JP2004112756A - Output image adjustment of image file - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To automatically and properly adjust the image quality, in response to individual image data. <P>SOLUTION: When a memory card MC is inserted into a slot 34, a control circuit 30 of a color printer 20 obtains image processing control information GC from the memory card MC and analyzes it. A CPU 31 corrects the reference values with respect to image quality parameters, indicating the characteristics of the image data by reflecting the image processing control information GC. The CPU 31 corrects the image quality parameters for bringing them closer to the corrected reference values and adjusts the image quality of the image data, reflecting the corrected image quality parameters. <P>COPYRIGHT: (C)2004,JPO

Description

【００５７】
ＣＰＵ３１は、こうして得られたＲＧＢ色空間に基づく画像データに対して、ガンマ補正、並びに、マトリックス演算Ｍを実行する（ステップＳ２２０）。ガンマ補正を実行する際には、ＣＰＵ３１は画像処理制御情報ＧＣからＤＳＣ側のガンマ値を取得し、取得したガンマ値を用いて映像データに対してガンマ変換処理を実行する。すなわち、ガンマ値も画像処理制御情報ＧＣによって指定される画像処理制御パラメータ値に含まれる。マトリックス演算ＭはＲＧＢ色空間をＸＹＺ色空間に変換するための演算処理である。本実施例において用いられる画像ファイルＧＦは、画像処理時に用いるべき色空間情報を指定することができるので、画像ファイルＧＦが色空間情報を含んでいる場合には、ＣＰＵ３１は、マトリックス演算Ｍを実行するに際して、色空間情報を参照し、指定された色空間に対応するマトリックス（Ｍ）を用いてマトリックス演算を実行する。マトリックス演算Ｍは以下に示す演算式である。
【００５８】
【数２】

【００５９】
マトリックス演算Ｍの実行後に得られる画像データＧＤの色空間はＸＹＺ色空間である。従来は、プリンタまたはコンピュータにおける画像処理に際して用いられる色空間はｓＲＧＢに固定されており、ディジタルスチルカメラ１２の有する色空間を有効に活用することができなかった。これに対して、本実施例では、画像ファイルＧＦによって色空間が指定されている場合には、色空間情報に対応してマトリックス演算Ｍに用いられるマトリックス（Ｍ）を変更するプリンタ（プリンタドライバ）を用いている。したがって、ディジタルスチルカメラ１２の有する色空間を有効に活用して、正しい色再現を実現することができる。
【００６０】
ＣＰＵ３１は、画像処理制御情報ＧＣに基づく画像調整を実行するために、画像データＧＤの色空間をＸＹＺ色空間からｗＲＧＢ色空間へ変換する処理、すなわち、マトリックス演算Ｎ^−１および逆ガンマ補正を実行する（ステップＳ２３０）。なお、ｗＲＧＢ色空間はｓＲＧＢ色空間よりも広い色空間である。ガンマ補正を実行する際には、ＣＰＵ３１はＲＯＭ３２からプリンタ側のデフォルトのガンマ値を取得し、取得したガンマ値の逆数を用いて映像データに対して逆ガンマ変換処理を実行する。マトリックス演算Ｎ^−１を実行する場合には、ＣＰＵ３１はＲＯＭ３１からｗＲＧＢ色空間への変換に対応するマトリックス（Ｎ^−１）を用いてマトリックス演算を実行する。マトリックス演算Ｎ^−１は以下に示す演算式である。
【００６１】
【数３】

【００６２】
マトリックス演算Ｎ^−１実行後に得られる画像データＧＤの色空間はｗＲＧＢ色空間である。このｗＲＧＢ色空間は既述のように、ｓＲＧＢ色空間よりも広い色空間であり、ディジタルスチルカメラ１２によって生成可能な色空間に対応している。
【００６３】
ＣＰＵ３１は、画像画質の自動調整処理を実行する（ステップＳ２４０）。本実施例における画質自動調整処理の概念について図１４を参照して説明する。画像ファイルＧＦには、画質調整の対象となる画像データＧＤと画質調整に際して用いられる画像処理制御情報ＧＣが含まれている。カラープリンタ２０（ＣＰＵ３１）は、画像データＧＤを解析して画像データＧＤの特性を示す画像統計値（特性パラメータ値）ＳＶを取得すると共に、画像処理制御情報ＧＣを解析して基準画質パラメータ値ＳＰ、および手動補正パラメータ値ＭＰを取得する。カラープリンタ２０は、画像統計値ＳＶおよび基準画質パラメータ値ＳＰに基づいて自動画質調整パラメータＡＰを決定し、さらに、最終画質調整パラメータＦＰ＝ＡＰ＋ＭＰを決定する。カラープリンタ２０は、決定した最終画質調整パラメータＦＰを用いて画像データＧＤの画質を調整し、調整済みの画像データＧＤ’をプリンタドライバへ出力する。
【００６４】
この自動画質調整処理の詳細について図１５を参照して詳細に説明する。ＣＰＵ３１は、先ず、画像データＧＤを解析して画像データＧＤの特性を示す各種の特性パラメータ値（画像統計値）ＳＶを取得し、ＲＡＭ３２に一時的に格納する（ステップＳ３００）。ＣＰＵ３１は、画像ファイルＧＦから画像処理制御情報ＧＣを取得し（ステップＳ３１０）、画像処理制御情報ＧＣに基づいて手動補正パラメータ値ＭＰを取得する（ステップＳ３２０）。手動補正パラメータ値ＭＰとして取得されるパラメータには、ホワイトバランス、露出補正量、露出時間、絞り、ＩＳＯ、焦点距離等といった画像処理制御パラメータが含まれる。これら手動補正パラメータ値ＭＰは、画像データＧＤの解析結果、すなわち、画像統計値ＳＶとは独立した値であり、最終画質調整パラメータＦＰにそのままの値が反映される。
【００６５】
ＣＰＵ３１は、取得した画像処理制御情報ＧＣに撮影モードを指定するパラメータ値が含まれているか否かを判定する（ステップＳ３２０）。本実施例では、自動画質調整パラメータ値ＡＰ、すなわち、画像データＧＤの画像統計値ＳＶを反映した自動画質調整量、を決定するにあたって、撮影シーン毎に複数の異なる画像処理制御パラメータが組み合わされた撮影モードを用いる。また、本実施例では、撮影モードは１，２．．．といった参照番号によって指定されるので、撮影モードが指定されている場合には、参照番号に基づいて各撮影モードを定義する個々の画像処理制御パラメータを解析、決定する必要が有る。ＣＰＵ３１は、撮影モードの指定がなされていると判定した場合には（ステップＳ３３０：Ｙｅｓ）、指定された参照番号に基づいて撮影モードを解析して撮影モードを定義する各画像処理制御パラメータを取得して、後述する手順にて基準画質パラメータ値ＳＰを決定する（ステップＳ３４０）。なお、撮影モードが設定されている場合であっても、手動補正パラメータ値ＭＰを並列して指定することができるのは既述の通りである。
【００６６】
撮影モードを定義する各画像処理制御パラメータの組み合わせと、撮影モードを指定する数値の組み合わせは図１６に示すとおりである。図１６は、撮影モード、画質パラメータ、撮影モードを指定する数値の組み合わせの一例を示す説明図である。各撮影モードに対するコントラスト、明るさといった項目は、画質自動調整の結果として得られる画質の状態をわかりやすく示しており、各項目が指定する画質の状態はＣＰＵ３１によって解析され、指定された画質の状態を実現するために、各項目に対して単数、または、複数の画像処理制御パラメータ値が設定される。撮影モード１は、例えば、標準的な撮影条件に適し、撮影モード２は、例えば、人物を撮影する撮影条件に適し、撮影モード３は、例えば、風景を撮影する撮影条件に適し、撮影モード４は、例えば、夕景を撮影する撮影条件に適し、撮影モード５は、例えば、夜景を撮影する撮影条件に適し、撮影モード６は、例えば、花を撮影する撮影条件に適する。撮影モード７は、例えば、マクロ撮影の撮影条件に適し、撮影モード８は、例えば、スポーツをしている人物を撮影する撮影条件に適し、撮影モード９は、例えば、逆光下での撮影条件に適し、撮影モード１０は、例えば、紅葉を撮影する撮影条件に適し、撮影モード１１は、例えば、記念撮影を撮影する撮影条件に適する。なお、撮影モードが設定されていない場合には、設定されている撮影モードを示すパラメータは、０に設定される。
【００６７】
ＣＰＵ３１は、撮影モードの指定がなされていない、すなわち、撮影モードのパラメータが０に設定されている判定した場合には（ステップＳ３３０：Ｎｏ）、画質調整処理において個々に設定されている画像処理制御パラメータを反映するためステップＳ３５０の処理に進む。
【００６８】
ＣＰＵ３１は、取得した画像処理制御パラメータの値を反映しつつ、各パラメータ毎に設定されている基準値を変更（修正）する。各パラメータ毎に設定されている基準値は、一般的な画像生成条件にて生成された画像データを想定した値である。そこで、撮影者（画像生成者）の意図を正しく反映した自動画質調整を実現するために、特に、撮影者が任意に設定可能な画像処理制御条件について、個々の画像処理制御条件を考慮して、基準値を変更する。なお、基準値は、定量評価と感応評価による画像評価によって予め定められた画像の出力結果が最適となるパラメータの指標値である。
【００６９】
例えば、撮影モードのパラメータが２に設定されている場合、明度基準値は標準値１２８からやや明るい値１４４に変更され、彩度基準値は標準値１２８からやや弱い値１０２に変更され、シャープネス基準値は標準値２００からやや弱い値１５０に変更される。また、コントラスト補正係数は標準値５からやや軟調な値２に変更され、カラーバランス補正係数は標準値５のまま維持される。各基準値、各係数の変更は、例えば、各基準値および各係数に対して数値を増減することにより、または、各基準値および各係数を所定の割合で増減することによって実現される。あるいは、例えば、明度基準値については、やや明るい値として１４４、やや暗い値として１１２をデフォルト値として用意しておき、やや明るい、やや暗いといった補正の傾向に応じて基準値を置き換えても良い。
【００７０】
ＣＰＵ３１は、上記のようにして修正された基準画質パラメータ値ＳＰと画質パラメータ値ＳＶとの偏差を求め、その偏差を自動画質調整パラメータ値ＡＰに決定する（ステップＳ３５０）。例えば、画質パラメータ値ＳＶとして、明度１６０、シャープネス１５５の場合には、明度についての自動画質調整パラメータ値ＡＰ＝１６０−１４４＝１６、シャープネスについての自動画質調整パラメータ値ＡＰ＝１５５−１５０＝５となる。
【００７１】
ＣＰＵ３１は、図１７に示すように、決定した自動画質調整パラメータ値ＡＰと取得した手動補正パラメータ値ＭＰとから最終画質調整パラメータＦＰ（画像データ補正量）＝ＡＰ＋ＭＰを求め、最終画質調整パラメータＦＰを反映して自動画質調整を実行する（ステップＳ３６０）。図１７は、明度、シャープネスについて、各パラメータＡＰ、ＭＰ、ＦＰ、ＦＰ’の例示値を示す説明図である。例えば、手動補正パラメータ値ＭＰとして、明度＋１０、シャープネス−１０が設定されている場合には、明度についての最終画質調整パラメータＦＰ＝１６＋１０＝２６、シャープネスについての最終画質調整パラメータＦＰ＝５−１０＝−５となる。ＣＰＵ３１は、シャドウ、ハイライト、明度、コントラスト、カラーバランス、記憶色補正の各画質パラメータに対しては、図１８に示す画像データＧＤのＲＧＢ成分の入力レベルと出力レベルとを対応付けるトーンカーブ（Ｓカーブ）を用いて画質の調整を実行する。図１８は最終画質調整パラメータＦＰを反映して変更されるトーンカーブを例示する説明図である。トーンカーブを用いて画質を調整する場合には、各画質パラメータに対する各ＦＰを反映して、ＲＧＢの各成分についてそれぞれの１つのトーンカーブを変更し、最後に、変更したＲＧＢの各成分に対応する各トーンカーブを用いて画像データＧＤのＲＧＢの各成分について入力−出力変換を行う。この結果、画質が調整された画像データＧＤが得られる。
