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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