JP2000175081A - Noise reduction circuit - Google Patents
Noise reduction circuitInfo
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- JP2000175081A JP2000175081A JP10341282A JP34128298A JP2000175081A JP 2000175081 A JP2000175081 A JP 2000175081A JP 10341282 A JP10341282 A JP 10341282A JP 34128298 A JP34128298 A JP 34128298A JP 2000175081 A JP2000175081 A JP 2000175081A
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- Controls And Circuits For Display Device (AREA)
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Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、ディジタル表示方
式で映像を表示するディスプレイ装置等に用いられるノ
イズ低減回路に関するものであり、メディアンフィルタ
（順序フィルタ）を用いて入力映像信号のノイズを低減
して画質を改善するためのノイズ低減回路に関するもの
である。ディジタル表示方式で映像を表示するディスプ
レイ装置には、ＰＤＰ（プラズマディスプレイパネル）
やＬＣＤ（液晶ディスプレイ）パネル等の表示パネルを
用いたものがある。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a noise reduction circuit used in a display device or the like for displaying an image in a digital display system, and reduces a noise of an input image signal by using a median filter (sequential filter). And a noise reduction circuit for improving image quality. 2. Description of the Related Art PDPs (Plasma Display Panels) are used for display devices that display images using a digital display method.
And a display panel such as a liquid crystal display (LCD) panel.
【０００２】[0002]
【従来の技術】従来、この種のノイズ低減回路は、図３
に示すように、入力端子１０に入力した映像信号を順次
１フレーム分ずつ遅延させて出力する第１、第２遅延部
１２、１４と、入力端子１０に入力した映像信号と第
１、第２遅延部１２、１４から出力した映像信号とに基
づいて、現フレームと前後のフレームの３つのフレーム
の同一位置にある３つの画素のうちの輝度レベルが中央
値の画素の信号を現フレームの画素信号として選択して
出力端子１８へ出力するメディアンフィルタ１６とを具
備し、フレーム間ノイズ低減後の映像信号を得るように
していた。2. Description of the Related Art Conventionally, this kind of noise reduction circuit is shown in FIG.
As shown in (1), first and second delay units 12 and 14 for sequentially delaying the video signal input to the input terminal 10 by one frame and outputting the same, and the video signal input to the input terminal 10 and the first and second delay units Based on the video signals output from the delay units 12 and 14, a signal of a pixel having a median luminance level among three pixels at the same position in the three frames of the current frame and the preceding and succeeding frames is converted to a pixel of the current frame. A median filter 16 for selecting a signal and outputting the selected signal to an output terminal 18 so as to obtain a video signal after noise reduction between frames.
【０００３】[0003]
【発明が解決しようとする課題】しかしながら、図３に
示した従来例では、入力映像信号の静止画部分、動画部
分に関係なく３つのフレーム間でメディアンフィルタ１
６によるフィルタ処理が行われていたので、静止画部分
についてはノイズ低減効果が得られるが、動画部分につ
いては映像自体が違ってきて画質が大幅に劣化してしま
うという問題点があった。However, in the conventional example shown in FIG. 3, the median filter 1 is not used between the three frames regardless of the still image portion and the moving image portion of the input video signal.
6, the noise reduction effect can be obtained for the still image portion, but there is a problem that the image itself is different for the moving image portion and the image quality is greatly deteriorated.
【０００４】本発明は、上述の問題点に鑑みなされたも
ので、動画部分について画質を劣化させることなく、静
止画部分についてノイズを低減することができ、しかも
回路構成を簡単にすることのできるノイズ低減回路を提
供することを目的とする。The present invention has been made in view of the above-described problems, and can reduce noise in a still image portion without deteriorating image quality in a moving image portion, and can simplify a circuit configuration. It is an object to provide a noise reduction circuit.
【０００５】[0005]
【課題を解決するための手段】本発明によるノイズ低減
回路は、入力映像信号を順次１フレーム分ずつ遅延させ
て出力する第１、第２遅延部と、入力映像信号と第１、
第２遅延部の出力信号に基づいて、現フレームと前後の
フレームの３つのフレームの同一位置にある３つの注目
領域（１又は複数の画素からなる）のうちの輝度レベル
が中央値の領域の信号を現フレームの注目領域の信号と
して選択して出力するメディアンフィルタと、入力映像
信号と第１、第２遅延部の出力信号のうちの少なくとも
２つの信号に基づいて、現フレームの各画素が動画素か
静止画素かを検出する動き検出部と、この動き検出部の
検出信号に基づき、注目領域を占める画素が動画素で、
この注目領域の周辺領域を占める画素の半数以上が静止
画素のときにノイズ有りと判定し、それ以外のときにノ
イズ無しと判定するノイズ判定部と、このノイズ判定部
のノイズ有りとノイズ無しの判定出力に基づいて、メデ
ィアンフィルタの出力信号と第１遅延部の出力信号を切
り替えて出力する出力切替部とを具備してなることを特
徴とする。A noise reduction circuit according to the present invention comprises first and second delay units for sequentially delaying an input video signal by one frame and outputting the same, and the input video signal and the first and second delay units.
