JPS6132658A - Picture signal processing device - Google Patents
Picture signal processing deviceInfo
- Publication number
- JPS6132658A JPS6132658A JP15439084A JP15439084A JPS6132658A JP S6132658 A JPS6132658 A JP S6132658A JP 15439084 A JP15439084 A JP 15439084A JP 15439084 A JP15439084 A JP 15439084A JP S6132658 A JPS6132658 A JP S6132658A
- Authority
- JP
- Japan
- Prior art keywords
- image signal
- correction amount
- signal level
- ranking
- pixels
- 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
Landscapes
- Facsimile Image Signal Circuits (AREA)
Abstract
Description
【発明の詳細な説明】
産業上の利用分野
本発明は階調画像を２値再生する機能を備えだ画像信号
処理装置に関するものである。DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an image signal processing device having a function of reproducing a gradation image in binary.
従来例の構成とその問題点
近年日常業務におけるファクシミリ利用がますます拡大
の一途であり、それとともに従来の白黒２値の他に階調
画像の再現に対する要望も強まりつつある。特に２値に
よる擬似階調再現は表示装置や記録装置との適応が良い
ので強く要望されている。Conventional configurations and their problems In recent years, the use of facsimiles in daily work has been expanding more and more, and along with this, there has been an increasing demand for reproduction of gradation images in addition to the conventional black and white binary. In particular, pseudo gradation reproduction based on binary values is strongly desired since it is well suited for display devices and recording devices.
これらの擬似階調再現は閾値のマトリクステーブルに従
って画像を２値化していく各種ディザ法が広く使われて
いる。しかしながらこれら従来の方法は階調再現性を良
くする為にはマトリクステーブルを大きくする必要があ
り、高分解能を得る為にはマトリクステーブルをノＪ・
さくしなければならないという矛盾があるため階調再現
性と高分解能の両立が困難であった。特に、階調画像と
２値画像が混在する画像に対してはそのいずれかを犠牲
にせざるをえなくなるという欠点を有していた。For these pseudo gradation reproductions, various dithering methods are widely used in which an image is binarized according to a matrix table of threshold values. However, in these conventional methods, it is necessary to increase the size of the matrix table in order to improve tone reproducibility, and in order to obtain high resolution, the matrix table must be
It has been difficult to achieve both gradation reproducibility and high resolution because of the contradiction of having to reduce the size of the image. In particular, for images in which a gradation image and a binary image coexist, one of them has to be sacrificed.
発明の目的
本発明は上記従来の問題点を解消するもので多階調再現
と高分解能を両立して擬似階調再現することのできる画
像信号処理装置を提供することを目的とする。OBJECTS OF THE INVENTION It is an object of the present invention to solve the above-mentioned conventional problems, and to provide an image signal processing device that can reproduce pseudo gradations while achieving both multi-gradation reproduction and high resolution.
発明の構成
本発明は、
（１）原画像における各画素の再配分画像信号レベルｕ
＋１ビットの上位Ｕビットを記憶する再配分用記憶手段
の所定位置におけるＭ−１個の画像信号レベルの和を求
め、下位Ｌビットに０を補った値Ｓｕと２値化補正量Ｅ
ａと再配分補正量Ｓｌと原画像の画像信号レベルとの和
Ｓを求め、次に所定の画像信号レベルＣの配分数Ｎと残
差Ａを求める配分値演算手段と、
＠）原画像における各画素の画像信号レベルを記憶する
順位付用記憶手段の前記所定位置と対応した画素の一部
に近傍補正量Ｅｂを加えたＭ個の画素の画像信号レベル
の値により、画素順位を決定する順位決定手段と、
（３）前記画素順位により前記配分数Ｎの前記所定の画
像信号レベルＣと前記残差Ａと０とを上位Ｕビットと下
位Ｌビットに分け前記上位Ｕビットを前記再配分用記憶
手段の所定位置の再配分済画素を除くＭ−１個の画素に
割り当て、前記Ｍ−１個の画素に対応する画像信号レベ
ルの前記下位Ｌビットの和を新たな再配分補正量Ｓｌと
し、前記再配分済画素には全ビットを割り轟てる再配分
手段と、
（４）前記割り当てた画素のうち再配分済画素の画像信
号レベルと前記再配分済画素の２値化画像信号レベルか
ら前記２値化補正量Ｅａを演算し、更新する２値化補正
手段と、
（５）順位付補正量Ｅｃを記憶する補正量記憶手段の前
記所定位置と対応する画素の近傍の順位付補正量Ｅｃか
ら前記近傍補正量Ｅｂを演算し前記順位決定手段に与え
、さらに前記順位付補正量Ｅｃと前記順位付用記憶手段
の画素の一部の画像信号レベルと前記２値化画像信号レ
ベルとから新たな順位付補正量Ｅｃを演算する順位付補
正手段とを具備した画像信号処理装置であり、
原画像の濃度に応じて再生画像の黒画素密度を決定する
と共に原画像の濃度変化に応じて再生画像の黒画素配置
を決定することにより、多階調再現と高分解能を両立し
て擬似階調再現することのできるものである。Structure of the Invention The present invention provides: (1) redistribution image signal level u of each pixel in the original image;
The sum of M-1 image signal levels at a predetermined position of the redistribution storage means that stores the upper U bits of +1 bits is calculated, and the value Su obtained by supplementing the lower L bits with 0 and the binarization correction amount E are obtained.
