JPH08317250A - Dynamic picture control circuit - Google Patents
Dynamic picture control circuitInfo
- Publication number
- JPH08317250A JPH08317250A JP7121599A JP12159995A JPH08317250A JP H08317250 A JPH08317250 A JP H08317250A JP 7121599 A JP7121599 A JP 7121599A JP 12159995 A JP12159995 A JP 12159995A JP H08317250 A JPH08317250 A JP H08317250A
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- Prior art keywords
- video signal
- level
- apl
- output
- input
- Prior art date
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Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、ＬＣＤやＰＤＰのよう
に表示階調に制限のある表示装置を用いて、テレビ映像
等のようにＡＰＬ（平均映像レベル）の変動する映像信
号を表示するとき、コントラストの改善された表示を行
うダイナミック映像制御回路に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention displays a video signal having a variable APL (average video level), such as a television video, by using a display device having a limited display gradation such as an LCD or a PDP. At this time, the present invention relates to a dynamic image control circuit that performs display with improved contrast.
【０００２】[0002]
【従来の技術】ＬＣＤやＰＤＰのように表示階調に制限
のある表示装置に、テレビ映像のようなＡＰＬの変動す
る動画を表示するとき、表示画のコントラストが不足す
るため、一般に立体感のない表示画像となる。ＡＰＬ付
近のガンマ値を大きくする方法も有るが、ダイナミック
レンジの拡大が十分行われないという問題が有った。2. Description of the Related Art When a moving image with a variable APL such as a television image is displayed on a display device such as an LCD or a PDP having a limited display gradation, the contrast of the displayed image is insufficient, so that a stereoscopic effect is generally given. There will be no display image. There is also a method of increasing the gamma value near APL, but there is a problem that the dynamic range is not sufficiently expanded.
【０００３】[0003]
【発明が解決しようとする課題】本発明は、上記問題点
に鑑みなされたもので、表示階調に制限のある表示装置
においても、実質上のコントラスト比を増大させた、立
体感の有る表示を行うことにある。SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and provides a three-dimensional display having a substantially increased contrast ratio even in a display device having a limited display gradation. To do.
【０００４】[0004]
【課題を解決するための手段】映像信号のフィールド毎
又はフレーム毎のＡＰＬの算出手段及び同ヒストグラム
の算出手段と、その算出手段で得られたＡＰＬとヒスト
グラムを解析する信号解析手段と、映像信号の入出力特
性変換手段と、同入出力変換手段の特性を制御する制御
手段とを設け、前記算出手段で得られたＡＰＬとヒスト
グラムのデータに基づいて、当該映像信号の最小レベル
と最大レベルの範囲を、出力映像信号レベル範囲内の略
イッパイに拡大し、且つＡＰＬ付近に対応する入出力特
性のガンマ値を大きくする。Means for solving the problems APL calculation means and field histogram calculation means for each field or frame of a video signal, signal analysis means for analyzing the APL and histogram obtained by the calculation means, and a video signal The input / output characteristic conversion means and the control means for controlling the characteristics of the input / output conversion means are provided, and based on the data of the APL and the histogram obtained by the calculation means, the minimum level and the maximum level of the video signal can be determined. The range is expanded to substantially the same as the output video signal level range, and the gamma value of the input / output characteristic corresponding to the vicinity of APL is increased.
【０００５】ＡＰＬの最低閾値と同最大閾値を設け、Ａ
ＰＬが最低閾値と最大閾値の間にあるときは、出力映像
信号の最小レベル及び最大レベルを出力映像信号レベル
範囲の最小値及び最大値とし、ＡＰＬが最低閾値より小
さいときは、出力映像信号の最大レベルを出力映像信号
レベル範囲の最大値より小さいレベルとし、ＡＰＬが最
大閾値より大きいときは、出力映像信号の最小レベルを
出力映像信号レベル範囲の最小値より大きいレベルとす
る。A minimum threshold value and a maximum threshold value of APL are set, and A
When PL is between the minimum threshold value and the maximum threshold value, the minimum level and the maximum level of the output video signal are set to the minimum value and the maximum value of the output video signal level range, and when APL is smaller than the minimum threshold value, the output video signal The maximum level is set to a level smaller than the maximum value of the output video signal level range, and when APL is larger than the maximum threshold, the minimum level of the output video signal is set to a level larger than the minimum value of the output video signal level range.
