JPS58151773A - Facsimile capable of correcting intermediate gradation - Google Patents
Facsimile capable of correcting intermediate gradationInfo
- Publication number
- JPS58151773A JPS58151773A JP57034697A JP3469782A JPS58151773A JP S58151773 A JPS58151773 A JP S58151773A JP 57034697 A JP57034697 A JP 57034697A JP 3469782 A JP3469782 A JP 3469782A JP S58151773 A JPS58151773 A JP S58151773A
- Authority
- JP
- Japan
- Prior art keywords
- density
- distribution
- picture
- signal
- converter
- 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.)
- Pending
Links
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N1/00—Scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission; Details thereof
- H04N1/40—Picture signal circuits
Landscapes
- Engineering & Computer Science (AREA)
- Multimedia (AREA)
- Signal Processing (AREA)
- Facsimile Image Signal Circuits (AREA)
Abstract
Description
【発明の詳細な説明】
本発明はファクシミリ装置に関し、特に中間調階調補正
に関する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to facsimile machines, and more particularly to halftone gradation correction.
従来、ファクシミリ受信機においてN階調の中間調我現
を行う場合、送られてき友画信号濃度にリニアな信号を
記録素子に印加し階調記録を行ってい友ため、濃度分布
のかたよっ友画信号を受信記録し良場合、記録面ににと
んど記録濃度変化の我われない記録部分が存在し、記録
面のコントラストが明瞭でないという問題があり次。Conventionally, when performing halftone recording of N gradations in a facsimile receiver, a signal linear to the density of the received image signal is applied to the recording element to perform gradation recording. When the signal is received and recorded successfully, there are recorded areas on the recording surface where the recording density changes uncontrollably, and the next problem is that the contrast of the recording surface is not clear.
本発明の目的はN#調の中間aS現を行う時、濃度のか
たより九部分において階調設定を密にするといったよう
に階調間隔を濃度分布に応じて変化させることにより上
記のような記録面の濃度変化の表われない部分を減少さ
せ、コントラストめ明瞭な鮮明な記録#Jt−可能にす
る中間調階調補正方式を提供するところにある。The purpose of the present invention is to achieve the above-described recording by changing the gradation interval according to the density distribution, such as making the gradation setting denser in the 9th part than the density distribution, when performing intermediate aS recording of N# tone. The object of the present invention is to provide a halftone gradation correction method that reduces areas where density changes do not appear on a surface and enables sharp recording with clear contrast.
本発明は、ファクシミリ受信機において入力画信号を記
憶する手段と、蚊入力画信号の濃度分布を計測する手段
と、該濃度分布に応じ記録の濃度指定を設定する手段と
を含み、前記入力画信号の前記濃度分布を計測し、前記
入力画信号と記録の濃度との対応関係を変化させること
によりコントラストの明瞭な記録面を再生するものであ
る。The present invention includes means for storing an input image signal in a facsimile receiver, means for measuring the density distribution of the mosquito input image signal, and means for setting a density specification for recording according to the density distribution, By measuring the density distribution of the signal and changing the correspondence between the input image signal and the recorded density, a recorded surface with clear contrast is reproduced.
次に本発明の実施例について図面上参照して説明する。Next, embodiments of the present invention will be described with reference to the drawings.
