JP4691814B2 - Information signal processing apparatus, information signal processing method, and recording medium - Google Patents

Description

【００８２】
そして、動きクラス検出回路１２５では、上述したように算出された平均値ＡＶが１個または複数個のしきい値と比較されて動きクラスのクラス情報ＭＶが得られる。例えば、３個のしきい値ｔｈ１，ｔｈ２，ｔｈ３（ｔｈ１＜ｔｈ２＜ｔｈ３）が用意され、４つの動きクラスを検出する場合、ＡＶ≦ｔｈ１のときはＭＶ＝０、ｔｈ１＜ＡＶ≦ｔｈ２のときはＭＶ＝１、ｔｈ２＜ＡＶ≦ｔｈ３のときはＭＶ＝２、ｔｈ３＜ＡＶのときはＭＶ＝３とされる。
【００８３】
また、画像信号処理部１１０は、空間クラス検出回路１２４より出力される空間クラスのクラス情報としての再量子化コードｑｉと、動きクラス検出回路１２５より出力される動きクラスのクラス情報ＭＶに基づき、作成すべきＨＤ信号（１０５０ｉ信号）の画素（注目画素）が属するクラスを示すクラスコードＣＬを得るためのクラス合成回路１２６を有している。
【００８４】
このクラス合成回路１２６では、（３）式によって、クラスコードＣＬの演算が行われる。なお、（３）式において、Ｎａは空間クラスタップのデータ（ＳＤ画素データ）の個数、ＰはＡＤＲＣにおける再量子化ビット数を示している。
【００８５】
【数２】

【００８６】
また、画像信号処理部１１０は、係数メモリ１３４を有している。この係数メモリ１３４は、後述する推定予測演算回路１２７で使用される推定式の係数データを、クラス毎に、格納するものである。この係数データは、ＳＤ信号（５２５ｉ信号）を、ＨＤ信号（１０５０ｉ信号）に変換するための情報である。係数メモリ１３４には上述したクラス合成回路１２６より出力されるクラスコードＣＬが読み出しアドレス情報として供給され、この係数メモリ１３４からはクラスコードＣＬに対応した係数データが読み出され、推定予測演算回路１２７に供給されることとなる。
【００８７】
また、画像信号処理部１１０は、情報メモリバンク１３５を有している。この情報メモリバンクには、各クラスの係数種データが予め蓄えられている。この係数種データは、上述した係数メモリ１３４に格納するための係数データを生成するための生成式の係数データである。
【００８８】
後述する推定予測演算回路１２７では、予測タップのデータ（ＳＤ画素データ）ｘｉと、係数メモリ１３４より読み出される係数データＷｉとから、（４）式の推定式によって、作成すべきＨＤ画素データｙが演算される。第１のタップ選択回路１２１で選択される予測タップが１０個であるとき、（４）式におけるｎは１０となる。
【００８９】
【数３】

【００９０】
そして、この推定式の係数データＷｉ（ｉ＝１〜ｎ）は、（５）式に示すように、水平、垂直の解像度を示すパラメータｈ，ｖを含む生成式によって生成される。情報メモリバンク１３５には、この生成式の係数データである係数種データｗ₁₀〜ｗ_n9が、クラス毎に、記憶されている。この係数種データの生成方法については後述する。
【００９１】
【数４】

【００９２】
また、画像信号処理部１１０は、各クラスの係数種データおよびパラメータｈ，ｖの値を用い、（５）式によって、クラス毎に、パラメータｈ，ｖの値に対応した推定式の係数データＷｉ（ｉ＝１〜ｎ）を生成する係数生成回路１３６を有している。この係数生成回路１３６には、情報メモリバンク１３５から、上述した各クラスの係数種データがロードされる。また、この係数生成回路１３６には、システムコントローラ１０１より、パラメータｈ，ｖの値が供給される。
【００９３】
ここで、システムコントローラ１０１より係数生成回路１３６に供給されるパラメータｈ，ｖの値は、上述の設定モードで画質確認を行う際には、既存の設定値ｈo，ｖoや新たな設定値ｈn，ｖnであり、設定モードが解除されている状態では、設定値ｈo，ｖoである。この係数生成回路１３６で生成される各クラスの係数データＷｉ（ｉ＝１〜ｎ）は、上述した係数メモリ１３４に格納される。
【００９４】
また、画像信号処理部１１０は、係数生成回路１３６で生成される各クラスの係数データＷｉ（ｉ＝１〜ｎ）に対応した正規化係数Ｓを、（６）式によって、演算する正規化係数生成回路１３７と、ここで生成された正規化係数Ｓを、クラス毎に格納する正規化係数メモリ１３８を有している。正規化係数メモリ１３８には上述したクラス合成回路１２６より出力されるクラスコードＣＬが読み出しアドレス情報として供給され、この正規化係数メモリ１３８からはクラスコードＣＬに対応した正規化係数Ｓが読み出され、後述する正規化演算回路１２８に供給されることとなる。
【００９５】
【数５】

【００９６】
また、画像信号処理部１１０は、第１のタップ選択回路１２１で選択的に取り出される予測タップのデータ（ＳＤ画素データ）ｘｉと、係数メモリ１３４より読み出される係数データＷｉとから、作成すべきＨＤ信号の画素（注目画素）のデータを演算する推定予測演算回路１２７を有している。
【００９７】
上述したように、ＳＤ信号（５２５ｉ信号）をＨＤ信号（１０５０ｉ信号）に変換する際には、ＳＤ信号の１画素に対してＨＤ信号の４画素を得る必要があることから、この推定予測演算回路１２７では、ＨＤ信号を構成する２×２の単位画素ブロック毎に、画素データが生成される。すなわち、この推定予測演算回路１２７には、第１のタップ選択回路１２１より単位画素ブロック内の４画素（注目画素）に対応した予測タップのデータｘｉと、係数メモリ１３４よりその単位画素ブロックを構成する４画素に対応した係数データＷｉとが供給され、単位画素ブロックを構成する４画素のデータｙ₁〜ｙ₄は、それぞれ個別に上述した（４）式の推定式で演算される。
【００９８】
また、画像信号処理部１１０は、推定予測演算回路１２７より順次出力される４画素のデータｙ₁〜ｙ₄を、正規化係数メモリ１３８より読み出され、それぞれの演算に使用された係数データＷｉ（ｉ＝１〜ｎ）に対応した正規化係数Ｓで除算して正規化する正規化演算回路１２８を有している。上述せずも、係数生成回路１３６で係数種データより生成式によって推定式の係数データＷｉを求めるものであるが、生成される係数データは丸め誤差を含み、係数データＷｉ（ｉ＝１〜ｎ）の総和が１．０になることは保証されない。そのため、推定予測演算回路１２７で演算される各画素のデータｙ₁〜ｙ₄は、丸め誤差によってレベル変動したものとなる。上述したように、正規化演算回路１２８で正規化することで、その変動を除去できる。
【００９９】
また、画像信号処理部１１０は、正規化演算回路１２８で正規化されて順次供給される単位画素ブロック内の４画素のデータｙ₁′〜ｙ₄′を線順次化して１０５０ｉ信号のフォーマットで出力する後処理回路１２９を有している。
【０１００】
次に、画像信号処理部１１０の動作を説明する。
【０１０１】
バッファメモリ１０９に記憶されているＳＤ信号（５２５ｉ信号）より、第２のタップ選択回路１２２で、作成すべきＨＤ信号（１０５０ｉ信号）を構成する単位画素ブロック内の４画素（注目画素）の周辺に位置する空間クラスタップのデータ（ＳＤ画素データ）が選択的に取り出される。この第２のタップ選択回路１２２で選択的に取り出される空間クラスタップのデータ（ＳＤ画素データ）は空間クラス検出回路１２４に供給される。この空間クラス検出回路１２４では、空間クラスタップのデータとしての各ＳＤ画素データに対してＡＤＲＣ処理が施されて空間クラス（主に空間内の波形表現のためのクラス分類）のクラス情報としての再量子化コードｑｉが得られる（（１）式参照）。
【０１０２】
また、バッファメモリ１０９に記憶されているＳＤ信号（５２５ｉ信号）より、第３のタップ選択回路１２３で、作成すべきＨＤ信号（１０５０ｉ信号）を構成する単位画素ブロック内の４画素（注目画素）の周辺に位置する動きクラスタップのデータ（ＳＤ画素データ）が選択的に取り出される。この第３のタップ選択回路１２３で選択的に取り出される動きクラスタップのデータ（ＳＤ画素データ）は動きクラス検出回路１２５に供給される。この動きクラス検出回路１２５では、動きクラスタップのデータとしての各ＳＤ画素データより動きクラス（主に動きの程度を表すためのクラス分類）のクラス情報ＭＶが得られる。
【０１０３】
この動き情報ＭＶと上述した再量子化コードｑｉはクラス合成回路１２６に供給される。このクラス合成回路１２６では、これら動き情報ＭＶと再量子化コードｑｉとから、作成すべきＨＤ信号（１０５０ｉ信号）を構成する単位画素ブロック毎にその単位画素ブロック内の４画素（注目画素）が属するクラスを示すクラスコードＣＬが得られる（（３）式参照）。そして、このクラスコードＣＬは、係数メモリ１３４および正規化係数メモリ１３８に読み出しアドレス情報として供給される。
【０１０４】
係数メモリ１３４には、パラメータｈ，ｖの値に対応した各クラスの推定式の係数データＷｉ（ｉ＝１〜ｎ）が係数生成回路１３６で生成されて格納される。また、正規化係数メモリ１３８には、上述したように係数生成回路１３６で生成された各クラスの係数データＷｉ（ｉ＝１〜ｎ）に対応した正規化係数Ｓが正規化係数演算部１３７で生成されて格納される。
【０１０５】
係数メモリ１３４に上述したようにクラスコードＣＬが読み出しアドレス情報として供給されることで、この係数メモリ１３４からクラスコードＣＬに対応した係数データＷｉが読み出されて推定予測演算回路１２７に供給される。また、バッファメモリ１０９に記憶されているＳＤ信号（５２５ｉ信号）より、第１のタップ選択回路１２１で、作成すべきＨＤ信号（１０５０ｉ信号）を構成する単位画素ブロック内の４画素（注目画素）の周辺に位置する予測タップのデータ（ＳＤ画素データ）が選択的に取り出される。この第１のタップ選択回路１２１で選択的に取り出される予測タップのデータ（ＳＤ画素データ）ｘｉは推定予測演算回路１２７に供給される。
【０１０６】
推定予測演算回路１２７では、予測タップのデータ（ＳＤ画素データ）ｘｉと、係数メモリ１３４より読み出される４画素分の係数データＷｉとから、作成すべきＨＤ信号を構成する単位画素ブロック内の４画素（注目画素）のデータｙ₁〜ｙ₄が同時的に演算される（（４）式参照）。そして、この推定予測演算回路１２７より順次出力されるＨＤ信号を構成する単位画素ブロック内の４画素のデータｙ₁〜ｙ₄は正規化演算回路１２８に供給される。
【０１０７】
正規化係数メモリ１３８には上述したようにクラスコードＣＬが読み出しアドレス情報として供給され、この正規化係数メモリ１３８からはクラスコードＣＬに対応した正規化係数Ｓ、つまり推定予測演算回路１２７より出力されるＨＤ画素データｙ₁〜ｙ₄の演算に使用された係数データＷｉに対応した正規化係数Ｓが読み出されて正規化演算回路１２８に供給される。この正規化演算回路１２８では、推定予測演算回路１２７より出力されるＨＤ画素データｙ₁〜ｙ₄がそれぞれ対応する正規化係数Ｓで除算されて正規化される。これにより、係数種データを用いて生成式（（５）式参照）で推定式（（４）式参照）の係数データを求める際の丸め誤差によるデータｙ₁〜ｙ₄のレベル変動が除去される。
【０１０８】
このように正規化演算回路１２８で正規化されて順次出力される単位画素ブロック内の４画素のデータｙ₁′〜ｙ₄′は後処理回路１２９に供給される。この後処理回路１２９では、正規化演算回路１２８より順次供給される単位画素ブロック内の４画素のデータｙ₁′〜ｙ₄′が線順次化され、１０５０ｉ信号のフォーマットで出力される。つまり、この後処理回路１２９からは、ＨＤ信号としての１０５０ｉ信号が出力される。
【０１０９】
上述したように、係数生成回路１３６で、情報メモリバンク１３５よりロードされる係数種データを用いて、クラス毎に、パラメータｈ，ｖの設定値ｈo，ｖoに対応した推定式の係数データＷｉ（ｉ＝１〜ｎ）が生成され、これが係数メモリ１３４に格納される。そして、この係数メモリ１３４より、クラスコードＣＬに対応して読み出される係数データＷｉ（ｉ＝１〜ｎ）を用いて推定予測演算回路１２７でＨＤ画素データｙが演算される。したがって、ユーザは、上述した設定モードにおいて、パラメータｈ，ｖの値を設定することで、ＨＤ信号によって得られる画像の水平および垂直の画質を任意に調整できる。
【０１１０】
また、ユーザは、パラメータｈ，ｖの値を設定する際に、上述の推奨設定範囲を享受することを選択できる。その場合、ユーザによって設定されるパラメータｈ，ｖの値は推奨設定範囲内に規制され、画像信号処理部１１０から出力されるＨＤ信号による画像の画質が大幅に劣化したものとなることはなく、ユーザはパラメータｈ，ｖの値の設定を効果的に行うことができる。
【０１１１】
また、ユーザがパラメータｈ，ｖの値を設定する際に推奨設定範囲を享受する場合に、さらに入力信号ｘ，ｙの０〜２５５が、パラメータｈ，ｖのａx〜ｂx，ａy〜ｂyに対応するようにすることで、入力信号ｘ，ｙが１だけ変化した場合のｈ，ｖの変化（設定ステップ幅）を小さくでき、それだけパラメータｈ，ｖの値を細かく設定できる。またこの場合、入力信号ｘ，ｙの０〜２５５の全体が推奨設定範囲に対応したものとなるため、ユーザの例えばジョイスティック２０２等による操作に無駄となる部分がなく、操作性が向上する。
【０１１２】
なお、上述では、予め推奨設定範囲が１つだけ設定されているものを示したが、複数の推奨設定範囲の情報をシステムコントローラ１０１内のメモリ等に記憶しておき、ユーザがその中から任意の推奨設定範囲を選択して使用できるようにしてもよい。例えば、図７の３次元マトリクス表示を参考にし、範囲が順次広くなる、「きれい」、「普通」、「ノイズあり」の推奨設定範囲を予め用意しておくことができる。
【０１１３】
また、上述では、係数データＷｉ（ｉ＝１〜ｎ）を（５）式を使用して生成したものであるが、他の次数の異なった多項式や、他の関数で表現される式を使用することもできる。
【０１１４】
上述したように、情報メモリバンク１３５には、係数種データが、クラス毎に記憶されている。この係数種データは、予め学習によって生成されたものである。
【０１１５】
まず、この生成方法の一例について説明する。ここでは、（５）式の生成式における係数データである係数種データｗ₁₀〜ｗ_n9を求める例を示すものとする。
【０１１６】
ここで、以下の説明のため、（７）式のように、ｔｉ（ｉ＝０〜９）を定義する。
【０１１７】