a, a distribution value calculation means for calculating the sum S of the redistribution correction amount Sl and the image signal level of the original image, and then calculating the distribution number N and residual A of a predetermined image signal level C; A pixel ranking is determined based on the value of the image signal level of M pixels obtained by adding a neighborhood correction amount Eb to a part of the pixel corresponding to the predetermined position of the ranking storage means for storing the image signal level of each pixel. (3) dividing the predetermined image signal level C of the allocation number N and the residuals A and 0 into upper U bits and lower L bits according to the pixel ranking, and redistributing the upper U bits; The sum of the lower L bits of the image signal level corresponding to the M-1 pixels is assigned as a new redistribution correction amount Sl. (4) an image signal level of the reallocated pixels among the allocated pixels and a binarized image signal level of the reallocated pixels; (5) Binarization correction means for calculating and updating the binarization correction amount Ea from the above, and (5) ranking correction near the pixel corresponding to the predetermined position of the correction amount storage means for storing the ranking correction amount Ec. Calculates the neighborhood correction amount Eb from the amount Ec and provides it to the ranking determining means, and further calculates the ranking correction amount Ec, the image signal level of some of the pixels in the ranking storage means, and the binarized image signal level. This image signal processing device is equipped with a ranking correction means for calculating a new ranking correction amount Ec from By determining the black pixel arrangement of the reproduced image, it is possible to achieve pseudo gradation reproduction while achieving both multi-gradation reproduction and high resolution.
実施例の説明
第１図は本発明の一実施例における画像信号処理装置の
ブロック図を示すものである。本実施例では前記発明の
構成（１） 、 （２） 、 （３）におけるＭ個を４
個とし、構成（６）における近傍の順位付補正量Ｅｃは
４個とする説明にしている。説明の都合上、各画素には
次のような記号を付与している。DESCRIPTION OF THE EMBODIMENTS FIG. 1 shows a block diagram of an image signal processing apparatus according to an embodiment of the present invention. In this embodiment, the number M in configurations (1), (2), and (3) of the invention is 4.
In the explanation, it is assumed that the number of adjacent ranked correction amounts Ec in configuration (6) is four. For convenience of explanation, the following symbols are given to each pixel.
構成（１） 、 （３）の４個の画素はＲｏ。、Ｒｏｌ
、Ｒ１゜。The four pixels of configurations (1) and (3) are Ro. , Rol
, R1°.
Ｒ１１とし、構成（２）の４個の画素はＯｏ。、Ｏｏｌ
。R11, and the four pixels of configuration (2) are Oo. ,Ool
.
０１゜、ｏｌｌとし、構成（６）の近傍の順位付補正量
Ｅｃの記憶位置はＥｃｌ １Ｅｃ２＋Ｅｃ３＋Ｅｃ４と
し、新たな順位付補正量Ｅｃの記憶位置はＥｃ６とする
。01°, oll, the storage location of the ranked correction amount Ec in the vicinity of configuration (6) is set to Ecl 1Ec2+Ec3+Ec4, and the storage location of the new ranked correction amount Ec is set to Ec6.
各画素の画像空間上の対応位置はＲ８゜と０゜。とＥｃ
６が同じ位置に対応する。The corresponding positions of each pixel in the image space are R8° and 0°. and Ec
6 corresponds to the same position.
前記各記号グループを走査窓と定義し、Ｒｏ。。Each symbol group is defined as a scanning window, Ro. .