第1図を参照すると実施例は、8階調の中間iiM]表
現を行う揚台であり、画信号入力端子1゜アナログ信号
rディジタル信号に変換するA/D変換器9、該画信号
t1ライン分遅延する丸めのシフトレジスタ2,1ライ
/中の濃度分布を計測する濃度分布計測回路3.3種類
の階調特性指定に応じて画信号の濃FILを変換するD
/D変換s4゜D/D変換器の出力レベルに応じてサー
マルヘッド7の各記録素子に印加される電力の印加時間
を設定する電力印加時間制御回路5、サーマルヘッド7
t−駆動するドライバ6、サーマルヘッド7及びクロッ
ク発生aSIII−含む。今入力端子1よ抄アナログ信
号が印加され、A/D変換lS1でディジタル信号に変
換される。A/D変換器で要求される量子化階調数は濃
度分布のかmよりに応じ粗密の階gqa定を行うため、
記録再現階調数よ抄も多く2倍以上の量子化階調数が望
まれる。本実施例においては記録再現階調数t−8階調
としているので5ビツトの量子化【行う。A/D変換l
)9で変換された信号のlライン分の濃度分布t、S度
分布計測回路3で計測する。第2図に濃度分布計測回路
3の詳細を示す。この回路では、コンパレータ10Mで
濃度の高い画信号を検出し、コンパレータ10bで濃度
の低い画信号t−I/*出する。丁なわち規準レベル発
生i)10m、10bにはそれぞれ高濃度の規準レベル
及び低濃度の規準レベルが設定しである。NORゲート
端子11からは、高い濃度にも低い濃度にも線画しない
比較的濃度分布のか良よりか小さな画信号t−WIi出
する。カウンタ121@ 12be 12Cにより
、コンパレータ10 m、10 be及びNORゲート
熾子1lより検出嘔れた濃度分布ごとに分けられ九画信
号の画素数tslライン分カウントアカウントパレータ
13mは、カウンタ12mとカラ/り12bの出力を比
較し、カラ/り12aのカウント出力が大きいとき出力
をHighとする。コンパレータ13bはカウンタ12
bとカウンタ12Cの出力【比較し、カラ/り12bの
カウント出力が大きいとき出力をHighとするコンパ
レータ13Cはカラ/り12Cとカウンタ12at−比
較し、カラ/り12Cのカウント出力が大きいときHi
ghとする。Referring to FIG. 1, the embodiment is a platform for expressing 8 gray scale intermediate iiM], an image signal input terminal 1°, an A/D converter 9 for converting an analog signal r into a digital signal, and an A/D converter 9 for converting the image signal t1 into a digital signal. A rounding shift register with a line delay 2. A density distribution measurement circuit that measures the density distribution within 1 line/medium 3. D that converts the dark FIL of the image signal according to three types of gradation characteristic specifications
/D conversion s4゜A power application time control circuit 5 that sets the application time of power applied to each recording element of the thermal head 7 according to the output level of the D/D converter, and the thermal head 7
t-driver 6, thermal head 7 and clock generator aSIII-. An analog signal is now applied to the input terminal 1, and is converted into a digital signal by the A/D converter IS1. The number of quantization gradations required by the A/D converter is determined by determining the density level gqa according to the concentration distribution.
The number of quantization tones is greater than the number of recording reproduction tones, and it is desirable to have twice or more the number of quantization tones. In this embodiment, since the number of recorded reproduction gradations is t-8 gradations, 5-bit quantization is performed. A/D conversion
) The density distribution t and S degree distribution measuring circuit 3 measure the density distribution for l lines of the signal converted in step 9. FIG. 2 shows details of the concentration distribution measuring circuit 3. In this circuit, a comparator 10M detects a high-density image signal, and a comparator 10b outputs a low-density image signal t-I/*. In other words, reference level generation i) A high density reference level and a low density reference level are set at 10m and 10b, respectively. The NOR gate terminal 11 outputs an image signal t-WIi with a comparatively good density distribution that does not cause line drawing at either high density or low density. The counter 121 @ 12be 12C counts the number of pixels of the 9-pixel signal for each density distribution detected by the comparators 10m and 10be and the NOR gate 1l for each line. The output of the color/return 12b is compared, and when the count output of the color/return 12a is large, the output is set to High. The comparator 13b is the counter 12
The comparator 13C compares the output of the color/return 12C with the output of the counter 12C and sets the output to High when the count output of the color/return 12b is large.
gh.
これよ勤コ/パレータ131,131)e 13C@
ANDゲート14ae 14b@ 14C及びアリ
ツブ70ツブ18 a、 18 b、 18 cに
おいて、濃度分布が比較的高い部分に集まっている時は
、ANDゲー)14Mが選択されフリップ70ツブIB
akセツトし出力端子15がHighとなり。This is Kinko/Pareta 131, 131)e 13C@
When the concentration distribution is concentrated in a relatively high part in the AND gates 14ae 14b @ 14C and the flip 70 knobs 18a, 18b, and 18c, the AND gate 14M is selected and the flip 70 knob IB is selected.
ak is set and output terminal 15 becomes High.
比較的濃度分布のかたよりが少ないときはANDゲート
14Cが選択され、フリップ70ツブ18b9rセツト
し、出力端子16がHighとなL濃度分布が比較的低
い部分に集まっている時は、ANDゲート14Cが選択
されスリップ70ツブ18Ct−セットし、出力端子1
7がHighとなる。When the concentration distribution is relatively small, the AND gate 14C is selected, the flip 70 block 18b9r is set, and the output terminal 16 is High. When the L concentration distribution is concentrated in a relatively low part, the AND gate 14C is selected. Selected slip 70 tube 18Ct-set, output terminal 1
7 becomes High.
