JPS6019709B2 - Signal binarization device - Google Patents
Signal binarization deviceInfo
- Publication number
- JPS6019709B2 JPS6019709B2 JP52086834A JP8683477A JPS6019709B2 JP S6019709 B2 JPS6019709 B2 JP S6019709B2 JP 52086834 A JP52086834 A JP 52086834A JP 8683477 A JP8683477 A JP 8683477A JP S6019709 B2 JPS6019709 B2 JP S6019709B2
- Authority
- JP
- Japan
- Prior art keywords
- signal
- low
- analog
- circuit
- information
- 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.)
- Expired
Links
Landscapes
- Exposure Or Original Feeding In Electrophotography (AREA)
- Image Input (AREA)
- Facsimile Image Signal Circuits (AREA)
Description
【発明の詳細な説明】
本発明は、光電変換素子等を用いて原稿上の書画像等の
情報をライン状に論取り走査を行ないアナログ画信号に
変換して信号処理を行なうファクシミリ、複写機等にお
ける信号２値化装置に関するものである。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a facsimile and a copying machine that use a photoelectric conversion element or the like to scan information such as a written image on a document in a line shape, convert it into an analog image signal, and perform signal processing. The present invention relates to a signal binarization device such as the above.
従来、この種の装置として、例へば第１図の線図に示す
ような手段が用いられていた。Conventionally, as an example of this type of apparatus, a means as shown in the diagram of FIG. 1 has been used.
図中、イは原稿上の書画像等の情報を光学的に撮像し、
光電変換素子を用いてライン状に読取り走査を行なって
得られるアナログ画信号であり、口は直流レベル固定の
閥値、ハは、アナログ画信号イの閥値口による２値化出
力波形図である。すなわち、第１図に示すように光亀変
換されたアナログ画信号イは、所定のレベルに固定され
た閥値口で２値化を行う方法が従来一般的であったが、
この種の装置に用いられる原稿は、同一原稿内で背景濃
度やコントラストが変化し、かつまた濃度の低い背景内
に高濃度の情報が存在する場合が多く、たとえば、第１
図イにおけるＡおよびＢに示す部分が２値化出力ハに示
すように判別できないなどの次点があった。In the figure, A optically captures information such as a calligraphy image on the manuscript.
This is an analog image signal obtained by reading and scanning in a line using a photoelectric conversion element, where ``a'' is a fixed DC level threshold, and ``C'' is a binarized output waveform diagram at the edge of the analog image signal A. be. That is, as shown in FIG. 1, it has been common practice to binarize the optically converted analog image signal A at a threshold fixed at a predetermined level.
The originals used in this type of device often have varying background density and contrast within the same original, and high-density information exists within a low-density background.
There were some runner-up results, such as parts A and B in Figure A that could not be distinguished as shown in binarized output C.
本発擬は、上記のような従来のものの次点を解消するた
めになされたもので、アナログ画信号イの低周波成分に
より閥値口を制御することによって、原稿上の書画像等
の情報をできるだけ忠実に再現させることを目的として
いる。This simulation was made to solve the runner-up problem of the conventional ones as described above, and by controlling the threshold by the low frequency component of the analog image signal A, information such as the calligraphy image on the manuscript can be detected. The aim is to reproduce it as faithfully as possible.
以下、本発明の一実施例を第２図のブロック図について
説明すると、図中、１は、低域通過フィル夕、２は限流
回路、８は、信号遅延回路、４は、２値化回路である。Hereinafter, one embodiment of the present invention will be explained with reference to the block diagram of FIG. 2. In the figure, 1 is a low-pass filter, 2 is a current limiting circuit, 8 is a signal delay circuit, and 4 is a binarization circuit. It is a circuit.
第３図、第４図および第５図は各ブロックの信号の波形
図である。いま、原稿上の書画像等の情報を光電変換し
たアナログ画信号イの低域周波数成分を取り出すと、第
３図に示す破線二のように信号波形となる。FIGS. 3, 4, and 5 are waveform diagrams of signals of each block. Now, when the low frequency component of the analog image signal A obtained by photoelectrically converting information such as a calligraphic image on a manuscript is extracted, the signal waveform becomes as shown by the broken line 2 in FIG. 3.