Ｒｏｌ １Ｒ１０１Ｒ１１を走査窓ｗｒとし％ ｏＯＯ
ｌｏｏｌｌｏｌ（） ＋ ０１１を走査窓Ｗｏとし％
Ｅｏｌ １Ｅｃ２１Ｅｃ３１Ｅｃ４ｔ Ｅｃ５を走査窓
Ｗ。とする。第１図において各走査窓はそれぞれの対応
する記憶手段上を原画像の主走査とともに右方向へ移動
していくものとする。Rol 1R101R11 is the scanning window wr% oOO
Let loolol() + 011 be the scanning window Wo%
Eol 1Ec21Ec31Ec4t Ec5 is scanned by window W. shall be. In FIG. 1, it is assumed that each scanning window moves to the right on its corresponding storage means as the original image is main-scanned.
第１図において、１は原画像を走査し画像信号レベルを
出力する原画像走査手段、２は後述する再配分手段の出
力信号である再配分用画像信号レベルを上位Ｕビットと
下位Ｌビットに分け、前記上位Ｕビットを走査窓Ｗ２Ｏ
３個の画素Ｒ０゜。In FIG. 1, 1 is an original image scanning means that scans an original image and outputs an image signal level, and 2 is an output signal of a redistribution means, which will be described later, and a redistribution image signal level is divided into upper U bits and lower L bits. and the upper U bits are scanned by the scanning window W2O.
Three pixels R0°.
Ｒｏｌ １Ｒ１゜に入力として記憶し、走査窓Ｗｒの３
個の画素Ｒ０゜１Ｒ０１１Ｒ１０の画像信号レベルを出
力とする再配分用記憶手段、３は再配分用記憶手段２の
出力信号である走査窓Ｗｒの３個の画素Ｒ０゜、Ｒｏｌ
、Ｒ１゜の画像信号レベルの和を求め、下位Ｌビットに
Ｑを補った値Ｓｕと後述する２値化補正手段の出力信号
である２値化補正量Ｅａと原画像走査手段１の出力信号
である原画像の画像信号レベルＦ０と再配分補正量Ｓｌ
とを入力とじて加算した和Ｓから配分数Ｎと残差Ａを出
力する配分値演算手段、４は走査手段１の出力信号であ
る原画像の画像信号レベルを入力として記憶した走査窓
Ｗ０の４個（７）画素ｏ０゜、ｏｏｌ、ｏｌ。、０１１
の画像信号レベルを出力とする順位付用記憶手段、５は
順位付用記憶手段４の出力信号である走査窓Ｗ０の４個
の画素Ｏ０゜、００１，０１゜、０１１の画像信号レベ
ルと後述する順位付補正手段の出方である近傍補正量Ｅ
ｂを入力とし、４個の画素の画像信号レベルの比較によ
多画素順位を決定しそれを出力とする順位決定手段、６
は配分値演算手段３の出力信号である配分数Ｎと残差Ａ
と順位決定手段５の出力信号である画素順位とを入力と
して画素順位に応じてＮ個の数の画像信号レベルの最大
値Ｃと残差Ａと０との配分を決定しその再配分用画像信
号レベルを上位Ｕビットと下位Ｌビットに分け、前記上
位Ｕビットを前記再配分記憶手段２の走査窓Ｗｒの３個
の画素Ｒ０１，Ｒ１ｏ、Ｒ１１と前記下位Ｌビットの和
を新たな再配分補正量Ｓｌとして出力するとともに、前
記再配分用記憶手段２の走査窓Ｗ工のＲ８に対応した再
配分画像信号レベルの全ビットを出力とする再配分手段
、７は前記走査窓ＷｒのＲｏ。に対応した再配分画像信
号レベルを入力とし固定閾値により２値化処理し２値化
画像信号レベルとして出力とすると共に入力画像信号レ
ベルと２値化画像信号レベルとの差分を２値化補正量Ｅ
ａとして出力する２値化補正手段、８は順位付用記憶手
段４の出力信号である走査窓Ｗ０の画素Ｏ０゜の画像信
号レベルと２値化補正手段７の出力信号である２値化画
像信号レベルと後述する補正量記憶手段の出力信号であ
る順位付補正量Ｅｃとを入力とし後述する演算にょシ近
傍補正量Ｅｂと新たな順位付補正量Ｅｃとを出力とする
順位付補正手段、９は既に記憶しである順位付補正量Ｅ
ｃを出力とし順位付補正手段８の出力信号である新たな
゛順位付補正量Ｅｃを記憶する補正量記憶手段、１ｏは
２値化補正手段７の出力信号である２値化画像信号レベ
ルを入力とし２値画像を記録または表示する画像記録・
表示手段である。Rol 1R1° is stored as an input, and the scanning window Wr 3
3 is the output signal of the redistribution storage means 2, which is the output signal of the three pixels R0°, Rol of the scanning window Wr.
