JPH03204275A - Color picture recording method - Google Patents
Color picture recording methodInfo
- Publication number
- JPH03204275A JPH03204275A JP1343129A JP34312989A JPH03204275A JP H03204275 A JPH03204275 A JP H03204275A JP 1343129 A JP1343129 A JP 1343129A JP 34312989 A JP34312989 A JP 34312989A JP H03204275 A JPH03204275 A JP H03204275A
- Authority
- JP
- Japan
- Prior art keywords
- edge
- picture
- signal
- share
- color
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 238000000034 method Methods 0.000 title claims description 11
- 230000015572 biosynthetic process Effects 0.000 claims description 3
- 238000003708 edge detection Methods 0.000 abstract description 6
- 230000006866 deterioration Effects 0.000 abstract description 2
- 230000003247 decreasing effect Effects 0.000 abstract 1
- 230000002542 deteriorative effect Effects 0.000 abstract 1
- 239000000976 ink Substances 0.000 description 21
- 238000010586 diagram Methods 0.000 description 5
- 239000000872 buffer Substances 0.000 description 3
- 238000009499 grossing Methods 0.000 description 3
- 238000006243 chemical reaction Methods 0.000 description 2
- 238000001514 detection method Methods 0.000 description 2
- 238000009792 diffusion process Methods 0.000 description 2
- 230000000740 bleeding effect Effects 0.000 description 1
- 239000003086 colorant Substances 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000011159 matrix material Substances 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 230000003595 spectral effect Effects 0.000 description 1
Landscapes
- Color, Gradation (AREA)
- Facsimile Image Signal Circuits (AREA)
- Color Image Communication Systems (AREA)
- Dot-Matrix Printers And Others (AREA)
Abstract
Description
【発明の詳細な説明】
［産業上の利用分野］
本発明はドツトそのものの濃度の異なるドツトを用いて
階調表現するカラー画像記録方法に関するものである。DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a color image recording method for expressing gradations using dots having different densities.
［従来の技術］
従来、インクジェット方式の様な２値出力画像はデイザ
法や誤差拡散法などによって階調表現してきた。ざらに
より高品位な画像形成のため同色について濃度の異なる
インクを複数個備え、これらインクを画像濃度に応じ使
い分は広い範囲の階調を再現する濃淡多値印字記録方式
も考えられている。[Prior Art] Conventionally, binary output images such as those produced by an inkjet method have been expressed in gradation using a dither method, an error diffusion method, or the like. In order to form a high-quality image with even roughness, a multi-value print recording system is also being considered, in which a plurality of inks of the same color with different densities are provided, and these inks are used depending on the image density to reproduce a wide range of gradations.
［発明が解決しようとしている課題］
しかしなから上記従来例では画像の濃度に応じて淡イン
クと濃いインクを混在して印字する為、画像中のエツジ
部、特に小さな漢字等の文字部では濃インクと淡インク
のレジのずれ、インクの重ね打ちによるにじみ等で解像
度が落ちるなど画質が劣化するような欠点があった。[Problems to be Solved by the Invention] However, in the conventional example described above, a mixture of light ink and dark ink is printed depending on the density of the image. The disadvantages were that image quality deteriorated, such as a drop in resolution due to misregistration between ink and light ink, and bleeding due to overprinting of ink.
本発明はかかる課題を解決したカラー画像記録方法を提
供することを目的とする。An object of the present invention is to provide a color image recording method that solves these problems.
［課題を解決するための方法］
本発明のカラー画像記録方法は上述の目的を達成するた
め与えられたカラー画像信号に応じドツトそのものの濃
度が異なるドツトを用いてカラー画像を記録する方法で
あって、前記画像信号に対して色成分毎にフィルター演
算を行い、該演算の結果に応じて前記濃度が異なるドツ
トの形成状態を制御することを特徴とする。[Method for Solving the Problems] In order to achieve the above-mentioned object, the color image recording method of the present invention is a method of recording a color image using dots having different densities depending on a given color image signal. The present invention is characterized in that a filter calculation is performed on the image signal for each color component, and the formation state of the dots having different densities is controlled according to the result of the calculation.