Based on the output signal of the second delay unit, the luminance level of the region of the central value of the luminance level among the three regions of interest (consisting of one or a plurality of pixels) at the same position of the three frames of the current frame and the preceding and succeeding frames is A median filter that selects and outputs a signal as a signal of a region of interest of the current frame; and a pixel of the current frame based on at least two of the input video signal and the output signals of the first and second delay units. A motion detection unit that detects whether the pixel is a moving image element or a still pixel, and a pixel occupying a region of interest is a motion pixel based on a detection signal of the motion detection unit
A noise determination unit that determines that there is noise when more than half of the pixels occupying the peripheral region of the attention region are still pixels, and otherwise determines that there is no noise; An output switching unit that switches and outputs an output signal of the median filter and an output signal of the first delay unit based on the determination output.
【０００６】ノイズ判定部は、動き検出部の検出信号に
基づき、注目領域を占める画素が動画素で、この注目領
域の周辺領域を占める画素の半数以上が静止画素のとき
にノイズ有りと判定し、それ以外のときにノイズ無しと
判定する。ノイズ有りとノイズ無しの判定出力に基づい
て出力切替部がメディアンフィルタでノイズ低減処理さ
れた入力映像信号とメディアンフィルタを通さない入力
映像信号とを切り替えて出力する。このため、注目領域
を占める画素が動画素で周辺領域を占める画素の半数以
上が静止画素のときのみ、注目領域の画素がノイズによ
って誤って動画素と判断されたものとして、入力映像信
号がメディアンフィルタでノイズ低減処理されて出力す
る。The noise determination unit determines that there is noise when a pixel occupying a region of interest is a moving pixel and half or more of the pixels occupying a peripheral region of the region of interest are still pixels based on a detection signal of the motion detection unit. Otherwise, it is determined that there is no noise. An output switching unit switches between an input video signal that has been subjected to noise reduction processing by a median filter and an input video signal that does not pass through a median filter based on a determination output indicating whether there is noise or not. Therefore, only when more than half of the pixels occupying the region of interest are moving pixels and the pixels occupying the peripheral region are still pixels, the pixels of the region of interest are erroneously determined to be moving pixels due to noise, and the input video signal is The noise is reduced by the filter and output.
【０００７】ノイズ判定部の判定誤りを可及的に少なく
するために、ノイズ判定部は、動き検出部の検出信号に
基づき、注目領域を占める画素が動画素で、周辺領域を
占める画素の全部が静止画素のときにノイズ有りと判定
し、それ以外のときにノイズ無しと判定するように構成
する。In order to minimize the determination error of the noise determination unit, the noise determination unit determines, based on the detection signal of the motion detection unit, that the pixel occupying the region of interest is a moving pixel and the pixels occupying the peripheral region are all pixels. Is determined to have noise when is a static pixel, and is determined to be no noise otherwise.
【０００８】ノイズ判定部の判定誤りを可及的に少なく
するとともに、単一画素を注目領域としてノイズ低減処
理ができるようにするために、注目領域を占める画素を
単一画素とし、周辺領域を占める画素を注目領域の周囲
に隣接する８個の画素とする。[0008] In order to minimize the judgment error of the noise judging unit and to perform the noise reduction processing with a single pixel as a region of interest, the pixel occupying the region of interest is made a single pixel, and the peripheral region is made a single pixel. The occupied pixels are eight pixels adjacent to the periphery of the attention area.
【０００９】ノイズ判定部の判定誤りを可及的に少なく
するとともに、複数画素を注目領域としてノイズ低減処
理ができるようにするために、注目領域を占める画素を
水平方向に連続した３個の画素とし、周辺領域を占める
画素を注目領域の周囲に隣接する１２個の画素とする。[0009] In order to minimize the determination error of the noise determination unit and to perform the noise reduction process using a plurality of pixels as a region of interest, the pixels occupying the region of interest are divided into three consecutive pixels in the horizontal direction. The pixels occupying the peripheral area are assumed to be 12 pixels adjacent to the periphery of the attention area.