, R1°, and a value Su obtained by supplementing Q to the lower L bits, a binarization correction amount Ea which is an output signal of a binarization correction means to be described later, and an output signal of the original image scanning means 1. The image signal level F0 of the original image and the redistribution correction amount Sl
4 is a scanning window W0 which stores the image signal level of the original image, which is the output signal of the scanning means 1, as an input. 4 (7) pixels o0°, ool, ol. ,011
5 is the output signal of the ranking storage means 4, which is the image signal level of four pixels O0°, 001, 01°, and 011 of the scanning window W0, which will be described later. The neighborhood correction amount E, which is the output of the ranking correction means
6. Ranking determining means which receives pixel b as an input, determines a multi-pixel ranking by comparing the image signal levels of four pixels, and outputs it.
are the distribution number N which is the output signal of the distribution value calculation means 3 and the residual A
and the pixel rank, which is the output signal of the rank determining means 5, are input, and the distribution of the maximum value C of the N number of image signal levels, the residual error A, and 0 is determined according to the pixel rank, and the image for redistribution is determined. The signal level is divided into upper U bits and lower L bits, and the upper U bits are newly redistributed by the sum of the three pixels R01, R1o, R11 of the scanning window Wr of the redistribution storage means 2 and the lower L bits. Redistribution means outputs all bits of the redistributed image signal level corresponding to R8 of the scanning window W of the redistribution storage means 2 as well as the correction amount Sl, and 7 is Ro of the scanning window Wr. The redistributed image signal level corresponding to the input image signal level is input, binarized using a fixed threshold value, and output as a binarized image signal level, and the difference between the input image signal level and the binarized image signal level is converted into a binarized correction amount. E
8 is the image signal level of the pixel O0° of the scanning window W0, which is the output signal of the ranking storage means 4, and the binary image is the output signal of the binarization correction means 7. a ranking correction means which receives as input a signal level and a ranked correction amount Ec which is an output signal of a correction amount storage means to be described later, and outputs a calculated neighborhood correction amount Eb and a new ranked correction amount Ec, which will be described later; 9 is the ranking correction amount E that is already stored.
c is the output signal of the ranking correction means 8, and 1o is the output signal of the ranking correction means 8, which is a new ranking correction amount Ec. Image recording/displaying a binary image as input
It is a display means.
第２図は本実施例の具体的な回路図で第１図で示す画像
信号処理装置のブロック図の構成の主要部である再配分
用記憶手段２〜補正量記憶手段９をマイクロコンピュー
タで実現したものである。FIG. 2 is a specific circuit diagram of this embodiment, and the reallocation storage means 2 to correction amount storage means 9, which are the main parts of the block diagram of the image signal processing device shown in FIG. 1, are realized by a microcomputer. This is what I did.
第２図において１１は原画像走査手段１の出力信号であ
る原画像の画像信号レベルを入力する入力端子である。In FIG. 2, reference numeral 11 denotes an input terminal to which the image signal level of the original image, which is the output signal of the original image scanning means 1, is input.
インプットポート１２はゲートより構成されており、Ｃ
ＰＵ１３．よシ信号線１４を介して与えられる選択信号
により入力端子１１からの画像信号レベルをＣＰＵ１３
へ出力する。ＲＯＭ１６にはＣＰＵ１３を制御するプロ
グラムが書込まれており、ＣＰＵ１３はこのプログラム
に従ってインプットポート１２よシ必要とされる外部デ
ータを取込んだり、あるいはＲＡＭ１ｅとの間でデータ
の授受を行なったりしながら演算処理し、必要に応じて
処理したデータをアウトプットポート１了へ出力する。Input port 12 is composed of a gate, and C
PU13. The image signal level from the input terminal 11 is controlled by the CPU 13 according to the selection signal applied via the input signal line 14.
Output to. A program for controlling the CPU 13 is written in the ROM 16, and the CPU 13 reads necessary external data from the input port 12 or exchanges data with the RAM 1e according to this program. It performs arithmetic processing and outputs the processed data to output port 1 if necessary.
アウトプットポート１７はラッチ回路より構成されてお
り、信号線１８を介してアウトプットボート１７へ与え
られるＣ Ｆ Ｕ １３からの出力ポート指定信号を受
けて、そのポートにデータを一時記憶する。１９はアウ
トプットボート１７に一時記憶されているデータを２値
化した画像信号レベルとして画像信号記録・表示手段１
ｏへ出力する出力端子である。The output port 17 is composed of a latch circuit, receives an output port designation signal from the C F U 13 applied to the output port 17 via a signal line 18, and temporarily stores data in the port. Reference numeral 19 denotes an image signal recording/displaying means 1 that converts the data temporarily stored in the output boat 17 into a binary image signal level.
