、インク溢れ、文字のにじみ、及び、一様な単色面のムラといったような不具合を低減できよう。従って、従来よりも、満足な印刷結果をユーザは享受できるようになろう。
【図面の簡単な説明】
【図１】図１は、本実施形態に係る画像形成システムのハードウエア構成の一例を示す図である。
【図２】図２は、画像処理装置１００のソフトウエア構成の一例を示す図である。
【図３】図３は、プリンタドライバ２０８の内部処理構成を模式化した図である。
【図４】図４は、プリンタ用補正処理部３０２の詳細ブロック構成の一例を示す図である。
【図５】図５は、プリンタの色再現空間と表示装置の色再現空間との相違を説明するための図である。
【図６】図６は、彩度（Ｓ）方向へのガマット圧縮をＳＶ平面において概念的に示す図である。
【図７】図７は、新規に対応メディアを追加する際のフローチャートである。
【図８】図８は、例示的なインク打込み量判定テストパターンを示す図である。
【符号の説明】
４０１…画像信号入力部
４０２…カラーマッチング処理部
４０３…色分解処理部
４０４…出力ガンマ補正処理部
４０５…ハーフトーン処理部
４０６…画像信号出力部
４０７…マッチングテーブル部
４０８…色分解テーブル部
４０９…出力ガンマ補正テーブル部
４１０…色分解テーブル選択部
４１１…色分解テーブル作成部
４１２…ガマット判定部
４１３…マッチングテーブル選択部[0001]
BACKGROUND OF THE INVENTION
The present invention generally relates to an image forming method, and more particularly to an image forming method, an image forming program, and a recording medium that are meaningful when an unexpected recording medium (media) is used in an inkjet printer.
[0002]
[Prior art]
Conventional inkjet printers determine the number of recording media to be printed at the time of development, and create and mount image processing tables and image correction processing means individually so that they are determined and optimized for each medium. Was.
[0003]
[Problems to be solved by the invention]
In the conventional method, for an unexpected arbitrary medium that does not have an image processing table or image processing means, since the ink placement amount of the medium is unknown, an image processing table having an appropriate ink placement amount is selected. I couldn't.
[0004]
As a result, when an image is formed using an inappropriate image processing table, undesired image formation such as ink overflow, bleeding of characters, or unevenness of a uniform monochromatic surface may occur. there were.
[0005]
SUMMARY OF THE INVENTION Accordingly, the present invention provides a method, a program, and a reading medium on which a test pattern is formed by image formation, which is capable of determining a more suitable ink amount even on an unexpected recording medium. The purpose is to provide.
[0006]
[Means for Solving the Problems]
The present invention is to solve the above-mentioned problems.
Generating a test pattern composed of a plurality of regions or monochromatic surfaces having different hues adjacent to each other ;
Forming a plurality of the test patterns on the recording medium , each having a different amount of ink applied, which is a total amount of a plurality of inks each having a different color ;
A step of comparing the test pattern on the recording medium with preset image data by means of comparison;
A step of determining, by a first determination means, an ink ejection amount of a test pattern that is relatively less blurred among the plurality of test patterns formed on the recording medium based on the comparison result;
Selecting a color separation table corresponding to the determined ink placement amount from a plurality of color separation tables having different ink placement amounts by a first selection unit;
Determining a size of a color reproduction space of the recording medium in the selected color separation table by a second determination unit;
Selecting a matching table corresponding to the size of the color reproduction space of the recording medium from a plurality of matching tables having different sizes of the color reproduction space by the second selection means;
An image forming method is provided.
[0007]
With such a configuration, it is possible to provide a determination medium on which a test pattern capable of determining a more suitable ink amount is recorded. If this determination medium is used, even if an unexpected recording medium is used, it can be used to reduce “bleeding” and “unevenness” of ink.
[0008]
here,
The color material is, for example, ink such as dye ink or pigment ink.
The controller or the user may determine the appropriate ink ejection amount from the storage medium on which the plurality of test patterns are formed.