［実施例］
第１図に本発明の一実施例の構成を示すブロック図の一
例を示す。第１図においてはそれぞれ互いに濃度の異な
る同色濃淡２インクを用いて、画像のエツジ量に応じた
振り分けを行う実施例について説明する。[Embodiment] FIG. 1 shows an example of a block diagram showing the configuration of an embodiment of the present invention. In FIG. 1, an embodiment will be described in which two dark and light inks of the same color having different densities are used and the inks are distributed according to the edge amount of the image.
図中１０１はレッド（Ｒ）、グリーン（Ｇ）。In the figure, 101 is red (R) and green (G).
ブルー（Ｂ）の３色、色分解フィルターが塗布或いはマ
ウントされている光電変換素子（ＣＣＤ）で被読み取り
原稿に対してｒ、ｇ、ｂ信号を出力する。１０２は輝度
信号ｒ、ｇ、ｂを濃度信号Ｃ，Ｍ、Ｙに変換する階調補
正回路で、対数演算などによる変換が行われる。１０３
はインクの分光的な濁り等を補正する色修正回路で一般
に（１）式の様なマトリクス演算が行われる。A photoelectric conversion element (CCD) coated with or mounted with a three-color blue (B) color separation filter outputs r, g, and b signals to the original to be read. Reference numeral 102 denotes a gradation correction circuit that converts the luminance signals r, g, and b into density signals C, M, and Y, and the conversion is performed by logarithmic calculation or the like. 103
is a color correction circuit that corrects spectral turbidity of ink, and generally performs a matrix calculation as shown in equation (1).
（１）
１０４はＣ，Ｍ、Ｙの無彩色成分をに信号に置き換える
ＵＣＲ回路である。(1) 104 is a UCR circuit that replaces C, M, and Y achromatic color components with signals.
以上１０２，１０３，１０４で色再現処理の行われたＣ
、Ｍ、Ｙ、Ｋ（：号は濃淡振り分はテーブル１０５によ
ってＣ，Ｍ、Ｙ、にのそれぞれ信号値の大きさに応じて
農インク２値化回路又は談インク２値化回路に該Ｃ，Ｍ
、Ｙ、にの信号値が配分される。C, which has been subjected to color reproduction processing in steps 102, 103, and 104 above.
. ,M
, Y, are distributed.
１０６は前記２値化回路で、例えばデイザ法や誤差拡散
法等によって多値画像信号を、インクをＯＮ、ＯＦＦ
（打つ、打たない）の２値に変換し、プリンター１０７
＆：ＯＮ、ＯＦＦ信号を送り、印字、記録する。１０８
，１０９は後述するようなそれぞれ数ライン分のライン
バッファ、及び画像のエツジ部を検出するエツジ検出回
路であり、Ｒ，Ｇ、Ｂ各色用に３系統設けられており、
１１０はエツジ量に応じて濃淡振り分はテーブルを制御
する濃淡振り分は補正テーブルである。Reference numeral 106 is the binarization circuit, which converts the multivalued image signal by using the dither method, error diffusion method, etc., and turns on and off the ink.
Convert to binary value (hit, not hit), printer 107
&: Sends ON and OFF signals to print and record. 108
, 109 are line buffers for several lines and edge detection circuits for detecting edge portions of an image, which will be described later. Three systems are provided for each of R, G, and B colors.
Reference numeral 110 denotes a correction table for controlling the density distribution according to the edge amount.
以下第１図の信号の流れに沿って詳しく動作を説明する
。The operation will be explained in detail below along the signal flow shown in FIG.
