JPH03121687A - Noise reduction circuit for video signal - Google Patents
Noise reduction circuit for video signalInfo
- Publication number
- JPH03121687A JPH03121687A JP1258695A JP25869589A JPH03121687A JP H03121687 A JPH03121687 A JP H03121687A JP 1258695 A JP1258695 A JP 1258695A JP 25869589 A JP25869589 A JP 25869589A JP H03121687 A JPH03121687 A JP H03121687A
- Authority
- JP
- Japan
- Prior art keywords
- signal
- level
- video signal
- minute
- frequency
- 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
- 230000008030 elimination Effects 0.000 abstract 3
- 238000003379 elimination reaction Methods 0.000 abstract 3
- 238000010586 diagram Methods 0.000 description 5
- 238000000034 method Methods 0.000 description 3
- 238000006243 chemical reaction Methods 0.000 description 2
- 230000000007 visual effect Effects 0.000 description 2
- 208000027534 Emotional disease Diseases 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 230000004800 psychological effect Effects 0.000 description 1
- 230000035945 sensitivity Effects 0.000 description 1
Landscapes
- Television Systems (AREA)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
この発明は高精細度テレビジョン信号の高域に重畳する
ノイズを低減するノイズ低減回路に関し、特に高精細度
テレビジョンカメラの出力信号に重（従来の技術）
現行のテレビジョン方式に代わる新たなテレビジョン方
式として、画質および音質の向上はもちろん、現行テレ
ビジョン方式をはるかに上回る臨場感、迫力惑など高度
の視覚心理効果を奏することの出来る高精細度テレビジ
ョン方式、例えばハイビジョン方式が提案されている。[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a noise reduction circuit that reduces noise superimposed on the high frequency range of a high-definition television signal, and particularly relates to a noise reduction circuit that reduces noise superimposed on the high-frequency range of a high-definition television signal, and in particular, (Prior technology) As a new television system to replace the current television system, it not only improves picture and sound quality, but also provides advanced visual psychological effects such as a sense of realism and fascination that far exceeds that of the current television system. High-definition television systems, such as high-definition systems, have been proposed.
ハイビジョン方式は画面方式、走査方式、音声方式等が
現行テレビジョン方式、例えばＮＴＳＣ方式とは大幅に
異なるため、ＮＴＳＣ受像機を用いてハイビジョン信号
をそのまま再生することは出来ない。このため両方式間
における走査線数。Since the high-definition system is significantly different from current television systems, such as the NTSC system, in terms of screen format, scanning method, audio system, etc., it is not possible to reproduce high-definition signals as they are using an NTSC receiver. Therefore, the number of scan lines between both methods.
アスペクト比、水平走査周波数等の違いを吸収してハイ
ビジョン信号をＮＴＳＣ信号に変換して表示すｌる表示
方式が各種提案されている。Various display systems have been proposed that absorb differences in aspect ratio, horizontal scanning frequency, etc. and convert high-definition signals into NTSC signals for display.
第３図はそのようなハイビジョン／ＮＴＳＣ変換表示方
式の一例を示す画面構成図で、この表示方式は水平走査
線数１１２５本、アスペクト比１６：９のハイビジョン
画面（図（ａ））を、スキャンコンバータを用いて縦３
画面、横４画面の計１２画面に分割し、この分割した各
画面のハイビジョン信号を、Ｎ Ｔ Ｓ Ｃ信号に変換
して１２台のＮＴＳＣ受像機＃１〜＃１２からなる１画
面（図（１）） ）上に表示するもので、各Ｎ Ｔ Ｓ
Ｃ画面は水平走査線数５２５本、アスペクト比４：３
で構成されている。各ＮＴＳＣ受像機＃１〜＃１２とし
てマルチデイスプレィ用のプロジェクションユニットを
用いれば、実用的に十分な明るさで高精細度な画像を大
画面で表示することが出来る（特１頭昭６３９２９８７
号参照）。Figure 3 is a screen configuration diagram showing an example of such a high-definition/NTSC conversion display method. Vertical 3 using converter
The screen is divided into a total of 12 screens (4 screens horizontally), and the high-definition signals of each divided screen are converted to NTSC signals to create one screen consisting of 12 NTSC receivers #1 to #12 (Fig. 1)) ) shown above, each N T S
The C screen has 525 horizontal scanning lines and an aspect ratio of 4:3.
It consists of If a multi-display projection unit is used as each NTSC receiver #1 to #12, it is possible to display high-definition images on a large screen with sufficient brightness for practical use.
(see issue).