[0009]
Also,
The test pattern is, for example, a test pattern set so that at least one of the “bleeding” state and the “unevenness” state of the ink can be visually observed.
[0010]
Also,
In the test pattern, for example, a pattern for visually checking the “smearing” state of the ink includes a plurality of regions having mutually different hues.
[0011]
Also,
In the test pattern, the pattern for visually checking the “unevenness” state of the ink may include a substantially uniform monochromatic surface.
[0012]
In addition to the test pattern, information regarding the amount of ink applied may be formed on the recording medium.
[0013]
In this way, since the ink ejection amount index itself is printed on the same medium, the user can easily determine a suitable ink ejection amount.
[0014]
Furthermore, according to the present invention, there is provided a recording medium on which a test pattern is formed by the image forming method.
[0015]
Furthermore, according to the present invention,
On a recording medium on which an image is formed using ink, at least one of an ink “bleeding” state in a plurality of adjacent regions having different hues or an ink “unevenness” state on a uniform monochromatic surface can be visually observed. An ink ejection amount determination medium is provided in which the set test patterns are arranged on the same recording medium with a plurality of different amounts of ink.
[0016]
Furthermore, if the ink placement amount is recorded as numerical information, the user can find a suitable placement amount.
[0017]
Furthermore, according to the present invention,
Generating a test pattern composed of a plurality of regions or monochromatic surfaces having different hues adjacent to each other ;
Forming a plurality of the test patterns on the recording medium , each having a different amount of ink applied, which is a total amount of a plurality of inks each having a different color ;
A step of comparing the test pattern on the recording medium with preset image data by means of comparison;
A step of determining, by a first determination means, an ink ejection amount of a test pattern that is relatively less blurred among the plurality of test patterns formed on the recording medium based on the comparison result;
Selecting a color separation table corresponding to the determined ink placement amount from a plurality of color separation tables having different ink placement amounts by a first selection unit;
Determining a size of a color reproduction space of the recording medium in the selected color separation table by a second determination unit;
Selecting a matching table corresponding to the size of the color reproduction space of the recording medium from a plurality of matching tables having different sizes of the color reproduction space by the second selection means;
An image forming program for causing a computer to execute is provided.
Note that the image forming program stores the plurality of test patterns in the storage medium so that the computer or the user can determine the appropriate ink ejection amount from the storage medium on which the plurality of test patterns are formed. It may be formed on a medium.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the present invention is shown below. Of course, the following embodiments are provided for facilitating implementation by those skilled in the art of the present invention, and are only included in the technical scope of the present invention defined by the claims. It is only an embodiment of the part. Therefore, it will be apparent to those skilled in the art that even embodiments that are not directly described in the present specification are included in the technical scope of the present invention as long as they share the same technical idea.
[0019]
Note that although a plurality of embodiments are described for convenience, those skilled in the art can easily understand that these are not only individually established as inventions, but of course that the invention can also be realized by appropriately combining a plurality of embodiments. I can do it.
[0020]
FIG. 1 is a diagram illustrating an example of a hardware configuration of an image forming system according to the present embodiment. The image processing apparatus 100 is a personal computer or the like. The CPU 101 is a central processing unit that integrally controls each unit of the image processing apparatus 100 by executing an operating system, application programs, a devise driver, and the like. The RAM 102 is a memory that provides a work area for the CPU 100. The ROM 103 is a memory that stores a boot program such as BIOS. The HDD 104 is a fixed storage device such as a hard disk drive, and stores image data such as a test pattern image in addition to computer programs such as an application program, an operating system, and various driver programs. The communication IF 105 is an interface for performing data communication with an external device such as USB, IEEE 1394, wired LAN, or wireless LAN. The display IF 106 is a control unit for controlling display of image information and the like on a display device 109 connected to the outside or the inside. The operation unit 107 is an input device such as a pointing device or a key input device. The printer 108 is an image forming apparatus that forms an image on a medium by an inkjet method or a laser beam method. The display device 109 is a liquid crystal display for displaying image data and the like.