【０００６】ＡＰＬ付近のヒストグラムの分散を求め、
分散が小さいときは、その付近のガンマ値を大きくし、
同分散が小さいときは同ガンマ値を前記の場合のガンマ
値より小さくする。[0006] The variance of the histogram near APL is obtained,
If the variance is small, increase the gamma value in the vicinity,
When the variance is small, the gamma value is made smaller than the gamma value in the above case.
【０００７】ヒストグラムの算出は、複数の表示画素に
対応する映像信号毎に集計して求める。The histogram is calculated by summing up each video signal corresponding to a plurality of display pixels.
【０００８】ヒストグラムの算出は入力となるディジタ
ル映像信号の上位桁のみを用いて行う。The calculation of the histogram is performed by using only the upper digit of the input digital video signal.
【０００９】入出力特性変換手段は、制御手段により入
力信号レベルに対応するアドレスの、出力信号レベルに
対応するデータを書き換えるＲＡＭ（ランダムアクセス
メモリ）とする。The input / output characteristic conversion means is a RAM (random access memory) in which the control means rewrites the data corresponding to the output signal level at the address corresponding to the input signal level.
【００１０】[0010]
【作用】映像信号の１フィールド毎又は１フレーム毎の
ＡＰＬ（平均映像レベル）の算出手段及び同ヒストグラ
ムの算出手段と、その算出手段で得られたＡＰＬとヒス
トグラムを解析する信号解析手段と、映像信号の入出力
特性変換手段と、同入出力変換手段の特性を制御する制
御手段とを設け、前記算出手段で得られたＡＰＬとヒス
トグラムのデータに基づいて、当該映像信号の最小レベ
ルと最大レベルの範囲を、出力映像信号レベル範囲内の
略イッパイに拡大することで、実質上、映像信号のダイ
ナミックレンジが大きくなる。またＡＰＬ付近に対応す
る入出力特性のガンマ値を大きくすることで、表示画の
実質上のコントラスト比が増大する。Operation: APL (average video level) calculating means and histogram calculating means for each field or frame of a video signal; signal analyzing means for analyzing the APL and histogram obtained by the calculating means; A signal input / output characteristic conversion means and a control means for controlling the characteristics of the input / output conversion means are provided, and the minimum level and maximum level of the video signal are based on the APL and histogram data obtained by the calculation means. By expanding the range of (1) to substantially the output image signal level range, the dynamic range of the video signal is substantially increased. Further, by increasing the gamma value of the input / output characteristic corresponding to the vicinity of APL, the substantial contrast ratio of the display image is increased.
【００１１】ＡＰＬの最低閾値と同最大閾値を設け、Ａ
ＰＬが最低閾値と最大閾値の間にあるときは、出力映像
信号の最小レベル及び最大レベルを出力映像信号レベル
範囲の最小値及び最大値とすることで、ＡＰＬがダイナ
ミックレンジの略中央にある通常の画面では、入力映像
信号のダイナミックレンジを出力映像信号のダイナミッ
クレンジイッパイに拡大できる。また、ＡＰＬが最低閾
値より小さいときは、出力映像信号の最大レベルを出力
映像信号レベル範囲の最大値より小さいレベルとし、Ａ
ＰＬが最大閾値より大きいときは、出力映像信号の最小
レベルを出力映像信号レベル範囲の最小値より大きいレ
ベルとすることで、ＡＰＬが極端に小さい場合は、出力
映像信号レベルの最大値も極端に大きくならず、逆にＡ
ＰＬが極端に大きい場合又は、出力映像信号レベルの最
小値も極端に小さくならない。The minimum and maximum thresholds of APL are set to
When PL is between the minimum threshold value and the maximum threshold value, the minimum level and maximum level of the output video signal are set as the minimum value and the maximum value of the output video signal level range, so that the APL is generally in the center of the dynamic range. On the screen, the dynamic range of the input video signal can be expanded to the dynamic range of the output video signal. When APL is smaller than the minimum threshold, the maximum level of the output video signal is set to a level smaller than the maximum value of the output video signal level range, and A
When PL is larger than the maximum threshold value, the minimum level of the output video signal is set to a level higher than the minimum value of the output video signal level range. When APL is extremely small, the maximum output video signal level is also extremely high. It doesn't grow, and conversely A
When PL is extremely large, or the minimum value of the output video signal level does not become extremely small.