第1図のクロック発生!S8からは、lラインごとの周
波数からなるクロック8aと画素周波数からなるクロッ
ク8tl−発生する。A/D変換iG9で変換された信
号は、濃度分布計測回%3により濃度分布が計測される
一方シフトレジスタ2で濃度分布を計測される間lライ
ン分遅延される。D/D変換S4は濃度分布計測回路3
の結果に応じて出力端子15がHighのときは、濃度
の嵩い部分の階調指定を密とし、低い部分の階調指定が
粗となるように5/3ビツト変換する。この11度分布
が濃度の高砂部分に集まっている場合の濃度階調と量子
化レベルとの関係を第3図に示す。Clock generation in Figure 1! From S8, a clock 8a consisting of a frequency for every l line and a clock 8tl- consisting of a pixel frequency are generated. The signal converted by the A/D conversion iG9 is delayed by l line while the concentration distribution is measured by the shift register 2 while the concentration distribution is measured by the concentration distribution measurement time %3. D/D conversion S4 is concentration distribution measurement circuit 3
When the output terminal 15 is High in accordance with the result of , 5/3 bit conversion is performed so that the gradation specification for the high-density portion is made dense and the gradation specification for the low-density portion is coarse. FIG. 3 shows the relationship between the density gradation and the quantization level when this 11 degree distribution is concentrated in the Takasago part of the density.
D−P/F18bの出力端子16がHighのときは濃
度階調がリニアとなるように5/3ビツト変換する。こ
の濃度分布のかたよりが比較的小さい場合の濃度階調と
量子化レベルとの関係を第4図に示す。D−P/F18
cの出力端子17がHlghのときは、階調指定は濃度
の高い部分は粗゛に、濃度の低い部分は密になるよう5
/3ビツト変換する。この濃度分布が濃度の低い部分に
集まっている場合の濃度階調と量子化レベルとの関係倉
第5図に示す。When the output terminal 16 of the DP/F 18b is High, 5/3 bit conversion is performed so that the density gradation becomes linear. FIG. 4 shows the relationship between density gradation and quantization level when the deviation of this density distribution is relatively small. D-P/F18
When the output terminal 17 of
/3 bit conversion. FIG. 5 shows the relationship between density gradation and quantization level when this density distribution is concentrated in low density areas.
電力印加時間制御回路5はD/D変換器からの信号に応
じ、サーマルへラド7への記録印加時間を設定する。D
/D変換*4s電力印加時間制御回路5、ドライバ60
部分は既製の技術で容易に実現できるものが利用できる
。すなわちD/D変換器は1画信号濃度分布計測回路3
からの指定によって、それぞれ、第3図、第4図および
第5図に示したように画信号濃度を再生画偉号濃度に変
換するためにD/D変換器の量子比レベルを設定する。The power application time control circuit 5 sets the recording application time to the thermal radar 7 according to the signal from the D/D converter. D
/D conversion*4s power application time control circuit 5, driver 60
Parts that can be easily realized using off-the-shelf technology can be used. In other words, the D/D converter is the one-picture signal density distribution measuring circuit 3.
The quantum ratio level of the D/D converter is set in order to convert the image signal density to the reproduced image signal density as shown in FIGS. 3, 4, and 5, respectively, according to the specifications from .
本実施例において、濃度分布計測回路の濃度分布の種類
t1濃度の高い部分に集まっている場合。In this embodiment, the concentration distribution type t1 of the concentration distribution measurement circuit is concentrated in a high concentration area.
濃度の低い部分に集まっている場合、比較的濃度のかた
よりが少ない場合の3種類、濃度分布を計測する範囲k
lフィン分としたが、これらの数。There are three types: when the concentration is concentrated in an area with low concentration, when the concentration distribution is relatively small, and the range k for measuring the concentration distribution.
1 fin, but these numbers.
範囲は任意に取゛ることかできることはいうまでもない
。It goes without saying that the range can be set arbitrarily.
本発明は以上説明したようにファクシミリ受信機におい
て入力画信号を記憶すると同時に、濃度分布を計測し、
濃度階調指定を濃度分布に応じ濃度分布のかたよった部
分は密に、それ以外の部分は粗に設定することKよシ記
録画のコントラストを明瞭にしh記録面を鮮明にする効
果を与えるものである。As explained above, the present invention stores an input image signal in a facsimile receiver and simultaneously measures the density distribution.