【０１１８】
この（７）式を用いると、（５）式は、（８）式のように 書き換えられる。
【０１１９】
【数６】

【０１２０】
最終的に、学習によって未定係数ｗ_xyを求める。すなわち、クラス毎に、複数のＳＤ画素データとＨＤ画素データを用いて、二乗誤差を最小にする係数値を決定する。いわゆる最小二乗法による解法である。学習数をｍ、ｋ（１≦ｋ≦ｍ）番目の学習データにおける残差をｅ_k、二乗誤差の総和をＥとすると、（４）式および（５）式を用いて、Ｅは（９）式で表される。ここで、ｘ_ikはＳＤ画像のｉ番目の予測タップ位置におけるｋ番目の画素データ、ｙ_kはそれに対応するｋ番目のＨＤ画像の画素データを表している。
【０１２１】
【数７】

【０１２２】
最小二乗法による解法では、（９）式のｗ_xyによる偏微分が０になるようなｗ_xyを求める。これは、（１０）式で示される。
【０１２３】
【数８】

【０１２４】
以下、（１１）式、（１２）式のように、Ｘ_ipjq、Ｙ_ipを定義すると、（１０）式は、行列を用いて（１３）式のように書き換えられる。
【０１２５】
【数９】

【０１２６】
【数１０】

【０１２７】
この方程式は一般に正規方程式と呼ばれている。この正規方程式は、掃き出し法（Gauss-Jordanの消去法）等を用いて、ｗ_xyについて解かれ、係数種データが算出される。
【０１２８】
図１４は、上述した係数種データの生成方法の概念を示している。ＨＤ信号から複数のＳＤ信号を生成する。例えば、ＨＤ信号からＳＤ信号を生成する際に使用するフィルタの水平帯域と垂直帯域を可変するパラメータｈ，ｖの値をそれぞれ９段階に可変して、合計８１種類のＳＤ信号を生成している。このようにして生成した複数のＳＤ信号とＨＤ信号との間で学習を行って係数種データを生成する。
【０１２９】
図１５は、上述した概念で係数種データを生成する係数種データ生成装置１５０の構成を示している。
【０１３０】
この係数種データ生成装置１５０は、教師信号としてのＨＤ信号（１０５０ｉ信号）が入力される入力端子１５１と、このＨＤ信号に対して水平および垂直の間引き処理を行って、生徒信号としてのＳＤ信号（５２５ｉ信号）を得るＳＤ信号生成回路１５２とを有している。
【０１３１】
このＳＤ信号生成回路１５２には、パラメータｈ，ｖが制御信号として供給される。このパラメータｈ，ｖに対応して、ＨＤ信号からＳＤ信号を生成する際に使用するフィルタの水平帯域と垂直帯域とが可変される。ここで、フィルタの詳細について、いくつかの例を示す。
【０１３２】
例えば、フィルタを、水平帯域を制限する帯域フィルタと垂直帯域を制限する帯域フィルタとから構成することが考えられる。この場合、図１６に示すように、パラメータｈまたはｖの段階的な値に対応した周波数特性を設計し、逆フーリエ変換をすることにより、パラメータｈまたはｖの段階的な値に対応した周波数特性を持つ１次元フィルタを得ることができる。
【０１３３】
また例えば、フィルタを、水平帯域を制限する１次元ガウシアンフィルタと垂直帯域を制限する１次元ガウシアンフィルタとから構成することが考えられる。この１次元ガウシアンフィルタは（１４）式で示される。この場合、パラメータｈまたはｖの段階的な値に対応して標準偏差σの値を段階的に変えることにより、パラメータｈまたはｖの段階的な値に対応した周波数特性を持つ１次元ガウシアンフィルタを得ることができる。
【０１３４】
【数１１】

【０１３５】
また例えば、フィルタを、パラメータｈ，ｖの両方で水平および垂直の周波数特性が決まる２次元フィルタＦ(ｈ，ｖ）で構成することが考えられる。この２次元フィルタの生成方法は、上述した１次元フィルタと同様に、パラメータｈ，ｖの段階的な値に対応した２次元周波数特性を設計し、２次元の逆フーリエ変換をすることにより、パラメータｈ，ｖの段階的な値に対応した２次元周波数特性を持つ２次元フィルタを得ることができる。
【０１３６】
また、係数種データ生成装置１５０は、ＳＤ信号生成回路１５２より出力されるＳＤ信号（５２５ｉ信号）より、ＨＤ信号（１０５０ｉ信号）に係る注目画素の周辺に位置する複数のＳＤ画素のデータを選択的に取り出して出力する第１〜第３のタップ選択回路１５３〜１５５を有している。これら第１〜第３のタップ選択回路１５３〜１５５は、上述した画像信号処理部１１０の第１〜第３のタップ選択回路１２１〜１２３と同様に構成される。
また、係数種データ生成装置１５０は、第２のタップ選択回路１５４で選択的に取り出される空間クラスタップのデータ（ＳＤ画素データ）のレベル分布パターンを検出し、このレベル分布パターンに基づいて空間クラスを検出し、そのクラス情報を出力する空間クラス検出回路１５７を有している。この空間クラス検出回路１５７は、上述した画像信号処理部１１０の空間クラス検出回路１２４と同様に構成される。この空間クラス検出回路１５７からは、空間クラスタップのデータとしての各ＳＤ画素データ毎の再量子化コードｑｉが空間クラスを示すクラス情報として出力される。
【０１３７】
また、係数種データ生成装置１５０は、第３のタップ選択回路１５５で選択的に取り出される動きクラスタップのデータ（ＳＤ画素データ）より、主に動きの程度を表すための動きクラスを検出し、そのクラス情報ＭＶを出力する動きクラス検出回路１５８を有している。この動きクラス検出回路１５８は、上述した画像信号処理部１１０の動きクラス検出回路１２５と同様に構成される。この動きクラス検出回路１５８では、第３のタップ選択回路１５５で選択的に取り出される動きクラスタップのデータ（ＳＤ画素データ）からフレーム間差分が算出され、さらにその差分の絶対値の平均値に対してしきい値処理が行われて動きの指標である動きクラスが検出される。
【０１３８】
また、係数種データ生成装置１５０は、空間クラス検出回路１５７より出力される空間クラスのクラス情報としての再量子化コードｑｉと、動きクラス検出回路１５８より出力される動きクラスのクラス情報ＭＶに基づき、ＨＤ信号（５２５ｐ信号または１０５０ｉ信号）に係る注目画素が属するクラスを示すクラスコードＣＬを得るためのクラス合成回路１５９を有している。このクラス合成回路１５９も、上述した画像信号処理部１１０のクラス合成回路１２６と同様に構成される。
【０１３９】
また、係数種データ生成装置１５０は、入力端子１５１に供給されるＨＤ信号より得られる注目画素データとしての各ＨＤ画素データｙと、この各ＨＤ画素データｙにそれぞれ対応して第１のタップ選択回路１５３で選択的に取り出される予測タップのデータ（ＳＤ画素データ）ｘｉと、各ＨＤ画素データｙにそれぞれ対応してクラス合成回路１５９より出力されるクラスコードＣＬと、パラメータｈ，ｖとから、各クラス毎に、係数種データｗ₁₀〜ｗ_n9を得るための正規方程式（（１３）式参照）を生成する正規方程式生成部１６０を有している。
【０１４０】
この場合、一個のＨＤ画素データｙとそれに対応するｎ個の予測タップ画素データとの組み合わせで学習データが生成されるが、ＳＤ信号生成回路１５２へのパラメータｈ，ｖが順次変更されていって水平および垂直の帯域が段階的に変化した複数のＳＤ信号が順次生成されていき、これにより正規方程式生成部１６０では多くの学習データが登録された正規方程式が生成される。
【０１４１】
ここで、ＨＤ信号と、そのＨＤ信号から帯域が狭いフィルタを作用させて生成したＳＤ信号との間で学習して算出した係数種データは、解像度の高いＨＤ信号を得るためのものとなる。逆に、ＨＤ信号と、そのＨＤ信号から帯域が広いフィルタを作用させて生成したＳＤ信号との間で学習して算出した係数種データは解像度の低いＨＤ信号を得るためのものとなる。上述したように複数のＳＤ信号を順次生成して学習データを登録することで、連続した解像度のＨＤ信号を得るための係数種データを求めることが可能となる。
【０１４２】
なお、図示せずも、第１のタップ選択回路１５３の前段に時間合わせ用の遅延回路を配置することで、この第１のタップ選択回路１５３から正規方程式生成部１６０に供給されるＳＤ画素データｘｉのタイミング合わせを行うことができる。
【０１４３】
また、係数種データ生成装置１５０は、正規方程式生成部１６０でクラス毎に生成された正規方程式のデータが供給され、クラス毎に正規方程式を解いて、各クラスの係数種データｗ₁₀〜ｗ_n9を求める係数種データ決定部１６１と、この求められた係数種データｗ₁₀〜ｗ_n9を記憶する係数種メモリ１６２とを有している。係数種データ決定部１６１では、正規方程式が例えば掃き出し法などによって解かれて、係数データｗ₁₀〜ｗ_n9が求められる。
【０１４４】
図１５に示す係数種データ生成装置１５０の動作を説明する。入力端子１５１には教師信号としてのＨＤ信号（１０５０ｉ信号）が供給され、そしてこのＨＤ信号に対してＳＤ信号生成回路１５２で水平および垂直の間引き処理が行われて生徒信号としてのＳＤ信号（５２５ｉ信号）が生成される。この場合、ＳＤ信号生成回路１５２にはパラメータｈ，ｖが制御信号として供給され、水平および垂直の帯域が段階的に変化した複数のＳＤ信号が順次生成されていく。
【０１４５】
このＳＤ信号（５２５ｉ信号）より、第２のタップ選択回路１５４で、ＨＤ信号（１０５０ｉ信号）に係る注目画素の周辺に位置する空間クラスタップのデータ（ＳＤ画素データ）が選択的に取り出される。この第２のタップ選択回路１５４で選択的に取り出される空間クラスタップのデータ（ＳＤ画素データ）は空間クラス検出回路１５７に供給される。この空間クラス検出回路１５７では、空間クラスタップのデータとしての各ＳＤ画素データに対してＡＤＲＣ処理が施されて空間クラス（主に空間内の波形表現のためのクラス分類）のクラス情報としての再量子化コードｑｉが得られる（（１）式参照）。
【０１４６】
また、ＳＤ信号生成回路１５２で生成されたＳＤ信号より、第３のタップ選択回路１５５で、ＨＤ信号に係る注目画素の周辺に位置する動きクラスタップのデータ（ＳＤ画素データ）が選択的に取り出される。この第３のタップ選択回路１５５で選択的に取り出される動きクラスタップのデータ（ＳＤ画素データ）は動きクラス検出回路１５８に供給される。この動きクラス検出回路１５８では、動きクラスタップのデータとしての各ＳＤ画素データより動きクラス（主に動きの程度を表すためのクラス分類）のクラス情報ＭＶが得られる。
【０１４７】
この動き情報ＭＶと上述した再量子化コードｑｉはクラス合成回路１５９に供給される。このクラス合成回路１５９では、これら動き情報ＭＶと再量子化コードｑｉとから、ＨＤ信号（１０５０ｉ信号）に係る注目画素が属するクラスを示すクラスコードＣＬが得られる（（３）式参照）。
【０１４８】
また、ＳＤ信号生成回路１５２で生成されるＳＤ信号より、第１のタップ選択回路１５３で、ＨＤ信号に係る注目画素の周辺に位置する予測タップのデータ（ＳＤ画素データ）が選択的に取り出される。そして、入力端子１５１に供給されるＨＤ信号より得られる注目画素データとしての各ＨＤ画素データｙと、この各ＨＤ画素データｙにそれぞれ対応して第１のタップ選択回路１５３で選択的に取り出される予測タップのデータ（ＳＤ画素データ）ｘｉと、各ＨＤ画素データｙにそれぞれ対応してクラス合成回路１５９より出力されるクラスコードＣＬと、パラメータｈ，ｖとから、正規方程式生成部１６０では、クラス毎に、係数種データｗ₁₀〜ｗ_n9を生成するための正規方程式（（１３）式参照）が生成される。
【０１４９】
そして、係数種データ決定部１６１でその正規方程式が解かれ、各クラスの係数種データｗ₁₀〜ｗ_n9が求められ、その係数種データｗ₁₀〜ｗ_n9はクラス別にアドレス分割された係数種メモリ１６２に記憶される。
【０１５０】
正規方程式生成部１６０で、ＨＤ画素データｙとそれに対応するｎ個の予測タップ画素データとの組み合わせで生成される学習データを、ＨＤ画素データｙが奇数、偶数のいずれのＨＤ信号のものか、さらにはそのＨＤ信号を構成する上述した２×２の単位画素ブロック内の４画素のいずれであるかの情報によって分別することで、奇数、偶数のそれぞれのフィールドにおけるＨＤ信号（１０５０ｉ信号）を構成する２×２の単位画素ブロック内の４画素に対応した係数種データｗ₁₀〜ｗ_n9を求めるための正規方程式（（１３）式参照）を個別に生成できる。
【０１５１】
これにより、係数種データ決定部１６１では、奇数、偶数のそれぞれのフィールドにおけるＨＤ信号（１０５０ｉ信号）を構成する２×２の単位画素ブロック内の４画素に対応した係数種データｗ₁₀〜ｗ_n9を求めることができ、係数種メモリ１６２に記憶できる。
【０１５２】
なお、図１の画像信号処理部１１０では、複数の特徴量が水平、垂直の解像度であるものを示したが、複数の特徴量が解像度とノイズ抑圧度であるものも同様に構成することができる。この場合、ユーザは、解像度を示すパラメータｒおよびノイズ抑圧度（ノイズ低減度）を示すパラメータｚの値を、図２あるいは図１１に示すようなユーザインタフェースによって設定する。
【０１５３】
図１７Ａ，Ｂは、リモコン送信機２００の表示部２０１またはテレビ受信機１００のディスプレイ部１１１に表示される設定表示部１１５を示している。図１７Ａに示す状態は、推奨設定範囲を享受することが選択されていない状態である。図１７Ｂに示す状態は、推奨設定範囲を享受することが選択されている状態である。この場合、パラメータｒの推奨設定範囲はａr≦ｒ≦brでり、パラメータｚの推奨設定範囲はａz≦ｚ≦bzである。これらの推奨設定範囲も、例えばＳＮ比に基づいて設定できる（図７参照）。
【０１５４】
この場合、係数データＷｉ（ｉ＝１〜ｎ）を生成する生成式として、例えば、（１５）式等を使用でき、さらに次数の異なった多項式や、他の関数で表現される式でも実現可能である。
【０１５５】
【数１２】

