JPH0569353B2 - - Google Patents
Info
- Publication number
- JPH0569353B2 JPH0569353B2 JP1364086A JP1364086A JPH0569353B2 JP H0569353 B2 JPH0569353 B2 JP H0569353B2 JP 1364086 A JP1364086 A JP 1364086A JP 1364086 A JP1364086 A JP 1364086A JP H0569353 B2 JPH0569353 B2 JP H0569353B2
- Authority
- JP
- Japan
- Prior art keywords
- noise
- noise reduction
- decoder
- signal
- low
- 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 - Lifetime
Links
- 230000005540 biological transmission Effects 0.000 claims description 22
- 238000000034 method Methods 0.000 description 18
- 238000010586 diagram Methods 0.000 description 4
- 230000003068 static effect Effects 0.000 description 4
- 230000006866 deterioration Effects 0.000 description 3
- 230000004044 response Effects 0.000 description 3
- 238000005070 sampling Methods 0.000 description 3
- 230000006835 compression Effects 0.000 description 2
- 238000007906 compression Methods 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 238000013459 approach Methods 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 229940028444 muse Drugs 0.000 description 1
- GMVPRGQOIOIIMI-DWKJAMRDSA-N prostaglandin E1 Chemical compound CCCCC[C@H](O)\C=C\[C@H]1[C@H](O)CC(=O)[C@@H]1CCCCCCC(O)=O GMVPRGQOIOIIMI-DWKJAMRDSA-N 0.000 description 1
- 238000001228 spectrum Methods 0.000 description 1
- 230000002123 temporal effect Effects 0.000 description 1
Landscapes
- Television Systems (AREA)
Description
【発明の詳細な説明】
［産業上の利用分野］
本発明は多重サブサンプル伝送方式の受像機を
構成する場合のデコーダーに関するものである。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a decoder for constructing a receiver using a multiple subsample transmission method.
［開示の概要］
本発明は例えば後述するような多重サブサンプ
ル伝送方式を用いたハイビジヨン放送システムに
おいて、所要受信Ｃ／Ｎを下げるために、動き領
域の再生信号に対してのみ、いわゆるノイズコア
リングを行い、動／静領域に対する伝送路ノイズ
の影響のバランスを取るものである。[Summary of the Disclosure] The present invention applies so-called noise coring only to the reproduced signal in the motion area in order to lower the required received C/N in a high-definition broadcasting system using a multiplex subsample transmission method as described later. This is to balance the influence of transmission line noise on the dynamic/static domain.
［従来の技術］
一方、ノイズコアリングの方法は、従来家庭用
VTRの再生回路等に用いられている。[Conventional technology] On the other hand, the noise coring method is
Used in VTR playback circuits, etc.
しかし、方式的に本発明のような用い方を行つ
た例は存在しない。また、従来のように動／静に
関係なくノイズコアリングを固定的に使用した場
合は、確かにノイズは低減されるが、それにも増
して、デイテールが無くなり、大きな画質劣化を
もたらしており、良い応用例とは云えなかつた。 However, there is no example of using the method as in the present invention. In addition, when noise coring is used in a fixed manner, regardless of motion or static, as in the past, noise is certainly reduced, but in addition, details are lost, resulting in a significant deterioration of image quality. It could not be called an application example.
［発明が解決しようとする問題点］
テレビジヨン信号を帯域圧縮する方法の１つ
に、フレーム間とフイールド間のオフセツトサブ
サンプリングを用いた多重サブサンプル伝送方
式、例えばMUSE（Multiple Sub−Nyquist
Sampling Encoding）と呼ばれる現行の高品位
テレビジヨン信号多重サブサンプル伝送方式があ
り、有効に帯域圧縮が実現されている。その詳細
は、例えば「電子通信学会技術研究報告 画像工
学 IE84−72」に述べられている。[Problems to be Solved by the Invention] One of the methods for band compression of television signals is a multiple subsample transmission method using offset subsampling between frames and between fields, such as MUSE (Multiple Sub-Nyquist).