Specify the density gradation according to the density distribution, setting it densely in areas where the density distribution is uneven, and coarsely in other areas.It gives the effect of making the contrast of the recorded image clearer and the recording surface sharper. It is.
第1図は本発明の実施例のブロック図、第2図は濃度分
布計測回路の詳細ブロック図、第3図は濃度の高いはう
に分布のある場合の濃度と量子化レベルとの関係1−、
第4図は濃度分布のか九よりか少ない場合の濃度と量子
化レベルの関係t、第1・・・・・・画像入力端子、2
・・・・・・シフトレジスタ、3・・・・・・濃度分布
計測回路、4・・・・・・D/D変換器。
5・・・・・・電力印加時間制御回路、6・・・・・・
ドライバ。
7・・・・・・サーマルヘッド、8・旧・・クロック発
振S。
8a・・・・・・ラインクロック、8b・・・・・・画
素クロック。
9・・・・・・A/D変換iT)、lOa、xob、l
0C113a、 13 b、 13 C・・−・・
・コンパレータ、12鳳@ 12b@ 12C・・
・・・・カウンタ、181@ 18beisc・・・
・・・Dフリップフロップ120as20b・・・・・
・規準レベル発生器。FIG. 1 is a block diagram of an embodiment of the present invention, FIG. 2 is a detailed block diagram of a concentration distribution measuring circuit, and FIG. 3 is a relationship between concentration and quantization level when there is a high concentration distribution. ,
Figure 4 shows the relationship t between density and quantization level when the density distribution is less than 9, 1st... image input terminal, 2
...Shift register, 3...Concentration distribution measuring circuit, 4...D/D converter. 5...Power application time control circuit, 6...
driver. 7... Thermal head, 8. Old... Clock oscillation S. 8a...Line clock, 8b...Pixel clock. 9...A/D conversion iT), lOa, xob, l
0C113a, 13 b, 13 C...
・Comparator, 12 Otori @ 12b @ 12C...
...Counter, 181@18beisc...
...D flip-flop 120as20b...
・Reference level generator.
Claims (1)
を計測する手段と、濃度分布に応じて記録濃ft指定す
る手段と、指定記録濃度に応じて前記入力画信号の強度
を変換する手段と、この変換された強度に応じて画信号
を再生する手段とを含むファクシミリ装置。means for storing a human image signal, means for measuring the density distribution of the input image signal, means for specifying a recording density ft according to the density distribution, and converting the intensity of the input image signal according to the specified recording density. and means for reproducing an image signal according to the converted intensity.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP57034697A JPS58151773A (en) | 1982-03-05 | 1982-03-05 | Facsimile capable of correcting intermediate gradation |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP57034697A JPS58151773A (en) | 1982-03-05 | 1982-03-05 | Facsimile capable of correcting intermediate gradation |
Publications (1)
Publication Number | Publication Date |
---|---|
JPS58151773A true JPS58151773A (en) | 1983-09-09 |
Family
ID=12421555
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP57034697A Pending JPS58151773A (en) | 1982-03-05 | 1982-03-05 | Facsimile capable of correcting intermediate gradation |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPS58151773A (en) |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS61157191A (en) * | 1984-12-28 | 1986-07-16 | Mitsubishi Electric Corp | Video printer device |
JPS63139481A (en) * | 1986-12-02 | 1988-06-11 | Canon Inc | Automatic picture quality controller |
JPH01132277A (en) * | 1988-10-18 | 1989-05-24 | Fuji Xerox Co Ltd | Digital color copying device |
US7373011B2 (en) | 2004-10-07 | 2008-05-13 | Polaroid Corporation | Density-dependent sharpening |
-
1982
- 1982-03-05 JP JP57034697A patent/JPS58151773A/en active Pending
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS61157191A (en) * | 1984-12-28 | 1986-07-16 | Mitsubishi Electric Corp | Video printer device |
JPS63139481A (en) * | 1986-12-02 | 1988-06-11 | Canon Inc | Automatic picture quality controller |
JPH01132277A (en) * | 1988-10-18 | 1989-05-24 | Fuji Xerox Co Ltd | Digital color copying device |
US7373011B2 (en) | 2004-10-07 | 2008-05-13 | Polaroid Corporation | Density-dependent sharpening |
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