【００７２】
各画質パラメータに対する画質の自動調整処理は、例えば、以下のように具体的に実行される。
・コントラスト、シャドー、ハイライトについては、画像データからシャドウポイントとハイライトポイントとを検出して基準値に基づくレベル補正を実行し、ヒストグラムの伸張を実行する。また、輝度標準偏差に基づいて、基準値に基づいてトーンカーブの補正を実行する。
・明るさについては、画像データを１４分割した個々の領域から計算される輝度値に基づいて、画像が暗い（露出不足）か明るい（露出超過）であるかを判定し、基準値に基づいてトーンカーブの補正を実行する。
・カラーバランスについては、画像データのＲ成分、Ｇ成分、Ｂ成分の各ヒストグラムからカラーバランスの偏りを分析し、Ｒ成分、Ｇ成分、Ｂ成分の各トーンカーブをＲＧＢ各成分に対する基準値に基づいてそれぞれ補正して色かぶりを軽減する。なお、撮影モードが４，５に設定されている場合には、たとえ色かぶりが発生していても意図的な色かぶりであるため、カラーバランスの自動調整は実行せず、ユーザの意図を反映させた画質補正を実行する。
・彩度については、画像データの彩度分布を分析し、基準値に基づいて彩度の強調を実行する。したがって、低彩度の画像データほど彩度強調のレベルが大きくなる。
・シャープネスについては、画像データの周波数とエッジの強度分布を解析し、基準値に基づいてアンシャープマスクを実施することにより補正が実行される。基準値は、周波数分布に基づいて決定され、高周波画像データ（風景等）ほど基準値が小さくなり、低周波画像データ（人物等）ほど基準値が大きくなる。また、アンシャープマスクの適用量は、エッジ強度分布に依存しており、ぼけた特性を有する画像データほどその適用量が大きくなる。
・記憶色については、一般的に、記憶色と呼ばれる「肌色」、「緑色」、「空色」、「夕陽の赤色」等について、画像データから該当する画層を抽出し、好ましいと思われる色になるよう補正を実行する。
・ノイズ除去については、ＹＣｂＣｒの色差成分ＣｂＣｒについて平滑化フィルタを作用させることによって、カラーノイズを軽減することにより実行する。
【００７３】
画像処理制御パラメータには、最終画質調整パラメータＦＰの適用のレベル、すなわち、画像データＤＧを基準値に基づく画像データに近づける程度を指定するレベル指定パラメータＬＰも含まれる。レベル指定パラメータＬＰは、例えば、ＦＰ’＝ＡＰ＊（ＬＰ／５）＋ＭＰといったように用いられ、自動補正パラメータ値ＡＰに対してのみ反映され、手動補正パラメータ値ＭＰには反映されない。したがって、例えば、ＬＰ＝１０の場合には、図１７に示すように最終画質調整パラメータＡＰの値が２倍され、ＬＰ＝５の場合には、最終画質調整パラメータＡＰの値は１倍される。トーンカーブは、ＦＰ’に基づいて変更され、ＬＰ＝１０の場合には、トーンカーブの変更量が２倍となる。また、基準値を変更することなく、基準値へ近づけるレベルのみを画像処理制御情報ＧＣに基づいて変更しても良い。
【００７４】
次に、測光方式、レンズ焦点距離といったディジタルスチルカメラ１２の作動（撮影）条件に対応する画像処理制御パラメータを反映した画質自動調整処理について説明する。測光方式の画像処理制御パラメータが、スポット測光、マルチスポット測光、部分測光を示す場合には、明度（明るさ）についての自動画質調整処理を行わない。一般的な測光方式では、画面全体の明るさを演算して適正露出を取得するが、スポット測光では、画面の部分的な明るさを測光して、測光した領域が適正になるように露出を決定する。つまり、ユーザによって、画面の特定の領域を適正露出にして欲しいとの意図が指示されることになる。このような場合に、明度を自動調整してしまうと、ユーザの意図が反映されない画質調整処理が実行されることになる。したがって、これら３つの測光モードの時には、明度の自動調整を実行しない。
【００７５】
撮影時におけるレンズ焦点距離とＦナンバーとに基づいて、シャープネスの基準値を変更する。一般的に、「ぼけ」はレンズの焦点距離とＦナンバー（絞り）とによって決定される。したがって、シャープネスを自動調整する際に、シャープネスに対応する基準値をレンズ焦点距離とＦナンバーとに関連づけることによって、撮影時に想定されたぼけを反映した画質調整処理を実行することができる。例えば、広角レンズ（３５ｍｍ以下）でＦ１３（絞り大）の場合、一般的に、風景や記念撮影などで手前から背景に至るまで画面全体にわたってピントを合わせてシャープに撮影したいという意図が撮影者にはあるものと判定することができる。そこで、かかる場合には、シャープネスの基準値を小さくしてより多くの画祖にシャープネス効果を与え、シャープネスの適用量を多くしてよりシャープになるように画質調整を実行する。一方、望遠レンズ（１００ｍｍ以上）でＦ２（絞り開放）の場合、一般的に、ポートレイトなどで、被写体を浮き上がらせるために背景をぼかしたいという意図が撮影者にはあるものと判定することができる。そこで、かかる場合には、シャープネスの基準値を大きくして、肌などの滑らかな領域にはシャープネス効果を与えず、背景と被写体との境界画素にのみシャープネス効果を与え、シャープネスの適用量を小さくして、肌などを荒らさないように画質調整処理を実行する。
【００７６】
レンズ焦点距離ｆ（ｍｍ）とＦナンバーとから求められるぼかし指数をｆ／Ｆと定義すると図１９に示すような関係となる。図１９はレンズ焦点距離ｆ（ｍｍ）とＦナンバーとから求められるぼかし指数をｆ／Ｆを説明する説明図である。
【００７７】
ＣＰＵ３１は、上記の画質自動調整を実行した後（ステップＳ３６０）、メインルーチンである画像処理ルーチンにリターンする。
【００７８】
ＣＰＵ３１は、画質自動調整処理を終了すると、印刷のためのｗＲＧＢ色変換処理およびハーフトーン処理を実行する（ステップＳ２５０）。ｗＲＧＢ色変換処理では、ＣＰＵ３１は、ＲＯＭ３１内に格納されているｗＲＧＢ色空間に対応したＣＭＹＫ色空間への変換用ルックアップテーブル（ＬＵＴ）を参照し、画像データの色空間をｗＲＧＢ色空間からＣＭＹＫ色空間へ変更する。すなわち、Ｒ・Ｇ・Ｂの階調値からなる画像データをカラープリンタ２０で使用する、例えば、Ｃ・Ｍ・Ｙ・Ｋ・ＬＣ・ＬＭの各６色の階調値のデータに変換する。
【００７９】
ハーフトーン処理では、色変換済みの画像データを受け取って、階調数変換処理を行う。本実施例においては、色変換後の画像データは各色毎に２５６階調幅を持つデータとして表現されている。これに対し、本実施例のカラープリンタ２０では、「ドットを形成する」，「ドットを形成しない」のいずれかの状態しか採り得ず、本実施例のカラープリンタ２０は局所的には２階調しか表現し得ない。そこで、２５６階調を有する画像データを、カラープリンタ２０が表現可能な２階調で表現された画像データに変換する。この２階調化（２値化）処理の代表的な方法として、誤差拡散法と呼ばれる方法と組織的ディザ法と呼ばれる方法とがある。
【００８０】
カラープリンタ２０では、色変換処理に先立って、画像データの解像度が印刷解像度よりも低い場合は、線形補間を行って隣接画像データ間に新たなデータを生成し、逆に印刷解像度よりも高い場合は、一定の割合でデータを間引くことによって、画像データの解像度を印刷解像度に変換する解像度変換処理を実行する。また、カラープリンタ２０は、ドットの形成有無を表す形式に変換された画像データを、カラープリンタ２０に転送すべき順序に並べ替えてるインターレス処理を実行する。
【００８１】
以上、説明したように本実施例におけるディジタルスチルカメラ１２によれば、ディジタルスチルカメラ１２上において、プリンタ２０において実行される画質調整処理における画像処理制御条件を設定することができる。したがって、撮影時に、画像データに対する所望の画像処理制御条件を設定することが可能となり、撮影時に望んでいた画像処理制御条件を適切に反映した画質調整処理を実現することができる。また、画像データと撮影時に想定した画像処理制御条件とを容易に関連付けることができると共に、各画像データに適した個々の画像処理制御条件を付すことができる。さらに、画像データの画質を自動調整する際に、改めて画像処理制御条件を設定する必要がなく、画像処理制御条件を反映した画質調整処理を容易化することができる。
【００８２】
また、本実施例におけるカラープリンタ２０によれば、画像ファイルＧＦ内に含まれる画像処理制御情報ＧＣを反映して画像データＧＤの画質を自動調整することができる。したがって、撮影時の撮影条件を反映して、個々の画像データに適した画質自動調整を実行することができる。さらに、ユーザによって恣意的に画像データの画質調整条件が設定されている場合には、恣意的に設定された画像処理制御条件を反映して画質自動調整が実行されるので、恣意的な出力画質調整条件が修正され、ユーザの意図を反映することができないという、従来の画質自動調整機能における問題を解決することができる。
【００８３】
また、画像ファイルＧＦに含まれている画像処理制御情報ＧＣを用いて自動的に画質を調整することができるので、フォトレタッチアプリケーションまたはプリンタドライバ上で画質調整を行うことなく、手軽にユーザの撮影意図を反映した、高品質の印刷結果を得ることができる。
【００８４】
なお、上記実施例では、自動的に画質調整処理を実行する例について説明しているが、カラープリンタ２０の操作パネル上に画質自動調整ボタンを供え、かかる画質自動調整ボタンによって画質自動調整が選択されている場合にだけ、上記実施例の画質自動調整処理を実行するようにしても良い。
【００８５】
Ｆ．その他の実施例：
上記実施例では、画像処理制御情報ＧＣを反映するにあたって、画像処理制御情報ＧＣを解析し、画像処理制御パラメータを取得して基準値、適用レベルを変更しているが、画像処理制御情報ＧＣに基づいて画像データＧＤを直接補正しても良い。このとき、画像処理制御情報ＧＣは、画像データＧＤをどの程度変化させるか、例えば、明度の補正量を＋１０増加させる、明度を＋１０％増加させるといった情報を有すればよい。かかる場合には、画像データＧＤの画質特性に左右されることなく、ユーザの意図する補正の傾向を画質調整処理に反映することができる。
【００８６】
上記実施例では、パーソナルコンピュータＰＣを介することなく、カラープリンタ２０において全ての画像処理を実行し、生成された画像データＧＤに従って、ドットパターンが印刷媒体上に形成されるが、画像処理の全て、または、一部をコンピュータ上、ネットワークを介したサーバ上で実行するようにしても良い。この場合には、コンピュータのハードディスク等にインストールされている、レタッチアプリケーション、プリンタドライバといった画像データ処理アプリケーション（プログラム）に図１４を参照して説明した画像処理機能を持たせることによって実現される。ディジタルスチルカメラ１２にて生成された画像ファイルＧＦは、ケーブルを介して、あるいは、メモリカードＭＣを介してコンピュータに対して提供される。コンピュータ上では、ユーザの操作によってアプリケーションが起動され、画像ファイルＧＦの読み込み、画像処理制御情報ＧＣの解析、画像データＧＤの変換、調整が実行される。あるいは、メモリカードＭＣの差込を検知することによって、またあるいは、ケーブルの差込を検知することによって、アプリケーションが自動的に起動し、画像ファイルＧＦの読み込み、画像処理制御情報ＧＣの解析、画像データＧＤの変換、調整が自動的になされても良い。
【００８７】