ＣＣＤ １０１から出力されたＲ、Ｇ、Ｂ画像信号は図
示されないＡ／Ｄコンバータでデジタルデータに変換さ
れ、ラインバッファメモリ１０８にＲ，Ｇ、Ｂ各面につ
いてメモリされる。又はＲＧ、Ｂ信号を線型結合演算し
て得られる輝度信号Ｙをメモリされる。メモリされたＲ
、Ｇ、Ｂ信号又はＹ信号はエツジ検出回路１０９に人力
し、例えば第２図の様なラプラシアンフィルターを施さ
れ画像中のエツジ量Ｅを出す。The R, G, and B image signals output from the CCD 101 are converted into digital data by an A/D converter (not shown), and are stored in the line buffer memory 108 for each of the R, G, and B surfaces. Alternatively, the luminance signal Y obtained by linearly combining the RG and B signals is stored. memorized R
, G, B signals, or Y signals are input to an edge detection circuit 109 and subjected to a Laplacian filter as shown in FIG. 2, for example, to output an edge amount E in the image.
エツジ量Ｅは濃淡振分は補正テーブル１１０に人力し、
第３図に示す様に量子化され出力α１〜α４を得る。一
方、色処理された画像信号Ｙ。The edge amount E is manually input to the correction table 110 for density distribution.
As shown in FIG. 3, the outputs are quantized and outputs α1 to α4 are obtained. On the other hand, the color-processed image signal Y.
Ｍ、Ｃ，には濃淡振分はテーブル１０５に人力しエツジ
量α１〜α４に応じてテーブル４０１〜４０４が選択さ
れる。For M, C, shading is manually assigned to table 105, and tables 401 to 404 are selected according to edge amounts α1 to α4.
第４図において４０１〜４０４は淡インク用振り分はテ
ーブル４０５〜４０８は淡インク用振り分はテーブルを
示した。４０１〜４０８においていずれも横軸を人力信
号、たて軸を出力信号とした。例えば原稿読取り部がエ
ツジ部でない時や、エツジ量が小さい時すなわち、エツ
ジ量がα１やα２の時、振り分はテーブルは、４０１，
４０５や４０２，４０６が用いられる。一方、文字等の
エツジ量が大きい所α３．α４などでは振り分はテーブ
ル４０３．４０７や４０４，４０８が用いられる。淡イ
ンクでは４０１か６４０４へと人力信号の中間値から以
後配分比率が小さくなり、農インクテーブル４０５から
４０８へと濃いインクの配分比率が高くなっている。In FIG. 4, 401 to 404 are tables for light ink distribution, and 405 to 408 are tables for light ink distribution. In all of 401 to 408, the horizontal axis represents the human input signal, and the vertical axis represents the output signal. For example, when the document reading section is not the edge section, or when the edge amount is small, that is, when the edge amount is α1 or α2, the distribution table is 401,
405, 402, and 406 are used. On the other hand, where the amount of edges such as characters is large, α3. In α4 and the like, tables 403, 407 and 404, 408 are used for distribution. For light ink, the distribution ratio decreases from the intermediate value of the human input signal to 401 or 6404, and the distribution ratio for dark ink increases from agricultural ink table 405 to 408.
以上８つのテーブルを合わせて４００に淡インクと濃イ
ンクのテーブルを合わせて示す。A total of 400 of the above eight tables are shown together with tables for light ink and dark ink.
［実施例２］
第５図は濃淡インクの振り分けを制御するフィルター演
算として第１図に示した実施例１でのエツジ検出の前に
スムージング演算を行なう場合である。ＣＣＤで読み取
られた画像信号はあらかじめ５０２の様なスムージング
回路によって画像中のノイズなどによる孤立点などのエ
ツジが除去される。次にノイズ等の除去された画像信号
はエツジ検出回路１０９に人力しエツジ部を検出され濃
淡振り分は補正テーブル１１０へと人力しエツジ量αを
得る。[Embodiment 2] FIG. 5 shows a case where a smoothing operation is performed before edge detection in Embodiment 1 shown in FIG. 1 as a filter operation for controlling distribution of dark and light inks. The image signal read by the CCD is subjected to a smoothing circuit such as 502 in advance to remove edges such as isolated points due to noise in the image. Next, the image signal from which noise and the like have been removed is manually input to an edge detection circuit 109 to detect edge portions, and the shading portion is manually input to a correction table 110 to obtain an edge amount α.