【００１０】[0010]
【発明の実施の形態】以下、本発明によるノイズ低減回
路の一実施形態例を図１以下を用いて説明する。図１に
おいて図３と同一部分は同一符号とする。図１におい
て、１０は映像信号（例えば８ビットの画像デ−タ）を
入力する入力端子である。１２、１４は第１、第２遅延
部、１６はメディアンフィルタ、１８は出力端子、２０
は動き検出部、２２はノイズ判定部、２４は出力切替部
である。DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of a noise reduction circuit according to the present invention will be described below with reference to FIG. In FIG. 1, the same parts as those in FIG. In FIG. 1, reference numeral 10 denotes an input terminal for inputting a video signal (for example, 8-bit image data). 12 and 14 are first and second delay units, 16 is a median filter, 18 is an output terminal, 20
Denotes a motion detection unit, 22 denotes a noise determination unit, and 24 denotes an output switching unit.
【００１１】前記第１、第２遅延部１２、１４は、前記
入力端子１０に入力した映像信号を順次１フレーム分ず
つ遅延させて出力する。前記メディアンフィルタ１６
は、前記入力端子１０に入力した映像信号と前記第１、
第２遅延部１２、１４から出力した映像信号とに基づい
て、現フレームと前後フレームの３つのフレームの同一
位置にある３つの注目領域（単一画素からなる）のうち
の輝度レベルが中央値の領域の信号を現フレームの注目
領域の信号として選択して出力する。The first and second delay units 12 and 14 sequentially delay the video signal input to the input terminal 10 by one frame and output it. The median filter 16
Is the video signal input to the input terminal 10 and the first,
Based on the video signals output from the second delay units 12 and 14, the luminance level of the three target regions (consisting of a single pixel) at the same position of the three frames of the current frame and the preceding and succeeding frames is the median value. Is selected and output as the signal of the region of interest in the current frame.
【００１２】動き検出部２０は、前記入力端子１０に入
力した映像信号と前記第１、第２遅延部１２、１４から
出力した映像信号のうちの少なくとも２つの信号に基づ
いて、現フレームの各画素が動画素か静止画素かを検出
する。例えば、対象とする画素についてのフレーム間差
分（例えば現フレームと前フレームの間の輝度レベル
差）をとり、予め設定した閾値と比較し、閾値を超えて
いるときには動画素と判定し、閾値以下のときには静止
画素と判定して対応した検出信号を出力する。[0012] The motion detecting section 20 determines each of the current frame based on at least two of the video signal input to the input terminal 10 and the video signal output from the first and second delay sections 12 and 14. It detects whether a pixel is a moving pixel or a still pixel. For example, an inter-frame difference (for example, a luminance level difference between the current frame and the previous frame) of a target pixel is obtained and compared with a preset threshold. In the case of, the pixel is determined as a still pixel and a corresponding detection signal is output.
【００１３】前記ノイズ判定部２２は、前記動き検出部
２０の検出信号に基づき、注目領域を占める画素が動画
素で、周辺領域を占める８個の画素全部が静止画素のと
きにノイズ有りと判定し、それ以外のときにノイズ無し
と判定し対応した判定信号を出力する。前記出力切替部
２４は、前記ノイズ判定部２２のノイズ有りとノイズ無
しの判定出力に基づいて、前記メディアンフィルタ１６
でノイズ低減処理された入力映像信号と、前記第１遅延
部１２から出力し前記メディアンフィルタ１６を通さな
い入力映像信号とを切り替えて出力する。The noise determination unit 22 determines that there is noise when a pixel occupying a region of interest is a moving pixel and all eight pixels occupying a peripheral region are still pixels based on a detection signal of the motion detection unit 20. Otherwise, it is determined that there is no noise, and a corresponding determination signal is output. The output switching unit 24 is configured to determine whether or not the median filter 16
, And the input video signal output from the first delay unit 12 and not passed through the median filter 16 is switched and output.
【００１４】つぎに、図１の作用を図２（ａ）を併用し
て説明する。 （１）第１、第２遅延部１２、１４は入力端子１０に入
力した映像信号を順次１フレーム分ずつ遅延して出力す
る。 （２）メディアンフィルタ１６は、入力端子１０に入力
した映像信号と、第１、第２遅延部１２、１４から出力
した映像信号とに基づいて現フレームと前後のフレーム
の３つのフレームの同一位置にある３つの注目領域のう
ちの輝度レベルが中央値の領域の信号を現フレームの注
目領域の信号として選択して出力する。Next, the operation of FIG. 1 will be described with reference to FIG. (1) The first and second delay units 12 and 14 sequentially delay the video signal input to the input terminal 10 by one frame and output it. (2) Based on the video signal input to the input terminal 10 and the video signals output from the first and second delay units 12 and 14, the median filter 16 determines the same position of the three frames of the current frame and the previous and next frames. Of the three regions of interest in which the luminance level is the median value is selected and output as the signal of the region of interest in the current frame.