さらに、画質自動調整を実行する特性パラメータ値を選択できるようにしても良い。例えば、カラープリンタ２０にパラメータの選択ボタン、あるいは、被写体に応じて所定のパラメータの組み合わせた撮影モードパラメータの選択ボタンを供え、これら選択ボタンによって画質自動調整を実行するパラメータを選択しても良い。また、画質自動調整がパーソナルコンピュータ上で実行される場合には、プリンタドライバまたはレタッチアプリケーションのユーザーインタフェース上にて画質自動調整を実行するパラメータが選択されても良い。
【００８８】
カラープリンタ２０における画像処理は、図２０に示すように画質自動調整処理を先に実行し、後に色空間の変換を実行しても良い。基本情報を処理しても良い。
【００８９】
上記実施例では、共に出力装置としてカラープリンタ２０を用いているが、出力装置にはＣＲＴ、ＬＣＤ、プロジェクタ等の表示装置を用いることもできる。かかる場合には、出力装置としての表示装置によって、例えば、図１２、図１３等を用いて説明した画像処理を実行する画像処理プログラム（ディスプレイドライバ）が実行される。あるいは、ＣＲＴ等がコンピュータの表示装置として機能する場合には、コンピュータ側にて画像処理プログラムが実行される。ただし、最終的に出力される画像データは、ＣＭＹＫ色空間ではなくＲＧＢ色空間を有している。
【００９０】
かかる場合には、カラープリンタ２０を介した印刷結果に画像データ生成時の情報を反映できたのと同様にして、ＣＲＴ等の表示装置における表示結果に画像データ生成時の画像処理制御情報ＧＣを反映することができる。したがって、ディジタルスチルカメラ１２によって生成された画像データＧＤをより正確に表示させることができる。
【００９１】
以上、実施例に基づき本発明に係る出力装置、画像処理装置、プログラムを説明してきたが、上記した発明の実施の形態は、本発明の理解を容易にするためのものであり、本発明を限定するものではない。本発明は、その趣旨並びに特許請求の範囲を逸脱することなく、変更、改良され得ると共に、本発明にはその等価物が含まれることはもちろんである。
【００９２】
上記実施例では、ディジタルスチルカメラ１２において撮影モード、画像処理制御パラメータが設定され、設定された撮影モード、画像処理制御パラメータをプリンタ２０において解析した後に、基準値を変更している。すなわち、画像処理制御コマンドを用いて画像データＧＤの自動画質調整処理が実行されている。しかしながら、ディジタルスチルカメラ１２において撮影モード、画像処理制御パラメータから基準値を変更する処理を実行し、プリンタ２０に対しては基準値、適用レベル、すなわち、値そのものを提供するようにしてもよい。かかる場合には、プリンタ２０には基準値を用いた画質調整機能が備わっていれば、個々の撮影条件にあった画質調整処理、ユーザの意図を反映した画質調整処理を自動的に実行することができる。
【００９３】
上記実施例では、画像処理制御情報ＧＣとして、光源、露出補正量、ターゲット色空間、明るさ、シャープネスといったパラメータを用いているが、どのパラメータを画像処理制御情報ＧＣとして用いるかは任意の決定事項である。
【００９４】
また、図８の表に例示した各パラメータの値は、あくまでも例示に過ぎず、この値によって本願に係る発明が制限されることはない。さらに、各数式におけるマトリックスＳ、Ｍ、Ｎ^−１の値は例示に過ぎず、ターゲットとする色空間、あるいは、カラープリンタ２０において利用可能な色空間等によって適宜変更され得ることはいうまでもない。
【００９５】
上記実施例では、画像ファイル生成装置としてディジタルスチルカメラ１２を用いて説明したが、この他にもスキャナ、ディジタルビデオカメラ等が用いられ得る。スキャナを用いる場合には、画像ファイルＧＦの取り込みデータ情報の指定はコンピュータＰＣ上で実行されても良く、あるいは、スキャナ上に情報設定用に予め設定情報が割り当てられているプリセットボタン、任意設定のための表示画面および設定用ボタンを供えておき、スキャナ単独で実行可能にしてもよい。
【００９６】
上記実施例では、ｓＲＧＢ色空間からｗＲＧＢ色空間への色空間特性の変更に際して、マトリクスＭおよびマトリクスＮ^−１をそれぞれ独立して演算処理しているが、マトリクスＭおよびマトリクスＮ^−１を合成した合成マトリクス（ＭＮ^−１）を用いたマトリクス演算によって実行されても良い。さらに、必要に応じて様々な変換系マトリクスを合成するようにしても良い。マトリクスの合成により、一連のマトリクス演算処理を高速化することができる。
【００９７】
上記実施例では、画像ファイルＧＦの具体例としてＥｘｉｆ形式のファイルを例にとって説明したが、本発明に係る画像ファイルの形式はこれに限られない。すなわち、画像データ生成装置において生成された画像データと、画像データの生成時条件（情報）を記述する画像処理制御情報ＧＣとが含まれている画像ファイルであれば良い。このようなファイルであれば、画像ファイル生成装置において生成された画像データの画質を、適切に自動調整して出力装置から出力することができる。
【００９８】
上記実施例において用いたディジタルスチルカメラ１２、カラープリンタ２０はあくまで例示であり、その構成は各実施例の記載内容に限定されるものではない。ディジタルスチルカメラ１２にあっては、上記実施例に係る画像ファイルＧＦを生成できる機能を少なくとも備えていればよい。また、カラープリンタ２０にあっては、少なくとも、本実施例に係る画像ファイルＧＦの画像処理制御情報ＧＣを解析し、特に明度に関してユーザの意図を反映して画質を自動調整し、画像を出力（印刷）できればよい。
【００９９】
なお、画像データと画像処理制御情報ＧＣとが含まれる画像ファイルＧＦには、画像処理制御情報ＧＣとを関連付ける関連付けデータを生成し、１または複数の画像データと画像処理制御情報ＧＣとをそれぞれ独立したファイルに格納し、画像処理の際に関連付けデータを参照して画像データと画像処理制御情報ＧＣとを関連付け可能なファイルも含まれる。かかる場合には、画像データと画像処理制御情報ＧＣとが別ファイルに格納されているものの、画像処理制御情報ＧＣを利用する画像処理の時点では、画像データおよび画像処理制御情報ＧＣとが一体不可分の関係にあり、実質的に同一のファイルに格納されている場合と同様に機能するからである。すなわち、少なくとも画像処理の時点において、画像データと画像処理制御情報ＧＣとが関連付けられて用いられる態様は、本実施例における画像ファイルＧＦに含まれる。さらに、ＣＤ−ＲＯＭ、ＣＤ−Ｒ、ＤＶＤ−ＲＯＭ、ＤＶＤ−ＲＡＭ等の光ディスクメディアに格納されている動画像ファイルも含まれる。
【図面の簡単な説明】
【図１】第１の実施例に係る画像処理装置を適用可能な画像データ処理システムの一例を示す説明図である。
【図２】第１の実施例に係る画像処理装置が処理する画像ファイル（画像データ）を生成可能なディジタルスチルカメラの概略構成を示すブロック図である。
【図３】第１の実施例において用いられ得る画像ファイルの内部構成を概念的に示す説明図である。
【図４】Ｅｘｉｆファイル形式にて格納されている画像ファイルの概略的な内部構造を示す説明図である。
【図５】第１の実施例に用いられ得る画像ファイルＧＦの付属情報格納領域１１２のデータ構造の一例を示す説明図である。
【図６】第１の実施例におけるカラープリンタ２０の概略構成を示すブロック図である。
【図７】カラープリンタ２０の制御回路３０の内部構成を示す説明図である。
【図８】ディジタルスチルカメラ１２における画像ファイルＧＦの生成処理の流れを示すフローチャートである。
【図９】液晶ディスプレイ１２７の例示的な表示態様を示す説明図である。
【図１０】液晶ディスプレイ１２７の例示的な表示態様を示す説明図である。
【図１１】液晶ディスプレイ１２７の例示的な表示態様を示す説明図である。
【図１２】第１の実施例におけるカラープリンタ２０における画像処理の処理ルーチンを示すフローチャートである。
【図１３】第１の実施例におけるカラープリンタ２０において実行される画像処理の流れを示すフローチャートである。
【図１４】第１の実施例におけるカラープリンタ２０における自動画質調整処理の概念を示す説明図である。
【図１５】カラープリンタ２０における自動画質調整の処理ルーチンを示すフローチャートである。
【図１６】撮影モード、画質パラメータ、撮影モードを指定する参照番号の組み合わせの一例を示す説明図である。
【図１７】明度、シャープネスについて、各パラメータＡＰ、ＭＰ、ＦＰ、ＦＰ’の例示値を示す説明図である。
【図１８】最終画質調整パラメータＦＰを反映して変更されるトーンカーブを例示する説明図である。
【図１９】レンズ焦点距離ｆ（ｍｍ）とＦナンバーとから求められるぼかし指数をｆ／Ｆを説明する説明図である。
【図２０】他の実施例における画像処理の処理ルーチンを示すフローチャートである。
【符号の説明】
１０…画像処理システム
１２…ディジタルスチルカメラ
１２１…光学回路
１２２…画像取得回路
１２３…画像処理回路
１２４…制御回路
１２６…選択・決定ボタン
１２７…液晶ディスプレイ
１４…ディスプレイ
２０…カラープリンタ
２１…キャリッジ
２１１…印字ヘッド
２１２…インクカートリッジ
２１３…インクカートリッジ
２１４〜２２０…インク吐出用ヘッド
２２…キャリッジモータ
２３…プラテン
２４…紙送りモータ
２５…摺動軸
２６…駆動ベルト
２７…プーリ
２８…位置検出センサ
２９…操作パネル
３０…制御回路
３１…演算処理装置（ＣＰＵ）
３２…プログラマブルリードオンリメモリ（ＰＲＯＭ）
３３…ランダムアクセスメモリ（ＲＡＭ）
３４…ＰＣＭＣＩＡスロット
３５…周辺機器入出力部（ＰＩＯ）
３６…タイマ
３７…駆動バッファ
３８…バス
３９…発振器
４０…分配出力器
１００…画像ファイル（Ｅｘｉｆファイル）
１０１…ＪＰＥＧ画像データ格納領域
１０２…付属情報格納領域
１０３…Ｍａｋｅｒｎｏｔｅ格納領域
ＭＣ…メモリカード[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an image adjustment technique for adjusting the image quality of an image file.
[0002]
[Prior art]
The image quality of image data generated by a digital still camera (DSC), digital video camera (DVC), scanner, or the like can be arbitrarily adjusted by using an image retouching application on a personal computer. Generally, an image retouching application has an image adjustment function for automatically adjusting the image quality of image data. By using this image adjustment function, the image quality of image data output from an output device can be easily adjusted. Can be improved. As an image file output device, for example, a CRT, an LCD, a printer, a projector, a television receiver, and the like are known.
[0003]
A printer driver that controls the operation of a printer, which is one of the output devices, also has a function of automatically adjusting the image quality of image data. The image quality of the image data can be easily improved.