以上の実施例においてはインクを用いたプリンタを例に
とって説明したが本発明はかかるインクに限らず、サー
マルプリンタへ電子写真プリンタにおいてもドツトその
ものの濃度が異なるドツトの形成状態を制御する場合に
も適用することが出来る。Although the above embodiments have been explained by taking a printer using ink as an example, the present invention is not limited to such ink, but can also be applied to thermal printers, electrophotographic printers, and when controlling the formation state of dots having different densities. It can be applied.
［発明の効果］
以上説明した様に本発明に依れば画像のエツジ部におい
て解像度が低下することもなく画像の劣化を防止しつつ
広い範囲の階調を再現出来る。[Effects of the Invention] As explained above, according to the present invention, a wide range of gradations can be reproduced while preventing image deterioration without reducing the resolution at the edge portions of the image.
特に色成分毎にフィルター演算を行っているので画像の
エツジ部の検出効率を向上させることが出来る。In particular, since filter calculations are performed for each color component, the detection efficiency of image edges can be improved.
第１図は本発明の第１の実施例の構成を示すブロック図
、
第２図は第１図示の検出回路１０９の係数を示す図、
第３図はテーブル１１０の特性を示す図、第４図はテー
ブル１０５の特性を示す図、第５図は本発明の第２の実
施例の構成を示すブロック図である。
１０８・・・ラインバッファ
１０９・・・エツジ検出回路
１０５．１１０・・・濃淡振り分はテーブル５０２・・
・スムージング回路1 is a block diagram showing the configuration of the first embodiment of the present invention, FIG. 2 is a diagram showing the coefficients of the detection circuit 109 shown in FIG. 1, FIG. 3 is a diagram showing the characteristics of the table 110, and FIG. The figure shows the characteristics of the table 105, and FIG. 5 is a block diagram showing the configuration of the second embodiment of the present invention. 108...Line buffer 109...Edge detection circuit 105.110...Table 502...
・Smoothing circuit
Claims (1)
の濃度が異なるドットを用いてカラー画像を記録する方
法であって、前記画像信号に対して色成分毎にフィルタ
ー演算を行い、該演算の結果に応じて前記濃度が異なる
ドットの形成状態を制御することを特徴とするカラー画
像記録方法。(1) A method of recording a color image using dots with different densities depending on a given color image signal, in which a filter operation is performed for each color component on the image signal, and the result of the operation is A color image recording method characterized in that the formation state of the dots having different densities is controlled depending on the density of the dots.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1343129A JP3039664B2 (en) | 1989-12-29 | 1989-12-29 | Image forming device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1343129A JP3039664B2 (en) | 1989-12-29 | 1989-12-29 | Image forming device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH03204275A true JPH03204275A (en) | 1991-09-05 |
| JP3039664B2 JP3039664B2 (en) | 2000-05-08 |
Family
ID=18359145
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1343129A Expired - Fee Related JP3039664B2 (en) | 1989-12-29 | 1989-12-29 | Image forming device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3039664B2 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006231867A (en) * | 2005-02-28 | 2006-09-07 | Ricoh Co Ltd | Image processor and image processing method |
| JP2007043394A (en) * | 2005-08-02 | 2007-02-15 | Ricoh Co Ltd | Apparatus and method for image processing, and program making computer implement same method |
-
1989
- 1989-12-29 JP JP1343129A patent/JP3039664B2/en not_active Expired - Fee Related
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006231867A (en) * | 2005-02-28 | 2006-09-07 | Ricoh Co Ltd | Image processor and image processing method |
| JP4539979B2 (en) * | 2005-02-28 | 2010-09-08 | 株式会社リコー | Image processing apparatus and image processing method |
| JP2007043394A (en) * | 2005-08-02 | 2007-02-15 | Ricoh Co Ltd | Apparatus and method for image processing, and program making computer implement same method |
| JP4485430B2 (en) * | 2005-08-02 | 2010-06-23 | 株式会社リコー | Image processing apparatus, image processing method, and program causing computer to execute the method |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3039664B2 (en) | 2000-05-08 |
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