[0021]
FIG. 2 is a diagram illustrating an example of a software configuration of the image processing apparatus 100. With reference to FIG. 1 and FIG. 2, a flow when printing out will be described. As the printer 108 that performs print output, a generally popular inkjet printer or the like can be used. When printing the output image data, the application 202 issues a print output request to the OS 201. For example, the graphics data part is composed of a graphics rendering command, and the image image data part issues a rendering command group indicating an output image composed of an image rendering command to the OS 201.
[0022]
The OS 201 receives an application output request and issues a drawing command group to the printer driver 208 corresponding to the output printer. The printer driver 208 processes a print request and a drawing command group input from the OS 201, creates print data that can be printed by the printer 108, and transfers the print data to the printer 108. When the printer 108 is a raster printer, the printer driver 208 sequentially performs image correction processing on the drawing commands from the OS 201, and sequentially rasterizes the drawing commands in the RGB 24-bit page memory, and rasterizes all the drawing commands. After that, the contents of the RGB 24-bit page memory are converted into a data format that the printer 108 can print, for example, CMYK data, and transferred to the printer 108.
[0023]
Next, processing performed by the printer driver 208 will be described with reference to FIG.
The image correction processing unit 301 performs image correction processing on color information included in the drawing command group input from the OS 201. As the image correction processing, for example, RGB color information is converted into luminance / color difference signals, exposure correction processing is performed on the luminance signals, and the corrected luminance / color difference signals are inversely converted into RGB color information.
[0024]
The printer correction processing unit 302 first rasterizes a rendering command based on RGB color information subjected to image correction processing, generates a raster image on an RGB 24-bit page memory, and performs color reproduction space mapping, color matching to CMYK, and color to CMYK The separation processing, gamma correction processing, and halftone processing are performed to generate CMYK data depending on the color reproducibility of the printer for each pixel, and the printable image data is transferred to the printer 108.
[0025]
1. Printer Correction Processing FIG. 3 is a diagram schematically showing the internal processing configuration of the printer driver 208. Processing in the printer correction processing unit 302 will be described in detail. FIG. 4 is a diagram illustrating an example of a detailed block configuration of the printer correction processing unit 302. In the following, for the sake of simplicity of explanation, it is assumed that a color space usually expressed in three dimensions is schematically expressed in two dimensions (FIG. 5 and the like).
[0026]
First, RGB 8-bit image data whose brightness, contrast, and color tone are adjusted by the image correction processing unit 301 is input to the image signal input unit 401 in the printer correction processing unit 302. The RGB 8-bit image data input to the image signal input unit 401 corresponds to the color reproduced on the display device 109. For example, in the coordinate values of the CIE L * a * b * color system which is a uniform color space, the image data represents a color (L_Monitor, a_Monitor, b_Monitor).
[0027]
However, as can be seen from FIG. 5, the color reproduction space of the display device 109 and the color reproduction space of the printer 108 do not coincide with each other in a uniform color space such as an L * a * b * space. This is because the printer cannot form an image outside the color reproduction space of the printer shown in FIG. 5 and in an area (shaded area) in the color reproduction space of the display device. More specifically, the subsequent color separation processing unit 403 performs RGB-CMYK conversion on the image data expressed on the display device 109, and the output γ correction processing unit 404 performs gradation correction processing. Even if the halftone processing unit 405 executes binarization processing and then outputs the image to the image output unit 406, an area where image formation is impossible, that is, an area on the color space that cannot be expressed by the printer 108 (shaded area) Will occur.
[0028]
Therefore, on the printer 108 side, a pseudo color (L * a * b * value), that is, a display for an area (shaded portion) in the color space that can be reproduced by the display device 109 but cannot be reproduced by the printer 108. It is necessary to print by generating a pseudo color different from the color of the device 109.