[0004]
[Problems to be solved by the invention]
However, in the image quality automatic adjustment function provided by the image retouching application and the printer driver, image quality correction is performed based on image data having general image quality characteristics. On the other hand, since image data to be subjected to image processing can be generated under various conditions, even if the image quality automatic adjustment function is executed uniformly and the image quality parameter value of the image data is changed using the specified value, In some cases, the image quality cannot be improved.
[0005]
Some image data generating apparatuses such as DSCs can arbitrarily adjust the image quality of image data when generating image data, and a user can intentionally generate image data having a predetermined image quality. Alternatively, the user can generate image data suitable for the shooting condition with a shooting quality set in advance according to the shooting condition. When the image quality automatic adjustment function is performed on such image data, even the intentional image quality of the image data is automatically adjusted based on the reference image quality. There was a problem that adjustment could not be performed. Further, there is a problem that the photographing conditions set on the DSC side are not properly reflected in the automatic image quality adjustment. Note that such a problem is not limited to the DSC, and is a common problem in other image file generation devices such as a DVC.
[0006]
The present invention has been made to solve the above-described problem, and has as its object to appropriately and automatically adjust the image quality in accordance with individual image data. Another object of the present invention is to automatically adjust the image quality of image data without impairing the image quality adjustment condition arbitrarily set.
[0007]
[Means for Solving the Problems and Functions / Effects]
According to a first aspect of the present invention, there is provided an image processing apparatus for performing image processing using image data and information on generation of image data associated with the image data. Image quality characteristic information acquiring means for acquiring image quality characteristic information, which is information indicating characteristics related to the image quality of the image data, and a correction amount for correcting the image data based on the acquired image quality characteristic information. And image quality adjustment means for adjusting the image quality of the image data by determining the determined correction amount based on the generation time information, and applying the changed correction amount to the image data. It is characterized by.
[0008]
According to the image processing apparatus according to the first aspect of the present invention, a correction amount for correcting image data is determined based on the acquired image quality characteristic information, and the determined correction amount is changed by the generation time information, Since the image quality of the image data is adjusted by applying the changed correction amount to the image data, the image quality adjustment is performed without damaging the generation time information arbitrarily set for each image data. be able to.
[0009]
In the image processing device according to the first aspect of the present invention, the image quality characteristic information includes a value of an image quality parameter indicating an image quality characteristic of the image data, and the image quality adjustment unit determines the image quality parameter value in advance. The image quality adjustment by the image quality adjusting means has a predetermined reference image quality parameter value serving as a reference for image quality adjustment, and a correction amount for correcting the image data based on the reference image quality parameter value and the image quality parameter value. And increasing or decreasing the correction amount based on the result of analyzing the generation information, and adjusting the image quality of the image data by reflecting the increased or decreased correction amount. With such a configuration, the image quality of the image data can be brought close to or equal to the standard of image quality adjustment, and the image quality of the image data can be adjusted and improved by indirectly reflecting the information at the time of generation.
[0010]
In the image processing apparatus according to the first aspect of the present invention, the image quality characteristic information is a combination of a plurality of image quality parameter values indicating image quality characteristics of the image data, and the image quality parameter value is the plurality of image quality parameter values. Each of the parameter values may be predetermined. With this configuration, it is possible to make the image quality of the image data close to or equal to the image quality adjustment standard for a plurality of image quality parameter values, adjust the image quality of the image data by indirectly reflecting the generation time information, Can be improved.
[0011]
In the image processing apparatus according to the first aspect of the present invention, the increase or decrease of the correction amount based on a result of analyzing the generation information is performed by changing the reference image quality parameter value based on a result of analyzing the generation information. The correction may be performed, or may be performed by determining an application level of the correction amount based on a result of analyzing the generation information. In the former case, the reference image quality parameter value serving as an adjustment index of the image quality parameter value can be corrected, so that the image quality adjustment can be performed without impairing the characteristics of the individual image data. In the latter case, since the application level of the correction amount can be determined based on the result of analyzing the generation information, the image quality adjustment can be performed without deteriorating the characteristics of the individual image data.
[0012]
In the image processing device according to the first aspect of the present invention, the reference image quality parameter value is a combination of parameter values selected from a plurality of values corresponding to the acquired image quality parameter values based on the generation time information. It may be. Further, the information at the time of generation may include at least correction information for any one of information relating to contrast, brightness, color balance, saturation, sharpness, memory color, and information related to noise removal. The image data and the generation information may be stored in the same image file.
[0013]
A second aspect of the present invention provides an output device that outputs an image using image data and information at the time of generation of the image data associated with the image data. An output device according to a fourth aspect of the present invention includes an image processing device according to the first invention of the present invention, and an image output unit that outputs an image of image data that has been subjected to image processing by the image processing device. It is characterized by having.
[0014]
According to the output device according to the second aspect of the present invention, the output device supports each image data by reflecting the generation time information used when adjusting the image quality of the image data and the image quality characteristic information of the acquired image data. Thus, an image of image data whose image quality has been automatically adjusted appropriately can be output. Further, it is possible to output an image of image data whose image quality has been adjusted without losing arbitrarily set generation time information.
[0015]
A third aspect of the present invention provides an image processing method for performing image processing using image data and information on generation of image data associated with the image data. An image processing method according to a third aspect of the present invention analyzes the image data, acquires image quality characteristic information that is information indicating a characteristic related to the image quality of the image data, and stores the acquired image quality characteristic information in the acquired image quality characteristic information. A correction amount for correcting the image data is determined based on the image data, and the determined correction amount is changed according to the generation time information, and the changed correction amount is applied to the image data. The image quality is adjusted.
[0016]
The image processing method according to the third aspect of the present invention has the same operation and effect as the image processing apparatus according to the first aspect of the present invention, and performs the same operation as the image processing apparatus according to the first aspect of the present invention. It is realized in various modes.
[0017]
A fourth aspect of the present invention provides an image processing program for performing image processing using image data and information at the time of generation of the image data associated with the image data. An image processing program according to a fourth aspect of the present invention has a function of analyzing the image data and acquiring image quality characteristic information that is information indicating a characteristic related to the image quality of the image data; Determining a correction amount for correcting the image data based on information, changing the determined correction amount according to the generation information, and applying the changed correction amount to the image data. The function of adjusting the image quality of data is executed by a computer.
[0018]
The image processing program according to the fourth aspect of the present invention has the same operation and effect as the image processing apparatus according to the first aspect of the present invention, and has the same function as the image processing apparatus according to the first aspect of the present invention. It is realized in various modes.
[0019]
A fifth aspect of the present invention provides an image processing apparatus for generating output image data using image data and information on generation of image data associated with the image data. An image processing apparatus according to a fifth aspect of the present invention includes: an image data storage unit that stores image data to be adjusted for image quality; an image data acquisition unit that acquires image data from the image data storage unit; Analyzing the obtained image data, image quality characteristic information obtaining means for obtaining image quality characteristic information that is information indicating characteristics related to the image quality of the image data, and the image data based on the obtained image quality characteristic information Determining a correction amount for correcting the image data, changing the determined correction amount according to the generation time information, and adjusting the image quality of the image data by applying the changed correction amount to the image data. The image processing apparatus further includes an adjustment unit, and an image data output unit that outputs the image data whose image quality has been adjusted.
[0020]
According to the image processing apparatus according to the fifth aspect of the present invention, the image data acquired from the image data storage unit is analyzed to acquire image quality characteristic information, and the correction amount for correcting the image data based on the acquired image quality characteristic information Is determined, the determined correction amount is changed by the generation time information, and the image quality of the image data is adjusted by applying the changed correction amount to the image data. The image quality adjustment can be performed without damaging the arbitrarily set generation time information.
[0021]
In the image processing device according to a fifth aspect of the present invention, the image data storage means may be removable.
[0022]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, image adjustment of an image file according to the present invention will be described based on some embodiments with reference to the drawings in the following order.
A. Configuration of image processing system:
B. Structure of image file:
C. Configuration of image output device:
D. Image processing in digital still cameras:
E. FIG. Image processing in the printer:
F. Other embodiments:
[0023]
A. Configuration of image processing system:
A configuration of an image processing system to which the image processing apparatus according to the first embodiment can be applied will be described with reference to FIGS. FIG. 1 is an explanatory diagram illustrating an example of an image processing system to which the image processing device according to the first embodiment can be applied. FIG. 2 is a block diagram illustrating a schematic configuration of a digital still camera capable of generating an image file (image data) output by the image processing apparatus according to the first embodiment.
[0024]
An image processing system 10 includes a digital still camera 12 as an input device that generates an image file, and a color printer as an output device that executes image processing based on the image file generated by the digital still camera 12 and outputs an image. 20. As the output device, in addition to the printer 20, a monitor 14 such as a CRT display and an LCD display, a projector, and the like can be used. In the following description, the color printer 20 is used as the output device.
[0025]
The digital still camera 12 is a camera that obtains an image by forming light information on a digital device (CCD or photomultiplier tube), and includes a CCD or the like for collecting light information as shown in FIG. An optical circuit 121, an image acquisition circuit 122 for controlling the optical circuit 121 to acquire an image, an image processing circuit 123 for processing an acquired digital image, and a control circuit 124 including a memory and controlling each circuit. Have. The digital still camera 12 stores the obtained image as digital data in a memory card MC as a storage device. As a storage format of image data in the digital still camera 12, a JPEG format is generally used, but other storage formats such as a TIFF format, a GIF format, a BMP format, and a RAW format may be used.
[0026]
In the digital still camera 12, a plurality of image processing control parameters are set in advance according to individual image processing control parameters such as brightness, contrast, exposure correction amount (exposure correction value), white balance and the like, and shooting conditions. A selection / decision button 126 for setting the current shooting mode, a liquid crystal display 127 for previewing a shot image, and setting a shooting mode and the like using the selection / decision button 126 are provided. The setting procedure of the shooting mode and the image quality parameter using the selection / decision button 126 and the liquid crystal display 127 will be described later.
[0027]
The digital still camera 12 used in the image processing system 10 stores image processing control information GC of image data in addition to the image data GD in the memory card MC as an image file GF. That is, the image processing control information GC is automatically stored in the memory card MC as an image file GF together with the image data GD at the time of shooting. When the user selects a shooting mode suitable for shooting conditions such as a person, a night view, and a sunset view, the parameter value of the image processing control parameter corresponding to the selected shooting mode, or the exposure correction amount, When an image processing control parameter such as white balance is set to an arbitrary value, an image file GF including the set value of the set image processing control parameter as image processing control information GC is stored in the memory card MC. .
[0028]
When photographing is performed in the automatic photographing mode in the digital still camera 12, the values of parameters such as exposure time, white balance, aperture, shutter speed, and focal length of the lens that are automatically set at the time of photographing are displayed in the image. Image files GF that are treated as processing control parameters and include these image processing control parameters are stored in the memory card MC. Note that parameters and parameter values applied to each shooting mode are held in a memory in the control circuit 124 of the digital still camera 12.
[0029]
The image file GF generated by the digital still camera 12 is sent to the color printer 20 via, for example, the cable CV, the computer PC, or the cable CV. Alternatively, the memory card MC storing the image file GF in the digital still camera 12 is connected to the printer 20 via the computer PC mounted in the memory card slot or directly to the printer 20. Thus, the image file is sent to the color printer 20. The following description is based on the case where the memory card MC is directly connected to the color printer 20.