【００１５】（３）動き検出部２０は、入力端子１０に
入力した映像信号と第１、第２遅延部１２、１４から出
力した映像信号のうちの少なくとも２つの信号（例えば
第１、第２遅延部１２、１４から出力した映像信号）に
基づいて、現フレームの各画素が動画素か静止画素かを
検出する。 （４）ノイズ判定部２２は、動き検出部２０の検出信号
に基づき、注目領域の画素が動画素で周辺領域の画素の
全部が静止画であるときのみノイズ有りと判定し、それ
以外の場合にはノイズ無しと判定する。例えば、図２
（ａ）に示すように、動き検出部２０の検出信号に基づ
き、注目領域３０の画素が動画素（図中では「動」と表
示）で、周辺領域３２の８個の画素全部が静止画素（図
中では「静」と表示）であると判断されたときには、ノ
イズ有りの判定信号を出力する。(3) The motion detecting section 20 outputs at least two signals (for example, the first and second signals) of the video signal input to the input terminal 10 and the video signals output from the first and second delay sections 12 and 14. Based on the video signals output from the delay units 12 and 14, it is detected whether each pixel of the current frame is a moving pixel or a still pixel. (4) The noise determination unit 22 determines that there is noise only when the pixel of the attention area is a moving pixel and all the pixels of the peripheral area are still images based on the detection signal of the motion detection unit 20, and in other cases. Is determined to have no noise. For example, FIG.
As shown in (a), based on the detection signal of the motion detection unit 20, the pixel of the attention area 30 is a moving pixel (indicated as “moving” in the figure), and all eight pixels of the peripheral area 32 are still pixels. (Displayed as “static” in the drawing), a noise determination signal is output.
【００１６】（５）出力切替部２４は、ノイズ判定部２
２がノイズ有りと判定したときには、メディアンフィル
タ１６でノイズ低減処理された入力映像信号を出力端子
１８へ出力し、ノイズ判定部２２がノイズ無しと判定し
たときには、第１遅延部１２から出力した映像信号をメ
ディアンフィルタ１６を通さずに出力端子１８へ出力す
る。 （６）このため、注目領域３０の画素が動画素で周辺領
域３２の画素全部が静止画素である場合のみ、注目領域
３０の画素がノイズによって誤って動画素と判断された
ものとして、対応した入力映像信号がメディアンフィル
タ１６でノイズ低減処理されて出力する。(5) The output switching section 24 includes the noise determination section 2
2 determines that there is noise, outputs the input video signal subjected to the noise reduction processing by the median filter 16 to the output terminal 18, and when the noise determination unit 22 determines that there is no noise, the video output from the first delay unit 12 The signal is output to the output terminal 18 without passing through the median filter 16. (6) Therefore, only when the pixel of the attention area 30 is a moving pixel and all the pixels of the peripheral area 32 are still pixels, the pixel of the attention area 30 is erroneously determined to be a moving pixel due to noise. The input video signal is subjected to noise reduction processing by the median filter 16 and output.
【００１７】前記実施形態例では、ノイズ判定部の判定
誤りを可及的に少なくするために、ノイズ判定部は、注
目領域を占める単一画素が動画素で、周辺領域を占める
８個の画素全部が静止画素のときにノイズ有りと判定
し、それ以外のときにノイズ無しと判定するように構成
したが、本発明はこれに限るものでなく、ノイズ判定部
の多少の判定誤りを許容できるような場合には、ノイズ
判定部は、注目領域を占める単一画素が動画素で、周辺
領域を占める８個の画素の半数以上が静止画素のときに
ノイズ有りと判定し、それ以外のときにノイズ無しと判
定するように構成した場合についても利用することがで
きる。In the embodiment described above, in order to minimize the determination error of the noise determination unit, the noise determination unit determines that the single pixel occupying the region of interest is a moving pixel and the eight pixels occupying the peripheral region are It is configured to determine that there is noise when all pixels are still pixels, and to determine that there is no noise at other times. However, the present invention is not limited to this, and a slight determination error of the noise determination unit can be tolerated. In such a case, the noise determination unit determines that there is noise when a single pixel occupying the region of interest is a moving pixel and half or more of the eight pixels occupying the peripheral region are still pixels. It can also be used for a case where it is determined that there is no noise.