This is an output terminal that outputs to o.
なお、ＣＰＵ１３ 、ＲＯＭ１５ 、ＲＡＭ１６は周知
のマイクロコンピュータによシ構成することができる。Note that the CPU 13, ROM 15, and RAM 16 can be configured by a well-known microcomputer.
ＲＯＭ１ｅｓに書込まれているプログラムをフローチャ
ートで示すと第３図のようになる０以下第３図に従って
第１図に示した画像信号処理装置の動作を説明する。The program written in the ROM 1es is shown in a flowchart as shown in FIG. 3.The operation of the image signal processing apparatus shown in FIG. 1 will be explained according to FIG.
プログラムがスタートすると、まず再配分用記憶手段２
、順位付用記憶手段４、補正量記憶手段９の内容と２値
化補正手段７の２値化補正量Ｅａと再配分手段６の再配
分補正量Ｓｌを０クリヤし初期設定を行う（ステップ１
）。次に原画像の画像信号レベルＦ０を配分値演算手段
３と順位付用記憶手段４の走査窓Ｗ０の画素０１１に読
込む（ステップ２）０次に再配分用記憶手段２の走査窓
Ｗ。When the program starts, first the redistribution storage means 2
, the contents of the ranking storage means 4 and the correction amount storage means 9, the binarization correction amount Ea of the binarization correction means 7, and the redistribution correction amount Sl of the redistribution means 6 are cleared to 0 and initial settings are performed (step 1
). Next, the image signal level F0 of the original image is read into the pixel 011 of the scanning window W0 of the allocation value calculating means 3 and the ranking storage means 4 (step 2).
内の３個の画素Ｒ０゜、Ｒｏｌ、Ｒ１゜の画像信号レベ
ルの和を求め、下位Ｌビットの０を補った値Ｓｕと２値
化補正量Ｅａと再配分補正量Ｓｌと原画像の画像信号レ
ベルＦ０との和Ｓ（＝Ｓｍ＋Ｅａ＋Ｓｌ＋ Ｆ ｏ ）
を演算し、５＝ＣｘＮ＋Ａとなる画像信号レベルの最大
値Ｃの配分数Ｎと残差Ａを演算する（ステップ３）。次
に補正量記憶手段９の走査窓ｗ、内の順位付補正量記憶
位置Ｅｃ１ ＋Ｅｃ２＋Ｅｃ３＋Ｅｃ４の４個の順位付
補正量Ｅｃの平均値Ｅｃａと係数Ｋａから近傍補正量Ｅ
ｂ（＝ＫａｘＥｏ８）を演℃る（ステップ４）０次に順
位付用記憶手段４の走査窓Ｗ０の画素０゜。の画像信号
レベルに近傍補正量Ｅｂを加算した後、４個の画素０゜
。。The sum of the image signal levels of the three pixels R0°, Rol, and R1° is calculated, and the value Su obtained by supplementing the 0 of the lower L bit, the binarization correction amount Ea, the redistribution correction amount Sl, and the original image Sum S with signal level F0 (=Sm+Ea+Sl+F o )
is calculated, and the distribution number N of the maximum value C of the image signal level and the residual error A are calculated such that 5=CxN+A (step 3). Next, from the average value Eca and coefficient Ka of the four ranked correction amounts Ec of the ranked correction amount storage position Ec1 + Ec2 + Ec3 + Ec4 within the scanning window w of the correction amount storage means 9, the neighboring correction amount E
b (=KaxEo8) (Step 4) Pixel 0° of the scanning window W0 of the ranking storage means 4. After adding the neighborhood correction amount Eb to the image signal level of , the four pixels are 0°. .
Ｏｏｌ、ｏｌ。、ｏ、１の画像信号レベルをそれぞれ比
較し大きい順に画素順位を決定する（ステップ苧）。Ool, ol. , o, and 1 are compared, and the pixel ranking is determined in ascending order (step).