[0029]
Hereinafter, the L * a * b * space as a uniform color space is copied to the cylindrical coordinates H (= atan (b / a)), S (= sqrt (a * 2 + b * 2)), and V (= L *). Considering HSV space, a case where color space compression is performed for the entire space will be described. Here, atan (x) is a function for obtaining the arc tangent of x. Further, sqrt (x) is a function for obtaining √x.
[0030]
2. Color Matching Processing Unit The color matching processing unit 402 in the printer correction processing unit 302 compresses an area that cannot be reproduced by the printer 108 in the color reproduction space (monitor gamut) of the display device 109, so that the printer 108. Are associated with points in the color reproduction space (printer gamut). That is, the RGB 8-bit data processed by the color matching processing unit 402 is converted into R′G′B ′ 8-bit data corresponding to points on the printer color reproduction space.
[0031]
Specifically, the color matching processing unit 402 performs conversion from the RGB color signal space of the display device 109 to the R′G′B ′ color signal space of the printer 108 according to the following procedure.
[0032]
In the color matching processing unit 402 shown in FIG. 4, for example, the color L is maintained while maintaining the lightness L * so that the monitor RGB gamut is inside the printer R′G′B ′ gamut in the L * a * b * space. Compression is performed by performing processing such as lowering the degree S (= sqrt (a ** a * + b ** b *)). An example of this compression processing is shown in FIG.
[0033]
FIG. 6 is a diagram conceptually showing gamut compression in the saturation (S) direction on the SV plane. That is, the set of L * a * b * values in the printer gamut corresponding to the monitor RGB values is obtained. When the monitor gamut after compression fits in the printer gamut, for example, the color difference ΔE (= sqrt ((L * ′ − L *) 2+ (a * ′ − a *) 2+ (b * ′ − b *) 2 )) Is minimized so that a set of monitor (R, G, B) and printer (R ′, G ′, B ′) is determined by using L * a * b * value as a key. The printer R′G′B ′ value corresponding to the value can be determined. Of course, the color matching processing unit 402 can be realized by using a LUT (Look Up Table).
[0034]
In this embodiment, since the size of the printer gamut differs depending on the type of recording medium (medium), a plurality of matching tables are held in the matching table unit 407 as LUTs for each medium.
[0035]
3. Color Separation Processing Unit Next, processing in the color separation processing unit 403 in the printer correction processing unit 302 will be described.
[0036]
In the color separation processing unit 403, the 8-bit signal of each color converted into R′G′B ′ for the printer by the color matching processing unit 402 is converted into an 8-bit signal value of CMYK corresponding to the ink color of the printer. Convert. As a method for converting a color signal from R′G′B ′ to CMYK, for example, a method by color masking is known. The color conversion method by this color masking is shown in the following formula.
[0037]
[Expression 1]

[0038]
[Expression 2]

By calculating these mathematical formulas, CMY values can be obtained. There are various methods for determining the K (black) signal value. For example, the rightmost side in the determinant is replaced with a vector [Dr−K Dg−K Db−K] t obtained by subtracting the K value from each of the vector elements, and each color signal value CMY corresponding to the ink amount is always positive or The K value can be determined by obtaining a masking matrix erroneously by trial chain while constraining the K value using the condition of 0. Of course, the color separation processing unit 403 can be realized by using an LUT.
[0039]
In the present embodiment, since the appropriate ink amount varies depending on the type of media, the color separation table unit 408 holds a plurality of color separation tables as LUTs for each medium.
[0040]
4). Output Gamma Correction Processing Unit Next, processing in the output gamma correction processing unit 404 in the printer correction processing unit 302 will be described.
[0041]
In the output gamma correction processing unit 404, CMYK 8-bit data output by sequentially converting the color signal of the input image in the color matching processing unit 402 and the color separation processing unit 403 is processed in the subsequent halftone processing unit 405. The data is converted into data, and C′M′Y′K ′ 8-bit data is output. The halftone processing unit 405 performs adjustment using a one-dimensional LUT for each ink in order to compensate for nonlinear characteristics with respect to lightness.