【００１８】前記実施形態例では、周辺領域を占める画
素が８個の場合について説明したが、本発明はこれに限
るものでなく、８個より少ない場合についても利用する
ことができる。例えば、注目領域を占める単一画素の上
下左右に隣接する４個の画素を周辺領域を占める画素と
し、注目領域を占める単一画素が動画素で、周辺領域を
占める４個の画素の全部（又は半数以上）が静止画素の
ときにノイズ判定部によってノイズ有りと判定し、それ
以外のときにノイズ無しと判定するように構成した場合
についても利用することができる。In the above-described embodiment, the case where the number of pixels occupying the peripheral area is eight has been described. However, the present invention is not limited to this, and can be used even when the number of pixels is less than eight. For example, four pixels vertically and horizontally adjacent to a single pixel occupying a region of interest are pixels occupying a peripheral region, a single pixel occupying the region of interest is a moving pixel, and all of the four pixels occupying the peripheral region ( (Or more than half) are still pixels, the noise determination unit may determine that there is noise, and otherwise determine that there is no noise.
【００１９】前記実施形態例では、単一画素を注目領域
としてノイズ低減処理ができるようにするために、注目
領域を占める画素が単一画素の場合について説明した
が、本発明はこれに限るものでなく、注目領域を占める
画素が複数の場合についても利用することができる。例
えば、注目領域３０ａを占める画素を水平方向に連続し
た３個の画素とし、周辺領域３２ａを占める画素を注目
領域３０ａの周囲に隣接した１２個の画素とした場合に
ついても利用することができる。この場合、ノイズ判定
部は、動き検出部の検出信号に基づき、注目領域３０ａ
を占める３つの画素が動画素で、周辺領域３２ａを占め
る１２個の画素の全部（又は半数以上）が静止画素のと
きにノイズ有りと判定し、それ以外のときにノイズ無し
と判定する。In the above embodiment, the case where the pixel occupying the region of interest is a single pixel in order to enable noise reduction processing with the single pixel as the region of interest has been described. However, the present invention is not limited to this. Alternatively, the present invention can be used for a case where a plurality of pixels occupy the attention area. For example, the present invention can also be applied to a case where the pixels occupying the attention area 30a are three pixels continuous in the horizontal direction, and the pixels occupying the peripheral area 32a are 12 pixels adjacent to the periphery of the attention area 30a. In this case, the noise determination unit determines the attention area 30a based on the detection signal of the motion detection unit.
Are determined as having noise when all (or more than half) of the twelve pixels occupying the peripheral region 32a are still pixels, and otherwise there is no noise.
【００２０】例えば、図２（ｂ）に示すように、動き検
出部２０の検出信号に基づき、注目領域３０ａを占める
３個の画素が動画素（図中では「動」と表示）で、周辺
領域３２ａを占める１２個の画素の全てが静止画素（図
中では「静」と表示）のときのみ、ノイズ判定部２２は
ノイズ有りと判定し、出力切替部２４がメディアンフィ
ルタ１６でノイズ低減処理された入力映像信号を出力端
子１８へ出力する。そして、注目領域３０ａの３個の画
素と周辺領域の１２個の画素の状態が図２（ｂ）と異な
るときには、ノイズ判定部２２はノイズ無しと判定し、
出力切替部２４が第１遅延部１２から出力した映像信号
をメディアンフィルタ１６を通さずに直接出力端子１８
へ出力する。このため、注目領域を占める画素が動画素
で周辺領域を占める画素の全部が静止画である場合の
み、注目領域の画素がノイズによって誤って動画素と判
断されたものとして、対応した入力映像信号がメディア
ンフィルタ１６でノイズ低減処理されて出力する。For example, as shown in FIG. 2B, three pixels occupying the region of interest 30a are moving pixels (indicated as "moving" in the figure) based on the detection signal of the motion detecting section 20, Only when all of the twelve pixels occupying the region 32a are still pixels (displayed as “static” in the figure), the noise determination unit 22 determines that there is noise, and the output switching unit 24 performs noise reduction processing by the median filter 16. The output input video signal is output to the output terminal 18. When the state of the three pixels in the attention area 30a and the state of the twelve pixels in the peripheral area are different from those in FIG. 2B, the noise determination unit 22 determines that there is no noise.
The output switching unit 24 directly outputs the video signal output from the first delay unit 12 to the output terminal 18 without passing through the median filter 16.
Output to Therefore, only when all the pixels occupying the region of interest are moving pixels and all the pixels occupying the peripheral region are still images, the pixels of the region of interest are erroneously determined to be moving pixels due to noise, and the corresponding input video signal Are subjected to noise reduction processing by the median filter 16 and output.