[0030]
B. Structure of image file:
A schematic configuration of an image file that can be used in the present embodiment will be described with reference to FIG. FIG. 3 is an explanatory diagram conceptually showing an example of the internal configuration of an image file that can be used in the present embodiment. The image file GF includes an image data storage area 101 for storing image data GD, and an image processing control information storage area for storing image processing control information (image quality adjustment processing conditions) GC which is referred to and applied during automatic image quality adjustment of image data. 102 is provided. The image data GD is stored in, for example, a JPEG format, and the image processing control information GC is stored in a TIFF format. Note that terms such as file structure, data structure, and storage area in this embodiment mean an image of a file or data in a state where the file or data is stored in the storage device.
[0031]
The image processing control information GC is information for specifying image processing conditions when performing image processing on image data generated by an image data generation device such as the digital still camera 12, and includes exposure time, which can be arbitrarily set by a user, It may include parameters related to ISO sensitivity, aperture, shutter speed, focal length, and image processing control parameters such as exposure correction amount, white balance, shooting mode, and target color space arbitrarily set by the user. Alternatively, when a shooting mode is specified by the user, a combination of image processing control parameters related to the specified shooting mode may be automatically included as image processing control information GC.
[0032]
The image file GF according to the present embodiment can be generated not only by the digital still camera 12, but also by an input device (image file generating device) such as a digital video camera and a scanner. When generated by a digital video camera, for example, an image file storing still image data and output control information or a moving image file including moving image data in MPEG format and output control information is generated. You. When this moving image file is used, output control according to the output control information is performed on all or some frames of the moving image.
[0033]
The image file GF according to the present embodiment basically only needs to include the image data area 101 and the image processing control information storage area 102, and has a file structure according to a file format that has already been standardized. be able to. Hereinafter, a case where the image file GF according to the present embodiment is adapted to a standardized file format will be specifically described.
[0034]
The image file GF according to the present embodiment can have a file structure according to, for example, an image file format standard for digital still cameras (Exif). The specification of the Exif file is defined by the Japan Electronics and Information Technology Industries Association (JEITA). A schematic structure inside a file when the image file GF according to the present embodiment has a file format according to the Exif file format will be described with reference to FIG. FIG. 4 is an explanatory diagram showing a schematic internal structure of the image file GF according to the present embodiment stored in the Exif file format.
[0035]
The image file GFE as an Exif file includes a JPEG image data storage area 111 for storing JPEG image data, and an auxiliary information storage area 112 for storing various information related to the stored JPEG image data. The JPEG data storage area 111 corresponds to the image data storage area 101, and the attached information storage area 112 corresponds to the image processing control information storage area 102. That is, the attached information storage area 112 stores image processing control information GC (image quality adjustment processing conditions) referred to when outputting a JPEG image such as shooting date and time, exposure, shutter speed, white balance, exposure correction amount, and target color space. ) Is stored. Further, in the attached information storage area 112, in addition to the image processing control information GC, thumbnail image data of the JPEG image stored in the JPEG image data storage area 111 is stored in TIFF format. Note that, as is well known to those skilled in the art, in the Exif format file, tags are used to specify each data, and each data may be referred to by a tag name.
[0036]
The detailed data structure of the attached information storage area 112 will be described with reference to FIG. FIG. 5 is an explanatory diagram showing an example of the data structure of the attached information storage area 112 of the image file GF that can be used in this embodiment.
[0037]
In the attached information storage area 112, parameter values for image processing control information GC such as exposure time, lens F value, exposure control mode, ISO sensitivity, exposure correction amount, white balance, flash, focal length, shooting mode, etc. Are stored according to a predetermined address or offset value. On the output device side, the image processing control information GC can be obtained by specifying an address or an offset value corresponding to desired information (parameter). Note that the image processing control information GC is an undefined area in the attached information storage area 112 and is stored in a user-defined area that is open to the user.
[0038]
C. Configuration of image output device:
The schematic configuration of the image output device according to the present embodiment, that is, the color printer 20, will be described with reference to FIG. FIG. 6 is a block diagram illustrating a schematic configuration of the color printer 20 according to the present embodiment.
[0039]
The color printer 20 is a printer capable of outputting a color image and, for example, ejects four color inks of cyan (C), magenta (M), yellow (Y), and black (K) onto a print medium. This is an ink jet printer that forms an image by forming a dot pattern. Alternatively, it is an electrophotographic printer that forms an image by transferring and fixing a color toner on a print medium. As the color ink, in addition to the above four colors, light cyan (light cyan, LC), light magenta (light magenta, LM), and dark yellow (dark yellow, DY) may be used.
[0040]
As shown, the color printer 20 drives a print head 211 mounted on a carriage 21 to eject ink and form dots, and reciprocates the carriage 21 in the axial direction of a platen 23 by a carriage motor 22. The control circuit 30 includes a mechanism for causing the print paper P to be conveyed by the paper feed motor 24, and a control circuit 30. The mechanism for reciprocating the carriage 21 in the axial direction of the platen 23 includes an endless drive between a slide shaft 25 for slidably holding the carriage 21 erected in parallel with the axis of the platen 23 and the carriage motor 22. It is composed of a pulley 27 on which a belt 26 is stretched, a position detection sensor 28 for detecting the origin position of the carriage 21, and the like. The mechanism for transporting the printing paper P includes a platen 23, a paper feed motor 24 for rotating the platen 23, a paper feed auxiliary roller (not shown), and a gear train for transmitting the rotation of the paper feed motor 24 to the platen 23 and the paper feed auxiliary roller. (Not shown).
[0041]
The control circuit 30 appropriately controls the movements of the paper feed motor 24, the carriage motor 22, and the print head 211 while exchanging signals with the operation panel 29 of the printer. The printing paper P supplied to the color printer 20 is set so as to be sandwiched between the platen 23 and the paper feed auxiliary roller, and is fed by a predetermined amount according to the rotation angle of the platen 23.
[0042]
An ink cartridge 212 and an ink cartridge 213 are mounted on the carriage 21. The ink cartridge 212 contains black (K) ink, and the ink cartridge 213 contains other inks, namely, cyan (C), magenta (M), and yellow (Y) inks, as well as light cyan (LC). ), Light magenta (LM), and dark yellow (DY).
[0043]
Next, an internal configuration of the control circuit 30 of the color printer 20 will be described with reference to FIG. FIG. 7 is an explanatory diagram showing the internal configuration of the control circuit 30 of the color printer 20. As shown in the figure, inside the control circuit 30, a peripheral device I / O for exchanging data with the CPU 31, the PROM 32, the RAM 33, the PCMCIA slot 34 for acquiring data from the memory card MC, the paper feed motor 24, the carriage motor 22, and so on A unit (PIO) 35, a timer 36, a driving buffer 37, and the like are provided. The drive buffer 37 is used as a buffer that supplies a dot on / off signal to the ink ejection heads 214 to 220. These are connected to each other via a bus 38 so that data can be exchanged with each other. The control circuit 30 also includes an oscillator 39 that outputs a drive waveform at a predetermined frequency, and a distribution output device 40 that distributes the output from the oscillator 39 to the ink ejection heads 214 to 220 at a predetermined timing.
[0044]
The control circuit 30 reads the image file GF from the memory card MC, analyzes the attached information AI, and executes image processing based on the analyzed control information AI. The control circuit 30 outputs dot data to the drive buffer 37 at a predetermined timing while synchronizing with the movements of the paper feed motor 24 and the carriage motor 22. The detailed flow of image processing executed by the control circuit 30 will be described later.
[0045]
D. Image processing in digital still cameras:
Hereinafter, the image processing in the digital still camera 12 will be described with reference to FIG. FIG. 8 is a flowchart showing the flow of the process of generating the image file GF in the digital still camera 12.
[0046]
Prior to photographing, the control circuit 124 of the digital still camera 12 determines whether or not the photographing mode or image processing control information (image processing control parameters) such as white balance and exposure correction amount has been set by the user (see FIG. 1). Step S100). The setting of the image processing control information is executed by operating the selection / setting button 126 and selecting by the user from the shooting modes prepared in advance and displayed on the liquid crystal display 127. Alternatively, it is executed by operating the selection / setting button 126 in the same manner and setting the values of image processing control parameters such as brightness and contrast on the liquid crystal display 127 by the user.
[0047]
The procedure for setting the image processing control parameters on the liquid crystal display 127 using the select / set button 126 will be described with reference to FIGS. 9 to 11 are explanatory diagrams illustrating exemplary display modes of the liquid crystal display 127. FIG. When the “image processing control” area A1 displayed on the liquid crystal display 127 is selected by operating the selection / setting button 126 (see FIG. 9), the “photographing mode” area A2 and the “image processing control parameter” area A3 are changed. It is displayed on the liquid crystal display 127 (see FIG. 10). The shooting modes are numbered 1, 2,. . . The image processing control parameters are set by inputting a desired number. For example, when one of the shooting modes is set, the setting state of each image processing control parameter set in the set shooting mode is displayed on the liquid crystal display 127 as shown in FIG. In this example, the setting state of each image processing control parameter is displayed in a manner that is easy for the user to understand, but a parameter value may be displayed.
[0048]
When the control circuit 124 determines that the image processing control information is set (step S100: Yes), the control circuit 124 is specified by the set image processing control information in response to a shooting request, for example, pressing down a shutter button. The image data GD is generated using the parameter values (step S110). The control circuit 124 stores the generated image data GD and image processing control information GC including arbitrarily set correction conditions and automatically applied correction conditions in the memory card MC as an image file GF (step S120). ), End this processing routine. The data generated by the digital still camera 12 is converted from the RGB color space and is represented by the YCbCr color space.
[0049]
On the other hand, when the control circuit 124 determines that the image processing control information is not set (step S100: No), the control circuit 124 generates the image data GD in response to the photographing request (step S130). The control circuit 124 stores the generated image data GD and the image processing control information GC including the correction conditions automatically given at the time of generating the image data in the memory card MC as the image file GF (step S140), and performs this processing. End the routine. Note that the image processing control information GC is stored in a user-defined area in a file structure having a predetermined file format, as described above.
[0050]
By the above processing executed in the digital still camera 12, the image file GF stored in the memory card MC and the image data GD together with the correction conditions automatically given when the image data is generated and the correction conditions arbitrarily set Is provided.
[0051]
E. FIG. Image processing in the color printer 20:
Image processing in the color printer 20 according to the present embodiment will be described with reference to FIGS. FIG. 12 is a flowchart illustrating a processing routine of image processing in the color printer 20 according to the present embodiment. FIG. 13 is a flowchart showing the flow of image processing in the color printer 20. FIG. 14 is an explanatory diagram showing the concept of the automatic image quality adjustment processing in the color printer 20. FIG. 15 is a flowchart showing a processing routine for automatic image quality adjustment in the color printer 20. In the image processing in the color printer 20 according to the present embodiment, the color space conversion processing is executed first, and then the automatic image quality adjustment is executed.
[0052]
When the memory card MC is inserted into the slot 34, the control circuit 30 (CPU 31) of the color printer 20 reads the image file GF from the memory card MC, and temporarily stores the read image file GF in the RAM 33 (Step S100). . The CPU 31 searches the attached information storage area 102 of the read image file GF for image processing control information GC indicating information at the time of generating image data (step S110). When the image processing control information has been searched for and found (step S120: Yes), the CPU 31 acquires and analyzes the image processing control information GC at the time of generating the image data (step S130). The CPU 31 executes image processing described later in detail based on the analyzed image processing control information GC (step S140), and prints out the processed image data (step S150).
[0053]
When the image processing control information cannot be searched and found (step S120: No), the CPU 31 cannot reflect the image processing control information at the time of generating the image data. Image processing control information, that is, various parameter values, is acquired from the ROM 32 and normal image processing is executed (step S160). CPU 31 prints out the processed image data (step S150), and terminates this processing routine.