【０１５６】
このようにパラメータｒ，ｚを含む生成式の係数データである係数種データは、上述したパラメータｈ，ｖを含む生成式の係数データである係数種データを生成する場合と同様に、図１５に示す係数種データ生成装置１５０により生成できる。その場合、ＳＤ信号生成回路１５２には、パラメータｒ，ｚが制御信号として供給され、このパラメータｒ，ｚの値に対応して、ＨＤ信号からＳＤ信号を生成する際に、ＳＤ信号の水平、垂直の帯域と、ＳＤ信号に対するノイズ付加状態とが段階的に可変される。
【０１５７】
図１８は、パラメータｒ，ｚの値に対応したＳＤ信号の生成例を示している。この例では、パラメータｒ，ｚはそれぞれ９段階に可変され、合計８１種類のＳＤ信号が生成される。なお、パラメータｒ，ｚを９段階よりもさらに多くの段階に可変するようにしてもよい。その場合には、算出される係数種データの精度は良くなるが、計算量は増えることとなる。
【０１５８】
ここで、パラメータｚの値に対応したノイズ付加方法の詳細について、いくつかの例を示す。
【０１５９】
例えば、図１９Ａに示すように、ＳＤ信号に振幅レベルを段階的に変化させたノイズ信号を加えて、段階的にノイズレベルが変化するＳＤ信号を生成する。
【０１６０】
また例えば、図１９Ｂに示すように、ＳＤ信号に一定振幅レベルのノイズ信号を加えるが、加える画面領域を段階的に可変する。
【０１６１】
さらに例えば、図１９Ｃに示すように、ＳＤ信号（１画面分）として、ノイズが含まれていないものと、ノイズが含まれているものとを用意する。そして、正規方程式を生成する際に、それぞれのＳＤ信号に対して複数回の学習を行う。
【０１６２】
例えば、「ノイズ０」ではノイズなしのＳＤ信号に対して１００回の学習を行い、「ノイズｉ」ではノイズなしのＳＤ信号に対して３０回の学習を行うと共にノイズありのＳＤ信号に対して７０回の学習を行う。この場合、「ノイズｉ」の方がノイズ抑圧度が高い係数種データを算出する学習系になる。このように、ノイズなしとノイズありのＳＤ信号に対する学習回数を段階的に変化させて学習を行うことにより、連続したノイズ抑圧度を得るための係数種データを得ることができる。
【０１６３】
また、図１の画像信号処理部１１０では、複数の特徴量が水平、垂直の解像度であるものを示したが、複数の特徴量が水平、垂直の解像度とノイズ抑圧度であるものも同様に構成することができる。この場合、ユーザは、水平、垂直の解像度を示すパラメータｈ，ｖとノイズ抑圧度を示すパラメータｚの値を、図２あるいは図１１に示すようなユーザインタフェースによって設定する。
【０１６４】
図２０Ａ，Ｂは、リモコン送信機２００の表示部２０１またはテレビ受信機１００のディスプレイ部１１１に表示される設定表示部１１５を示している。図２０Ａ，Ｂは、３つのパラメータに対する推奨設定範囲を説明したものである。３つのパラメータの種類としては、例えば水平解像度ｈ、垂直解像度ｖ、ノイズ抑圧度ｚが考えられる。
【０１６５】
図２０Ａに示す状態は、推奨設定範囲を享受することが選択されていない状態である。図２０Ｂに示す状態は、推奨設定範囲を享受することが選択されている状態である。ここで、パラメータｈ，ｖはジョイスティック２０２の左右、上下の方向の動きで変更でき、さらにパラメータｚはジョイスティック２０２の斜め方向の動きで変更できる。
【０１６６】
この場合、係数データＷｉ（ｉ＝１〜ｎ）を生成する生成式として、例えば、（１６）式等を使用でき、さらに次数の異なった多項式や、他の関数で表現される式でも実現可能である。
【０１６７】
【数１３】