There is a current high-definition television signal multiplex sub-sampling transmission method called Sampling Encoding, which effectively achieves band compression. The details are described in, for example, ``Technical Research Report of the Institute of Electronics and Communication Engineers, Image Engineering IE84-72''.
また伝送信号の低域にフレーム間の折り返し成
分を含まない伝送方式も提案されている（特願昭
60−106132号参照）。 In addition, a transmission method that does not include aliasing components between frames in the low frequency range of the transmission signal has also been proposed (patent application
60-106132).
例えば伝送信号の低域にフレーム間の折り返し
成分を含まない伝送方式等の受像機において、受
信Ｃ／Ｎが低下すると当然画像のＳ／Ｎが低下す
るが、視覚的に見た場合、その程度は画像の静止
部分では少なく、動き領域において大きい。 For example, in a receiver that uses a transmission method that does not include aliasing components between frames in the low frequency range of the transmitted signal, if the received C/N decreases, the image S/N will naturally decrease, but visually, the degree of is small in static parts of the image and large in moving areas.
その理由は前述した高品位テレビジヨン信号多
重サブサンプル伝送方式あるいは伝送信号の低域
にフレーム間の折り返し成分を含まない多重サブ
サンプル伝送方式（なお、特にことわらない限
り、両方式は区別せず、単に多重サブサンプリン
グ伝送方式という）のデコードにおいて、静止画
像部分はテンポラル内挿を行つており、伝送路で
混入したノイズが（２次元的に見て）高域化さ
れ、視覚的に目立たなくなる。しかし動き領域に
関してはこのようなことはなく、伝送路ノイズが
そのまま画像に表れる。 The reason for this is the aforementioned high-definition television signal multiplex subsample transmission method or the multiplex subsample transmission method that does not include aliasing components between frames in the low frequency range of the transmitted signal (unless otherwise specified, the two methods are not distinguished). In decoding using the multiple subsampling transmission method (simply referred to as multiple subsampling transmission method), temporal interpolation is performed on the still image portion, and the noise mixed in the transmission path is raised to a higher frequency (from a two-dimensional perspective) and becomes visually less noticeable. . However, this is not the case with regard to motion areas, and the transmission path noise appears as is in the image.
即ちストレートに伝送した8.1MHzのテレビジ
ヨン系で表示されると同じノイズレベルになる。 In other words, the noise level will be the same when displayed on an 8.1MHz television system transmitted straight.
従つて受信Ｃ／Ｎが低い時に動／静でノイズの
見え方のアンバランスが発生する。この傾向は、
通常の伝送信号の低域にフレーム間の折り返し成
分を含まない伝送方式の受信機では内蔵のフレー
ムメモリーを利用したノイズリダクシヨンシステ
ムを用いているため、さらに強まる。 Therefore, when the received C/N is low, an unbalance in the appearance of noise occurs between moving and static signals. This trend is
Receivers with transmission systems that do not include aliasing components between frames in the low frequency range of normal transmission signals use noise reduction systems that utilize built-in frame memory, making this noise even stronger.
［問題点を解決するための手段］
本発明はこの点を解決しようとするものであつ
て、問題の動領域に関して、フイールド内のノイ
ズリダクシヨンを用いるものである。フイールド
内のノイズリダクシヨン方式は決して一通りでは
ないが、簡単であること、その方式固有の劣化が
動領域信号に対して目立たなくなることを考えて
検討した結果、ノイズコアリングを用いるのが最
良であることが判明した。[Means for Solving the Problem] The present invention attempts to solve this problem by using in-field noise reduction for the dynamic region in question. Although there is no one-size-fits-all method for noise reduction in the field, after considering the fact that it is simple and that the inherent deterioration of the method is less noticeable in the dynamic domain signal, we found that it is best to use noise coring. It turns out that there is something.