[0054]
The image processing executed in the color printer 20 will be described in detail with reference to FIG. The CPU 31 of the color printer 20 extracts the image data GD from the read image file GF (Step S200). As described above, the digital still camera 12 stores image data as a JPEG file. In the JPEG file, the image data is stored using a YCbCr color space in order to increase the compression ratio.
[0055]
The CPU 31 executes a 3 × 3 matrix operation S in order to convert image data based on the YCrCb color space into image data based on the RGB color space (step S210). The matrix operation S is an operation expression shown below.
[0056]
(Equation 1)

[0057]
The CPU 31 executes gamma correction and matrix operation M on the image data based on the RGB color space thus obtained (step S220). When performing gamma correction, the CPU 31 obtains a DSC-side gamma value from the image processing control information GC, and performs gamma conversion processing on video data using the obtained gamma value. That is, the gamma value is also included in the image processing control parameter value specified by the image processing control information GC. The matrix operation M is an operation for converting an RGB color space into an XYZ color space. Since the image file GF used in the present embodiment can specify color space information to be used at the time of image processing, when the image file GF includes color space information, the CPU 31 executes the matrix operation M At this time, a matrix operation is executed using the matrix (M) corresponding to the designated color space with reference to the color space information. The matrix operation M is an operation expression shown below.
[0058]
(Equation 2)

[0059]
The color space of the image data GD obtained after the execution of the matrix operation M is an XYZ color space. Conventionally, a color space used for image processing in a printer or a computer is fixed to sRGB, and the color space of the digital still camera 12 cannot be effectively used. On the other hand, in the present embodiment, when the color space is specified by the image file GF, a printer (printer driver) that changes the matrix (M) used for the matrix operation M according to the color space information. Is used. Therefore, correct color reproduction can be realized by effectively utilizing the color space of the digital still camera 12.
[0060]
The CPU 31 executes a process of converting the color space of the image data GD from the XYZ color space to the wRGB color space, that is, the matrix operation N− ¹ and the inverse gamma correction, in order to perform image adjustment based on the image processing control information GC. (Step S230). Note that the wRGB color space is a color space wider than the sRGB color space. When performing gamma correction, the CPU 31 obtains a default gamma value on the printer side from the ROM 32, and performs inverse gamma conversion processing on video data using the reciprocal of the obtained gamma value. When executing the matrix operation N- ¹ , the CPU 31 executes the matrix operation using the matrix (N- ¹ ) corresponding to the conversion from the ROM 31 to the wRGB color space. The matrix operation N- ¹ is an operation expression shown below.
[0061]
[Equation 3]

[0062]
The color space of the image data GD obtained after execution of the matrix operation N- ¹ is a wRGB color space. As described above, the wRGB color space is a color space wider than the sRGB color space, and corresponds to a color space that can be generated by the digital still camera 12.
[0063]
The CPU 31 executes an automatic adjustment process of the image quality (step S240). The concept of the image quality automatic adjustment process in the present embodiment will be described with reference to FIG. The image file GF includes image data GD to be adjusted and image processing control information GC used for adjusting the image quality. The color printer 20 (CPU 31) analyzes the image data GD to obtain an image statistical value (characteristic parameter value) SV indicating a characteristic of the image data GD, and analyzes the image processing control information GC to obtain a reference image quality parameter value SP. , And a manual correction parameter value MP. The color printer 20 determines the automatic image quality adjustment parameter AP based on the image statistics SV and the reference image quality parameter value SP, and further determines the final image quality adjustment parameter FP = AP + MP. The color printer 20 adjusts the image quality of the image data GD using the determined final image quality adjustment parameter FP, and outputs the adjusted image data GD ′ to the printer driver.
[0064]
Details of the automatic image quality adjustment processing will be described in detail with reference to FIG. First, the CPU 31 analyzes the image data GD, acquires various characteristic parameter values (image statistical values) SV indicating the characteristics of the image data GD, and temporarily stores them in the RAM 32 (step S300). The CPU 31 acquires the image processing control information GC from the image file GF (step S310), and acquires the manual correction parameter value MP based on the image processing control information GC (step S320). The parameters acquired as the manual correction parameter value MP include image processing control parameters such as white balance, exposure correction amount, exposure time, aperture, ISO, and focal length. The manual correction parameter value MP is a value independent of the analysis result of the image data GD, that is, a value independent of the image statistical value SV, and is reflected as it is in the final image quality adjustment parameter FP.
[0065]
The CPU 31 determines whether or not the acquired image processing control information GC includes a parameter value that specifies a shooting mode (step S320). In this embodiment, a plurality of different image processing control parameters are combined for each shooting scene in determining the automatic image quality adjustment parameter value AP, that is, the automatic image quality adjustment amount reflecting the image statistics SV of the image data GD. Use the shooting mode. In this embodiment, the shooting modes are 1, 2,. . . Therefore, when a shooting mode is specified, it is necessary to analyze and determine individual image processing control parameters that define each shooting mode based on the reference number. When determining that the shooting mode has been designated (step S330: Yes), the CPU 31 analyzes the shooting mode based on the designated reference number and acquires each image processing control parameter defining the shooting mode. Then, the reference image quality parameter value SP is determined according to a procedure described later (step S340). Note that, even when the shooting mode is set, the manual correction parameter value MP can be specified in parallel as described above.
[0066]
Combinations of the respective image processing control parameters that define the shooting mode and combinations of numerical values that specify the shooting mode are as shown in FIG. FIG. 16 is an explanatory diagram showing an example of a combination of a shooting mode, an image quality parameter, and a numerical value designating a shooting mode. Items such as contrast and brightness for each shooting mode clearly show the image quality obtained as a result of the automatic image quality adjustment. The image quality specified by each item is analyzed by the CPU 31, and the specified image quality is displayed. In order to realize the above, a single or a plurality of image processing control parameter values are set for each item. The shooting mode 1 is suitable for, for example, standard shooting conditions, the shooting mode 2 is suitable for, for example, a shooting condition for shooting a person, the shooting mode 3 is suitable for, for example, a shooting condition for shooting a landscape, and the shooting mode 4 Is suitable for, for example, a shooting condition for shooting a sunset, the shooting mode 5 is suitable for, for example, a shooting condition for shooting a night view, and the shooting mode 6 is suitable for, for example, a shooting condition for shooting a flower. The shooting mode 7 is suitable for, for example, shooting conditions for macro shooting, the shooting mode 8 is suitable for, for example, shooting conditions for a person playing sports, and the shooting mode 9 is, for example, suitable for shooting conditions under backlight. The photographing mode 10 is suitable for, for example, photographing conditions for photographing autumn leaves, and the photographing mode 11 is suitable for, for example, photographing conditions for commemorative photographing. If the shooting mode is not set, the parameter indicating the set shooting mode is set to 0.
[0067]
If the CPU 31 determines that the shooting mode is not specified, that is, if the shooting mode parameter is set to 0 (step S330: No), the image processing control individually set in the image quality adjustment processing is performed. The process proceeds to step S350 to reflect the parameters.
[0068]
The CPU 31 changes (corrects) the reference value set for each parameter while reflecting the acquired value of the image processing control parameter. The reference value set for each parameter is a value assuming image data generated under general image generation conditions. Therefore, in order to realize automatic image quality adjustment that correctly reflects the intention of the photographer (image creator), particularly, regarding the image processing control conditions that can be arbitrarily set by the photographer, the individual image processing control conditions are considered. , Change the reference value. Note that the reference value is an index value of a parameter that optimizes an output result of an image determined in advance by image evaluation based on quantitative evaluation and sensitivity evaluation.
[0069]
For example, when the shooting mode parameter is set to 2, the lightness reference value is changed from the standard value 128 to a slightly brighter value 144, the saturation reference value is changed from the standard value 128 to a slightly weaker value 102, and the sharpness reference value is changed. The value is changed from the standard value 200 to a slightly weaker value 150. Further, the contrast correction coefficient is changed from the standard value 5 to a slightly soft value 2, and the color balance correction coefficient is maintained at the standard value 5. The change of each reference value and each coefficient is realized, for example, by increasing or decreasing a numerical value with respect to each reference value and each coefficient, or by increasing or decreasing each reference value and each coefficient at a predetermined ratio. Alternatively, for example, as the lightness reference value, 144 may be prepared as a default value as a slightly bright value, and 112 may be prepared as a default value as a slightly dark value, and the reference value may be replaced according to the tendency of correction such as slightly bright or slightly dark.
[0070]
The CPU 31 obtains a deviation between the reference image quality parameter value SP and the image quality parameter value SV corrected as described above, and determines the deviation as the automatic image quality adjustment parameter value AP (step S350). For example, when the image quality parameter values SV are lightness 160 and sharpness 155, the automatic image quality adjustment parameter value AP for lightness is 160-144 = 16, and the automatic image quality adjustment parameter value AP for sharpness is 155-150 = 5. Become.
[0071]
As shown in FIG. 17, the CPU 31 obtains a final image quality adjustment parameter FP (image data correction amount) = AP + MP from the determined automatic image quality adjustment parameter value AP and the acquired manual correction parameter value MP, and determines the final image quality adjustment parameter FP. The automatic image quality adjustment is executed with the reflection (step S360). FIG. 17 is an explanatory diagram showing exemplary values of parameters AP, MP, FP, and FP ′ for brightness and sharpness. For example, when the lightness +10 and the sharpness -10 are set as the manual correction parameter values MP, the final image quality adjustment parameter FP for lightness FP = 16 + 10 = 26 and the final image quality adjustment parameter FP for sharpness FP = 5-10 = It becomes -5. For each image quality parameter of shadow, highlight, brightness, contrast, color balance, and memory color correction, the CPU 31 associates the input level and the output level of the RGB components of the image data GD shown in FIG. Curve) to adjust the image quality. FIG. 18 is an explanatory diagram illustrating a tone curve changed by reflecting the final image quality adjustment parameter FP. When adjusting the image quality using the tone curve, one tone curve is changed for each of the RGB components, reflecting each FP for each image quality parameter, and finally, each of the RGB components is changed. The input-output conversion is performed for each of the RGB components of the image data GD using the respective tone curves. As a result, image data GD with adjusted image quality is obtained.
[0072]
The image quality automatic adjustment process for each image quality parameter is specifically executed as follows, for example.
For contrast, shadow, and highlight, a shadow point and a highlight point are detected from image data, level correction is performed based on a reference value, and histogram expansion is performed. Further, the tone curve is corrected based on the reference value based on the luminance standard deviation.
Regarding the brightness, it is determined whether the image is dark (underexposure) or bright (overexposure) based on a luminance value calculated from each area obtained by dividing the image data into 14 parts, and based on a reference value. Execute tone curve correction.
Regarding the color balance, the bias of the color balance is analyzed from the histograms of the R component, the G component, and the B component of the image data, and the tone curves of the R component, the G component, and the B component are determined based on the reference values for the RGB components. To reduce the color cast. When the shooting mode is set to 4 or 5, the color balance is intentionally set even if the color cast occurs, so that the automatic adjustment of the color balance is not executed and the user's intention is reflected. Execute the image quality correction.
Regarding the saturation, the saturation distribution of the image data is analyzed, and the saturation is enhanced based on the reference value. Therefore, the level of saturation enhancement is higher for lower-saturation image data.
Regarding sharpness, correction is performed by analyzing the frequency distribution of image data and the intensity distribution of edges, and performing an unsharp mask based on a reference value. The reference value is determined based on the frequency distribution. The higher the high-frequency image data (landscape, etc.), the smaller the reference value, and the lower the frequency image data (person, etc.), the larger the reference value. Further, the application amount of the unsharp mask depends on the edge intensity distribution, and the application amount increases as the image data has blurred characteristics.