次にステップ５で求めた画素順位に従って、ステップ３
で求めたＮ個の数の画像信号レベルの最大値Ｃと残差Ａ
と０とを再配分用記憶手段２の走査窓Ｗｒの３個の画素
Ｒ０１，Ｒ１゜、Ｒ１１の画像信号レベルを上位Ｕビッ
トと下位Ｌビットに分けた前記上位Ｕビットを記憶し、
前記走査窓ＷｒのＲ８０に対応した再配分済画素の画像
信号レベルは全ビットとするとともに前記走査窓Ｗｒの
３個の画素Ｒｏ１．Ｒ１ｏ、Ｒ１１に対応した前記下位
Ｌピットの和を新たな再配分補正量Ｓｌ とする（ステ
ップ６）。Next, according to the pixel order obtained in step 5, step 3
The maximum value C of the N number of image signal levels found in and the residual A
and 0, and the image signal levels of the three pixels R01, R1°, and R11 of the scanning window Wr of the redistribution storage means 2 are divided into upper U bits and lower L bits, and the upper U bits are stored,
The image signal level of the redistributed pixels corresponding to R80 of the scanning window Wr is set to all bits, and the level of the image signal of the redistributed pixels corresponding to R80 of the scanning window Wr is set to three pixels Ro1. The sum of the lower L pits corresponding to R1o and R11 is set as a new redistribution correction amount Sl (step 6).
次に再配分手段２の前記走査窓Ｗ、に対応した再配分画
素の画像信号レベルと前記再配分済画素の画像信号レベ
ルを２値化した画像信号レベルとの差分を次回のステッ
プ３における２値化補正量Ｅａとする（ステップ７）。Next, the difference between the image signal level of the redistributed pixel corresponding to the scanning window W of the redistribution means 2 and the image signal level obtained by binarizing the image signal level of the redistributed pixel is calculated as 2 in the next step 3. The value correction amount is set as Ea (step 7).
次にステップ４における平均値Ｅｃａと係数Ｋｂを乗算
した値に走査窓■。Next, a scanning window ■ is applied to the value obtained by multiplying the average value Eca by the coefficient Kb in step 4.
内の画素０゜０の画像信号レベルを加算し、その値とス
テップ７における２値化画像信号レベルとの差分を新た
な順位付補正量Ｅｃとし走査窓Ｗ。The image signal level of pixel 0°0 within the scanning window W is added, and the difference between that value and the binarized image signal level in step 7 is set as a new ranking correction amount Ec.
内の画素Ｅｃ５に記憶する（ステップ８）。次にステッ
プ７で２値化した画像信号レベルを画像記録・表示手段
１０へ出力する（ステップ９）０次にすべての原画像信
号レベルに対して主走査方向および副走査方向の処理終
了判定をしくステップ１ｏ）、未終了であれば走査窓の
移動を行い（ステップ１１）ステシブ２よシ繰返す。も
し終了であれば全原画像信号に対して処理を完了する。(Step 8). Next, in step 7, the binarized image signal level is output to the image recording/display means 10 (step 9).Next, the processing completion judgment in the main scanning direction and the sub-scanning direction is performed for all original image signal levels. Step 1o) is completed, and if it is not completed, the scanning window is moved (Step 11) and Step 2 is repeated. If the processing is completed, the processing is completed for all original image signals.
ただし、主走査方向の処理が終了する毎にステップ１１
において２値化補正量Ｅａを０クリアする。However, each time processing in the main scanning direction is completed, step 11
In this step, the binarization correction amount Ea is cleared to 0.
なお上記説明ではマイクロコンピュータにより再配分記
憶手段２〜補正量記憶手段９を実現したが、これらの手
段はそれぞれ論理回路、外部メモリ等により実現するこ
ともできる。In the above description, the redistribution storage means 2 to the correction amount storage means 9 are realized by a microcomputer, but each of these means can also be realized by a logic circuit, an external memory, etc.
さらに順位付補正手段８の係数Ｋａは３Ａ”（ただしｎ
は正の整数）にすることによシ、また係数Ｋｂは１−３
Ａ！１１１（ただしｍは正の整数）にすることによシマ
イクロコンピュータで実現し、た場合には演算を容易に
することができ、論理回路で実現した場合にはノ・−ド
ウエアを軽減することができる。Furthermore, the coefficient Ka of the ranking correction means 8 is 3A'' (however, n
is a positive integer), and the coefficient Kb is 1-3.
A! 111 (where m is a positive integer), it can be realized with a microcomputer, in which case the calculations can be made easier, and if realized with a logic circuit, the hardware can be reduced. I can do it.
発明の効果
以上のように本発明によれば、原画像の濃度に応じて再
生画像の黒画素密度を決定すると共に原画像の濃度変化
に応じて再生画像の黒画素配置を決定したことによシ、
多階調再現と高分解能を両立して擬似階調再現を可能に
するとともに、再生画像を劣化することなく再配分用記
憶手段のバッハメモリのビット構成をＵ＋Ｌビットから
Ｕビットに削減することが可能となる。Effects of the Invention As described above, according to the present invention, the black pixel density of the reproduced image is determined according to the density of the original image, and the black pixel arrangement of the reproduced image is determined according to the density change of the original image. C,
It is possible to realize pseudo gradation reproduction by achieving both multi-gradation reproduction and high resolution, and to reduce the bit configuration of Bach memory, which is a storage means for redistribution, from U+L bits to U bits without deteriorating the reproduced image. It becomes possible.