即ち本発明は多重サブサンプル伝送信号のデコ
ーダーにおいて、動画像部分に対してのみ、その
高域信号成分のレベルの小さい部分を圧縮してノ
イズ低減を図るノイズ低減部を具える。 That is, the present invention provides a decoder for a multiplex sub-sampled transmission signal, which includes a noise reduction section that reduces noise by compressing a portion where the level of a high frequency signal component is low only for a moving image portion.
［実施例］ 第１図に本発明の具体的な実施例を示す。[Example] FIG. 1 shows a specific embodiment of the present invention.
第１図において、１はフレームメモリー、２は
２次元内挿フイルター、３はノイズリダクシヨ
ン、４はミツクス（MIX）回路、Ｓ１，Ｓ２は
スイツチである。 In FIG. 1, 1 is a frame memory, 2 is a two-dimensional interpolation filter, 3 is a noise reduction, 4 is a mix circuit, and S1 and S2 are switches.
本実施例では動領域用の２次元内挿フイルター
２の出力にノイズリダクシヨン３を設ける。した
がつて、ノイズリダクシヨンは動領域用の信号に
対してのみ掛るので、特にノイズリダクシヨンを
動／静に応じて切り替えるようなことは不要であ
る。 In this embodiment, a noise reduction 3 is provided at the output of the two-dimensional interpolation filter 2 for the moving region. Therefore, since the noise reduction is applied only to the signal for the moving region, it is not necessary to switch the noise reduction depending on whether the signal is moving or not.
さてノイズリダクシヨン３の実際回路は第２図
に示すようなものである。第２図において、５，
６はＤ型フリツプフロツプ、７はノンリニアー
（NL）回路、８，９は加算器、１０は乗数1/2の
乗算器、１１は乗数1/4の乗算器、１２は差算器
である。このノイズリダクシヨン回路の動作は若
干分り難いが、次のように考えると分り易い。な
おノンリニアー回路７（実際はROM）の特性の
一例は第３図に実線で示すようなものであつて、
第３図において、横軸は入力信号のレベル、縦軸
は出力信号のレベルを各々示す。 Now, the actual circuit of the noise reduction 3 is as shown in FIG. In Figure 2, 5,
6 is a D-type flip-flop, 7 is a non-linear (NL) circuit, 8 and 9 are adders, 10 is a multiplier with a multiplier of 1/2, 11 is a multiplier with a multiplier of 1/4, and 12 is a subtracter. The operation of this noise reduction circuit is a little difficult to understand, but it is easy to understand if you think about it as follows. An example of the characteristics of the non-linear circuit 7 (actually ROM) is as shown by the solid line in Figure 3.
In FIG. 3, the horizontal axis shows the level of the input signal, and the vertical axis shows the level of the output signal.
まず、NL回路７の出力が０の場合は、この系
の特性はオール（All）パスになる。要するにイ
ンパルスレスポンスは１である（lz0）。 First, when the output of the NL circuit 7 is 0, the characteristics of this system are all-pass. In short, the impulse response is 1 (lz 0 ).
一方、NL回路７のゲインが１とすると、忠実
に図通りのインパルスレスポンスを求めると、
lz0＋１／4z-1＋１／4z4−１／2z0
＝１／4z-1＋１／2z0＋１／4z1 (1)
となる。この式は良く知られた通り第４図に示す
ようなローパス特性を示す。 On the other hand, if the gain of the NL circuit 7 is 1, then if we faithfully obtain the impulse response as shown in the figure, lz 0 + 1/4z -1 + 1/4z 4 -1/2z 0 = 1/4z -1 + 1/2z 0 +1 /4z 1 (1). As is well known, this equation exhibits a low-pass characteristic as shown in FIG.