-Regarding the memory color, for the "skin color", "green", "sky blue", "red in the sunset", etc., which are generally called memory colors, the corresponding image layer is extracted from the image data, and the color considered to be preferable Execute the correction so that
The noise removal is executed by reducing the color noise by applying a smoothing filter to the color difference component CbCr of YCbCr.
[0073]
The image processing control parameters also include a level of application of the final image quality adjustment parameter FP, that is, a level designation parameter LP for designating the degree to which the image data DG approaches the image data based on the reference value. The level designation parameter LP is used, for example, as FP ′ = AP * (LP / 5) + MP, and is reflected only in the automatic correction parameter value AP, not in the manual correction parameter value MP. Therefore, for example, when LP = 10, the value of the final image quality adjustment parameter AP is doubled as shown in FIG. 17, and when LP = 5, the value of the final image quality adjustment parameter AP is multiplied by one. . The tone curve is changed based on FP ′, and when LP = 10, the change amount of the tone curve is doubled. Further, only the level approaching the reference value may be changed based on the image processing control information GC without changing the reference value.
[0074]
Next, an image quality automatic adjustment process that reflects image processing control parameters corresponding to operation (photographing) conditions of the digital still camera 12, such as a photometry method and a lens focal length, will be described. When the image processing control parameter of the photometry method indicates spot photometry, multi-spot photometry, or partial photometry, the automatic image quality adjustment processing for lightness (brightness) is not performed. In general photometry, the brightness of the entire screen is calculated to obtain an appropriate exposure.In spot metering, however, the brightness of a portion of the screen is measured and the exposure is adjusted so that the metered area is appropriate. decide. That is, the user instructs that a specific area of the screen is to be properly exposed. In such a case, if the brightness is automatically adjusted, an image quality adjustment process that does not reflect the user's intention is executed. Therefore, in these three photometric modes, automatic brightness adjustment is not performed.
[0075]
The reference value of sharpness is changed based on the lens focal length and the F number at the time of shooting. Generally, “blur” is determined by the focal length of the lens and the F number (aperture). Therefore, when automatically adjusting the sharpness, the image quality adjustment processing reflecting the blur assumed at the time of shooting can be executed by associating the reference value corresponding to the sharpness with the lens focal length and the F-number. For example, in the case of F13 (large aperture) with a wide-angle lens (35 mm or less), the photographer generally intends to focus on the entire screen from the foreground to the background and shoot sharply in landscapes, commemorative photography, etc. Can be determined to be. Therefore, in such a case, the image quality is adjusted so that the sharpness reference value is reduced and a sharpness effect is applied to more images, and the sharpness is applied by increasing the amount of sharpness applied. On the other hand, in the case of F2 (open aperture) with a telephoto lens (100 mm or more), it is generally determined that the photographer intends to blur the background in order to make the subject stand out in a portrait or the like. it can. Therefore, in such a case, the sharpness reference value is increased, and the sharpness effect is applied only to the boundary pixels between the background and the subject without applying the sharpness effect to smooth areas such as skin, and the amount of sharpness applied is reduced. Then, the image quality adjustment processing is executed so as not to roughen the skin or the like.
[0076]
When the blurring index obtained from the lens focal length f (mm) and the F number is defined as f / F, the relationship becomes as shown in FIG. FIG. 19 is an explanatory diagram for explaining f / F as a blur index obtained from the lens focal length f (mm) and the F number.
[0077]
After executing the above-described automatic image quality adjustment (step S360), the CPU 31 returns to the image processing routine which is the main routine.
[0078]
Upon ending the image quality automatic adjustment process, the CPU 31 executes a wRGB color conversion process and a halftone process for printing (step S250). In the wRGB color conversion processing, the CPU 31 refers to a lookup table (LUT) for conversion into a CMYK color space corresponding to the wRGB color space stored in the ROM 31, and changes the color space of the image data from the wRGB color space to the CMYK. Change to color space. That is, the image data composed of the R, G, and B gradation values is converted into data of gradation values of six colors, for example, C, M, Y, K, LC, and LM, to be used in the color printer 20.
[0079]
In the halftone process, color-converted image data is received, and a tone number conversion process is performed. In the present embodiment, the image data after the color conversion is expressed as data having 256 gradation widths for each color. On the other hand, the color printer 20 according to the present embodiment can take only one of the states “form dots” and “do not form dots”. Only the key can be expressed. Therefore, image data having 256 gradations is converted into image data expressed in two gradations that can be expressed by the color printer 20. As typical methods of the binarization (binarization) processing, there are a method called an error diffusion method and a method called an organized dither method.
[0080]
In the color printer 20, prior to the color conversion processing, if the resolution of the image data is lower than the printing resolution, linear interpolation is performed to generate new data between adjacent image data, and conversely, if the resolution is higher than the printing resolution. Performs a resolution conversion process of converting the resolution of image data into a print resolution by thinning out data at a fixed rate. In addition, the color printer 20 executes an interlace process of rearranging the image data converted into a format representing the presence or absence of dot formation into an order to be transferred to the color printer 20.
[0081]
As described above, according to the digital still camera 12 in the present embodiment, it is possible to set image processing control conditions in the image quality adjustment processing executed by the printer 20 on the digital still camera 12. Therefore, it is possible to set desired image processing control conditions for image data at the time of shooting, and it is possible to realize image quality adjustment processing that appropriately reflects image processing control conditions desired at the time of shooting. In addition, image data and image processing control conditions assumed at the time of shooting can be easily associated with each other, and individual image processing control conditions suitable for each image data can be given. Further, when automatically adjusting the image quality of the image data, it is not necessary to newly set the image processing control conditions, and the image quality adjustment processing reflecting the image processing control conditions can be facilitated.
[0082]
Further, according to the color printer 20 of the present embodiment, the image quality of the image data GD can be automatically adjusted by reflecting the image processing control information GC included in the image file GF. Therefore, the image quality automatic adjustment suitable for each image data can be executed by reflecting the photographing conditions at the time of photographing. Further, when the image quality adjustment condition of the image data is arbitrarily set by the user, the image quality automatic adjustment is performed by reflecting the arbitrarily set image processing control condition. It is possible to solve a problem in the conventional image quality automatic adjustment function that the adjustment condition is corrected and the intention of the user cannot be reflected.
[0083]
In addition, since the image quality can be automatically adjusted using the image processing control information GC included in the image file GF, the user can easily take a picture without adjusting the image quality on a photo retouching application or a printer driver. It is possible to obtain a high quality print result reflecting the intention.
[0084]
In the above embodiment, an example in which the image quality adjustment processing is automatically executed is described. However, an image quality automatic adjustment button is provided on the operation panel of the color printer 20, and the image quality automatic adjustment is selected by the image quality automatic adjustment button. The automatic image quality adjustment processing of the above embodiment may be executed only when the image quality adjustment is performed.
[0085]
F. Other embodiments:
In the above embodiment, in reflecting the image processing control information GC, the image processing control information GC is analyzed, the image processing control parameters are acquired, and the reference value and the application level are changed. The image data GD may be directly corrected based on this. At this time, the image processing control information GC may include information indicating how much the image data GD is changed, for example, increasing the correction amount of the brightness by +10 or increasing the brightness by + 10%. In such a case, the correction tendency intended by the user can be reflected in the image quality adjustment processing without being affected by the image quality characteristics of the image data GD.
[0086]
In the above embodiment, all image processing is executed in the color printer 20 without the intervention of the personal computer PC, and a dot pattern is formed on a print medium in accordance with the generated image data GD. Alternatively, a part may be executed on a computer or a server via a network. In this case, this is realized by providing an image data processing application (program) such as a retouch application and a printer driver installed on a hard disk or the like of the computer with the image processing function described with reference to FIG. The image file GF generated by the digital still camera 12 is provided to a computer via a cable or via a memory card MC. On the computer, an application is started by a user's operation to read the image file GF, analyze the image processing control information GC, and convert and adjust the image data GD. Alternatively, by detecting the insertion of the memory card MC, or alternatively, by detecting the insertion of the cable, the application starts automatically, reads the image file GF, analyzes the image processing control information GC, Conversion and adjustment of the data GD may be automatically performed.
[0087]
Further, a characteristic parameter value for executing the automatic image quality adjustment may be made selectable. For example, the color printer 20 may be provided with a parameter selection button or a shooting mode parameter selection button in which predetermined parameters are combined in accordance with a subject, and these selection buttons may be used to select a parameter for performing automatic image quality adjustment. When the automatic image quality adjustment is performed on a personal computer, a parameter for executing the automatic image quality adjustment may be selected on a user interface of a printer driver or a retouch application.
[0088]
In the image processing in the color printer 20, as shown in FIG. 20, the image quality automatic adjustment processing may be executed first, and the color space conversion may be executed later. Basic information may be processed.
[0089]
In the above embodiments, the color printer 20 is used as an output device, but a display device such as a CRT, an LCD, and a projector can be used as the output device. In such a case, for example, an image processing program (display driver) for executing the image processing described with reference to FIGS. 12 and 13 is executed by the display device as the output device. Alternatively, when a CRT or the like functions as a display device of a computer, the computer executes an image processing program. However, the finally output image data has not the CMYK color space but the RGB color space.
[0090]
In such a case, the image processing control information GC at the time of generating the image data is displayed on the display result of the display device such as the CRT in the same manner as the information at the time of generating the image data is reflected on the print result via the color printer 20. Can be reflected. Therefore, the image data GD generated by the digital still camera 12 can be displayed more accurately.
[0091]
As described above, the output device, the image processing device, and the program according to the present invention have been described based on the embodiments. However, the above embodiments of the present invention are for facilitating the understanding of the present invention. There is no limitation. The present invention can be modified and improved without departing from the spirit and scope of the claims, and it is needless to say that the present invention includes equivalents thereof.
[0092]
In the above embodiment, the photographing mode and the image processing control parameters are set in the digital still camera 12, and the reference values are changed after the set photographing mode and image processing control parameters are analyzed in the printer 20. That is, the automatic image quality adjustment processing of the image data GD is performed using the image processing control command. However, the digital still camera 12 may execute a process of changing the reference value from the shooting mode and the image processing control parameter, and provide the printer 20 with the reference value and the applied level, that is, the value itself. In such a case, if the printer 20 is provided with an image quality adjustment function using a reference value, the image quality adjustment process suited to each shooting condition and the image quality adjustment process reflecting the user's intention are automatically executed. Can be.
[0093]
In the above embodiment, the parameters such as the light source, the exposure correction amount, the target color space, the brightness, and the sharpness are used as the image processing control information GC. However, which parameter is used as the image processing control information GC is determined arbitrarily. It is.
[0094]
The values of the parameters illustrated in the table of FIG. 8 are merely examples, and the invention according to the present application is not limited by the values. Furthermore, the values of the matrices S, M, and N− ¹ in each mathematical expression are merely examples, and it goes without saying that the values can be appropriately changed depending on the target color space, the color space available in the color printer 20, and the like. .
[0095]
In the above embodiment, the digital still camera 12 has been described as the image file generating device. However, a scanner, a digital video camera, or the like may be used. When a scanner is used, the specification of the data to be captured of the image file GF may be executed on the computer PC, or a preset button, in which setting information is assigned in advance for information setting on the scanner, or an optional setting. May be provided with a display screen and a setting button, and the scanner can be executed alone.
[0096]
In the above embodiment, when the color space characteristics are changed from the sRGB color space to the wRGB color space, the matrix M and the matrix N- ¹ are independently processed, but the matrix M and the matrix N- ¹ are combined. It may be executed by a matrix operation using a synthesis matrix (MN ⁻¹ ). Further, various conversion system matrices may be synthesized as needed. By combining the matrices, a series of matrix operation processing can be speeded up.