【００１２】ＡＰＬ付近のヒストグラムの分散を求め、
分散が小さいときは、その付近のガンマ値を大きくする
ことで、表示画の主要部の実質上のコントラスト比が改
善される。また同分散が小さく表示画の主要部が画面全
体に広がるときは、同ガンマ値を前記の場合のガンマ値
より小さくして略そのまま表示することで、自然な表示
となる。The variance of the histogram near APL is calculated,
When the variance is small, the gamma value in the vicinity thereof is increased to improve the substantial contrast ratio of the main part of the display image. Further, when the variance is small and the main part of the display image spreads over the entire screen, the same gamma value is made smaller than the gamma value in the above case and the display is performed almost as it is, thereby providing a natural display.
【００１３】ヒストグラムの算出は、複数の表示画素に
対応する映像信号毎に集計して求めることで、表示画の
２次元相関を利用して、精度を損ねずに構成部品の削減
ができる。The calculation of the histogram is performed by aggregating and calculating for each of the video signals corresponding to a plurality of display pixels, and the two-dimensional correlation of the display image can be used to reduce the number of components without impairing the accuracy.
【００１４】ヒストグラムの算出は入力となるディジタ
ル映像信号の上位桁のみを用いて行うことで、ノイズの
影響を避け、且つ構成部品の削減ができる。By calculating the histogram using only the upper digit of the digital video signal to be input, the influence of noise can be avoided and the number of components can be reduced.
【００１５】入出力特性変換手段は、制御手段により実
時間で入力信号レベルに対応するアドレスの、出力信号
レベルに対応するデータを書き換えるＲＡＭ（ランダム
アクセスメモリ）とすることで、簡単な構成で、ダイナ
ミックに入出力特性を制御できる。The input / output characteristic conversion means is a RAM (random access memory) for rewriting the data corresponding to the output signal level at the address corresponding to the input signal level in real time by the control means, and has a simple structure. Input / output characteristics can be controlled dynamically.
【００１６】[0016]
【実施例】以下、本発明によるダイナミック映像制御回
路について、図を用いて詳細に説明する。図１は、本発
明によるダイナミック映像制御回路の一実施例のブロッ
ク図である。テレビ受像機等からの必要に応じてガンマ
補正のされたアナログ映像信号Ｓ１をアナログ／ディジ
タル変換器１でディジタル映像信号とし、ＲＡＭ等から
なる入出力特性変換部２で所望の映像信号特性に変換
後、ＰＤＰ等からなる表示部３に表示する。一方、三原
色Ｒ、Ｇ、Ｂ等からなるディジタル映像信号をマトリク
ス回路４で輝度信号とし、ＡＰＬ算出部５でフィールド
毎又はフレーム毎にＡＰＬを算出し制御部７に渡す。ま
たヒストグラム算出部６では、前記輝度信号からフィー
ルド毎又はフレーム毎に各映像信号レベル毎のヒストグ
ラムを算出し制御部７に渡す。制御部７では、これらＡ
ＰＬ及びヒストグラムのデータをダイナミックレンジ処
理部８とガンマ特性処理部９の手順に従って解析して、
入力映像信号に最適なダイナミックレンジ及びガンマ特
性を算出して、その変換特性をＲＡＭ等からなる入出力
特性変換部２に設定する。DESCRIPTION OF THE PREFERRED EMBODIMENTS A dynamic video control circuit according to the present invention will be described in detail below with reference to the drawings. FIG. 1 is a block diagram of an embodiment of a dynamic image control circuit according to the present invention. The analog video signal S1 that has been gamma-corrected as necessary from a television receiver or the like is converted into a digital video signal by the analog / digital converter 1 and converted into a desired video signal characteristic by the input / output characteristic conversion unit 2 including a RAM. After that, it is displayed on the display unit 3 made of a PDP or the like. On the other hand, a digital video signal composed of the three primary colors R, G, B, etc. is converted into a luminance signal by the matrix circuit 4, and the APL calculation unit 5 calculates the APL for each field or each frame and transfers it to the control unit 7. Further, the histogram calculation unit 6 calculates a histogram for each video signal level for each field or frame from the luminance signal and passes it to the control unit 7. In the control unit 7, these A
The PL and histogram data are analyzed according to the procedures of the dynamic range processing unit 8 and the gamma characteristic processing unit 9,
The optimum dynamic range and gamma characteristic for the input video signal are calculated, and the conversion characteristic is set in the input / output characteristic conversion unit 2 including a RAM or the like.