【０１６８】
このようにパラメータｈ，ｖ，ｚを含む生成式の係数データである係数種データは、上述したパラメータｈ，ｖを含む生成式の係数データである係数種データを生成する場合と同様に、図１５に示す係数種データ生成装置１５０により生成できる。その場合、ＳＤ信号生成回路１５２には、パラメータｈ，ｖ，ｚが制御信号として供給され、このパラメータｈ，ｖ，ｚの値に対応して、ＨＤ信号からＳＤ信号を生成する際に、ＳＤ信号の水平、垂直の帯域と、ＳＤ信号に対するノイズ付加状態とが段階的に可変される。
【０１６９】
図２１は、パラメータｈ，ｖ，ｚの値に対応したＳＤ信号の生成例を示している。この例では、パラメータｈ，ｖ，ｚはそれぞれ９段階に可変され、合計７２９種類のＳＤ信号が生成される。なお、パラメータｈ，ｖ，ｚを９段階よりもさらに多くの段階に可変するようにしてもよい。その場合には、算出される係数種データの精度は良くなるが、計算量は増えることとなる。
【０１７０】
なお、図１の画像信号処理部１１０における処理を、例えば図２２に示すような画像信号処理装置３００によって、ソフトウェアで実現することも可能である。
【０１７１】
まず、図２２に示す画像信号処理装置３００について説明する。この画像信号処理装置３００は、装置全体の動作を制御するＣＰＵ３０１と、このＣＰＵ３０１の動作プログラムや係数種データ等が格納されたＲＯＭ（read only memory）３０２と、ＣＰＵ３０１の作業領域を構成するＲＡＭ（random access memory）３０３とを有している。これらＣＰＵ３０１、ＲＯＭ３０２およびＲＡＭ３０３は、それぞれバス３０４に接続されている。
【０１７２】
また、画像信号処理装置３００は、外部記憶装置としてのハードディスクドライブ（ＨＤＤ）３０５と、フロッピーディスク３０６をドライブするフロッピーディスクドライブ（ＦＤＤ）３０７とを有している。これらドライブ３０５，３０７は、それぞれバス３０４に接続されている。
【０１７３】
また、画像信号処理装置３００は、インターネット等の通信網４００に有線または無線で接続する通信部３０８を有している。この通信部３０８は、インタフェース３０９を介してバス３０４に接続されている。
【０１７４】
また、画像信号処理装置３００は、ユーザインタフェース部を備えている。このユーザインタフェース部は、リモコン送信機２００からのリモコン信号ＲＭを受信するリモコン信号受信回路３１０と、ＬＣＤ（liquid crystal display）等からなるディスプレイ３１１とを有している。受信回路３１０はインタフェース３１２を介してバス３０４に接続され、同様にディスプレイ３１１はインタフェース３１３を介してバス３０４に接続されている。ユーザは、このユーザインタフェース部によって、上述したパラメータｈ，ｖの値の設定を行うことができる。
【０１７５】
また、画像信号処理装置３００は、ＳＤ信号を入力するための入力端子３１４と、ＨＤ信号を出力するための出力端子３１５とを有している。入力端子３１４はインタフェース３１６を介してバス３０４に接続され、同様に出力端子３１５はインタフェース３１７を介してバス３０４に接続される。
【０１７６】
ここで、上述したようにＲＯＭ３０２に処理プログラムや係数種データ等を予め格納しておく代わりに、例えばインターネットなどの通信網４００より通信部３０８を介してダウンロードし、ハードディスクやＲＡＭ３０３に蓄積して使用することもできる。また、これら処理プログラムや係数種データ等をフロッピーディスク３０６で提供するようにしてもよい。
【０１７７】
また、処理すべきＳＤ信号を入力端子３１４より入力する代わりに、予めハードディスクに記録しておき、あるいはインターネットなどの通信網４００より通信部３０８を介してダウンロードしてもよい。また、処理後のＨＤ信号を出力端子３１５に出力する代わり、あるいはそれと並行してディスプレイ３１１に供給して画像表示をしたり、さらにはハードディスクに格納したり、通信部３０８を介してインターネットなどの通信網４００に送出するようにしてもよい。
【０１７８】
図２３のフローチャートを参照して、図２２に示す画像信号処理装置３００における、ＳＤ信号よりＨＤ信号を得るため処理手順を説明する。
【０１７９】
まず、ステップＳＴ１で、処理を開始し、ステップＳＴ２で、ＳＤ画素データをフレーム単位またはフィールド単位で入力する。このＳＤ画素データが入力端子３１４より入力される場合には、このＳＤ画素データをＲＡＭ３０３に一時的に格納する。また、このＳＤ画素データがハードディスクに記録されている場合には、ハードディスクドライブ３０７でこのＳＤ画素データを読み出し、ＲＡＭ３０３に一時的に格納する。そして、ステップＳＴ３で、入力ＳＤ画素データの全フレームまたは全フィールドの処理が終わっているか否かを判定する。処理が終わっているときは、ステップＳＴ４で、処理を終了する。一方、処理が終わっていないときは、ステップＳＴ５に進む。
【０１８０】
このステップＳＴ５では、上述したようにユーザが設定したパラメータｈ，ｖの値（画質指定値）を例えばＲＡＭ３０３より読み込む。そして、ステップＳＴ６で、読み込んだ画質指定値および各クラスの係数種データを使用して、生成式（例えば（５）式）によって、各クラスの推定式（（４）式参照）の係数データＷｉを生成する。
【０１８１】
次に、ステップＳＴ７で、ステップＳＴ２で入力されたＳＤ画素データより、生成すべき各ＨＤ画素データに対応して、クラスタップおよび予測タップの画素データを取得する。そして、ステップＳＴ８で、入力されたＳＤ画素データの全領域においてＨＤ画素データを得る処理が終了したか否かを判定する。終了しているときは、ステップＳＴ２に戻り、次のフレームまたはフィールドのＳＤ画素データの入力処理に移る。一方、処理が終了していないときは、ステップＳＴ９に進む。
【０１８２】
このステップＳＴ９では、ステップＳＴ７で取得されたクラスタップのＳＤ画素データからクラスコードＣＬを生成する。そして、ステップＳＴ１０で、そのクラスコードＣＬに対応した係数データと予測タップのＳＤ画素データを使用して、推定式により、ＨＤ画素データを生成し、その後にステップＳＴ７に戻って、上述したと同様の処理を繰り返す。
【０１８３】
このように、図２３に示すフローチャートに沿って処理をすることで、入力されたＳＤ信号を構成するＳＤ画素データを処理して、ＨＤ信号を構成するＨＤ画素データを得ることができる。上述したように、このように処理して得られたＨＤ信号は出力端子３１５に出力されたり、ディスプレイ３１１に供給されてそれによる画像が表示されたり、さらにはハードディスクドライブ３０５に供給されてハードディスクに記録されたりする。
【０１８４】
なお、上述実施の形態においては、ＨＤ信号を生成する際の推定式として線形一次方程式を使用したものを挙げたが、これに限定されるものではなく、例えば推定式として高次方程式を使用するものであってもよい。
【０１８５】
また、上述実施の形態においては、ＳＤ信号（５２５ｉ信号）をＨＤ信号（１０５０ｉ信号）に変換する例を示したが、この発明はそれに限定されるものでなく、推定式を使用して第１の画像信号を第２の画像信号に変換するその他の場合にも同様に適用できることは勿論である。
【０１８６】
また、上述実施の形態においては、２つまたは３つの特徴量を示すパラメータを設定するものを示したが、さらに多くの特徴量を示すパラメータを設定するものにも、この発明を同様に適用することができる。
【０１８７】
また、上述実施の形態においては、情報メモリバンク１３５に係数種データを格納しておき、この係数種データを使用してパラメータｈ，ｖの値に対応した係数データを係数生成回路１３６で生成し、その係数データを係数メモリ１３４に格納するものを示したが、情報メモリバンク１３５にパラメータｈ，ｖの値の各組み合わせに対応した多くの係数データを格納しておき、パラメータｈ，ｖの値に対応した係数データをその情報メモリバンク１３５から読み出して係数メモリ１３４に格納する構成とすることもできる。
【０１８８】
また、上述実地の形態においては、情報信号が画像信号である場合を示したが、この発明はこれに限定されない。例えば、情報信号が音声信号である場合にも、この発明を同様に適用することができる。音声信号の複数の特徴量としては、例えば、周波数帯域（解像度）と歪率（ノイズ抑圧度）等が考えられる。
【０１８９】
【発明の効果】
この発明によれば、第１の情報信号を第２の情報信号に変換する際に、第２の情報信号によって得られる出力の質を決める複数の特徴量をそれぞれ示す複数パラメータの値に対応して、第２の情報信号に係る注目点の情報データを生成するようにしているので、ユーザは、複数パラメータの値の設定を変更することで、第２の情報信号によって得られる出力の質を任意に調整できる。
【０１９０】
また、この発明によれば、第１の情報信号を第２の情報信号に変換する際に使用され、第２の情報信号によって得られる出力の質を決める複数の特徴量をそれぞれ示す複数のパラメータの値を推奨設定範囲内に規制するものであり、ユーザは複数のパラメータの値の設定を効果的に行うことができる。
【図面の簡単な説明】
【図１】実施の形態としてのテレビ受信機の構成を示すブロック図である。
【図２】水平、垂直の解像度を示すパラメータｈ，ｖの値を設定するためのユーザインタフェース例を示す図である。
【図３】パラメータｈ，ｖの設定動作を説明するためのフローチャート（１／２）である。
【図４】パラメータｈ，ｖの設定動作を説明するためのフローチャート（２／２）である。
【図５】推奨設定範囲の選択を説明するための図である。
【図６】推奨設定範囲の設定動作を説明するためのフローチャートである。
【図７】水平、垂直の解像度を示すパラメータｈ，ｖとＳＮ比との関係を示す図である。
【図８】入力信号ｘ，ｙとパラメータｈ，ｖの関係を説明するための図である。
【図９】画質確認の選択を説明するための図である。
【図１０】位置記録の選択を説明するための図である。
【図１１】パラメータｈ，ｖの値を設定するための他のユーザインタフェース例を示す図である。
【図１２】パラメータｈ，ｖの設定動作を説明するためのフローチャート（１／２）である。
【図１３】パラメータｈ，ｖの設定動作を説明するためのフローチャート（２／２）である。
【図１４】係数種データの生成方法の概念を示す図である。
【図１５】係数種データ生成装置の構成を示すブロック図である。
【図１６】帯域フィルタの周波数特性の一例を示す図である。
【図１７】解像度を示すパラメータｒとノイズ抑圧度を示すパラメータｚの設定を行うための設定表示部を示す図である。
【図１８】ＳＤ信号（パラメータｒ，ｚ）の生成例を示す図である。
【図１９】ノイズ付加方法を説明するための図である。
【図２０】水平、垂直の解像度を示すパラメータｈ，ｖとノイズ抑圧度を示すパラメータｚの設定を行うための設定表示部を示す図である。
【図２１】ＳＤ信号（パラメータｈ，ｖ，ｚ）の生成例を示す図である。
【図２２】ソフトウェアで実現するための画像信号処理装置の構成を示すブロック図である。
【図２３】画像信号の処理手順を示すフローチャートである。
【図２４】５２５ｉ信号と１０５０ｉ信号の画素位置関係を説明するための図である。
【符号の説明】
１００・・・テレビ受信機、１０１・・・システムコントローラ、１０２・・・リモコン信号受信回路、１０５・・・受信アンテナ、１０６・・・チューナ、１１０・・・画像信号処理部、１１１・・・ディスプレイ部、１１２・・・ＯＳＤ回路、１１５・・・設定表示部、１１５ａ・・・推奨設定範囲、１１６・・・アイコン、１１７・・・メニュー表示部、１２１・・・第１のタップ選択回路、１２２・・・第２のタップ選択回路、１２３・・・第３のタップ選択回路、１２４・・・空間クラス検出回路、１２５・・・動きクラス検出回路、１２６・・・クラス合成回路、１２７・・・推定予測演算回路、１２８・・・正規化回路、１２９・・・後処理回路、１３４・・・係数メモリ、１３５・・・情報メモリバンク、１３６・・・係数生成回路、１３７・・・正規化係数演算部、１３８・・・正規化係数メモリ、２００・・・リモコン送信機、２０１・・・表示部、２０２・・・ジョイスティック、２０３・・・移動キー、２０４・・・動作スイッチ、３００・・・画像信号処理装置[0001]
BACKGROUND OF THE INVENTION
  The present invention is, for example, an information signal processing apparatus and an information signal processing method suitable for application when converting an NTSC video signal to a high-definition video signal, andRecordIt relates to the medium. Specifically, a plurality of parameter values that are used when converting the first information signal into the second information signal and that respectively indicate a plurality of feature quantities that determine the quality of the output obtained by the second information signal are recommended settings. The present invention relates to an information signal processing device or the like that allows a user to effectively set a plurality of parameter values by being regulated within the range.
[0002]
[Prior art]
Conventionally, a format conversion for converting a 525i signal as an SD (Standard Definition) signal into a 1050i signal as an HD (High Definition) signal has been proposed. The 525i signal means an interlaced image signal having 525 lines, and the 1050i signal means an interlaced image signal having 1050 lines.
[0003]
FIG. 24 shows a pixel position relationship between the 525i signal and the 1050i signal. Here, a large dot is a pixel of a 525i signal, and a small dot is a pixel of a 1050i signal. In addition, pixel positions in odd fields are indicated by solid lines, and pixel positions in even fields are indicated by broken lines. When converting a 525i signal to a 1050i signal, it is necessary to obtain four pixels of the 1050i signal corresponding to one pixel of the 525i signal in each of the odd and even fields.
[0004]
Conventionally, when the pixel data of the 1050i signal is obtained from the pixel data of the 525i signal in order to perform the format conversion as described above, the coefficient data of the estimation formula corresponding to the phase of each pixel of the 1050i signal with respect to the pixel of the 525i signal is obtained. It has been proposed that pixel data of a 1050i signal is obtained by an estimation formula using the coefficient data stored in a memory.
[0005]
[Problems to be solved by the invention]
As described above, in the case of obtaining the pixel data of the 1050i signal by the estimation formula, the resolution of the image by the 1050i signal is fixed, and it is desired according to the image content or the like like the conventional adjustment of contrast, sharpness, etc. The resolution could not be achieved.
[0006]
Therefore, in the present invention, for example, an information signal processing device is provided in which the user can arbitrarily adjust the image quality of the image, and can effectively set a plurality of feature amounts for determining the image quality of the image. The purpose is to do.
[0007]
[Means for Solving the Problems]
An information signal processing apparatus according to the present invention is an information signal processing apparatus that converts a first information signal made up of a plurality of information data into a second information signal made up of a plurality of information data. Feature quantity setting means for setting a plurality of parameter values respectively indicating a plurality of feature quantities that determine the quality of the output to be obtained, storage means for storing information on recommended setting ranges of the plurality of parameter values, and feature quantity setting means Corresponding to the second information signal corresponding to the feature value regulating means for restricting the values of the plurality of parameters set in the recommended setting range and the values of the plurality of parameters set by the feature quantity setting means. Information data generating means for generating point information data.
[0008]
For example, the information data generation means includes coefficient data acquisition means for acquiring coefficient data of the estimation formula corresponding to the values of the plurality of parameters set by the feature amount setting means, and second information from the first information signal. From the data selection means for selecting a plurality of information data located around the attention point related to the signal, the coefficient data acquired by the coefficient data acquisition means, and the plurality of information data selected by the data selection means, the estimation formula And calculating means for calculating the information data of the attention point.
[0009]
  The information signal processing method according to the present invention converts a first information signal composed of a plurality of information data into a second information signal composed of a plurality of information data.Information signal processorAn information signal processing method, a first step of setting values of a plurality of parameters respectively indicating a plurality of feature quantities that determine the quality of output obtained by the second information signal, and is set in the first step The second step of restricting the values of the plurality of parameters within the recommended setting range, and the information of the attention point related to the second information signal corresponding to the values of the plurality of parameters set in the first step And a third step of generating data.
  The third step obtains coefficient data of the estimation formula corresponding to the set values of the plurality of parameters, and from the first information signal, a plurality of points positioned around the point of interest related to the second information signal Information data is selected, and the information data of the attention point is calculated from the acquired coefficient data and a plurality of selected information data using the estimation formula.
[0010]
  Further, according to the present inventionRecordThe medium performs each step of the information signal processing method described above.In the computer of the information processing deviceTo runTheProgramIs recordedIs.
[0011]
In the present invention, the user sets values of a plurality of parameters respectively indicating a plurality of feature amounts that determine the quality of output obtained by the second information signal. When the information signal is an image signal, the plurality of feature amounts include a horizontal resolution and a vertical resolution, a resolution and a noise suppression degree, a horizontal resolution, a vertical resolution, and a noise removal degree. When the information signal is an audio signal, the plurality of feature amounts are a frequency band (resolution), a distortion rate (noise suppression degree), and the like. The position where the values of the plurality of parameters are in the variable range is displayed on a display element, for example. The user can easily adjust the values of a plurality of parameters with reference to this display.
[0012]
The values of the plurality of parameters set by the user are regulated within a preset recommended setting range. For example, depending on the combination of the values of a plurality of parameters, the quality of the output obtained by the second information signal is greatly deteriorated. For example, the recommended setting range is set to a range excluding such a combination.
[0013]
When setting the values of a plurality of parameters, the user can instruct whether or not to enjoy the recommended setting range described above. In this case, only when the user gives an instruction to enjoy the recommended setting range, the values of the plurality of parameters set by the user are regulated within the recommended setting range.
[0014]
In this way, when the values of a plurality of parameters set by the user are regulated within the recommended setting range, the quality of the output obtained by the second information signal is not greatly deteriorated, The user can effectively set a plurality of parameter values.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a configuration of a television receiver 100 as an embodiment. The television receiver 100 obtains a 525i signal as an SD signal from a broadcast signal, converts the 525i signal into a 1050i signal as an HD signal, and displays an image based on the 1050i signal.
[0016]
The television receiver 100 includes a microcomputer, and includes a system controller 101 for controlling the operation of the entire system, and a remote control signal receiving circuit 102 that receives a remote control signal. A remote control signal receiving circuit 102 is connected to the system controller 101, receives a remote control signal RM output in response to a user operation from a remote control transmitter 200 including a microcomputer, and an operation signal corresponding to the signal RM. Is supplied to the system controller 101.
[0017]
Further, the television receiver 100 is supplied with a receiving antenna 105 and a broadcast signal (RF modulation signal) captured by the receiving antenna 105, and performs a channel selection process, an intermediate frequency amplification process, a detection process, and the like to generate an SD signal ( The tuner 106 for obtaining the 525i signal) and the buffer memory 109 for temporarily storing the SD signal output from the tuner 106 are provided.
[0018]
Further, the television receiver 100 converts an SD signal (525i signal) temporarily stored in the buffer memory 109 into an HD signal (1050i signal), and an output from the image signal processing unit 110. A display unit 111 for displaying an image by an HD signal, an OSD (On Screen Display) circuit 112 for generating a display signal SCH for displaying a character figure or the like on the screen of the display unit 111, and And a synthesizer 113 for synthesizing the display signal SCH with the HD signal output from the image signal processing unit 110 and supplying it to the display unit 111.
[0019]
The display unit 111 is configured by a flat panel display such as a CRT (cathode-ray tube) display or an LCD (liquid crystal display). Further, the generation operation of the display signal SCH in the OSD circuit 112 is controlled by the system controller 101.
[0020]
The operation of the television receiver 100 shown in FIG. 1 will be described.
[0021]
The SD signal (525i signal) output from the tuner 106 is supplied to the buffer memory 109 and temporarily stored. The SD signal temporarily stored in the buffer memory 109 is supplied to the image signal processing unit 110 and converted into an HD signal (1050i signal). That is, the image signal processing unit 110 obtains pixel data (hereinafter referred to as “HD pixel data”) constituting an HD signal from pixel data (hereinafter referred to as “SD pixel data”) that constitutes an SD signal. The HD signal output from the image signal processing unit 110 is supplied to the display unit 111 via the synthesizer 113, and an image based on the HD signal is displayed on the screen of the display unit 111.
[0022]
Further, although not described above, the user can arbitrarily adjust the horizontal and vertical resolutions of the image displayed on the screen of the display unit 111 as described above by operating the remote control transmitter 200. As will be described later, the image signal processing unit 110 calculates HD pixel data by an estimation formula. As the coefficient data of this estimation formula, data corresponding to the values of the parameters h and v indicating the horizontal and vertical resolutions set by the user in the setting mode are generated and used by the generation formula including these parameters h and v. The Thereby, the horizontal and vertical resolutions of the image by the HD signal output from the image signal processing unit 110 correspond to the set values of the parameters h and v.
[0023]
FIG. 2 shows an example of a user interface for setting the values of the parameters h and v. The remote control transmitter 200 includes a display unit 201 composed of, for example, an LCD, a joystick 202, up / down / left / right movement keys 203, an operation switch 204 used when setting values of parameters h and v, and other operations. And a key group 205.
[0024]
The system controller 101 advances the setting operation of the values of the parameters h and v as follows in accordance with the depression of the operation switch 204. This setting operation will be described with reference to the flowcharts of FIGS.
[0025]
(1) When the operation switch 204 is pushed down for the first time, the mode shifts to the setting mode (step ST1). When the mode is shifted to the setting mode, the setting display unit 115 for setting the values of the parameters h and v is displayed on the display unit 201 of the remote control transmitter 200 and the display unit 111 of the television receiver 100 (step ST2). In the setting display section 115, the existing setting values ho and vo are displayed with black circle icons 116. The existing set values ho and vo may be further displayed numerically. The range of the parameters h and v in the setting display unit 115 in this state is 0 to 8 which is the maximum variable range.
[0026]
(2) When the operation switch 204 is pushed down for the second time (step ST3), the user is in a state of selecting whether or not to enjoy the recommended variable range (step ST4). At this time, in addition to the setting display unit 115, for example, a selection display unit “recommended range: ONOFF” is displayed on the display unit 201 of the remote control transmitter 200 and the display unit 111 of the television receiver 100. 5A to 5C show the display unit 201 of the remote control transmitter 200. FIG.
[0027]
In this state, the user uses the movement key 203 to select “ON” or “OFF”. For example, the default is “OFF”. The selected side is in a state surrounded by a frame, for example.
[0028]
FIG. 5A shows a state in which “OFF” is selected, and the ranges of the parameters h and v in the setting display unit 115 in this state are 0 to 8, which is the maximum variable range. FIG. 5B shows a state in which “ON” is selected. In the setting display unit 115 in this state, the range h is the recommended setting range ax to bx, and the range v is the recommended setting range ay. ~ By (steps ST5 and ST7). Information on the recommended setting range is stored in advance in a memory (not shown) in the system controller 101. The recommended setting range information is also stored in advance in a memory (not shown) in the remote control transmitter 200.
[0029]
Even when “ON” is selected, as shown in FIG. 5C, the range of the parameters h and v in the setting display unit 115 is set to 0 to 8 which is the maximum variable range, and the recommended display in the setting display unit 115 is recommended. The setting range 115a may be displayed in an identifiable manner by dividing the setting range 115a with a boundary line or changing the display color. This setting procedure will be described with reference to the flowchart of FIG.
[0030]
Here, the recommended setting range is set as follows, for example. First, the parameters h and v are sequentially changed within the maximum variable range, the HD signal is sequentially generated by the image signal processing unit 110 as shown in FIG. 1, and the SN ratio data is acquired from the HD signal (step ST31). As shown in FIG. 7, a three-dimensional matrix showing a change in the SN ratio corresponding to each value of h and v is displayed (step ST32). Here, the SN ratio draws a curve that rises to the right from strong to weak on both axes of the parameters h and v.