[0042]
In the present embodiment, since the non-linear characteristic of brightness varies depending on the type of media, the gamma correction table unit 409 holds a plurality of gamma correction tables as LUTs for each medium.
[0043]
5. Halftone Processing Unit Next, processing in the halftone processing unit 405 in the printer correction processing unit 302 will be described.
[0044]
In the halftone processing unit 405, C′M′Y′K ′ each of 8 bits, which is sequentially converted by the color matching processing unit 402, the color separation processing unit 403, and the output gamma correction processing unit 404 from the color signal of the input image, is output. Data is converted into 2-bit data for each of C "M" Y "K" that can be printed by the printer.
[0045]
In this halftone processing method, for example, a Bayer-type 16 × 16 matrix is assigned to the input C′M′Y′K ′ image, and pixel values on the image corresponding to the elements of the matrix are assigned. This is realized by setting 1 when the value is large and 0 when the pixel value is equal to or less than the element of the matrix. In addition, an error diffusion method or the like can be used as another halftone processing method.
[0046]
The 2-bit data of C "M" Y "K" that can be printed by the printer thus obtained is sent to the printer 108 and an image is formed on the medium.
[0047]
6). Table by Media The tables prepared for each type of media are stored in the matching table unit 407, the color separation table unit 408, and the gamma correction table unit 409, respectively. In the matching table unit 407, a table is prepared for each size and shape of the media color reproduction space (gamut). In the color separation table unit 408, a table is prepared for each ink ejection amount of media. In the gamma correction table unit 409, a table is prepared for each media characteristic.
[0048]
A table corresponding to the type of media designated at the time of printing is selected from the plurality of tables.
[0049]
7). Addition of Corresponding Medium A process for newly adding a corresponding medium in the above-described image forming system will be described with reference to FIG.
[0050]
Step S701: A test pattern for determining a fixing state of a color material used for image formation on a recording medium is generated, and a plurality of test patterns are formed on a recording medium using different amounts of color material. Specifically, the image data of the ink ejection amount determination test pattern (FIG. 8) is formed on the medium to be added. For example, the image data of the test pattern stored in the HDD 104 is read out, the read image data is subjected to image processing by the printer driver 208, and the test pattern is formed by the printer 108 in which the target medium is set.
[0051]
Step S <b> 702: The medium on which the ink placement amount test pattern is formed is visually checked to determine the appropriate ink placement amount of the additional media. The CPU 101 sets a suitable ink ejection amount by setting the medium in an image reading device (not shown), reading the image, and comparing the read test pattern with image data relating to a preset “smear” state. You may judge.
[0052]
Step S703: The color separation table selection unit 410 inputs the ink placement amount determined in Step S702 from the operation unit 107, for example. If the color separation table corresponding to the input ink placement amount exists in the color separation table unit 408, the process proceeds to step S704, and if not, the process proceeds to step S705. Specifically, a database in which the identification information of each table is associated with the ink ejection amount of each table is stored in the RAM 102 or the HDD 104, and a table that matches the input ink ejection amount is stored in the color separation table selection unit. 410 may be extracted by a search process.
[0053]
Step S704: The color separation table selected by the color separation table selection unit 410 is newly registered in the color separation table unit 408 as a color separation table for additional media.
[0054]
Step S705: The table creation unit 411 selects two color separation tables that are before and after the ink placement amount determined in step S702, and performs interpolation calculation of the two color separation tables to obtain the color separation table for the corresponding ink placement amount. It is generated and newly registered in the color separation table unit 408 as a color separation table for additional media.
[0055]
Step S706: The gamut determination unit 412 determines the size of the color reproduction space (printer gamut) of the additional medium in the color separation table newly registered in step S704 or step S705.
[0056]
Step S707: The matching table selection unit 413 selects a matching table corresponding to the size of the color reproduction space of the additional medium determined in step S706 from the matching table unit 407, and newly sets a matching table as a matching table for the additional medium. Registered in the unit 407.