【００１７】図２は、本発明によるダイナミック映像制
御回路の一実施例である図１の制御部７及びダイナミッ
クレンジ処理部８での処理概要を示すための（Ａ）入力
映像信号のヒストグラムと、（Ｂ）入出力特性曲線であ
る。例えば入出力映像信号を８ビット構成とすると、そ
れぞれ信号のレベル数は０から２５５までの２５６階調
となる。入力映像信号のヒストグラムを図２（Ａ）のよ
うに、最小レベルＬｎと最大レベルＬｘの間に分布する
ものとする。この場合の入出力特性を同図（Ｂ）に示す
ように、最小入力レベルＬｎで最小出力レベルに対応す
る出力レベル０、最大入力レベルＬｘで最大出力レベル
に対応する出力レベル２５５とする直線Ｃ１となる。
尚、ＡＰＬが極端に小さい場合又は、極端に大きい場合
にもこの特性を適用すると、暗い部分が極端に明るくな
ったり、又は明るい部分が極端に暗くなったりするた
め、ＡＰＬの最大及び最小の閾値を設け、ＡＰＬがこの
範囲外のときは、出力範囲の制限を設けてその範囲内の
出力レベルとする。FIG. 2 is a histogram of an input video signal (A) for showing an outline of processing in the control unit 7 and the dynamic range processing unit 8 in FIG. 1 which is an embodiment of the dynamic video control circuit according to the present invention. (B) is an input / output characteristic curve. For example, when the input / output video signal has an 8-bit structure, the number of levels of each signal is 256 gradations from 0 to 255. It is assumed that the histogram of the input video signal is distributed between the minimum level Ln and the maximum level Lx as shown in FIG. In this case, the input / output characteristic is, as shown in FIG. 7B, a straight line C1 having the minimum input level Ln as the output level 0 corresponding to the minimum output level and the maximum input level Lx as the output level 255 corresponding to the maximum output level. Becomes
It should be noted that if this characteristic is applied even when the APL is extremely small or extremely large, the dark part becomes extremely bright or the bright part becomes extremely dark, so the maximum and minimum threshold values of the APL are set. When the APL is out of this range, the output range is limited and the output level is within that range.
【００１８】図３は、本発明によるダイナミック映像制
御回路の一実施例である図１の制御部７及びガンマ特性
処理部９での処理概要を示すための（Ａ）入出力特性曲
線と、（Ｂ）出力映像信号のヒストグラムである。ＡＰ
Ｌ算出部７で得たＡＰＬを図（Ａ）のＬａとすると、そ
の付近の入出力特性曲線Ｃ２の勾配、即ちガンマ値を大
きくして、図（Ｂ）のように図１（Ａ）に示す入力信号
のヒストグラムと比べて、ＡＰＬ付近のヒストグラムの
ピークがなだらかになり、信号レベルが広くなるため、
表示画面の実質的なコントラストが増大する。FIG. 3 shows (A) an input / output characteristic curve for showing an outline of processing in the control section 7 and the gamma characteristic processing section 9 of FIG. 1, which is an embodiment of the dynamic image control circuit according to the present invention, and (A). B) A histogram of the output video signal. AP
Assuming that APL obtained by the L calculation unit 7 is La in FIG. 1A, the gradient of the input / output characteristic curve C2 in the vicinity, that is, the gamma value is increased, and as shown in FIG. Compared to the histogram of the input signal shown, the peak of the histogram near APL is gentle and the signal level is wide, so
The substantial contrast of the display screen is increased.