[0031]
Next, the recommended SN ratio is limited (step ST33), and the ranges ax to bx and the ranges ay to by v corresponding to the recommended SN ratio are set as recommended setting ranges (step ST34).
[0032]
Further, the user can set the values of the parameters h and v by operating the joystick 202 while the setting display unit 115 is displayed. In that case, the display position of the icon 116 of the setting display unit 115 changes with the change of the values of the parameters h and v. At this time, the values of the parameters h and v may be further displayed numerically. Thereby, the user can know the change of the values of the parameters h and v accurately.
[0033]
Here, the input signals x and y for changing the values of the parameters h and v by operating the joystick 202 are, for example, 8-bit digital signals, and represent numbers from 0 to 255.
[0034]
When it is not selected to enjoy the recommended setting range, as shown in FIG. 8A, 0 to 255 of the input signals x and y are made to correspond to 0 to 8 of the parameters h and v, and within the maximum variable range. Is settable (step ST6). In this case, the change in the values of h and v when the input signals x and y change by 1 are both 8/255. Therefore, in this case, the input signals x and y are linearly converted into h and v by the equations (a) and (b), respectively.
[0035]
h = 8x / 255 (a)
v = 8y / 255 (b)
[0036]
Also, when it is selected to enjoy the recommended setting range, as shown in FIG. 8B, the input signals x and y 0 to 255 correspond to the parameters h and v ax to bx and ay to by. Then, a setting is possible within the recommended setting range (step ST8). In this case, changes in the values of h and v when the input signals x and y change by 1 are (bx−ax) / 255 and (by−ay) / 255, respectively. Therefore, in this case, the input signals x and y are linearly converted into h and v by the equations (c) and (d), respectively.
[0037]
h = (bx−ax) · x / 255 + ax (c)
v = (by−ay) · y / 255 + ay (d)
[0038]
As described above, the change in the values of h and v when the input signals x and y change by 1 when the enjoyment of the recommended setting range is selected is the case where the enjoyment of the recommended setting range is not selected. When the selection of enjoying the recommended setting range is smaller than the change of the values of h and v, the values of h and v can be set finely as compared with the case where it is not selected.
[0039]
(3) When the operation switch 204 is depressed for the third time (step ST9), the resolution values h and v indicated by the icon 116 at that time are determined as new setting values hn and vn (step ST10). In this case, new set values hn and vn are also stored in the memory in the system controller 101 in addition to the existing set values ho and vo.
[0040]
(4) When the operation switch 204 is depressed for the fourth time (step ST11), the image signal processing unit 110 sets the HD signal SHDo corresponding to the existing set values ho and vo or new set values hn and vn. The corresponding HD signal SHDn is output.
[0041]
At this time, for example, a selection display unit of “image quality confirmation: previous” is displayed on the display unit 201 of the remote control transmitter 200 and the display unit 111 of the television receiver 100 (step ST12). FIG. 9 shows the display unit 201 of the remote control transmitter 200.
[0042]
The user uses the movement key 203 to select “Previous” or “New”. For example, the default is “new”. The selected side is in a state surrounded by a frame, for example.
[0043]
When “Previous” is selected, the image signal processing unit 110 outputs the HD signal SHDo corresponding to the existing set values ho and vo (steps ST13 and ST15). In this case, the coefficient data of the estimation formula for calculating the HD pixel data is generated using the existing set values ho and vo. The display unit 111 displays an image based on the HD signal SHDo.
[0044]
In the state where “new” is selected, the image signal processing unit 110 outputs the HD signal SHDn corresponding to the new set values hn and vn (steps ST13 and ST14). In this case, the data generated using the new set values hn and vn is used as the coefficient data of the estimation formula for calculating the HD pixel data. The display unit 111 displays an image based on the HD signal SHDn.
[0045]
As described above, the user can view an image based on the HD signal SHDo or the HD signal SHDn on the display unit 111 by selecting “Previous” or “New”, and can compare the image quality of both.
[0046]
The image signal processing unit 110 does not output the HD signal SHDo or the HD signal SHDn according to the user's selection, for example, outputs the HD signal SHDo corresponding to the left half of the screen, and corresponds to the right half. Then, the HD signal SHDn may be output. In this case, an image based on the HD signal SHDo is displayed on the left half of the screen of the display unit 111, and an image based on the HD signal SHDn is displayed on the right half, and the user compares the image quality of both images on the same screen. it can.
[0047]
(5) When the operation switch 204 is depressed for the fifth time (step ST16), the user enters a state for setting whether or not the new set values hn and vn are set to the set values ho and vo. At this time, for example, a selection display unit of “position recording: OK NG” is displayed on the display unit 201 of the remote control transmitter 200 and the display unit 111 of the television receiver 100 (step ST17). FIG. 10 shows the display unit 201 of the remote control transmitter 200.
[0048]
The user uses the movement key 203 to select “OK” or “NG”. For example, the default is “NG”. The selected side is in a state surrounded by a frame, for example.
[0049]
When “NG” is selected, the set values ho and vo stored in the memory in the system controller 101 remain existing (steps ST18 and ST19). On the other hand, when “OK” is selected, new setting values hn and vn are stored as setting values ho and vo in the memory in the system controller 101 in place of the existing setting values ho and vo. (Step ST18, 20).
[0050]
In this way, when the new setting values hn and vn are stored in the memory as the setting values ho and vo in place of the existing setting values ho and vo, the system uses the past fixed number of setting values ho and vo as the history. It may be left in the memory in the controller 101. By leaving the history in this way, the user can select and use arbitrary set values ho and vo from the constant set values ho and vo in the past.
[0051]
(6) When the operation switch 204 is pushed down for the sixth time (step ST21), it returns to the original state even if the setting mode is canceled (steps ST22 and ST23).
[0052]
In the user interface example described above, the setting display unit 115 and various selection display units are displayed on both the display unit 201 of the remote control transmitter 200 and the display unit 111 of the television receiver 100. You may make it display only on one side.
[0053]
FIG. 11 shows another example of the user interface for setting the values of the parameters h and v. In FIG. 11, parts corresponding to those in FIG. 4 are denoted by the same reference numerals. The remote control transmitter 200 includes a joystick 202, up / down / left / right movement keys 203, an operation switch 204 used when setting values of parameters h and v, and other operation key groups 205. The setting operation will be described with reference to the flowcharts of FIGS.
[0054]
(1) The system controller 101 shifts to the setting mode when the operation switch 204 is depressed for the first time (step ST41). When the setting mode is entered, the setting display unit 115 and the menu display unit 117 for setting the values of the parameters h and v are displayed on the display unit 111 of the television receiver 100 (step ST42). On the setting display section 115, the existing setting values ho and vo are displayed with black circle icons 116. The existing set values ho and vo may be further displayed numerically.
[0055]
In the menu display section 117, “recommended range” is initially selected. The default is “OFF”. The selected side is in a state surrounded by a frame, for example. The user uses the movement key 203 to select “ON” or “OFF”. The range of h and v in the setting display unit 115 in a state where “OFF” is selected is 0 to 8 which is the maximum variable range. The range of h and v in the setting display unit 115 in a state where “ON” is selected is also a maximum variable range of 0 to 8, and is identified by dividing the recommended setting range 115a with a boundary line or changing the display color. Display is possible (see FIG. 5C).
[0056]
In this state, the user can set the values of the parameters h and v by operating the joystick 202. In that case, the display position of the icon 116 of the setting display unit 115 changes with the change of the values of the parameters h and v. At this time, the values of the parameters h and v may be further displayed numerically. Thereby, the user can know the change of the values of the parameters h and v accurately.
[0057]
Here, the input signals x and y for changing the values of the parameters h and v by operating the joystick 202 are, for example, 8-bit digital signals, and represent numbers from 0 to 255. In this state, 0 to 255 of the input signals x and y correspond to 0 to 8 of h and v. In this case, the change in the values of h and v when the input signals x and y change by 1 are both 8/255. Therefore, in this case, the input signals x and y are linearly converted into h and v by the above-described equations (a) and (b), respectively (see FIG. 8A).
[0058]
When “OFF” is selected in “Recommended range”, h and v can be set within the maximum variable range (steps ST43 and 44). When “ON” is selected in the “recommended range”, h and v can be set within the recommended setting range (steps ST43, 46, and 48). That is, h and v are regulated within the ranges of ax ≦ h ≦ bx and ay ≦ h ≦ by.
[0059]
(2) Next, a case where the user selects the “maximize” item on the menu display unit 117 will be described. In this state, the user uses the movement key 203 to select “ON” or “OFF”. For example, the default is “OFF”. The selected side is in a state surrounded by a frame, for example. This “maximization” item affects only when “ON” is selected in the “recommended range” item described above.
[0060]
When “ON” is selected in the “Recommended range” item and “ON” is selected in “Maximize”, the range of h in the setting display unit 115 is the recommended setting range ax to bx, and v Is a recommended setting range ay to by (steps ST45 and 47). Even in this state, the user can set the values of the parameters h and v by operating the joystick 202. In this case, 0 to 255 of the input signals x and y correspond to ax to bx and ay to by of h and v. In this case, the changes in the values of the parameters h and v when the input signals x and y are changed by 1 are (bx−ax) / 255 and (by−ay) / 255, respectively (step ST48). Therefore, in this case, the input signals x and y are linearly converted into h and v by the above-described equations (c) and (d), respectively (see FIG. 8B).
[0061]
Thus, when “ON” is selected in “maximization”, the change in the values of the parameters h and v when the input signals x and y are changed by 1 is small compared to the case where it is not selected. Accordingly, the values of parameters h and v can be set finely. Further, in this case, since the entire input signals x and y of 0 to 255 correspond to the recommended setting range, there is no useless portion for the user's operation with, for example, the joystick 202, and the operability is improved.
[0062]
(3) Next, a case where the user selects the “position determination” item on the menu display unit 117 will be described. In this case, the values of the parameters h and v indicated by the icon 116 at that time are determined as new setting values hn and vn (steps ST49 and 50). In this case, new set values hn and vn are also stored in the memory in the system controller 101 in addition to the existing set values ho and vo.
[0063]
(4) Next, a case where the user selects the “image quality check” item on the menu display unit 117 will be described. In this state, the user uses the movement key 203 to select “Previous” or “New”. For example, the default is “new”. The selected side is in a state surrounded by a frame, for example.
[0064]
When “Previous” is selected, the HD signal SHDo corresponding to the existing set values ho and vo is output from the image signal processing unit 110 for a predetermined time (steps ST51 and ST55). In this case, the coefficient data of the estimation formula for calculating the HD pixel data is generated using the existing set values ho and vo. The display unit 111 displays an image based on the HD signal SHDo.
[0065]
When “new” is selected, the HD signal SHDn corresponding to the new set values hn and vn is output from the image signal processing unit 110 for a predetermined time thereafter (steps ST52 and 54). In this case, the data generated using the new set values hn and vn is used as the coefficient data of the estimation formula for calculating the HD pixel data. The display unit 111 displays an image based on the HD signal SHDn.
[0066]
As described above, the user can view an image based on the HD signal SHDo or the HD signal SHDn on the display unit 111 by selecting “Previous” or “New”, and can compare the image quality of both. In addition, when displaying an image on the display unit 111 in this manner, the display of the setting display unit 115 and the menu display unit 117 is turned off because it is in the way. Then, the display of the setting display unit 115 and the menu display unit 117 is restored after a predetermined time when the image display ends.
[0067]
It should be noted that the image signal processing unit 110 does not output the HD signal SHDo or the HD signal SHDn according to the user's selection, but when the “image quality check” item is selected, a predetermined time, for example, the left half of the screen The HD signal SHDo may be output in correspondence with the right and the HD signal SHDn may be output in correspondence with the right half. In this case, an image based on the HD signal SHDo is displayed on the left half of the screen of the display unit 111, and an image based on the HD signal SHDn is displayed on the right half, and the user compares the image quality of both images on the same screen. it can.
[0068]
(5) Next, a case where the user selects the “position recording” item on the menu display unit 117 will be described. The user uses the movement key 203 to select “OK” or “NG”. For example, the default is “NG”. The selected side is in a state surrounded by a frame, for example.
[0069]
When “NG” is selected, the setting values ho and vo stored in the memory in the system controller 101 remain existing (steps ST53, 56, and 57). On the other hand, when “OK” is selected, new setting values hn and vn are stored as setting values ho and vo in the memory in the system controller 101 in place of the existing setting values ho and vo. (Steps ST53, 56, 58).
[0070]
In this way, when the new setting values hn and vn are stored in the memory as the setting values ho and vo in place of the existing setting values ho and vo, the system uses the past fixed number of setting values ho and vo as the history. It may be left in the memory in the controller 101. By leaving the history in this way, the user can select and use arbitrary set values ho and vo from the constant set values ho and vo in the past.
[0071]
(6) Next, a case where the user selects the “end” item on the menu display unit 117 will be described. In this case, even if the setting mode is canceled, the original state is restored (steps ST59 to ST61).
[0072]
In the user interface example described above, the user has changed the h and v by operating the joystick 202 of the remote control transmitter 200. For example, a gyro or the like is incorporated in the remote control transmitter 200 and the remote control transmitter 200 is incorporated. H and v may be changed using the physical movement information. Further, for example, a mouse may be connected to the system controller 101 of the television receiver 100, and h and v may be changed by clicking the mouse. Further, for example, the remote control transmitter 200 may be provided with a rotary knob such as an up key, a down key, or a jog dial for changing h and v.
[0073]
Next, details of the image signal processing unit 110 will be described. The image signal processing unit 110 selectively extracts data of a plurality of SD pixels located around the target pixel related to the HD signal (1050i signal) from the SD signal (525i signal) stored in the buffer memory 109. Output first to third tap selection circuits 121 to 123.
[0074]
The first tap selection circuit 121 selectively extracts data of SD pixels (referred to as “prediction taps”) used for prediction. The second tap selection circuit 122 selectively extracts data of SD pixels (referred to as “space class taps”) used for class classification corresponding to the level distribution pattern of the SD pixel data. The third tap selection circuit 123 selectively extracts data of SD pixels (referred to as “motion class taps”) used for class classification corresponding to motion. When the space class is determined using SD pixel data belonging to a plurality of fields, motion information is also included in this space class.
[0075]
Further, the image signal processing unit 110 detects the level distribution pattern of the space class tap data (SD pixel data) selectively extracted by the second tap selection circuit 122, and determines the space class based on the level distribution pattern. It has a spatial class detection circuit 124 that detects and outputs the class information.
[0076]
In the space class detection circuit 124, for example, an operation is performed to compress each SD pixel data from 8-bit data to 2-bit data. The space class detection circuit 124 outputs compressed data corresponding to each SD pixel data as class information of the space class. In the present embodiment, data compression is performed by ADRC (Adaptive Dynamic Range Coding). As the information compression means, DPCM (predictive coding), VQ (vector quantization), or the like may be used in addition to ADRC.
[0077]
Originally, ADRC is an adaptive requantization method developed for high performance coding for VTR (Video Tape Recorder), but it can efficiently express local patterns of signal level with short word length. It is suitable for use in data compression. When ADRC is used, the maximum value of space class tap data (SD pixel data) is MAX, the minimum value is MIN, the dynamic range of space class tap data is DR (= MAX−MIN + 1), and the number of requantization bits Is P, the requantized code qi as compressed data is obtained by the calculation of the equation (1) for each SD pixel data ki as the space class tap data. However, in the expression (1), [] means a truncation process. When there are Na SD pixel data as the space class tap data, i = 1 to Na.
[0078]
qi = [(ki-MIN + 0.5). 2^P/ DR] (1)
[0079]
The image signal processing unit 110 detects a motion class mainly representing the degree of motion from the motion class tap data (SD pixel data) selectively extracted by the third tap selection circuit 123, and A motion class detection circuit 125 that outputs class information is provided.
[0080]
In the motion class detection circuit 125, the inter-frame difference is calculated from the motion class tap data (SD pixel data) mi, ni selectively extracted by the third tap selection circuit 123, and the average of absolute values of the differences is calculated. Threshold processing is performed on the value to detect a motion class that is an index of motion. That is, in the motion class detection circuit 125, the average value AV of the absolute value of the difference is calculated by the equation (2). When the third tap selection circuit 123 extracts, for example, six SD pixel data m1 to m6 and six SD pixel data n1 to n6 one frame before as class tap data, the equation (2) Nb in is 6.
[0081]
[Expression 1]