第１図は本発明の一実施例における画像信号処理装置の
ブロック図、第２図は同装置をマイクロコンピュータで
実現した具体的な回路図、第３図は本実施例の動作を説
明するフローチャートである。
１・・・・・・原画像走査手段、２・・・・・・再配分
用記憶手段、３・・・・・・配分値演算手段、４・・・
・・・順位付用記憶手段、５・・・・・・順位決定手段
、６・・・・・・再配分手段、７・・・・・・２値化補
正手段、８・・・・・・順位付補正手段、９・・・・・
・補正量記憶手段、１０・・・・・・画像記録・表示手
段、１１・・・・・・入力端子、１２・・・・・・イン
プットポー）、１３・・・・・・ＣＰＵ、１４・１８・
・・・・・信号線、１６・・・・・・ＲＯＭ、１６・・
・・・・ＲＡＭ、１７・・・・・・アウトプットポート
、１９・・・・・・出力端子。FIG. 1 is a block diagram of an image signal processing device according to an embodiment of the present invention, FIG. 2 is a specific circuit diagram of the same device realized by a microcomputer, and FIG. 3 is a flowchart explaining the operation of this embodiment. It is. 1...Original image scanning means, 2...Redistribution storage means, 3...Distribution value calculation means, 4...
... Ranking storage means, 5 ... Ranking determining means, 6 ... Redistribution means, 7 ... Binarization correction means, 8 ......・Ranking correction means, 9...
・Correction amount storage means, 10... Image recording/display means, 11... Input terminal, 12... Input port), 13... CPU, 14・18・
...Signal line, 16...ROM, 16...
...RAM, 17...output port, 19...output terminal.
Claims (3)
＋１ビットの上位ｕビットを記憶する再配分用記憶手段
の所定位置におけるＭ−１個の画像信号レベルの和を求
め、下位ＬビットにＯを補った値Ｓ＿ｕと２値化補正量
Ｅ＿ａと再配分補正量Ｓ＿ｌと原画像の画像信号レベル
との和Ｓを求め、次に所定の画像信号レベルＣの配分数
Ｎと残差Ａを求める配分値演算手段と、原画像における
各画素の画像信号レベルを記憶する順位付用記憶手段の
前記所定位置と対応した画素の一部に近傍補正量Ｅ＿ｂ
を加えたＭ個の画素の画像信号レベルの値により、画素
順位を決定する順位決定手段と、前記画素順位により前
記配分数Ｎの前記所定の画像信号レベルＣと前記残差Ａ
とＯとを上位Ｕビットと下位Ｌビットに分け前記上位Ｕ
ビットを前記再配分用記憶手段の所定位置の再配分済画
素を除くＭ−１個の画素に割り当て、前記Ｍ−１個の画
素に対応する画像信号レベルの前記下位Ｌビットの和を
新たな再配分補正量Ｓ＿ｌとし、前記再配分済画素には
全ビットを割り当てる再配分手段と、前記割り当てた画
素のうち再配分済画素の画像信号レベルと前記再配分済
画素の２値化画像信号レベルから前記２値化補正量Ｅ＿
ａを演算し、更新する２値化補正手段と、順位付補正量
Ｅ＿ｃを記憶する補正量記憶手段の前記所定位置と対応
する画素の近傍の順位付補正量Ｅ＿ｃから前記近傍補正
量Ｅ＿ｂを演算し前記順位決定手段に与え、さらに前記
順位付補正量Ｅ＿ｃと前記順位付用記憶手段の画素の一
部の画像信号レベルと前記２値化画像信号レベルとから
新たな順位付補正量Ｅ＿ｃを演算する順位付補正手段と
を具備した画像信号処理装置。(1) Redistribution image signal level u of each pixel in the original image
The sum of M-1 image signal levels at a predetermined position of the redistribution storage means that stores the upper U bit of the +1 bit is calculated, and the value S_u obtained by supplementing O to the lower L bit and the binarization correction amount E_a are calculated. a distribution value calculating means for determining the sum S of the distribution correction amount S_l and the image signal level of the original image, and then determining the distribution number N and residual A of a predetermined image signal level C; and an image signal of each pixel in the original image. A neighborhood correction amount E_b is applied to a part of the pixel corresponding to the predetermined position of the ranking storage means for storing levels.
a ranking determining means for determining a pixel ranking based on the value of the image signal level of M pixels added to the image signal level;
and O are divided into upper U bits and lower L bits.