[0057]
Through the above steps, a new compatible medium is added.
[0058]
8). Ink ejection amount determination test pattern The ink ejection amount determination test pattern is a combination of fine lines such as a monochrome surface, background, and characters, and is adjusted to have a predetermined ink ejection amount under a specific gamma correction table. Image data. This image data is printed out by inputting a specific gamma correction table to the set output gamma correction processing unit 404.
[0059]
The ink absorption limit of the media can be determined using the single color surface of the test pattern. For example, when the ink hit amount exceeds the absorption limit of the medium, the uniform monochromatic surface becomes “unevenness”. Therefore, if this “unevenness” is present on the monochromatic surface, it can be determined that the ink ejection amount is too large. If the background of the test pattern and thin lines such as characters are used, the “smearing” state of the ink can be determined. For example, if the thin line is blurred, the ink will be blurred. As a combination of the background and the character color, a secondary color such as RGB or a tertiary color added with K may be used so that they are adjacent to each other. Thereby, “smudge” at the boundary between adjacent colors is visually confirmed and determined.
[0060]
FIG. 8 is an example of a medium on which a test pattern is formed on the surface. In this example, various types of implantation amounts (150%, 175%, 200%, 225%, 250%) are also formed on the side of the test pattern. As described above, since a plurality of test patterns having different driving amounts are formed on one medium, the appropriate ink driving amount of the medium can be easily determined visually.
[0061]
(Other embodiments)
In the above-described embodiment, the case where ink is used as a color material has been described as an example. However, it goes without saying that the present invention can be applied to other color materials such as toner as well.
[0062]
A storage medium storing software program codes for realizing the functions of the above-described embodiments is supplied to a system or apparatus, and a program code stored in the storage medium by a computer (or CPU or MPU) of the system or apparatus It goes without saying that the object of the present invention can also be achieved by reading and executing. In this case, the program code itself read from the storage medium realizes the novel function of the present invention, and the storage medium storing the program code constitutes the present invention.
[0063]
As a storage medium for supplying the program code, for example, a flexible disk, a hard disk, an optical disk, a magneto-optical disk, a CD-ROM, a CD-R, a magnetic tape, a nonvolatile memory card, a ROM, or the like can be used.
[0064]
In addition to executing the program code read out by the computer, the functions of the above-described embodiments are realized, and an OS running on the computer is part of the actual processing based on an instruction of the program code. Alternatively, the functions of the above-described embodiment can be realized by performing all of them and performing the processing.
[0065]
Further, after the program code read from the storage medium is written to a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer, the function expansion is performed based on the instruction of the program code. The CPU or the like provided in the board or the function expansion unit performs part or all of the actual processing, and the functions of the above-described embodiments can be realized by the processing.
[0066]
The invention of the present application is also applied to a case where the program is distributed to a requester via a communication line such as personal computer communication from a storage medium in which the program code of the software realizing the functions of the above-described embodiments is recorded. Needless to say, you can.
【The invention's effect】
According to the present invention, it is possible to determine the amount of ink to be applied to an unexpected arbitrary medium for which a dedicated image processing table or a dedicated image processing apparatus is not prepared, and an appropriate amount of ink to be applied. The image processing table can be selected. As a result, problems such as ink overflow, bleeding of characters, and unevenness of a uniform monochromatic surface can be reduced. Therefore, the user will be able to enjoy a more satisfactory print result than before.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating an example of a hardware configuration of an image forming system according to an embodiment.
FIG. 2 is a diagram illustrating an example of a software configuration of the image processing apparatus 100.
FIG. 3 is a diagram schematically illustrating an internal processing configuration of a printer driver 208;
FIG. 4 is a diagram illustrating an example of a detailed block configuration of a printer correction processing unit 302;
FIG. 5 is a diagram for explaining a difference between a color reproduction space of a printer and a color reproduction space of a display device.
FIG. 6 is a diagram conceptually showing gamut compression in the saturation (S) direction on the SV plane.