[0082]
Then, in the motion class detection circuit 125, the average value AV calculated as described above is compared with one or a plurality of threshold values to obtain class information MV of the motion class. For example, three thresholds th1, th2, th3 (th1 <th2 <th3) are prepared, and when four motion classes are detected, when AV ≦ th1, MV = 0 and th1 <AV ≦ th2 Is MV = 2 when MV = 1, th2 <AV ≦ th3, and MV = 3 when th3 <AV.
[0083]
Also, the image signal processing unit 110 is based on the requantization code qi as the class information of the space class output from the space class detection circuit 124 and the class information MV of the motion class output from the motion class detection circuit 125. A class combining circuit 126 for obtaining a class code CL indicating a class to which a pixel (target pixel) of an HD signal (1050i signal) to be created belongs is provided.
[0084]
In the class synthesis circuit 126, the calculation of the class code CL is performed by the equation (3). In equation (3), Na represents the number of space class tap data (SD pixel data), and P represents the number of requantization bits in ADRC.
[0085]
[Expression 2]

[0086]
The image signal processing unit 110 has a coefficient memory 134. The coefficient memory 134 stores coefficient data of an estimation formula used in an estimated prediction calculation circuit 127 described later for each class. This coefficient data is information for converting an SD signal (525i signal) into an HD signal (1050i signal). The class code CL output from the class synthesis circuit 126 described above is supplied to the coefficient memory 134 as read address information. Coefficient data corresponding to the class code CL is read from the coefficient memory 134, and the estimated prediction calculation circuit 127. Will be supplied.
[0087]
Further, the image signal processing unit 110 has an information memory bank 135. In this information memory bank, coefficient seed data of each class is stored in advance. The coefficient seed data is coefficient data of a generation formula for generating coefficient data to be stored in the coefficient memory 134 described above.
[0088]
In the estimated prediction calculation circuit 127 described later, the HD pixel data y to be generated is calculated from the prediction tap data (SD pixel data) xi and the coefficient data Wi read from the coefficient memory 134 by the estimation expression (4). Calculated. When the number of prediction taps selected by the first tap selection circuit 121 is 10, n in Equation (4) is 10.
[0089]
[Equation 3]

[0090]
Then, the coefficient data Wi (i = 1 to n) of this estimation formula is generated by a generation formula including parameters h and v indicating horizontal and vertical resolutions as shown in the formula (5). In the information memory bank 135, coefficient seed data w which is coefficient data of this generation formula is stored._Ten~ W_n9Is stored for each class. A method for generating the coefficient seed data will be described later.
[0091]
[Expression 4]

[0092]
Further, the image signal processing unit 110 uses the coefficient seed data of each class and the values of the parameters h and v, and the coefficient data Wi of the estimation formula corresponding to the values of the parameters h and v for each class according to the equation (5). A coefficient generation circuit 136 that generates (i = 1 to n) is included. The coefficient generation circuit 136 is loaded with the above-described coefficient seed data of each class from the information memory bank 135. The coefficient generation circuit 136 is supplied with values of parameters h and v from the system controller 101.
[0093]
Here, the values of the parameters h and v supplied from the system controller 101 to the coefficient generation circuit 136 are the existing setting values ho and vo, the new setting values hn, and the like when the image quality is confirmed in the setting mode described above. In the state where vn and the setting mode is released, the setting values are ho and vo. The coefficient data Wi (i = 1 to n) of each class generated by the coefficient generation circuit 136 is stored in the coefficient memory 134 described above.
[0094]
Further, the image signal processing unit 110 calculates a normalization coefficient S corresponding to the coefficient data Wi (i = 1 to n) of each class generated by the coefficient generation circuit 136 according to the expression (6). A generation circuit 137 and a normalization coefficient memory 138 that stores the normalization coefficient S generated here for each class are provided. The normalization coefficient memory 138 is supplied with the class code CL output from the above class synthesis circuit 126 as read address information, and the normalization coefficient S corresponding to the class code CL is read from the normalization coefficient memory 138. This is supplied to the normalization operation circuit 128 described later.
[0095]
[Equation 5]

[0096]
Further, the image signal processing unit 110 generates an HD to be generated from the prediction tap data (SD pixel data) xi selectively extracted by the first tap selection circuit 121 and the coefficient data Wi read from the coefficient memory 134. An estimated prediction calculation circuit 127 that calculates data of a signal pixel (target pixel) is provided.
[0097]
As described above, when the SD signal (525i signal) is converted to the HD signal (1050i signal), it is necessary to obtain four pixels of the HD signal for one pixel of the SD signal. In the circuit 127, pixel data is generated for each 2 × 2 unit pixel block constituting the HD signal. That is, in the estimated prediction calculation circuit 127, the first tap selection circuit 121 configures the prediction pixel data xi corresponding to the four pixels (target pixel) in the unit pixel block and the unit memory block from the coefficient memory 134. The coefficient data Wi corresponding to the four pixels to be supplied is supplied, and the data y of the four pixels constituting the unit pixel block₁~ Y_FourAre individually calculated by the estimation equation (4) described above.
[0098]
The image signal processing unit 110 also outputs 4-pixel data y sequentially output from the estimated prediction calculation circuit 127.₁~ Y_FourIs normalized by dividing by the normalization coefficient S corresponding to the coefficient data Wi (i = 1 to n) used for each calculation. is doing. Although not described above, the coefficient generation circuit 136 obtains the coefficient data Wi of the estimation formula from the coefficient seed data by the generation formula. The generated coefficient data includes a rounding error, and the coefficient data Wi (i = 1 to n). Is not guaranteed to be 1.0. Therefore, the data y of each pixel calculated by the estimated prediction calculation circuit 127₁~ Y_FourBecomes a level fluctuation due to a rounding error. As described above, normalization by the normalization arithmetic circuit 128 can eliminate the fluctuation.
[0099]
The image signal processing unit 110 also normalizes the data y of four pixels in the unit pixel block that is normalized by the normalization calculation circuit 128 and sequentially supplied.₁′ 〜Y_Four′ Is line-sequentially processed and output in the format of a 1050i signal.
[0100]
Next, the operation of the image signal processing unit 110 will be described.
[0101]
From the SD signal (525i signal) stored in the buffer memory 109, the second tap selection circuit 122 uses the second tap selection circuit 122 to surround the four pixels (target pixel) in the unit pixel block constituting the HD signal (1050i signal) to be created The data of the space class tap located at (SD pixel data) is selectively extracted. The space class tap data (SD pixel data) selectively extracted by the second tap selection circuit 122 is supplied to the space class detection circuit 124. In this space class detection circuit 124, each of the SD pixel data as space class tap data is subjected to ADRC processing and re-used as class information of the space class (mainly class classification for waveform expression in space). A quantization code qi is obtained (see equation (1)).
[0102]
In addition, from the SD signal (525i signal) stored in the buffer memory 109, the third tap selection circuit 123 uses the four pixels (target pixel) in the unit pixel block constituting the HD signal (1050i signal) to be created. The data (SD pixel data) of the motion class tap located in the vicinity of is selectively extracted. The motion class tap data (SD pixel data) selectively extracted by the third tap selection circuit 123 is supplied to the motion class detection circuit 125. In this motion class detection circuit 125, class information MV of a motion class (mainly class classification for representing the degree of motion) is obtained from each SD pixel data as motion class tap data.
[0103]
The motion information MV and the above-described requantization code qi are supplied to the class synthesis circuit 126. In this class synthesizing circuit 126, from these motion information MV and requantization code qi, for each unit pixel block constituting the HD signal (1050i signal) to be created, four pixels (target pixel) in the unit pixel block are obtained. A class code CL indicating the class to which it belongs is obtained (see equation (3)). The class code CL is supplied to the coefficient memory 134 and the normalized coefficient memory 138 as read address information.
[0104]
In the coefficient memory 134, coefficient data Wi (i = 1 to n) of the estimation formula of each class corresponding to the values of the parameters h and v is generated and stored by the coefficient generation circuit 136. In the normalized coefficient memory 138, the normalized coefficient S corresponding to the coefficient data Wi (i = 1 to n) of each class generated by the coefficient generation circuit 136 as described above is stored in the normalized coefficient calculation unit 137. Generated and stored.
[0105]
As described above, the class code CL is supplied to the coefficient memory 134 as read address information, whereby the coefficient data Wi corresponding to the class code CL is read from the coefficient memory 134 and supplied to the estimated prediction calculation circuit 127. . Further, the four pixels (target pixel) in the unit pixel block constituting the HD signal (1050i signal) to be created by the first tap selection circuit 121 from the SD signal (525i signal) stored in the buffer memory 109. Prediction tap data (SD pixel data) located in the vicinity of the area is selectively extracted. The prediction tap data (SD pixel data) xi selectively extracted by the first tap selection circuit 121 is supplied to the estimated prediction calculation circuit 127.
[0106]
In the estimated prediction calculation circuit 127, four pixels in the unit pixel block constituting the HD signal to be created from the prediction tap data (SD pixel data) xi and the coefficient data Wi for four pixels read from the coefficient memory 134. Data of (attention pixel) y₁~ Y_FourAre calculated simultaneously (see equation (4)). Then, the data y of the four pixels in the unit pixel block constituting the HD signal sequentially output from the estimated prediction calculation circuit 127.₁~ Y_FourIs supplied to the normalization operation circuit 128.
[0107]
As described above, the class code CL is supplied to the normalization coefficient memory 138 as read address information, and is output from the normalization coefficient S corresponding to the class code CL, that is, the estimated prediction calculation circuit 127. HD pixel data y₁~ Y_FourThe normalization coefficient S corresponding to the coefficient data Wi used for the calculation is read out and supplied to the normalization calculation circuit 128. In the normalization operation circuit 128, the HD pixel data y output from the estimated prediction operation circuit 127 is displayed.₁~ Y_FourAre each divided by the corresponding normalization factor S and normalized. As a result, the data y due to the rounding error when the coefficient data of the estimation formula (see formula (4)) is obtained by the generation formula (see formula (5)) using the coefficient seed data.₁~ Y_FourLevel fluctuations are eliminated.
[0108]
In this way, the data y of the four pixels in the unit pixel block which are normalized by the normalization operation circuit 128 and sequentially output.₁′ 〜Y_Four'Is supplied to the post-processing circuit 129. In the post-processing circuit 129, data y of four pixels in the unit pixel block sequentially supplied from the normalization arithmetic circuit 128 is obtained.₁′ 〜Y_Four'Is line-sequentialized and output in the format of a 1050i signal. That is, the post-processing circuit 129 outputs a 1050i signal as an HD signal.
[0109]
As described above, the coefficient generation circuit 136 uses the coefficient seed data loaded from the information memory bank 135, and for each class, coefficient data Wi (() of the estimation formula corresponding to the set values ho and vo of the parameters h and v. i = 1 to n) are generated and stored in the coefficient memory 134. Then, the HD pixel data y is calculated by the estimated prediction calculation circuit 127 using the coefficient data Wi (i = 1 to n) read from the coefficient memory 134 corresponding to the class code CL. Therefore, the user can arbitrarily adjust the horizontal and vertical image quality of the image obtained by the HD signal by setting the values of the parameters h and v in the setting mode described above.
[0110]
Further, when setting the values of the parameters h and v, the user can select to enjoy the above recommended setting range. In that case, the values of the parameters h and v set by the user are regulated within the recommended setting range, and the image quality of the image by the HD signal output from the image signal processing unit 110 is not significantly degraded. The user can effectively set the values of the parameters h and v.
[0111]
In addition, when the user enjoys the recommended setting range when setting the values of the parameters h and v, the input signals x and y of 0 to 255 further correspond to the parameters h and v of ax to bx and ay to by. By doing so, the change (setting step width) of h and v when the input signals x and y change by 1 can be reduced, and the values of the parameters h and v can be set finely. In this case, since the entire input signals x and y of 0 to 255 correspond to the recommended setting range, there is no useless portion for the user's operation with the joystick 202 or the like, and the operability is improved.
[0112]
In the above description, only one recommended setting range is set in advance. However, information on a plurality of recommended setting ranges is stored in a memory or the like in the system controller 101, and the user can arbitrarily select one of them. The recommended setting range may be selected and used. For example, referring to the three-dimensional matrix display of FIG. 7, recommended setting ranges of “clean”, “normal”, and “noisy” in which the range gradually increases can be prepared in advance.
[0113]
In the above description, the coefficient data Wi (i = 1 to n) is generated using the equation (5), but other polynomials having different orders and equations expressed by other functions are used. You can also
[0114]
As described above, coefficient seed data is stored in the information memory bank 135 for each class. This coefficient seed data is generated by learning in advance.
[0115]
First, an example of this generation method will be described. Here, coefficient seed data w which is coefficient data in the generation formula of formula (5)_Ten~ W_n9The example which calculates | requires is shown.
[0116]
Here, for the following explanation, ti (i = 0 to 9) is defined as in the equation (7).
[0117]

[0118]
Using this equation (7), equation (5) can be rewritten as equation (8).
[0119]
[Formula 6]

[0120]
Finally, the undetermined coefficient w_xyAsk for. That is, for each class, a coefficient value that minimizes the square error is determined using a plurality of SD pixel data and HD pixel data. This is a so-called least square method. The learning number is m, and the residual in the kth learning data (1 ≦ k ≦ m) is e._kWhen E is the sum of the square errors, E is expressed by equation (9) using equations (4) and (5). Where x_ikIs the k-th pixel data at the i-th predicted tap position of the SD image, y_kRepresents pixel data of the k-th HD image corresponding thereto.
[0121]
[Expression 7]

[0122]
In the least square method, w in equation (9)_xyW such that the partial differential due to becomes zero_xyAsk for. This is shown by equation (10).
[0123]
[Equation 8]

[0124]
Hereinafter, as in the equations (11) and (12), X_ipjq, Y_ipIs defined, equation (10) can be rewritten as equation (13) using a matrix.
[0125]
[Equation 9]

[0126]
[Expression 10]