よってこの信号二を闇値とすると、アナログ画債号イの
Ａ及びＢ部でも判別できるようになる。この２値化出力
が第３図木である。ところが、アナログ画宿号イの低周
波成分を闇値としたため、アナログ画債号イの本来白ま
たは黒で統一されるべき部分であるＣ，Ｄ，ＥおよびＦ
部において、原稿上のわずかな濃度差やノイズ等に対し
て判別が不安定となり、本来白または黒で統一されるべ
き箇所であるにもかかわらず、２値化出力ホに示すよう
に不安定に判別されるという操れがある。したがって本
発明では、上記の不備を解消するため、アナログ画信号
イの低周波成分二の振幅を制限して、闇値が極端に白ま
たは黒レベル寄りに移行するのを防止する限流回路２を
設け、上記振幅を制限するレベルを第３図に示す。Ｅ，
およびＥｏとし、限流回路２によって振幅制限を行った
出力は第４図への信号波形となる。振幅制限レベルＥ，
は、通常白ピークレベルの７５％に「またＥｏは白ピー
クレベルの２５％に選定する。以上のようにして振幅制
限した信号へを閥値としてアナログ信号イを２値化すと
、第４図卜のように２値化出力は、アナログ画信号イの
ＡおよびＢ部が忠実に判別され、Ｃ，Ｄ，ＥおよびＦ部
のノイズは判別されて解消するという効果が得られる。
以上のような効果を得るため第２図の低域通過フィル夕
は通過帯城利得が“１”で、遮断周波数はアナログ画信
号の最高画周波数より低く、かつ１サイクルが一走査期
間より短いことが必要であり、通常は最高画周波数の１
／２〜１／５に設定する。さらに実際には、この低域通
過フィル夕を通過した信号は、位相がｔ時間だけ遅れる
ため、アナログ画信号イも第２図の遅延回路３によって
低域通過フィル夕で生じた遅延時間ｔだけ遅延させて第
５図に示す信号チを得ている。この信号チを閥値りで２
値化した出力は第５図ルのように得られる。上述のよう
にして、同一原稿内、特に一走査内での背景濃度やコン
トラストが不揃いで、さらに中程度の濃度の背景内に高
濃度の情報が存在する場合でも、忠実に２値化を行い得
る効果がある。Therefore, if this signal 2 is taken as the dark value, it will become possible to distinguish between the A and B portions of analog card number A. This binarized output is the tree in Figure 3. However, because the low frequency component of analog image number A was set as a dark value, C, D, E, and F, which should originally be unified as white or black, were
In some parts, the discrimination becomes unstable due to slight differences in density or noise on the original, and even though the parts should originally be unified as white or black, the binary output becomes unstable as shown in (E). There is a manipulation of being judged by someone. Therefore, in the present invention, in order to eliminate the above-mentioned deficiencies, the current limiting circuit 2 limits the amplitude of the low frequency component 2 of the analog image signal A to prevent the dark value from shifting extremely toward the white or black level. FIG. 3 shows the level at which the amplitude is limited. E,
and Eo, and the output whose amplitude is limited by the current limiting circuit 2 becomes the signal waveform shown in FIG. Amplitude limit level E,
Normally, Eo is selected to be 75% of the white peak level, and Eo is selected to be 25% of the white peak level.If the analog signal A is binarized using the amplitude-limited signal as described above as the threshold value, as shown in Figure 4. As shown in Fig. 5, the binarized output has the effect that the A and B portions of the analog image signal A are faithfully determined, and the noise in the C, D, E, and F portions are determined and eliminated.
In order to obtain the above effects, the low-pass filter shown in Figure 2 has a passband gain of "1", a cutoff frequency lower than the highest image frequency of the analog image signal, and one cycle shorter than one scanning period. Usually, the highest image frequency is 1
/2 to 1/5. Furthermore, in reality, the phase of the signal that has passed through this low-pass filter is delayed by time t, so that the analog image signal A is also delayed by the delay time t caused by the low-pass filter by the delay circuit 3 in FIG. By delaying the signal, the signal shown in FIG. 5 is obtained. This signal chi is 2 at the break price
The converted output is obtained as shown in Figure 5. As described above, even if the background density and contrast within the same document, especially within one scan, are uneven, and even if there is high density information within a background of medium density, binarization can be performed faithfully. There are benefits to be gained.
また第６図のように白レベルが長く継続する領域Ｊでは
、閥値ヌは白レベル寄りに移行し、白背景内の黒情報が
判別し易くなり、黒レベルが長く継続する領域Ｋでは、
閥値ヌは黒レベル寄りに移行し、黒背景内の白情報を判
別し易くするという効果がある。なお、上記実施例では
原稿上の書画像等の情報をライン状に編み取り走査を行
なうファクシミリ、複写機について説明したが、その他
のアナログ信号の２値化を行なう情報機器や、映像機器
でも同様の効果を奏する。In addition, in the area J where the white level continues for a long time as shown in FIG.