（発明が解決しようとする課題〕
第３図に示す表示方式において、帯域２０ＭＩＩｚのハ
・イビジョン信号を、スキャンコンバータを通して１２
面に拡大すると、帯域２．３３ＭＩＩｚのＮＴＳＣ信号
に変換される。この場合、ハイビジョンカメラの出力信
号を、直接１２而のＮ Ｔ Ｓ Ｃ信号に変換すると、
ハイビジョンカメラの出力信号には周波数に比例して振
幅が大きくなるノイズ（三角ノイズ）が含まれているた
め、ハイビジョン画面では目立たなかった高域ノイズ（
２０ＭＩＩｚ程度）が変換後のＮＴＳＣ画面では目立つ
ようになるという不都合がある。(Problems to be Solved by the Invention) In the display system shown in FIG.
When expanded to a plane, it is converted to an NTSC signal with a band of 2.33 MIIz. In this case, if the output signal of the high-definition camera is directly converted to 12 NTS C signals,
The output signal of a high-definition camera contains noise (triangular noise) whose amplitude increases in proportion to the frequency.
20 MIIz) becomes noticeable on the converted NTSC screen.
この理由は、帯域２０Ｍｌ１ｚのハイビジョン信号をス
キャンコンバータで１２面に拡大すると、帯域２．３３
ＭｔｌｚのＮＴＳＣ信号に変換され、同時に２０Ｍ１
１２のノイズも人間の目の視覚特性の感度が最も高い約
２ＭＩＩｚに変換されるため、ハイビジョン画面では目
立たなかった高域ノイズが変換後のＮＴＳＣ画面では目
立つことになるためである。The reason for this is that when a high-definition signal with a band of 20Ml1z is expanded to 12 screens using a scan converter, the band is 2.33
Converted to NTSC signal of Mtlz and 20M1 at the same time
This is because the noise of 12 is also converted to approximately 2 MIIz, which is the level at which the visual characteristics of the human eye have the highest sensitivity, so high-frequency noise that was not noticeable on a high-definition screen becomes noticeable on the converted NTSC screen.
そこで、この発明は高精細度テレビジョン信号に含まれ
る高域ノイズを予め低減させ、現行テレビジョン信号に
変換したときに目障りとなるノイズを減らすことを目的
とする。Therefore, it is an object of the present invention to reduce the high-frequency noise contained in a high-definition television signal in advance to reduce the noise that becomes an eyesore when converted to a current television signal.
〔課題を解決するための手段］
この発明は映像信号の高域レベルを抑圧する第１のフィ
ルタ手段と、このフィルタ手段から出力される映像信号
の微小レベルをカットする微小レベル除去手段と、微小
レベル除去手段から出力される信号の低域レベルを抑圧
する第２のフィルタ手段とを０１８え、第１および第２
のフィルタ手段の特性を、総合特性がフラットとなるよ
うに設定し、映像信号に重畳している高域ノイズを低減
するように構成する。[Means for Solving the Problems] The present invention includes a first filter means for suppressing a high frequency level of a video signal, a minute level removing means for cutting a minute level of a video signal output from the filter means, and a first filter means for suppressing a high frequency level of a video signal. a second filter means for suppressing the low frequency level of the signal output from the level removing means;
The characteristics of the filter means are set so that the overall characteristics are flat, and the high-frequency noise superimposed on the video signal is reduced.
この構成において、第１のフィルタ手段に入力された高
精細度テレビジョン信号は、高域の信号レベルが低域の
信号レベルに比べて相対的に抑圧された状態で微小レベ
ル除去手段に入力され、高域の微小レベルがカットされ
る。第２のフィルタ手段は第１のフィルタ手段とは逆に
、低域の信号レベルを抑圧するように構成されているの
で、高精細度テレビジョン信号は元のフラットな信号し
・＼ルに復帰し、かつ微小レベル除去手段で高域ノイズ
が除去された状態で出力される。In this configuration, the high-definition television signal input to the first filter means is input to the minute level removal means in a state where the high frequency signal level is relatively suppressed compared to the low frequency signal level. , the minute levels of high frequencies are cut. The second filter means is configured to suppress the low-frequency signal level, contrary to the first filter means, so that the high-definition television signal returns to the original flat signal. The signal is then output with high-frequency noise removed by the minute level removal means.
（実施例］
第１図はこの発明による映像信号のノイズ低減回路の一
実施例を示すブロック図である。(Embodiment) FIG. 1 is a block diagram showing an embodiment of a video signal noise reduction circuit according to the present invention.
このノイズ低減回路はハイビジョンカメラ１の出力信号
の高域レベルを抑圧するローパス・フィルタ（ＬＰＦ）
構成のフィルタ回路２と、このフィルタ回路２の出力信
号から微小な信号部分をカットする微小レベル除去回路
３と、微小レベル除去回路３の出力信号の高域レベルを
伸張するバイパス・フィルタ（）−Ｉ Ｐ Ｆ ）構成
のフィルタ回路４とから成る。This noise reduction circuit is a low-pass filter (LPF) that suppresses the high-frequency level of the output signal of the high-definition camera 1.