[0127]
This equation is generally called a normal equation. This normal equation can be calculated using the sweep-out method (Gauss-Jordan elimination method), etc._xyThe coefficient seed data is calculated.
[0128]
FIG. 14 shows the concept of the above-described coefficient seed data generation method. A plurality of SD signals are generated from the HD signal. For example, a total of 81 types of SD signals are generated by varying the values of parameters h and v for varying the horizontal band and vertical band of the filter used when generating the SD signal from the HD signal in 9 stages. . Learning is performed between the plurality of SD signals generated in this way and the HD signal to generate coefficient seed data.
[0129]
FIG. 15 shows a configuration of a coefficient seed data generation device 150 that generates coefficient seed data based on the above-described concept.
[0130]
The coefficient seed data generation device 150 performs an horizontal thinning process and a vertical thinning process on an input terminal 151 to which an HD signal (1050i signal) as a teacher signal is input, and an SD signal as a student signal. And an SD signal generation circuit 152 for obtaining (525i signal).
[0131]
The SD signal generation circuit 152 is supplied with parameters h and v as control signals. Corresponding to the parameters h and v, the horizontal band and the vertical band of the filter used when generating the SD signal from the HD signal are varied. Here, some examples of the details of the filter are shown.
[0132]
For example, it can be considered that the filter is composed of a band filter for limiting the horizontal band and a band filter for limiting the vertical band. In this case, as shown in FIG. 16, a frequency characteristic corresponding to the stepped value of the parameter h or v is designed and subjected to inverse Fourier transform to thereby generate a frequency characteristic corresponding to the stepped value of the parameter h or v. Can be obtained.
[0133]
For example, it is conceivable that the filter is composed of a one-dimensional Gaussian filter that limits the horizontal band and a one-dimensional Gaussian filter that limits the vertical band. This one-dimensional Gaussian filter is expressed by equation (14). In this case, a one-dimensional Gaussian filter having a frequency characteristic corresponding to the stepped value of the parameter h or v is obtained by changing the value of the standard deviation σ stepwise corresponding to the stepped value of the parameter h or v. Obtainable.
[0134]
[Expression 11]

[0135]
Further, for example, it is conceivable that the filter is constituted by a two-dimensional filter F (h, v) in which horizontal and vertical frequency characteristics are determined by both parameters h and v. This two-dimensional filter generation method, like the above-described one-dimensional filter, designs a two-dimensional frequency characteristic corresponding to the stepwise values of the parameters h and v, and performs a two-dimensional inverse Fourier transform to thereby create a parameter. A two-dimensional filter having a two-dimensional frequency characteristic corresponding to the stepwise values of h and v can be obtained.
[0136]
Further, the coefficient seed data generation device 150 selects data of a plurality of SD pixels located around the target pixel related to the HD signal (1050i signal) from the SD signal (525i signal) output from the SD signal generation circuit 152. The first to third tap selection circuits 153 to 155 for taking out and outputting the data are provided. These first to third tap selection circuits 153 to 155 are configured similarly to the first to third tap selection circuits 121 to 123 of the image signal processing unit 110 described above.
The coefficient seed data generation device 150 detects the level distribution pattern of the space class tap data (SD pixel data) selectively extracted by the second tap selection circuit 154, and the space class based on the level distribution pattern. And a space class detection circuit 157 for outputting the class information. The space class detection circuit 157 is configured in the same manner as the space class detection circuit 124 of the image signal processing unit 110 described above. From this space class detection circuit 157, a requantization code qi for each SD pixel data as space class tap data is output as class information indicating a space class.
[0137]
The coefficient seed data generation device 150 detects a motion class mainly representing the degree of motion from the motion class tap data (SD pixel data) selectively extracted by the third tap selection circuit 155, A motion class detection circuit 158 that outputs the class information MV is provided. The motion class detection circuit 158 is configured in the same manner as the motion class detection circuit 125 of the image signal processing unit 110 described above. In this motion class detection circuit 158, the inter-frame difference is calculated from the motion class tap data (SD pixel data) selectively extracted by the third tap selection circuit 155, and the difference between the absolute values of the absolute values of the difference is calculated. Then, threshold processing is performed to detect a motion class that is an index of motion.
[0138]
Also, the coefficient seed data generation device 150 is based on the requantization code qi as the class information of the space class output from the space class detection circuit 157 and the class information MV of the motion class output from the motion class detection circuit 158. And a class synthesis circuit 159 for obtaining a class code CL indicating a class to which the target pixel relating to the HD signal (525p signal or 1050i signal) belongs. The class synthesis circuit 159 is also configured similarly to the class synthesis circuit 126 of the image signal processing unit 110 described above.
[0139]
Also, the coefficient seed data generation device 150 selects each HD pixel data y as target pixel data obtained from the HD signal supplied to the input terminal 151, and a first tap selection corresponding to each HD pixel data y. From the prediction tap data (SD pixel data) xi selectively extracted by the circuit 153, the class code CL output from the class synthesis circuit 159 corresponding to each HD pixel data y, and the parameters h and v, Coefficient seed data w for each class_Ten~ W_n9A normal equation generation unit 160 that generates a normal equation (see equation (13)) for obtaining
[0140]
In this case, learning data is generated by a combination of one HD pixel data y and n prediction tap pixel data corresponding thereto, but the parameters h and v to the SD signal generation circuit 152 are sequentially changed. A plurality of SD signals in which the horizontal and vertical bands change stepwise are sequentially generated, whereby the normal equation generation unit 160 generates a normal equation in which a large amount of learning data is registered.
[0141]
Here, the coefficient seed data calculated by learning between the HD signal and the SD signal generated by applying a narrow band filter from the HD signal is used to obtain a high-resolution HD signal. Conversely, coefficient seed data calculated by learning between an HD signal and an SD signal generated by applying a filter having a wide band from the HD signal is used to obtain an HD signal having a low resolution. As described above, by sequentially generating a plurality of SD signals and registering learning data, it is possible to obtain coefficient seed data for obtaining HD signals with continuous resolution.
[0142]
Although not shown in the figure, SD pixel data supplied from the first tap selection circuit 153 to the normal equation generation unit 160 by arranging a delay circuit for time adjustment in the preceding stage of the first tap selection circuit 153. xi timing can be adjusted.
[0143]
Also, the coefficient seed data generation device 150 is supplied with the data of the normal equation generated for each class by the normal equation generation unit 160, solves the normal equation for each class, and generates the coefficient seed data w for each class._Ten~ W_n9The coefficient seed data determination unit 161 for determining the coefficient seed data w_Ten~ W_n9Is stored in the coefficient seed memory 162. In the coefficient seed data determination unit 161, the normal equation is solved by, for example, a sweeping method, and the coefficient data w_Ten~ W_n9Is required.
[0144]
The operation of the coefficient seed data generation device 150 shown in FIG. 15 will be described. An HD signal (1050i signal) as a teacher signal is supplied to the input terminal 151, and the HD signal is subjected to horizontal and vertical thinning processing by the SD signal generation circuit 152, and an SD signal (525i) as a student signal. Signal) is generated. In this case, parameters h and v are supplied as control signals to the SD signal generation circuit 152, and a plurality of SD signals whose horizontal and vertical bands change stepwise are sequentially generated.
[0145]
From this SD signal (525i signal), the second tap selection circuit 154 selectively extracts data of the space class tap (SD pixel data) located around the target pixel related to the HD signal (1050i signal). The space class tap data (SD pixel data) selectively extracted by the second tap selection circuit 154 is supplied to the space class detection circuit 157. In this space class detection circuit 157, each SD pixel data as space class tap data is subjected to ADRC processing to be re-used as class information of a space class (mainly class classification for waveform expression in space). A quantization code qi is obtained (see equation (1)).
[0146]
Further, from the SD signal generated by the SD signal generation circuit 152, the third tap selection circuit 155 selectively extracts data of the motion class tap (SD pixel data) located around the target pixel related to the HD signal. It is. The motion class tap data (SD pixel data) selectively extracted by the third tap selection circuit 155 is supplied to the motion class detection circuit 158. In this motion class detection circuit 158, class information MV of a motion class (mainly class classification for representing the degree of motion) is obtained from each SD pixel data as motion class tap data.
[0147]
The motion information MV and the above-described requantization code qi are supplied to the class synthesis circuit 159. The class synthesis circuit 159 obtains a class code CL indicating the class to which the pixel of interest related to the HD signal (1050i signal) belongs from the motion information MV and the requantization code qi (see equation (3)).
[0148]
Further, from the SD signal generated by the SD signal generation circuit 152, the first tap selection circuit 153 selectively extracts data of prediction taps (SD pixel data) located around the target pixel related to the HD signal. . Then, each HD pixel data y as target pixel data obtained from the HD signal supplied to the input terminal 151 and the first tap selection circuit 153 are selectively extracted corresponding to each HD pixel data y. From the prediction tap data (SD pixel data) xi, the class code CL output from the class synthesis circuit 159 corresponding to each HD pixel data y, and the parameters h and v, the normal equation generation unit 160 determines the class. Coefficient seed data w for each_Ten~ W_n9A normal equation (see equation (13)) is generated.
[0149]
Then, the coefficient seed data determining unit 161 solves the normal equation, and the coefficient seed data w of each class._Ten~ W_n9Is obtained and its coefficient seed data w_Ten~ W_n9Is stored in the coefficient seed memory 162 that is address-divided by class.
[0150]
In the normal equation generation unit 160, learning data generated by a combination of the HD pixel data y and n prediction tap pixel data corresponding to the HD pixel data y is whether the HD pixel data y is an odd or even HD signal, Further, the HD signal (1050i signal) in each of the odd and even fields is configured by classification according to information on which of the four pixels in the 2 × 2 unit pixel block described above constitutes the HD signal. Coefficient seed data w corresponding to 4 pixels in a 2 × 2 unit pixel block_Ten~ W_n9Can be generated individually (see equation (13)).
[0151]
As a result, the coefficient seed data determination unit 161 performs coefficient seed data w corresponding to four pixels in the 2 × 2 unit pixel block constituting the HD signal (1050i signal) in each of the odd and even fields._Ten~ W_n9Can be obtained and stored in the coefficient seed memory 162.
[0152]
In the image signal processing unit 110 in FIG. 1, a plurality of feature amounts have horizontal and vertical resolutions. However, a plurality of feature amounts having a resolution and a noise suppression degree may be configured similarly. it can. In this case, the user sets the parameter r indicating the resolution and the value of the parameter z indicating the noise suppression degree (noise reduction degree) using a user interface as shown in FIG.
[0153]
17A and 17B show the setting display unit 115 displayed on the display unit 201 of the remote control transmitter 200 or the display unit 111 of the television receiver 100. The state shown in FIG. 17A is a state where the user is not selected to enjoy the recommended setting range. The state illustrated in FIG. 17B is a state in which the user is selected to enjoy the recommended setting range. In this case, the recommended setting range of the parameter r is ar ≦ r ≦ br, and the recommended setting range of the parameter z is az ≦ z ≦ bz. These recommended setting ranges can also be set based on, for example, the SN ratio (see FIG. 7).
[0154]
In this case, for example, the expression (15) can be used as a generation expression for generating the coefficient data Wi (i = 1 to n), and can be realized by a polynomial having a different degree or an expression expressed by another function. It is.
[0155]
[Expression 12]

[0156]
As described above, the coefficient seed data that is the coefficient data of the generation formula including the parameters r and z is similar to that in the case of generating the coefficient seed data that is the coefficient data of the generation formula including the parameters h and v described above. The coefficient seed data generator 150 shown in FIG. In this case, the parameters r and z are supplied as control signals to the SD signal generation circuit 152, and when the SD signal is generated from the HD signal corresponding to the values of the parameters r and z, The vertical band and the noise addition state for the SD signal are varied stepwise.
[0157]
FIG. 18 shows an example of SD signal generation corresponding to the values of the parameters r and z. In this example, the parameters r and z are varied in 9 steps, respectively, and a total of 81 types of SD signals are generated. Note that the parameters r and z may be changed to more stages than nine stages. In this case, the accuracy of the calculated coefficient seed data is improved, but the calculation amount is increased.
[0158]
Here, some examples of the details of the noise addition method corresponding to the value of the parameter z are shown.
[0159]
For example, as shown in FIG. 19A, a noise signal whose amplitude level is changed stepwise is added to the SD signal to generate an SD signal whose noise level changes stepwise.
[0160]
Also, for example, as shown in FIG. 19B, a noise signal having a constant amplitude level is added to the SD signal, but the screen area to be added is changed stepwise.
[0161]
Further, for example, as shown in FIG. 19C, as the SD signal (for one screen), a signal that does not include noise and a signal that includes noise are prepared. Then, when generating a normal equation, learning is performed a plurality of times for each SD signal.
[0162]
For example, in “noise 0”, learning is performed 100 times for an SD signal without noise, and in “noise i”, learning is performed 30 times for an SD signal without noise and for an SD signal with noise. Learn 70 times. In this case, “noise i” is a learning system for calculating coefficient seed data having a higher degree of noise suppression. In this way, coefficient seed data for obtaining a continuous noise suppression degree can be obtained by performing learning by changing the number of learnings for a no-noise and no-noise SD signal in stages.
[0163]
Further, in the image signal processing unit 110 of FIG. 1, a plurality of feature amounts are shown having horizontal and vertical resolutions, but a plurality of feature amounts are also horizontal and vertical resolutions and noise suppression degrees. Can be configured. In this case, the user sets the values of the parameters h and v indicating the horizontal and vertical resolutions and the parameter z indicating the noise suppression degree using a user interface as shown in FIG.
[0164]
20A and 20B show the setting display unit 115 displayed on the display unit 201 of the remote control transmitter 200 or the display unit 111 of the television receiver 100. 20A and 20B illustrate the recommended setting ranges for the three parameters. As the types of the three parameters, for example, a horizontal resolution h, a vertical resolution v, and a noise suppression degree z can be considered.
[0165]
The state illustrated in FIG. 20A is a state in which the user is not selected to enjoy the recommended setting range. The state illustrated in FIG. 20B is a state in which enjoying the recommended setting range is selected. Here, the parameters h and v can be changed by the movement of the joystick 202 in the horizontal and vertical directions, and the parameter z can be changed by the movement of the joystick 202 in an oblique direction.
[0166]
In this case, for example, the expression (16) can be used as a generation expression for generating the coefficient data Wi (i = 1 to n), and can be realized by a polynomial having a different order or an expression expressed by another function. It is.
[0167]
[Formula 13]