【００１９】尚、図１のヒストグラム算出部６で求めた
ヒストグラムのデータを基に、制御部７で分散算出部１
０の手順に従って、ヒストグラムのＡＰＬ付近での分散
を求め、その分散がある一定の値より小さいときは、前
記のようにそのＡＰＬ付近のガンマ値を大きい値とする
が、その分散がある一定の値より大きいときは、略入力
信号のレベル分布のまま出力することで、元々コントラ
ストの大きい入力映像信号はそのまま表示する。Based on the data of the histogram obtained by the histogram calculating section 6 of FIG.
The variance near the APL of the histogram is obtained according to the procedure of 0, and when the variance is smaller than a certain value, the gamma value near the APL is set to a large value as described above, but the variance is constant. When it is larger than the value, the level distribution of the input signal is output as it is, so that the input video signal originally having a large contrast is displayed as it is.
【００２０】図１のＡＰＬ算出部５は、例えば計数器を
用いて各表示画素に対応するディジタル映像信号レベル
を累和して総和を求め、除算器を用いて全画素数で割っ
て求めることができる。また、映像信号レベルの累和
は、表示画面の数画素分毎に取り、その平均レベルを計
算して求めることもできる。一般に映像信号の表示画面
は、画面内の相関が大きいため、このようにして求めた
ＡＰＬも略前記のＡＰＬと同じ結果となる。また、累和
するディジタル映像信号は上位桁のみ、例えば８ビット
映像信号のとき上位６ビットのみとすることで、映像信
号のノイズによる悪影響を避けることができる。このよ
うな場合、計数器と除算器の規模を小さくできる。The APL calculator 5 in FIG. 1 sums the digital video signal levels corresponding to the respective display pixels using a counter to obtain a sum, and uses a divider to divide the total by the total number of pixels. You can Further, the cumulative sum of the video signal levels can be obtained by taking every several pixels of the display screen and calculating the average level. In general, since the display screen of the video signal has a large correlation within the screen, the APL thus obtained also has substantially the same result as the above APL. In addition, the digital video signal to be summed up is limited to only the upper digits, for example, only the upper 6 bits in the case of an 8-bit video signal, so that adverse effects due to noise of the video signal can be avoided. In such a case, the scale of the counter and the divider can be reduced.
【００２１】映像信号レベルの入出力特性の求め方の他
の実施例としては次のものがある。予め前記のようにし
て各ＡＰＬ及び分散に対して最適な入出力特性を決め、
これを幾つかの領域に分割し各領域毎に直線近似し、そ
の直線の係数（勾配）をＲＯＭ（リードオンリメモリ）
に書き込み図１の係数ＲＯＭ１１として制御部７から読
み出せるようにしておく。動作時には制御部７が入力映
像信号のＡＰＬと分散を求め、これに該当する各領域毎
の係数を係数ＲＯＭ１１から読み出し、各領域内の入出
力特性を直線として計算しそのデータをＲＡＭ２に書き
込む。Another example of the method for obtaining the input / output characteristics of the video signal level is as follows. Determine the optimum input / output characteristics for each APL and dispersion in advance as described above.
This is divided into several areas, each area is approximated to a straight line, and the coefficient (gradient) of the straight line is stored in ROM (Read Only Memory).
The coefficient ROM 11 of FIG. 1 can be read from the control unit 7. At the time of operation, the control unit 7 obtains the APL and variance of the input video signal, reads the coefficient for each area corresponding to this from the coefficient ROM 11, calculates the input / output characteristics in each area as a straight line, and writes the data in the RAM 2.