【００２１】[0021]
【発明の効果】本発明によるノイズ低減回路は、第１、
第２遅延部、メディアンフィルタ、動き検出部、ノイズ
判定部及び出力切替部を具備し、ノイズ判定部が、動き
検出部の検出信号に基づき、注目領域を占める画素が動
画素で、周辺領域を占める画素の半数以上が静止画素の
ときにノイズ有りと判定し、それ以外のときにノイズ無
しと判定し、ノイズ有りとノイズ無しの判定出力に基づ
いて出力切替部がメディアンフィルタでノイズ低減処理
された入力映像信号とメディアンフィルタを通さない入
力映像信号とを切り替えて出力するように構成した。こ
のため、注目領域を占める画素が動画素で周辺領域を占
める画素の半数以上が静止画素のときのみ、注目領域の
画素がノイズによって誤って動画素と判断されたものと
して、対応した入力映像信号がメディアンフィルタでノ
イズ低減処理されて出力する。したがって、動画部分に
ついて画質を劣化させることなく、静止画部分について
ノイズを低減することができ、しかも回路構成を簡単に
することのできる。The noise reduction circuit according to the present invention has first,
A second delay unit, a median filter, a motion detection unit, a noise determination unit, and an output switching unit. The noise determination unit determines a pixel occupying the attention area based on a detection signal of the motion detection unit as a moving pixel, and determines a peripheral area as a pixel. When more than half of the occupied pixels are still pixels, it is determined that there is noise. Otherwise, it is determined that there is no noise, and the output switching unit is subjected to noise reduction processing by the median filter based on the determination output of whether there is noise or no noise. The input video signal and the input video signal that does not pass through the median filter are switched and output. Therefore, only when more than half of the pixels occupying the region of interest are moving pixels and the pixels occupying the peripheral region are still pixels, the pixels of the region of interest are erroneously determined to be moving pixels due to noise, and the corresponding input video signal Is output after being subjected to noise reduction processing by the median filter. Therefore, the noise can be reduced in the still image portion without deteriorating the image quality in the moving image portion, and the circuit configuration can be simplified.
【００２２】ノイズ判定部が、動き検出部の検出信号に
基づき、注目領域を占める画素が動画素で、周辺領域を
占める画素の全部が静止画素のときにノイズ有りと判定
し、それ以外のときにノイズ無しと判定するように構成
した場合には、ノイズ判定部の判定誤りを可及的に少な
くすることができる。Based on the detection signal of the motion detecting section, the noise determining section determines that there is noise when the pixel occupying the attention area is a moving pixel and all the pixels occupying the peripheral area are still pixels. When it is configured to determine that there is no noise, it is possible to minimize the determination error of the noise determination unit as much as possible.
【００２３】注目領域を占める画素を単一画素とし、周
辺領域を占める画素を注目領域の周辺に隣接する８個の
画素とした場合には、ノイズ判定部の判定誤りを可及的
に少なくするとともに、単一画素を注目領域としてノイ
ズ低減処理を行うことができる。When the pixel occupying the region of interest is a single pixel and the pixels occupying the peripheral region are eight pixels adjacent to the periphery of the region of interest, the determination error of the noise determination unit is reduced as much as possible. At the same time, noise reduction processing can be performed using a single pixel as a region of interest.
【００２４】注目領域を占める画素を水平方向に連続し
た３つの画素とし、周辺領域を占める画素を注目領域の
周辺に隣接する１２個の画素とした場合には、ノイズ判
定部の判定誤りを可及的に少なくするとともに、複数画
素を注目領域としてノイズ低減処理を行うことができ
る。If the pixels occupying the region of interest are three pixels that are continuous in the horizontal direction, and the pixels occupying the peripheral region are 12 pixels adjacent to the periphery of the region of interest, a determination error of the noise determination unit is acceptable. As much as possible, the noise reduction processing can be performed using a plurality of pixels as the attention area.
【図１】本発明によるノイズ低減回路の一実施形態例を
示すブロック図である。FIG. 1 is a block diagram showing an embodiment of a noise reduction circuit according to the present invention.
【図２】図１中のノイズ判定部２２の作用を説明する図
で、（ａ）は注目領域を占める単一画素が動画素で周辺
領域を占める８個の画素全部が静止画素と検出されたと
きにノイズ有と判定する場合を示す説明図、（ｂ）は注
目領域を占める３個の画素が動画素で周辺領域を占める
１２個の画素全部が静止画素と検出されたときにノイズ
有と判定する場合を示す説明図である。2A and 2B are diagrams for explaining the operation of a noise determination unit 22 in FIG. 1. FIG. 2A shows that a single pixel occupying a region of interest is a moving pixel and all eight pixels occupying a peripheral region are detected as still pixels. FIG. 7B is a diagram illustrating a case where it is determined that there is noise when the pixel is detected. FIG. 7B shows a case where three pixels occupying the attention area are moving pixels and all 12 pixels occupying the peripheral area are detected as still pixels. It is explanatory drawing which shows the case where it determines.
【図３】従来例を示すブロック図である。FIG. 3 is a block diagram showing a conventional example.