従つて第３図に示すようなノンリニアー特性を
用いると、高域レベルが低い時は全体としては低
域フイルター（NL回路７の入力が高域成分にな
ることはインパルスレスポンスが１／4z-1−１／
2z0＋１／4z-1であるから自明であろう。）とな
り、高域レベルが高くなるとだんだんAllパス特
性に近づく。この方式は極端なスレツシホールド
を持たないので、極めて自然にノイズ低減が行わ
れる。このことを具体的に説明する。 Therefore, if we use the nonlinear characteristic shown in Figure 3, when the high frequency level is low, the overall low frequency filter (NL circuit 7 input becomes the high frequency component means that the impulse response becomes 1/4z -1 -1/
It is obvious since it is 2z 0 + 1/4z -1 . ), and as the high frequency level increases, it gradually approaches the All-pass characteristic. Since this method does not have extreme thresholds, noise reduction occurs very naturally. This will be explained specifically.
すなわち、テレビジヨン信号は一般に低域周波
数のエネルギーが大きく、高域周波数のエネルギ
ーは小さい。このため、低域から高域までほぼ同
一レベルのノイズが画像に混入しても、高域の方
がＳ／Ｎ比の劣化が大きい。また、FM変調を用
いると、ノイズは低域から高域にかけて直線的に
増大する。また、ノイズ成分は信号のピークレベ
ルよりも小さい。 That is, television signals generally have large energy in low frequencies and small energy in high frequencies. For this reason, even if substantially the same level of noise is mixed into the image from the low frequency range to the high frequency range, the deterioration of the S/N ratio is greater in the high frequency range. Furthermore, when FM modulation is used, noise increases linearly from low to high frequencies. Further, the noise component is smaller than the peak level of the signal.
このため、高域信号成分のレベルの小さい部分
を圧縮すれば、ノイズ低減を図ることができ、前
記NL回路７によつて、これが実現できる。 Therefore, noise reduction can be achieved by compressing the low-level portion of the high-frequency signal component, and the NL circuit 7 can achieve this.
なお、ここでローパスフイルターの−6dBが
8MHzになつており（即ち完全遮断が16MHz）、
4MHzでないことに注意しておく。前述した２つ
の多重サブサンプル伝送方式ではラインオフセツ
トサンプリングを行つており、動領域内挿はライ
ン内挿をも用いた２次元内挿をしているので、動
画像の周波数スペクトラムとしては16MHzまでの
びている。ただし、FM伝送系ではノイズは三角
ノイズとなり、そのピークは8MHzであるから、
むしろおさえるべきは8MHzで、第５図に示すよ
うな回路も適用できる。 Note that -6dB of the low-pass filter is
8MHz (i.e. complete cut-off is 16MHz),
Please note that it is not 4MHz. The two multiple subsample transmission methods mentioned above use line offset sampling, and the moving domain interpolation uses two-dimensional interpolation that also uses line interpolation, so the frequency spectrum of moving images can be up to 16 MHz. It's growing. However, in the FM transmission system, the noise is triangular noise, and its peak is 8MHz, so
Rather, the frequency that should be suppressed is 8MHz, and a circuit like the one shown in Figure 5 can also be applied.
第５図において、７はノンリニアー回路、８，
９は加算器、１０は乗数1/2の乗算器、１１は乗
数1/4の乗算器、１２は差算器、１３，１４，１
５，１６はＤ型フリツプフロツプである。 In FIG. 5, 7 is a non-linear circuit, 8,
9 is an adder, 10 is a multiplier with a multiplier of 1/2, 11 is a multiplier with a multiplier of 1/4, 12 is a subtracter, 13, 14, 1
5 and 16 are D-type flip-flops.
この第５図の場合はノイズは極めて有効に落ち
るが、その結果の周波数特性が中だるみになり質
感としては問題がある。ただしこれは落すべきノ
イズの量との関で決めるべきことで、どちらが良
いとも云えない。ただしFM伝送系を考えたら第
５図の系統の方が有利のように思える。 In the case shown in FIG. 5, the noise is reduced very effectively, but the resulting frequency characteristics become dull in the middle, which poses a problem in terms of texture. However, this must be decided based on the amount of noise that should be removed, and it cannot be said that one is better than the other. However, when considering the FM transmission system, the system shown in Figure 5 seems more advantageous.