【００２２】図１のヒストグラム算出部６は、例えば各
映像信号レベル毎の計数器を設け、各映像信号レベル毎
に各表示画素に対応するディジタル映像信号レベルを累
和することで求めることができる。この場合にも前記同
様に、各映像信号レベル毎のディジタル映像信号レベル
の累和は、表示画面の数画素分毎に求めることもでき
る。同様に累和するディジタル映像信号は上位桁のみ、
例えば８ビット映像信号のとき上位６ビットとすること
で、映像信号のノイズによる悪影響を避けることができ
る。この場合も、計数器の規模が小さくできる。The histogram calculating section 6 in FIG. 1 can be obtained by, for example, providing a counter for each video signal level and accumulating the digital video signal levels corresponding to each display pixel for each video signal level. . Also in this case, similarly to the above, the cumulative sum of the digital video signal levels for each video signal level can be obtained for every several pixels of the display screen. Similarly, the digital video signals that accumulate are only in the upper digits,
For example, by setting the upper 6 bits in the case of an 8-bit video signal, it is possible to avoid adverse effects due to noise in the video signal. Also in this case, the scale of the counter can be reduced.
【００２３】[0023]
【発明の効果】以上説明したように、ＬＣＤやＰＤＰの
ように表示階調の不足する表示デバイスで、テレビ映像
のようにダイナミックレンジが広く、ＡＰＬが変動する
映像を表示するとき、入力映像信号の最小レベルと最大
レベルの範囲を出力映像信号レベル範囲内で拡大し、Ａ
ＰＬ付近に対応する入出力特性のガンマ値を大きくする
ことで、表示画の実質上のコントラストが大きくなり、
立体感の有る映像表示が可能となる。As described above, when displaying an image having a wide dynamic range and varying APL, such as a television image, on a display device such as an LCD or a PDP having insufficient display gradation, an input image signal Expand the range of the minimum level and the maximum level of within the output video signal level range.
By increasing the gamma value of the input / output characteristic corresponding to the vicinity of PL, the actual contrast of the display image increases,
It is possible to display images with a stereoscopic effect.
【図１】本発明によるダイナミック映像制御回路の一実
施例のブロック図である。FIG. 1 is a block diagram of an embodiment of a dynamic image control circuit according to the present invention.
【図２】本発明によるダイナミック映像制御回路の一実
施例の（Ａ）入力映像信号のヒストグラムと、（Ｂ）入
出力特性曲線である。2A is a histogram of an input video signal and FIG. 2B is an input / output characteristic curve of an embodiment of a dynamic video control circuit according to the present invention.
【図３】本発明によるダイナミック映像制御回路の一実
施例の（Ａ）入出力特性曲線と、（Ｂ）出力映像信号の
ヒストグラムである。FIG. 3 is (A) an input / output characteristic curve of an embodiment of a dynamic image control circuit according to the present invention, and (B) a histogram of an output image signal.
Ｓ１ アナログ映像信号 １ アナログ／ディジタル変換器 ２ ＲＡＭ ３ 表示部 ４ マトリクス回路 ５ ＡＰＬ算出部 ６ ヒストグラム算出部 ７ 制御部 ８ ダイナミックレンジ処理部 ９ ガンマ特性処理部 １０ 分算処理部 １１ 係数ＲＯＭ Ｌｎ 入力映像信号の最小レベル Ｌｘ 入力映像信号の最大レベル Ｌａ ＡＰＬ Ｃ１ 入出力特性曲線 Ｃ２ 入出力特性曲線 S1 analog video signal 1 analog / digital converter 2 RAM 3 display unit 4 matrix circuit 5 APL calculation unit 6 histogram calculation unit 7 control unit 8 dynamic range processing unit 9 gamma characteristic processing unit 10 division processing unit 11 coefficient ROM Ln input image Minimum level of signal Lx Maximum level of input video signal La APL C1 Input / output characteristic curve C2 Input / output characteristic curve
Claims (6)
て、映像信号のフィールド毎又はフレーム毎のＡＰＬ
（平均映像レベル）算出手段及び同ヒストグラム算出手
段と、前記算出手段で得られたＡＰＬとヒストグラムを
解析する信号解析手段と、映像信号の入出力特性変換手
段と、同入出力変換手段の特性を制御する制御手段とを
設け、前記算出手段で得られたＡＰＬとヒストグラムの
データに基づいて、当該映像信号の最小レベルと最大レ
ベルの範囲を、出力映像信号レベル範囲内で拡大し、且
つＡＰＬ付近に対応する入出力特性のガンマ値を大きく
することを特徴としたダイナミック映像制御回路。1. A display device for displaying a television image or the like, the APL for each field or frame of a video signal.