１０…映像信号の入力端子、 １２…第１遅延部、 １
４…第２遅延部、 １６…メディアンフィルタ、 １８
…出力端子、 ２０…動き検出部、 ２２…ノイズ判定
部、 ２４…出力切替部、 ３０、３０ａ…注目領域、
３２、３２ａ…周辺領域。10: video signal input terminal, 12: first delay unit, 1
4 second delay unit 16 median filter 18
... output terminal, 20 ... motion detection unit, 22 ... noise determination unit, 24 ... output switching unit, 30, 30a ... attention area,
32, 32a ... peripheral area.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 池田 誠 神奈川県川崎市高津区末長1116番地 株式 会社富士通ゼネラル内 Ｆターム(参考） 5C021 PA38 RA01 SA22 SA25 XB16 YA01 5C082 AA02 BA12 BA41 BB25 BB26 CA21 CA85 CB01 DA01 DA51 MM00 MM10 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Makoto Ikeda 1116, Suenaga, Takatsu-ku, Kawasaki-shi, Kanagawa F-term in Fujitsu General Limited (reference) 5C021 PA38 RA01 SA22 SA25 XB16 YA01 5C082 AA02 BA12 BA41 BB25 BB26 CA21 CA85 CB01 DA01 DA51 MM00 MM10
Claims (4)
させて出力する第１、第２遅延部と、前記入力映像信号
と前記第１、第２遅延部の出力信号に基づいて、現フレ
ームと前後のフレームの３つのフレームの同一位置にあ
る３つの注目領域（１又は複数の画素からなる）のうち
の輝度レベルが中央値の領域の信号を現フレームの注目
領域の信号として選択して出力するメディアンフィルタ
と、前記入力映像信号と前記第１、第２遅延部の出力信
号のうちの少なくとも２つの信号に基づいて、現フレー
ムの各画素が動画素か静止画素かを検出する動き検出部
と、この動き検出部の検出信号に基づき、注目領域を占
める画素が動画素で、前記注目領域の周辺領域を占める
画素の半数以上が静止画素のときにノイズ有りと判定
し、それ以外のときにノイズ無しと判定するノイズ判定
部と、このノイズ判定部のノイズ有りとノイズ無しの判
定出力に基づいて、前記メディアンフィルタの出力信号
と前記第１遅延部の出力信号を切り替えて出力する出力
切替部とを具備してなることを特徴とするノイズ低減回
路。A first delay section for sequentially delaying an input video signal by one frame and outputting the current frame based on the input video signal and an output signal of the first and second delay sections; And a signal of a region having a median luminance level among three regions of interest (consisting of one or a plurality of pixels) at the same position of three frames before and after the frame is selected as a signal of a region of interest of the current frame. A motion filter for outputting a median filter, and detecting whether each pixel of the current frame is a moving pixel or a still pixel based on at least two of the input video signal and the output signals of the first and second delay units. Based on the detection signal of the motion detection unit, the pixel occupying the region of interest is a moving pixel, and when more than half of the pixels occupying the peripheral region of the region of interest are still pixels, it is determined that there is noise. When A noise determination unit that determines that there is no noise, and an output switching unit that switches and outputs the output signal of the median filter and the output signal of the first delay unit based on the determination output of the noise determination unit that there is noise and no noise. And a noise reduction circuit comprising:
させて出力する第１、第２遅延部と、前記入力映像信号
と前記第１、第２遅延部の出力信号に基づいて、現フレ
ームと前後のフレームの３つのフレームの同一位置にあ
る３つの注目領域（１又は複数の画素からなる）のうち
の輝度レベルが中央値の領域の信号を現フレームの注目
領域の信号として選択して出力するメディアンフィルタ
と、前記入力映像信号と前記第１、第２遅延部の出力信
号のうちの少なくとも２つの信号に基づいて、現フレー
ムの各画素が動画素か静止画素かを検出する動き検出部
と、この動き検出部の検出信号に基づき、注目領域を占
める画素が動画素で、前記注目領域の周辺領域を占める
画素の全部が静止画素のときにノイズ有りと判定し、そ
れ以外のときにノイズ無しと判定するノイズ判定部と、
このノイズ判定部のノイズ有りとノイズ無しの判定出力
に基づいて、前記メディアンフィルタの出力信号と前記
第１遅延部の出力信号を切り替えて出力する出力切替部
とを具備してなることを特徴とするノイズ低減回路。2. A first and second delay section for sequentially delaying an input video signal by one frame and outputting the current frame based on the input video signal and output signals of the first and second delay sections. And a signal of a region having a median luminance level among three regions of interest (consisting of one or a plurality of pixels) at the same position of three frames before and after the frame is selected as a signal of a region of interest of the current frame. A motion filter for outputting a median filter, and detecting whether each pixel of the current frame is a moving pixel or a still pixel based on at least two of the input video signal and the output signals of the first and second delay units. Based on the detection signal of the motion detection unit, the pixel occupying the region of interest is a moving pixel, and it is determined that there is noise when all the pixels occupying the peripheral region of the region of interest are still pixels. Nino No's and the determining the noise determination section,
An output switching unit that switches and outputs the output signal of the median filter and the output signal of the first delay unit based on the determination output of the presence of noise and the absence of noise of the noise determination unit. Noise reduction circuit.