A filter circuit 2 consisting of a filter circuit 2, a minute level removal circuit 3 that cuts a minute signal portion from the output signal of the filter circuit 2, and a bypass filter ()-- that extends the high frequency level of the output signal of the minute level removal circuit 3. It consists of a filter circuit 4 having an IP F ) configuration.
この構成によれば、ＬＰＦ２に入力されるハイビジョン
カメラ１の出力信号は、第２図（ａ）に示すように、高
域の信号レベルが低域の信号レベルに比べて相対的に抑
圧されて出力され、微小レベル除去回路３に入力される
。微小レベル除去回路３では、第２図（ｂ）に示すよう
に、微小レベル−！〜＋！間の微小信号をカットし、Ｈ
Ｐ Ｆ ４に人力する。ＨＰ Ｆ ４に入力される信号
はＬ Ｐ Ｉ” ２とは逆に、第２図（Ｃ）に示すよう
に、低域の信号レベルが抑圧されて出力される。フィル
タ２および４の特性は両フィルタの総合特性がフラット
となるように設定される。このため、ハイビジョンカメ
ラＩから出力される映像信号は高域に重畳しているノイ
ズが低減された状態で出力されることになる。According to this configuration, the high-frequency signal level of the output signal of the high-definition camera 1 input to the LPF 2 is relatively suppressed compared to the low-frequency signal level, as shown in FIG. 2(a). The signal is output and input to the minute level removal circuit 3. In the minute level removal circuit 3, as shown in FIG. 2(b), minute level -! ~+! Cuts the minute signal between H
PF 4 is manned. Contrary to the signal input to the HP F 4, the low frequency signal level is suppressed and output as shown in FIG. 2(C).The characteristics of the filters 2 and 4 are as follows. The overall characteristics of both filters are set to be flat.Therefore, the video signal output from the high-definition camera I is output with noise superimposed in the high frequency range reduced.
［発明の効果］
この発明によれば、簡易な手段で高精細度テレビジョン
信号に重畳している高域ノイズを低減することができ、
スキャンコンバータによって現行テレビジョン信号に変
換しても画面上に現れるノイズを減らすことが出来る。[Effects of the Invention] According to the present invention, high-frequency noise superimposed on a high-definition television signal can be reduced by a simple means,
Even when converted to a current television signal using a scan converter, the noise that appears on the screen can be reduced.
第１図はこの発明による映像信号のノイズ低減回路の一
実施例を示すブロック図、
第２図は第１図の動作を説明するための特性図、第３図
はハイビジョン／ＮＴＳＣ変換表示方式の画面構成図で
ある。
２・・・ローパス・フィルタ、３・・・微小レベル除去
回路、４・・・バイパス・フィルタ。
６１５−FIG. 1 is a block diagram showing an embodiment of a video signal noise reduction circuit according to the present invention, FIG. 2 is a characteristic diagram for explaining the operation of FIG. 1, and FIG. 3 is a high-definition/NTSC conversion display system. It is a screen configuration diagram. 2...Low pass filter, 3...Minute level removal circuit, 4...Bypass filter. 615-
Claims (1)
、 上記フィルタ手段から出力される映像信号の微小レベル
をカットする微小レベル除去手段と、上記微小レベル除
去手段から出力される信号の低域レベルを抑圧する第２
のフィルタ手段とを備え、 上記第１および第２のフィルタ手段の特性を、総合特性
がフラットとなるように設定し、上記映像信号に重畳し
ている高域ノイズを低減することを特徴とする映像信号
のノイズ低減回路。[Scope of Claims] A first filter means for suppressing a high frequency level of a video signal, a minute level removing means for cutting a minute level of the video signal output from the filter means, and an output from the minute level removing means. The second one suppresses the low frequency level of the signal
filter means, and the characteristics of the first and second filter means are set so that the overall characteristics are flat, thereby reducing high-frequency noise superimposed on the video signal. Video signal noise reduction circuit.
Priority Applications (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1258695A JPH03121687A (en) | 1989-10-05 | 1989-10-05 | Noise reduction circuit for video signal |
| EP19920100199 EP0480910A3 (en) | 1989-10-05 | 1990-07-03 | Image displaying system |
| EP19900112669 EP0425761A3 (en) | 1989-10-05 | 1990-07-03 | Noise reduction circuit for image signal and image displaying system |
| US07/562,535 US5159450A (en) | 1989-10-05 | 1990-08-03 | Noise reduction circuit and compatable plural-unit display |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1258695A JPH03121687A (en) | 1989-10-05 | 1989-10-05 | Noise reduction circuit for video signal |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH03121687A true JPH03121687A (en) | 1991-05-23 |
Family
ID=17323813
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1258695A Pending JPH03121687A (en) | 1989-10-05 | 1989-10-05 | Noise reduction circuit for video signal |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH03121687A (en) |
-
1989
- 1989-10-05 JP JP1258695A patent/JPH03121687A/en active Pending
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