［発明の効果］
本発明によれば、静止領域と動き領域の両方に
おいて、低Ｃ／Ｎ時のノイズのバランスを取るこ
とができる。従つて、所要Ｃ／Ｎはより強く影響
の出る方で決まるので、伝送系の所要Ｃ／Ｎを下
げることができる。[Effects of the Invention] According to the present invention, it is possible to balance noise at low C/N in both the stationary region and the moving region. Therefore, since the required C/N is determined by the one that has a stronger influence, the required C/N of the transmission system can be lowered.
第１図は本発明のブロツク図、第２図は本発明
一実施例のブロツク図、第３図はノンリニアー回
路の特性の一例を示す図、第４図は完全にローパ
ス動作をした時の特性の一例を示す図、第５図は
本発明の他の実施例のブロツク図である。
１…フレームメモリ、２…２次元内挿フイルタ
ー、３…ノイズリダクシヨン、４…ミツクス回
路。
Figure 1 is a block diagram of the present invention, Figure 2 is a block diagram of an embodiment of the present invention, Figure 3 is a diagram showing an example of the characteristics of a non-linear circuit, and Figure 4 is the characteristic when completely low-pass operation is performed. FIG. 5 is a block diagram of another embodiment of the present invention. 1...Frame memory, 2...2-dimensional interpolation filter, 3...Noise reduction, 4...Mix circuit.
Claims (1)
いて、動画像部分に対してのみ、その高域信号成
分のレベルの小さい部分を圧縮してノイズ低減を
図るノイズ低減部を具えたことを特徴とするデコ
ーダー。 ２ 特許請求の範囲第１項記載のデコーダーにお
いて、動画領域再生フイルターの出力に固定的に
前記ノイズ低減部を設けたことを特徴とするデコ
ーダー。 ３ 特許請求の範囲第１項記載のデコーダーにお
いて、動画領域再生フイルターの入力部に固定的
に前記ノイズ低減部を設けたことを特徴とするデ
コーダー。 ４ 特許請求の範囲第１項記載のデコーダーにお
いて、前記ノイズ低減部は、遅延手段およびノン
リニアー回路を有することを特徴とするデコーダ
ー。[Scope of Claims] 1. A decoder for multiplex sub-sampled transmission signals, comprising a noise reduction unit that reduces noise by compressing a portion with a low level of high-frequency signal components only for a moving image portion. Features a decoder. 2. The decoder according to claim 1, wherein the noise reduction section is fixedly provided at the output of the moving image area reproduction filter. 3. The decoder according to claim 1, wherein the noise reduction section is fixedly provided at an input section of a moving image area reproduction filter. 4. The decoder according to claim 1, wherein the noise reduction section includes a delay means and a nonlinear circuit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61013640A JPS62172889A (en) | 1986-01-27 | 1986-01-27 | Decoder constitution system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61013640A JPS62172889A (en) | 1986-01-27 | 1986-01-27 | Decoder constitution system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS62172889A JPS62172889A (en) | 1987-07-29 |
| JPH0569353B2 true JPH0569353B2 (en) | 1993-09-30 |
Family
ID=11838835
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP61013640A Granted JPS62172889A (en) | 1986-01-27 | 1986-01-27 | Decoder constitution system |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS62172889A (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE10033420A1 (en) * | 2000-07-08 | 2002-01-17 | Philips Corp Intellectual Pty | Device for reducing flicker interference |
| JP4892619B2 (en) * | 2010-02-22 | 2012-03-07 | 東亜高級継手バルブ製造株式会社 | Pipe fitting |
-
1986
- 1986-01-27 JP JP61013640A patent/JPS62172889A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS62172889A (en) | 1987-07-29 |
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