[0097]
In the above embodiment, an Exif format file has been described as a specific example of the image file GF, but the format of the image file according to the present invention is not limited to this. That is, any image file containing image data generated by the image data generation device and image processing control information GC describing conditions (information) at the time of generation of the image data may be used. With such a file, the image quality of the image data generated by the image file generation device can be automatically adjusted appropriately and output from the output device.
[0098]
The digital still camera 12 and the color printer 20 used in the above embodiments are merely examples, and the configuration is not limited to the contents described in each embodiment. The digital still camera 12 only needs to have at least the function of generating the image file GF according to the above embodiment. Further, in the color printer 20, at least the image processing control information GC of the image file GF according to the present embodiment is analyzed, and the image quality is automatically adjusted to reflect the user's intention, particularly regarding the brightness, and the image is output ( Printing).
[0099]
Note that in the image file GF including the image data and the image processing control information GC, association data for associating the image processing control information GC is generated, and one or a plurality of image data and the image processing control information GC are independent. A file that can be stored in a file that has been associated with the image data and image processing control information GC by referring to the association data at the time of image processing is also included. In such a case, although the image data and the image processing control information GC are stored in separate files, at the time of the image processing using the image processing control information GC, the image data and the image processing control information GC cannot be integrated. And functions in the same manner as when stored in the same file. That is, the mode in which the image data and the image processing control information GC are used in association with each other at least at the time of the image processing is included in the image file GF in the present embodiment. Furthermore, moving image files stored on optical disk media such as CD-ROM, CD-R, DVD-ROM, and DVD-RAM are also included.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram illustrating an example of an image data processing system to which an image processing apparatus according to a first embodiment can be applied.
FIG. 2 is a block diagram illustrating a schematic configuration of a digital still camera capable of generating an image file (image data) to be processed by the image processing apparatus according to the first embodiment.
FIG. 3 is an explanatory diagram conceptually showing the internal structure of an image file that can be used in the first embodiment.
FIG. 4 is an explanatory diagram showing a schematic internal structure of an image file stored in an Exif file format.
FIG. 5 is an explanatory diagram showing an example of a data structure of an accessory information storage area 112 of an image file GF that can be used in the first embodiment.
FIG. 6 is a block diagram illustrating a schematic configuration of a color printer 20 according to the first embodiment.
FIG. 7 is an explanatory diagram showing an internal configuration of a control circuit 30 of the color printer 20.
FIG. 8 is a flowchart showing a flow of a process of generating an image file GF in the digital still camera 12.
FIG. 9 is an explanatory diagram showing an exemplary display mode of the liquid crystal display 127.
FIG. 10 is an explanatory diagram showing an exemplary display mode of the liquid crystal display 127.
FIG. 11 is an explanatory diagram showing an exemplary display mode of the liquid crystal display 127.
FIG. 12 is a flowchart illustrating a processing routine of image processing in the color printer 20 according to the first embodiment.
FIG. 13 is a flowchart illustrating a flow of image processing executed in the color printer 20 according to the first embodiment.
FIG. 14 is an explanatory diagram illustrating the concept of automatic image quality adjustment processing in the color printer 20 according to the first embodiment.
FIG. 15 is a flowchart illustrating a processing routine for automatic image quality adjustment in the color printer 20.
FIG. 16 is an explanatory diagram showing an example of a combination of a shooting mode, an image quality parameter, and a reference number designating a shooting mode.
FIG. 17 is an explanatory diagram showing exemplary values of parameters AP, MP, FP, and FP ′ for brightness and sharpness.
FIG. 18 is an explanatory diagram illustrating a tone curve changed by reflecting a final image quality adjustment parameter FP.
FIG. 19 is an explanatory diagram illustrating a f / F as a blur index obtained from a lens focal length f (mm) and an F number.
FIG. 20 is a flowchart illustrating a processing routine of image processing according to another embodiment.
[Explanation of symbols]
10 Image processing system 12 Digital still camera 121 Optical circuit 122 Image acquisition circuit 123 Image processing circuit 124 Control circuit 126 Selection / decision button 127 Liquid crystal display 14 Display 20 Color printer 21 Carriage 211 Print head 212 ink cartridge 213 ink cartridges 214 to 220 ink discharge head 22 carriage motor 23 platen 24 paper feed motor 25 sliding shaft 26 drive belt 27 pulley 28 position detection sensor 29 operation Panel 30 Control circuit 31 Arithmetic processing unit (CPU)
32: Programmable read only memory (PROM)
33 Random access memory (RAM)
34 PCMCIA slot 35 Peripheral device input / output unit (PIO)
36 timer 37 driving buffer 38 bus 39 oscillator 40 distribution output device 100 image file (Exif file)
101: JPEG image data storage area 102: auxiliary information storage area 103: Makernote storage area MC: memory card

Claims (27)

An image processing apparatus that performs image processing using image data and information on generation of image data associated with the image data,
Analyzing the image data, image quality characteristic information acquisition means for acquiring image quality characteristic information that is information indicating characteristics related to the image quality of the image data,
A correction amount for correcting the image data is determined based on the acquired image quality characteristic information, the determined correction amount is changed by the generation time information, and the changed correction amount for the image data is determined. An image processing apparatus comprising: an image quality adjusting unit that adjusts the image quality of the image data by applying the image data. The image processing apparatus according to claim 1,
The image quality characteristic information includes an image quality parameter value indicating an image quality characteristic of the image data,
The image quality adjustment unit has a reference image quality parameter value that is predetermined for the image quality parameter value and is a reference for image quality adjustment,
The adjustment of the image quality by the image quality adjusting means determines a correction amount for correcting the image data based on the reference image quality parameter value and the image quality parameter value, and determines the correction amount based on a result of analyzing the generation information. An image processing apparatus that is executed by increasing or decreasing the image data and adjusting the image quality of the image data by reflecting the increased or decreased correction amount. The image processing apparatus according to claim 1,
The image quality characteristic information is a combination of a plurality of image quality parameter values indicating image quality characteristics of the image data,
The image processing device, wherein the reference image quality parameter value is predetermined for each of the plurality of image quality parameter values. The image processing device according to claim 3,
The image processing, wherein the increase or decrease of the correction amount based on a result of analyzing the generation time information is performed by modifying the reference image quality parameter value based on a result of analyzing the generation time information. apparatus. The image processing device according to claim 3,
The image, wherein the increase or decrease of the correction amount based on the analysis result of the generation time information is executed by determining an application level of the correction amount based on the analysis result of the generation time information. Processing equipment. The image processing apparatus according to any one of claims 1 to 5,
The image processing apparatus, wherein the information at the time of generation includes at least correction information for any one of information related to contrast, brightness, color balance, saturation, sharpness, memory color, and information related to noise removal. . The image processing apparatus according to claim 6,
The image processing device, wherein the generation time information is shooting information at the time of shooting image data. The image processing apparatus according to any one of claims 1 to 7,
The image processing apparatus, wherein the image data and the generation time information are stored in the same image file. An output device that outputs an image using image data and information at the time of generation of the image data associated with the image data,
An image processing apparatus according to any one of claims 1 to 8,
An output device comprising: an image output unit that outputs an image of image data that has been subjected to image processing by the image processing device. An image processing method for performing image processing using image data and generation information of the image data associated with the image data,
Analyzing the image data, to obtain image quality characteristic information that is information indicating characteristics related to the image quality of the image data,
Determine a correction amount for correcting the image data based on the acquired image quality characteristic information,
The determined correction amount is changed according to the generation time information,
An image processing method for adjusting image quality of the image data by applying the changed correction amount to the image data. The image processing method according to claim 10,
The image quality characteristic information includes an image quality parameter value indicating an image quality characteristic of the image data,
The image quality adjustment includes determining a correction amount for correcting the image data based on the reference image quality parameter value and the image quality parameter value, which are predetermined for the image quality parameter value, and serve as a reference for image quality adjustment. An image processing method, wherein the correction amount is increased or decreased based on a result of analyzing time information, and the image quality of the image data is adjusted and executed by reflecting the increased or decreased correction amount. The image processing method according to claim 11,
The image quality characteristic information is a combination of a plurality of image quality parameter values indicating image quality characteristics of the image data,
The image processing method, wherein the reference image quality parameter value is predetermined for each of the plurality of image quality parameter values. The image processing method according to claim 12,
The image processing, wherein the increase or decrease of the correction amount based on a result of analyzing the generation time information is performed by modifying the reference image quality parameter value based on a result of analyzing the generation time information. Method. The image processing method according to claim 12,
The image, wherein the increase or decrease of the correction amount based on the analysis result of the generation time information is executed by determining an application level of the correction amount based on the analysis result of the generation time information. Processing method. In the image processing method according to any one of claims 10 to 14,
The image processing method, wherein the information at the time of generation includes at least correction information on any one of information relating to contrast, brightness, color balance, saturation, sharpness, memory color, and information related to noise removal. . The image processing method according to claim 15,
The image processing method, wherein the generation time information is shooting information at the time of shooting image data. In the image processing method according to any one of claims 10 to 16,
The image processing method, wherein the image data and the generation time information are stored in the same image file. An image processing program that performs image processing using the image data and the generation information of the image data associated with the image data,
A function of analyzing the image data and acquiring image quality characteristic information that is information indicating characteristics related to the image quality of the image data;
A correction amount for correcting the image data is determined based on the acquired image quality characteristic information, the determined correction amount is changed by the generation time information, and the changed correction amount for the image data is determined. An image processing program for causing a computer to execute a function of adjusting image quality of the image data by applying the function. The image processing program according to claim 18, wherein
The image quality characteristic information includes an image quality parameter value indicating an image quality characteristic of the image data,
The image quality adjustment includes determining a correction amount for correcting the image data based on the reference image quality parameter value and the image quality parameter value, which are predetermined for the image quality parameter value, and serve as a reference for image quality adjustment. An image processing program executed by increasing or decreasing the correction amount based on a result of analyzing time information and adjusting the image quality of the image data by reflecting the increased or decreased correction amount. 20. The image processing program according to claim 19,
The image quality characteristic information is a combination of a plurality of image quality parameter values indicating image quality characteristics of the image data,
An image processing program wherein the reference image quality parameter value is predetermined for each of the plurality of image quality parameter values. The image processing program according to claim 20, wherein
An image processing program executed by increasing or decreasing the correction amount based on a result of analyzing the generation time information by correcting the reference image quality parameter value based on a result of analyzing the generation time information. The image processing program according to claim 20, wherein
An image processing program that is executed by increasing or decreasing the correction amount based on a result of analyzing the generation time information by determining an application level of the correction amount based on a result of analyzing the generation time information. An image processing program according to any one of claims 18 to 22, wherein
The image processing program according to claim 1, wherein the generation information includes at least correction information on any one of information related to contrast, brightness, color balance, saturation, sharpness, memory color, and noise removal. The image processing program according to claim 23,
The image processing program, wherein the generation time information is shooting information at the time of shooting image data. The image processing program according to any one of claims 18 to 24,
An image processing program, wherein the image data and the generation time information are stored in the same image file. An image processing apparatus that generates image data for output using image data and generation time information of image data associated with the image data,
Image data storage means for storing image data to be adjusted;
Image data acquisition means for acquiring image data from the image data storage means,
Analyzing the acquired image data, image quality characteristic information acquisition means for acquiring image quality characteristic information that is information indicating characteristics related to the image quality of the image data,
A correction amount for correcting the image data is determined based on the acquired image quality characteristic information, the determined correction amount is changed by the generation time information, and the changed correction amount for the image data is determined. Image quality adjusting means for adjusting the image quality of the image data by applying
An image data output unit that outputs the image data with the adjusted image quality. The image processing apparatus according to claim 26,
An image processing apparatus wherein the image data storage means is detachable.

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