The threshold value shifts toward the black level, which has the effect of making it easier to distinguish white information within a black background. In the above embodiment, a facsimile machine and a copying machine that weave and scan information such as a written image on a document in a line are explained, but the same applies to other information equipment and video equipment that binarizes analog signals. It has the effect of
以上のように、本発明によれば、アナログ信号の２値化
に際して、該アナログ信号の所定の周波数成分を制御さ
せることによって、同一原稿内、特に一走査内での背景
濃度、またはコントラストが不揃いで、かつまた、中程
度の濃度の背景内に高濃度の情報が存在する場合でも判
別が可能となり、白あるいは黒レベルが長く継続する場
合にも白背景内の黒あるいは黒背景内の白情報が判別さ
れ易くなり、したがって、原稿上の書画像等の情報を忠
実に再現するという効果を奏する。As described above, according to the present invention, when an analog signal is binarized, by controlling a predetermined frequency component of the analog signal, the background density or contrast within the same document, especially within one scan, is not uniform. In addition, it is possible to distinguish even when high density information exists within a medium density background, and even when the white or black level continues for a long time, black information within a white background or white information within a black background can be distinguished. This makes it easier to distinguish information such as a calligraphy image on a manuscript, thereby achieving the effect of faithfully reproducing information such as a calligraphy image on a manuscript.
第１図は従来の信号２値化装置の入出力信号波形図、第
２図は本発明の信号２値化装置の−実施例を示すブロッ
ク図、第３図および第４図は本発明を説明するための波
形図、第５図および第６図は本発明の各部信号の波形図
である。
図中、１：低域通過フィル夕、２：限流回路、３：信号
遅延回路、４：２値化回路。
なお図中、同一符号は同一、または相当部分を示す。濠
１図
多２図
簾３図
簾ム図
多５囚
多６図FIG. 1 is an input/output signal waveform diagram of a conventional signal binarization device, FIG. 2 is a block diagram showing an embodiment of the signal binarization device of the present invention, and FIGS. 3 and 4 are diagrams of the signal binarization device of the present invention. Waveform diagrams for explanation, FIGS. 5 and 6, are waveform diagrams of various signals of the present invention. In the figure, 1: low-pass filter, 2: current limiting circuit, 3: signal delay circuit, 4: binarization circuit. In the drawings, the same reference numerals indicate the same or corresponding parts. Moat 1 map 2 blinds 3 blinds 5 fences 6
Claims (1)
から所定の周波数以下の低域周波数成分のみを取り出す
低域通過フイルタ、該低域通過フイルタの出力信号の振
幅を所定レベルで制限する限流回路、上記アナログ画信
号を所定の時間だけ遅延させる遅延回路、および上記限
流回路の出力信号を閾値として上記遅延回路出力のアナ
ログ信号を２値化する２値化回路を備えてなる信号２値
化装置。1. A low-pass filter that extracts only low-frequency components below a predetermined frequency from an analog image signal obtained by photoelectrically converting information such as a document image, and limits the amplitude of the output signal of the low-pass filter to a predetermined level. A signal comprising a current limiting circuit, a delay circuit that delays the analog image signal by a predetermined time, and a binarization circuit that binarizes the analog signal output from the delay circuit using the output signal of the current limiting circuit as a threshold. Binarization device.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP52086834A JPS6019709B2 (en) | 1977-07-19 | 1977-07-19 | Signal binarization device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP52086834A JPS6019709B2 (en) | 1977-07-19 | 1977-07-19 | Signal binarization device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5421219A JPS5421219A (en) | 1979-02-17 |
| JPS6019709B2 true JPS6019709B2 (en) | 1985-05-17 |
Family
ID=13897832
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP52086834A Expired JPS6019709B2 (en) | 1977-07-19 | 1977-07-19 | Signal binarization device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6019709B2 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0455241Y2 (en) * | 1985-10-21 | 1992-12-25 | ||
| WO2007039059A1 (en) | 2005-09-20 | 2007-04-12 | Dsm Ip Assets B.V. | Novel carboxylic acid derivatives |
| CN100373331C (en) * | 1996-08-27 | 2008-03-05 | 松下电器产业株式会社 | Multithreaded processor for processing multiple instruction streams independently of each other by flexibly controlling throughput in each instruction stream |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS56129480A (en) * | 1980-03-17 | 1981-10-09 | Matsushita Graphic Commun Syst Inc | Binary discrimination system and its device |
| JPH0644281B2 (en) * | 1983-03-18 | 1994-06-08 | 株式会社日立製作所 | Pattern defect inspection system |
| JPS60134693A (en) * | 1983-12-23 | 1985-07-17 | Shimadzu Corp | Picture processor |
| JPH0263278A (en) * | 1989-06-15 | 1990-03-02 | Casio Comput Co Ltd | Gradation correction circuit for liquid crystal display device |
-
1977
- 1977-07-19 JP JP52086834A patent/JPS6019709B2/en not_active Expired
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0455241Y2 (en) * | 1985-10-21 | 1992-12-25 | ||
| CN100373331C (en) * | 1996-08-27 | 2008-03-05 | 松下电器产业株式会社 | Multithreaded processor for processing multiple instruction streams independently of each other by flexibly controlling throughput in each instruction stream |
| WO2007039059A1 (en) | 2005-09-20 | 2007-04-12 | Dsm Ip Assets B.V. | Novel carboxylic acid derivatives |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5421219A (en) | 1979-02-17 |
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