FIG. 7 is a flowchart when a corresponding medium is newly added.
FIG. 8 is a diagram illustrating an exemplary ink ejection amount determination test pattern.
[Explanation of symbols]
401 ... Image signal input unit 402 ... Color matching processing unit 403 ... Color separation processing unit 404 ... Output gamma correction processing unit 405 ... Halftone processing unit 406 ... Image signal output unit 407 ... Matching table unit 408 ... Color separation table unit 409 ... Output gamma correction table unit 410 ... color separation table selection unit 411 ... color separation table creation unit 412 ... gamut determination unit 413 ... matching table selection unit

Claims (9)

Generating a test pattern composed of a plurality of regions or monochromatic surfaces having different hues adjacent to each other ;
Forming a plurality of the test patterns on the recording medium , each having a different amount of ink applied, which is a total amount of a plurality of inks each having a different color ;
A step of comparing the test pattern on the recording medium with preset image data by means of comparison;
A step of determining, by a first determination means, an ink ejection amount of a test pattern that is relatively less blurred among the plurality of test patterns formed on the recording medium based on the comparison result;
Selecting a color separation table corresponding to the determined ink placement amount from a plurality of color separation tables having different ink placement amounts by a first selection unit;
Determining a size of a color reproduction space of the recording medium in the selected color separation table by a second determination unit;
Selecting a matching table corresponding to the size of the color reproduction space of the recording medium from a plurality of matching tables having different sizes of the color reproduction space by the second selection means;
An image forming method comprising:   The image forming method according to claim 1, wherein the test pattern is a test pattern set so that at least one of a “bleeding” state and an “unevenness” state of ink is visible. Together with the test pattern, image forming method according to claim 1 or 2 also information on applying amount of the ink and forming on the recording medium. Recording medium on which a test pattern is formed by image forming method according to any one of claims 1 to 3. Generating a test pattern composed of a plurality of regions or monochromatic surfaces having different hues adjacent to each other ;
Forming a plurality of the test patterns on the recording medium , each having a different amount of ink applied, which is a total amount of a plurality of inks each having a different color ;
A step of comparing the test pattern on the recording medium with preset image data by means of comparison;
A step of determining, by a first determination means, an ink ejection amount of a test pattern that is relatively less blurred among the plurality of test patterns formed on the recording medium based on the comparison result;
Selecting a color separation table corresponding to the determined ink placement amount from a plurality of color separation tables having different ink placement amounts by a first selection unit;
Determining a size of a color reproduction space of the recording medium in the selected color separation table by a second determination unit;
Selecting a matching table corresponding to the size of the color reproduction space of the recording medium from a plurality of matching tables having different sizes of the color reproduction space by the second selection means;
Forming program for causing a computer to execute. The image forming program according to claim 5 , wherein the test pattern is a test pattern set so that at least one of a “bleeding” state and an “unevenness” state of ink is visible. 7. The image forming program according to claim 5 , further comprising a step of forming information on an ink ejection amount on the recording medium together with the test pattern. A computer-readable medium having recorded thereon the image forming program according to any one of claims 5 to 7 . Means for generating a test pattern comprising a plurality of regions or monochromatic surfaces having different hues adjacent to each other ;
Means for forming on the recording medium a plurality of the test patterns, each of which has a different amount of ink applied, which is the total amount of a plurality of inks each having a different color ;
Means for comparing the test pattern on the recording medium with preset image data;
Means for determining an ink ejection amount of a test pattern having relatively less blur among the plurality of test patterns formed on the recording medium based on the comparison result;
Means for selecting a color separation table corresponding to the determined ink placement amount from a plurality of color separation tables having different ink placement amounts ;
Means for determining the size of the color reproduction space of the recording medium in the selected color separation table;
Means for selecting a matching table corresponding to the size of the color reproduction space of the recording medium from a plurality of matching tables each having a different size of the color reproduction space ;
An image formation control apparatus comprising:

Images