[0168]
As described above, the coefficient seed data that is the coefficient data of the generation formula including the parameters h, v, and z is similar to the case of generating the coefficient seed data that is the coefficient data of the generation formula including the parameters h and v described above. 15 can be generated by the coefficient seed data generating device 150 shown in FIG. In that case, the parameters h, v, and z are supplied as control signals to the SD signal generation circuit 152, and the SD signal is generated when an SD signal is generated from the HD signal corresponding to the values of the parameters h, v, and z. The horizontal and vertical bands of the signal and the noise addition state for the SD signal are varied in stages.
[0169]
FIG. 21 shows an example of SD signal generation corresponding to the values of parameters h, v, and z. In this example, the parameters h, v, and z are each changed in nine steps, and a total of 729 types of SD signals are generated. It should be noted that the parameters h, v, and z may be changed to more stages than nine stages. In this case, the accuracy of the calculated coefficient seed data is improved, but the calculation amount is increased.
[0170]
Note that the processing in the image signal processing unit 110 in FIG. 1 can be realized by software, for example, by an image signal processing device 300 as shown in FIG.
[0171]
First, the image signal processing apparatus 300 shown in FIG. 22 will be described. The image signal processing apparatus 300 includes a CPU 301 that controls the operation of the entire apparatus, a ROM (read only memory) 302 that stores an operation program of the CPU 301, coefficient seed data, and the like, and a RAM ( random access memory) 303. These CPU 301, ROM 302, and RAM 303 are each connected to a bus 304.
[0172]
The image signal processing apparatus 300 includes a hard disk drive (HDD) 305 as an external storage device and a floppy disk drive (FDD) 307 that drives the floppy disk 306. These drives 305 and 307 are each connected to a bus 304.
[0173]
In addition, the image signal processing apparatus 300 includes a communication unit 308 that is connected to a communication network 400 such as the Internet by wire or wirelessly. The communication unit 308 is connected to the bus 304 via the interface 309.
[0174]
In addition, the image signal processing device 300 includes a user interface unit. The user interface unit includes a remote control signal receiving circuit 310 that receives a remote control signal RM from the remote control transmitter 200, and a display 311 that includes an LCD (liquid crystal display) or the like. The receiving circuit 310 is connected to the bus 304 via the interface 312, and similarly the display 311 is connected to the bus 304 via the interface 313. The user can set the values of the parameters h and v described above using the user interface unit.
[0175]
The image signal processing apparatus 300 also has an input terminal 314 for inputting an SD signal and an output terminal 315 for outputting an HD signal. The input terminal 314 is connected to the bus 304 via the interface 316, and similarly, the output terminal 315 is connected to the bus 304 via the interface 317.
[0176]
Here, instead of storing the processing program, coefficient seed data, and the like in the ROM 302 in advance as described above, for example, they are downloaded from the communication network 400 such as the Internet via the communication unit 308 and stored in the hard disk or RAM 303 for use. You can also Further, these processing programs, coefficient seed data, and the like may be provided on the floppy disk 306.
[0177]
Further, instead of inputting the SD signal to be processed from the input terminal 314, it may be recorded in advance on a hard disk or downloaded from the communication network 400 such as the Internet via the communication unit 308. Also, instead of outputting the processed HD signal to the output terminal 315 or in parallel therewith, it is supplied to the display 311 to display an image, further stored in a hard disk, or via the communication unit 308 such as the Internet. It may be sent to the communication network 400.
[0178]
A processing procedure for obtaining an HD signal from an SD signal in the image signal processing apparatus 300 shown in FIG. 22 will be described with reference to the flowchart of FIG.
[0179]
First, in step ST1, processing is started, and in step ST2, SD pixel data is input in frame units or field units. When the SD pixel data is input from the input terminal 314, the SD pixel data is temporarily stored in the RAM 303. Further, when the SD pixel data is recorded on the hard disk, the SD pixel data is read by the hard disk drive 307 and temporarily stored in the RAM 303. In step ST3, it is determined whether or not processing of all frames or fields of input SD pixel data has been completed. When the process is finished, the process ends in step ST4. On the other hand, when the process is not finished, the process proceeds to step ST5.
[0180]
In step ST5, the values of the parameters h and v (image quality designation values) set by the user as described above are read from the RAM 303, for example. In step ST6, using the read image quality designation value and the coefficient seed data of each class, the coefficient data Wi of the estimation formula (see formula (4)) of each class is generated by a generation formula (for example, formula (5)). Is generated.
[0181]
Next, in step ST7, the pixel data of the class tap and the prediction tap is acquired from the SD pixel data input in step ST2 corresponding to each HD pixel data to be generated. In step ST8, it is determined whether or not the processing for obtaining HD pixel data has been completed in all areas of the input SD pixel data. If completed, the process returns to step ST2 and proceeds to the input process of SD pixel data of the next frame or field. On the other hand, when the process has not ended, the process proceeds to step ST9.
[0182]
In this step ST9, the class code CL is generated from the SD pixel data of the class tap acquired in step ST7. In step ST10, using the coefficient data corresponding to the class code CL and the SD pixel data of the prediction tap, HD pixel data is generated by the estimation formula, and then the process returns to step ST7 and is the same as described above. Repeat the process.
[0183]
In this way, by performing processing according to the flowchart shown in FIG. 23, it is possible to process the SD pixel data constituting the input SD signal and obtain HD pixel data constituting the HD signal. As described above, the HD signal obtained by such processing is output to the output terminal 315, supplied to the display 311 to display an image, and further supplied to the hard disk drive 305 to be stored on the hard disk. It is recorded.
[0184]
In the above-described embodiment, the linear equation is used as the estimation equation when generating the HD signal. However, the present invention is not limited to this, and for example, a higher-order equation is used as the estimation equation. It may be a thing.
[0185]
In the above-described embodiment, an example in which an SD signal (525i signal) is converted into an HD signal (1050i signal) has been described. However, the present invention is not limited to this, and the first equation is estimated using an estimation formula. Of course, the present invention can be similarly applied to other cases in which the image signal is converted into the second image signal.
[0186]
Further, in the above-described embodiment, the parameter indicating two or three feature values is set. However, the present invention is similarly applied to a parameter setting parameter indicating more feature values. be able to.
[0187]
In the above-described embodiment, coefficient seed data is stored in the information memory bank 135, and coefficient data corresponding to the values of the parameters h and v is generated by the coefficient generation circuit 136 using this coefficient seed data. Although the coefficient data is stored in the coefficient memory 134, a large amount of coefficient data corresponding to each combination of the parameters h and v is stored in the information memory bank 135, and the values of the parameters h and v are stored. The coefficient data corresponding to can be read from the information memory bank 135 and stored in the coefficient memory 134.
[0188]
Moreover, although the case where the information signal is an image signal has been shown in the above-described embodiment, the present invention is not limited to this. For example, the present invention can be similarly applied when the information signal is an audio signal. As the plurality of feature amounts of the audio signal, for example, a frequency band (resolution) and a distortion rate (noise suppression degree) can be considered.
[0189]
【The invention's effect】
According to the present invention, when the first information signal is converted into the second information signal, it corresponds to the values of the plurality of parameters respectively indicating the plurality of feature amounts that determine the quality of the output obtained by the second information signal. Thus, since the information data of the attention point related to the second information signal is generated, the user can change the setting of the values of the plurality of parameters to improve the quality of the output obtained by the second information signal. Can be adjusted arbitrarily.
[0190]
Further, according to the present invention, the plurality of parameters respectively used for converting the first information signal into the second information signal and indicating the plurality of feature amounts that determine the quality of the output obtained by the second information signal. Is regulated within the recommended setting range, and the user can effectively set a plurality of parameter values.
[Brief description of the drawings]
FIG. 1 is a block diagram illustrating a configuration of a television receiver as an embodiment.
FIG. 2 is a diagram illustrating an example of a user interface for setting values of parameters h and v indicating horizontal and vertical resolutions.
FIG. 3 is a flowchart (1/2) for explaining an operation of setting parameters h and v.
FIG. 4 is a flowchart (2/2) for explaining the setting operation of parameters h and v.
FIG. 5 is a diagram for explaining selection of a recommended setting range.
FIG. 6 is a flowchart for explaining a setting operation of a recommended setting range.
FIG. 7 is a diagram showing a relationship between parameters h and v indicating horizontal and vertical resolutions and an SN ratio.
FIG. 8 is a diagram for explaining a relationship between input signals x and y and parameters h and v.
FIG. 9 is a diagram for explaining selection of image quality confirmation;
FIG. 10 is a diagram for explaining selection of position recording.
FIG. 11 is a diagram illustrating another example of a user interface for setting values of parameters h and v.
FIG. 12 is a flowchart (1/2) for explaining the setting operation of parameters h and v.
FIG. 13 is a flowchart (2/2) for explaining the setting operation of parameters h and v.
FIG. 14 is a diagram showing a concept of a coefficient seed data generation method.
FIG. 15 is a block diagram illustrating a configuration of a coefficient seed data generation apparatus.
FIG. 16 is a diagram illustrating an example of frequency characteristics of a band filter.
FIG. 17 is a diagram illustrating a setting display unit for setting a parameter r indicating resolution and a parameter z indicating noise suppression.
FIG. 18 is a diagram illustrating a generation example of an SD signal (parameters r, z).
FIG. 19 is a diagram for explaining a noise addition method;
FIG. 20 is a diagram showing a setting display unit for setting parameters h and v indicating horizontal and vertical resolutions and a parameter z indicating a noise suppression degree.
FIG. 21 is a diagram illustrating a generation example of an SD signal (parameters h, v, z).
FIG. 22 is a block diagram illustrating a configuration of an image signal processing device to be realized by software.
FIG. 23 is a flowchart illustrating a processing procedure of an image signal.
FIG. 24 is a diagram for explaining a pixel position relationship between a 525i signal and a 1050i signal.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 100 ... Television receiver, 101 ... System controller, 102 ... Remote control signal receiving circuit, 105 ... Receiving antenna, 106 ... Tuner, 110 ... Image signal processing part, 111 ... Display unit 112... OSD circuit 115... Setting display unit 115 a. Recommended setting range 116... Icon 117. Menu display unit 121. 122 ... second tap selection circuit, 123 ... third tap selection circuit, 124 ... spatial class detection circuit, 125 ... motion class detection circuit, 126 ... class synthesis circuit, 127 ... Estimated prediction calculation circuit, 128 ... Normalization circuit, 129 ... Post-processing circuit, 134 ... Coefficient memory, 135 ... Information memory bank, 136 ... Coefficient Generation circuit, 137... Normalization coefficient calculation unit, 138... Normalization coefficient memory, 200... Remote control transmitter, 201... Display unit, 202. 204... Operation switch, 300... Image signal processing device

Claims (8)

An information signal processing device for converting a first information signal composed of a plurality of information data into a second information signal composed of a plurality of information data,
Feature amount setting means for setting values of a plurality of parameters respectively indicating a plurality of feature amounts that determine the quality of output obtained by the second information signal;
Storage means for storing recommended setting range information of the values of the plurality of parameters;
Feature quantity regulating means for regulating the values of the plurality of parameters set by the feature quantity setting means within the recommended setting range;
Corresponding to the values of the plurality of parameters set by the feature amount setting means, information data generating means for generating information data of a point of interest related to the second information signal ,
The information data generating means includes
Coefficient data acquisition means for acquiring coefficient data of an estimation equation corresponding to the values of the plurality of parameters set by the feature amount setting means;
Data selection means for selecting, from the first information signal, a plurality of information data located around the point of interest related to the second information signal;
An arithmetic means that calculates the information data of the attention point from the coefficient data acquired by the coefficient data acquisition means and the plurality of information data selected by the data selection means using the estimation formula. An information signal processing apparatus. An instruction signal input means for inputting an instruction signal for instructing whether or not to enjoy the recommended setting range;
The feature amount regulating means is
When an instruction signal for instructing the instruction signal input means to enjoy the recommended setting range is input, the values of the plurality of parameters set by the feature amount setting means are regulated within the recommended setting range.
Information signal processing apparatus according to 請 Motomeko 1. The feature amount setting means includes:
Input signal generating means for obtaining a plurality of input signals each corresponding to the plurality of parameters and taking a value within a certain range;
First linear conversion means for linearly converting the plurality of input signals so that the values thereof are values within the maximum variable range of the plurality of parameters, and obtaining a plurality of first signals;
Second linear conversion means for linearly converting the plurality of input signals such that the values thereof are values within the recommended setting range to obtain a plurality of second signals;
The feature amount regulating means is
When an instruction signal instructing not to enjoy the recommended setting range is input to the instruction signal input means, a plurality of first signals obtained by the first signal conversion means are set as the setting values of the plurality of parameters. When the instruction signal indicating that the recommended setting range is enjoyed is input to the instruction signal input means, the plurality of second signals obtained by the second signal conversion means are set as the setting values of the plurality of parameters. Do
Information signal processing apparatus according to 請 Motomeko 2. The storage means stores information of a plurality of recommended setting ranges,
A selection signal input means for inputting a selection signal for selecting one of the plurality of recommended setting ranges;
The feature amount regulating means is
The values of the plurality of parameters set by the feature amount setting means are regulated within one recommended setting range selected by the selection signal input to the selection signal input means.
Information signal processing apparatus according to 請 Motomeko 1. The values of a plurality of parameters set by the feature amount setting means are
Display control means for displaying on the display element which position is within the variable range is further provided.
Information signal processing apparatus according to 請 Motomeko 1. An information signal processing method of an information signal processing device for converting a first information signal composed of a plurality of information data into a second information signal composed of a plurality of information data,
A first step of setting values of parameters respectively indicating a plurality of feature quantities that determine the quality of output obtained by the second information signal;
A second step of restricting the values of the plurality of parameters set in the first step within a recommended setting range;
A third step of generating information data of a point of interest related to the second information signal corresponding to the values of the plurality of parameters set in the first step, and
The third step is
Obtain coefficient data of the estimation formula corresponding to the set multiple parameter values,
From the first information signal, select a plurality of information data located around the point of interest related to the second information signal,
An information signal processing method obtained by calculating information data of the attention point from the acquired coefficient data and the selected plurality of information data using the estimation formula . In the second step,
When it is instructed to enjoy the recommended setting range, the values of the plurality of parameters set in the first step are regulated within the recommended setting range.
Information signal processing method according to 請 Motomeko 6. A program for controlling an information processing apparatus that converts a first information signal composed of a plurality of information data into a second information signal composed of a plurality of information data ,
A first step of setting values of a plurality of parameters respectively indicating a plurality of feature quantities that determine the quality of output obtained by the second information signal;
A second step of restricting the values of the plurality of parameters set in the first step within a recommended setting range;
A third step of generating information data of a point of interest related to the second information signal corresponding to the values of the plurality of parameters set in the first step;
Including
The third step is
Obtain coefficient data of the estimation formula corresponding to the set multiple parameter values,
From the first information signal, select a plurality of information data located around the point of interest related to the second information signal,
Obtained from the obtained coefficient data and the selected plurality of information data by calculating the information data of the attention point using the estimation formula
A recording medium on which a program for causing a computer of an information processing apparatus to execute processing is recorded .

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