辺領域を占める画素を前記注目領域の周辺に隣接する８
個の画素としてなる請求項１又は２記載のノイズ低減回
路。3. A pixel occupying a region of interest is a single pixel, and a pixel occupying a peripheral region is adjacent to the periphery of the region of interest.
3. The noise reduction circuit according to claim 1, wherein the noise reduction circuit comprises a plurality of pixels.
た３つの画素とし、周辺領域を占める画素を前記注目領
域の周辺に隣接する１２個の画素としてなる請求項１又
は２記載のノイズ低減回路。4. The noise reduction according to claim 1, wherein the pixels occupying the region of interest are three pixels continuous in the horizontal direction, and the pixels occupying the peripheral region are 12 pixels adjacent to the periphery of the region of interest. circuit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP10341282A JP2000175081A (en) | 1998-12-01 | 1998-12-01 | Noise reduction circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP10341282A JP2000175081A (en) | 1998-12-01 | 1998-12-01 | Noise reduction circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JP2000175081A true JP2000175081A (en) | 2000-06-23 |
Family
ID=18344855
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP10341282A Pending JP2000175081A (en) | 1998-12-01 | 1998-12-01 | Noise reduction circuit |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2000175081A (en) |
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2004503187A (en) * | 2000-07-08 | 2004-01-29 | ベーテーエス ホールディング インターナショナル ベー ヴィ | Flicker noise reduction device |
| JP2007025684A (en) * | 2005-07-14 | 2007-02-01 | Samsung Electronics Co Ltd | Display device and method for correcting video signal |
| JP2007264661A (en) * | 2007-07-06 | 2007-10-11 | Seiko Epson Corp | Hold type image display device |
| JP2009145875A (en) * | 2007-11-20 | 2009-07-02 | Semiconductor Energy Lab Co Ltd | Liquid crystal display device and image display method of the same |
| JP2009271135A (en) * | 2008-04-30 | 2009-11-19 | Canon Inc | Dynamic image processing apparatus, method, and program |
| JP2010148017A (en) * | 2008-12-22 | 2010-07-01 | Nippon Hoso Kyokai <Nhk> | Noise reduction device and program therefor |
| JP2010166349A (en) * | 2009-01-16 | 2010-07-29 | Nippon Hoso Kyokai <Nhk> | Noise reduction apparatus and program therefor |
| JP2010171615A (en) * | 2009-01-21 | 2010-08-05 | Nippon Hoso Kyokai <Nhk> | Noise reduction device and noise reduction program |
| US8184705B2 (en) | 2008-06-25 | 2012-05-22 | Aptina Imaging Corporation | Method and apparatus for motion compensated filtering of video signals |
| JP2012118563A (en) * | 2012-02-03 | 2012-06-21 | Casio Comput Co Ltd | Video output apparatus and video output method |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2004503187A (en) * | 2000-07-08 | 2004-01-29 | ベーテーエス ホールディング インターナショナル ベー ヴィ | Flicker noise reduction device |
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| JP2007025684A (en) * | 2005-07-14 | 2007-02-01 | Samsung Electronics Co Ltd | Display device and method for correcting video signal |
| JP2007264661A (en) * | 2007-07-06 | 2007-10-11 | Seiko Epson Corp | Hold type image display device |
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| JP2009271135A (en) * | 2008-04-30 | 2009-11-19 | Canon Inc | Dynamic image processing apparatus, method, and program |
| US8184705B2 (en) | 2008-06-25 | 2012-05-22 | Aptina Imaging Corporation | Method and apparatus for motion compensated filtering of video signals |
| JP2010148017A (en) * | 2008-12-22 | 2010-07-01 | Nippon Hoso Kyokai <Nhk> | Noise reduction device and program therefor |
| JP2010166349A (en) * | 2009-01-16 | 2010-07-29 | Nippon Hoso Kyokai <Nhk> | Noise reduction apparatus and program therefor |
| JP2010171615A (en) * | 2009-01-21 | 2010-08-05 | Nippon Hoso Kyokai <Nhk> | Noise reduction device and noise reduction program |
| JP2012118563A (en) * | 2012-02-03 | 2012-06-21 | Casio Comput Co Ltd | Video output apparatus and video output method |
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