(Average video level) calculation means and histogram calculation means, signal analysis means for analyzing the APL and histogram obtained by the calculation means, video signal input / output characteristic conversion means, and characteristics of the input / output conversion means A control means for controlling is provided to expand the range of the minimum level and the maximum level of the video signal within the output video signal level range based on the data of the APL and the histogram obtained by the calculation means, and near the APL. A dynamic video control circuit characterized by increasing the gamma value of the input / output characteristics corresponding to.
ＰＬが最低閾値と最大閾値の間にあるときは、出力映像
信号の最小レベル及び最大レベルを出力映像信号レベル
範囲の最小レベル及び最大レベルとし、ＡＰＬが最低閾
値より小さいときは、出力映像信号の最大レベルを出力
映像信号レベル範囲の最大レベルより小さいレベルと
し、ＡＰＬが最大閾値より大きいときは、出力映像信号
の最小レベルを出力映像信号レベル範囲の最小レベルよ
り大きいレベルとすることを特徴とした請求項１記載の
ダイナミック映像制御回路。2. A minimum threshold and maximum threshold of APL are set to
When PL is between the minimum threshold and the maximum threshold, the minimum level and the maximum level of the output video signal are the minimum level and the maximum level of the output video signal level range, and when APL is smaller than the minimum threshold, the output video signal The maximum level is set to a level smaller than the maximum level of the output video signal level range, and when APL is larger than the maximum threshold, the minimum level of the output video signal is set to a level higher than the minimum level of the output video signal level range. The dynamic video control circuit according to claim 1.
ＡＰＬ付近のヒストグラムの分散を求め、同分散が小さ
いときは、その付近のガンマ値を大きくし、同分散が大
きいときは同ガンマ値を前記の場合のガンマ値より小さ
くすることを特徴とした請求項１記載のダイナミック映
像制御回路。3. A means for calculating the variance of a histogram is provided,
The variance of the histogram near the APL is obtained, and when the variance is small, the gamma value in the neighborhood is increased, and when the variance is large, the gamma value is made smaller than the gamma value in the above case. Item 1. The dynamic video control circuit according to item 1.
の表示画素に対応する映像信号毎に集計して求めること
を特徴とした請求項１、請求項２又は請求項３記載のダ
イナミック映像制御回路。4. The dynamic video control circuit according to claim 1, wherein the APL or the histogram is calculated by aggregating for each video signal corresponding to a plurality of display pixels.
なるディジタル映像信号の上位桁のみを用いて行うこと
を特徴とした請求項１、請求項２、請求項３又は請求項
４記載のダイナミック映像制御回路。5. The dynamic video control according to claim 1, claim 2, claim 3 or claim 4, wherein the APL or histogram is calculated using only the upper digit of the digital video signal to be input. circuit.
入力信号レベルに対応するアドレスの、出力信号レベル
に対応するデータを書き換えるＲＡＭ（ランダムアクセ
スメモリ）とすることを特徴とした請求項１、請求項
２、請求項３、請求項４又は請求項５記載のダイナミッ
ク映像制御回路。6. The input / output characteristic conversion means is a RAM (random access memory) for rewriting data corresponding to an output signal level at an address corresponding to an input signal level by the control means. The dynamic image control circuit according to claim 2, claim 3, claim 4, or claim 5.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7121599A JPH08317250A (en) | 1995-05-19 | 1995-05-19 | Dynamic picture control circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7121599A JPH08317250A (en) | 1995-05-19 | 1995-05-19 | Dynamic picture control circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH08317250A true JPH08317250A (en) | 1996-11-29 |
Family
ID=14815250
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP7121599A Pending JPH08317250A (en) | 1995-05-19 | 1995-05-19 | Dynamic picture control circuit |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH08317250A (en) |
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