Allocate the bits to M-1 pixels other than the re-allocated pixels at a predetermined position of the re-allocation storage means, and calculate the sum of the lower L bits of the image signal level corresponding to the M-1 pixels as a new sum. A redistribution unit that allocates all bits to the redistributed pixels with a redistribution correction amount S_l, an image signal level of the redistributed pixels among the allocated pixels, and a binarized image signal level of the redistributed pixels. from the binarization correction amount E_
The neighborhood correction amount E_b is calculated from the binarization correction means for calculating and updating a, and the ranking correction amount E_c in the vicinity of the pixel corresponding to the predetermined position of the correction amount storage means for storing the ranking correction amount E_c. and further calculates a new ranking correction amount E_c from the ranking correction amount E_c, the image signal level of some of the pixels in the ranking storage means, and the binarized image signal level. An image signal processing device comprising a ranking correction means.
均値Ｅ＿ｃ＿ａを求め、係数（１／２）＾ｎ（ただしｎ
は正の整数）を乗算して、近傍補正量Ｅ＿ｂを求めるこ
とを特徴とする特許請求の範囲第１項記載の画像信号処
理装置。(2) The ranking correction means calculates the average value E_c_a of the neighboring ranking correction amount E_c, and calculates the average value E_c_a of the neighboring ranking correction amount E_c, and calculates the coefficient (1/2)^n (where n
2. The image signal processing device according to claim 1, wherein the neighborhood correction amount E_b is determined by multiplying the neighborhood correction amount E_b by a positive integer.
均値Ｅ＿ｃ＿ａを求め、係数１−（１／２）＾ｍ（ただ
しｍは正の整数）を乗算して、順位付用記憶手段の画素
の一部の画像信号レベルを加算しさらに２値化画像信号
レベルを減算して、新たな順位付補正量Ｅ＿ｃを求める
ことを特徴とする特許請求の範囲第１項記載の画像信号
処理装置。(3) The ranking correction means calculates the average value E_c_a of the neighboring ranking correction amounts E_c, multiplies it by a coefficient 1-(1/2)^m (where m is a positive integer), and calculates the average value E_c_a of the neighboring ranking correction amount E_c, and multiplies it by a coefficient 1-(1/2)^m (where m is a positive integer). The image signal processing according to claim 1, characterized in that a new ranking correction amount E_c is obtained by adding the image signal levels of some of the pixels and further subtracting the binarized image signal level. Device.
Priority Applications (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP15439084A JPS6132658A (en) | 1984-07-25 | 1984-07-25 | Picture signal processing device |
| US06/758,961 US4692811A (en) | 1984-07-25 | 1985-07-25 | Apparatus for processing image signal |
| EP85305304A EP0174721B1 (en) | 1984-07-25 | 1985-07-25 | Apparatus for processing image signal |
| DE8585305304T DE3583474D1 (en) | 1984-07-25 | 1985-07-25 | IMAGE SIGNAL PROCESSING DEVICE. |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP15439084A JPS6132658A (en) | 1984-07-25 | 1984-07-25 | Picture signal processing device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6132658A true JPS6132658A (en) | 1986-02-15 |
| JPH04428B2 JPH04428B2 (en) | 1992-01-07 |
Family
ID=15583087
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP15439084A Granted JPS6132658A (en) | 1984-07-25 | 1984-07-25 | Picture signal processing device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6132658A (en) |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS57125579A (en) * | 1981-01-29 | 1982-08-04 | Ricoh Co Ltd | Processing method for intermediate tone picture |
| JPS5896458A (en) * | 1981-12-04 | 1983-06-08 | Fuji Xerox Co Ltd | Binary system |
| JPS58215167A (en) * | 1982-06-07 | 1983-12-14 | Toshiba Corp | Method and device for processing picture signal |
-
1984
- 1984-07-25 JP JP15439084A patent/JPS6132658A/en active Granted
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS57125579A (en) * | 1981-01-29 | 1982-08-04 | Ricoh Co Ltd | Processing method for intermediate tone picture |
| JPS5896458A (en) * | 1981-12-04 | 1983-06-08 | Fuji Xerox Co Ltd | Binary system |
| JPS58215167A (en) * | 1982-06-07 | 1983-12-14 | Toshiba Corp | Method and device for processing picture signal |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH04428B2 (en) | 1992-01-07 |
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