JP3544215B2 - Video camera system - Google Patents

Description

のように、検出計測枠ＦＭＤについて、検出輝度頻度特性Ｙ（ｘ、ｙ）（ｉ）と、基準輝度頻度特性ＹＳｔｄ（ｉ）との差の絶対値を輝度レベルｙ＝０〜 ２５５について合計することによりユークリツド距離Ｊ１（ｘ、ｙ）を求め、これを基準計測枠ＦＭＲ内の画像の輝度情報に対するアドレス（ｘ、ｙ）位置にある検出計測枠ＦＭＤ内の輝度情報の類似度を表す情報として得る。
【００２６】
また検出計測枠ＦＭＤの色相情報について、追従信号処理回路１６は次式、
【数２】

のように、アドレス（ｘ、ｙ）位置にある検出計測枠ＦＭＤの検出色相頻度特性Ｈｕｅ（ｘ、ｙ）（ｉ）と、基準色相頻度特性ＨｕｅＳｔｄ（ｉ）との差の絶対値を、色相角ｉ＝０°〜 ３５９°について合計することによりユークリツド距離Ｊ２（ｘ、ｙ）を求め、これにより基準計測枠ＦＭＲの画像がもつている基準色相パターンに対して位置（ｘ、ｙ）にある検出計測枠ＦＭＤがもつている画像の検出特徴パターンに対する類似度を表す情報を形成する。
【００２７】
追従信号処理回路１６はこのようにして輝度及び色相について求めたユークリツド距離Ｊ１（ｘ、ｙ）及びＪ２（ｘ、ｙ）に基づいて次式、
【数３】

のように、その和を演算することにより評価値Ｊ（ｘ、ｙ）を求める。
【００２８】
かくして追従信号処理回路１６は検出計測枠ＦＭＤのスキヤン位置（ｘ、ｙ）（ｘ＝０、１……１２、ｙ＝０、１……１２）にあるすべての検出計測枠ＦＭＤについての評価値Ｊ（ｘ、ｙ）（ｘ＝０、１……１２、ｙ＝０、１……１２）を得た状態において次のステツプＳＰ５に移つて、評価値Ｊ（ｘ、ｙ）が最小になる検出計測枠ＦＭＤの位置を現在の計測時における被写体の位置であると決定し、当該最小になる評価値Ｊ（ｘ、ｙ）が不存在確認用スレシヨルドレベル以下であること、従つて表示画面ＰＩＣ内に被写体の映像が存在することを確認して、次のステツプＳＰ６において当該新しい被写体の中央位置（ｘ、ｙ）が画面中央位置に設定されている基準計測枠ＦＭＲ（図４）位置に来るような追従制御信号Ｓ５をパンニング駆動モータ１２Ａ及びチルテイング駆動モータ１２Ｂに与える。
【００２９】
ここで、最小になる評価値が、大きければ、このことは検出計測枠から検出された新しい被写体の位置Ｊ（ｘ、ｙ）が表示画面ＰＩＣの中央部から遠い位置にあることを意味し、従つて追従信号処理回路１６は、当該最小になる評価値が所定の不存在確認用スレシヨルドレベル以上になつたときは、被写体の映像が表示画面ＰＩＣの外側にある（従つて被写体の映像が表示画面ＰＩＣには存在しない）と判断する。
【００３０】
続いて追従信号処理回路１６は、ステツプＳＰ７に移つて、新しく基準計測枠ＦＭＲに来た画像についての輝度信号及び色相信号の基準頻度特性データ（図５及び図６）を、基準特徴パターンとして更新した後、上述のステツプＳＰ３に戻つて次の測定サイクルに入る。
かくして追従信号処理回路１６はテレビジヨンカメラに対して被写体が移動した場合、表示画面ＰＩＣ全体について基準計測枠ＦＭＲの画像情報に対して最も類似性が大きい画像情報を有する検出計測枠ＦＭＤの位置を求め、当該最も類似性が大きい検出計測枠ＦＭＤの映像が基準計測枠ＦＭＲの位置に来るようにテレビジヨンカメラのレンズブロツク部１をパンニング及びチルテイング制御するようにしたことにより、被写体が移動したときこれに応動して表示画面ＰＩＣの中央位置に被写体の映像を戻すようにビデオカメラシステムＶＣＳを適応動作させることができる。
【００３１】
これに対して基準計測枠ＦＭＲ位置にある被写体が移動しなかつた場合には、基準計測枠ＦＭＲと同じ位置にある検出計測枠ＦＭＤから得られた検出特徴パターンについてこれが最も基準特徴パターンに対して類似性が大きいという評価をステツプＳＰ４において得ることができることにより、追従信号処理回路１６は追従制御信号Ｓ５によつて新しい被写体が引き続き検出計測枠ＦＭＲ内にある状態を保持させるようにビデオカメラシステムＶＣＳを制御する。
図７に示す自動追従処理手順によれば、ユーザが最初に被写体を画面中央の基準計測枠ＦＭＲに入るようにカメラ操作をした後記録を開始しさえすれば、その後被写体の映像が表示画面ＰＩＣ内を移動しても、追従信号処理回路１６が当該移動位置を輝度信号及び色相信号の頻度特性データに基づいて得られる検出特徴パターンと基準検出パターンとの比較によつて確実に検出することにより、ビデオカメラシステムを被写体の移動に適応動作させながら自動追尾させることができる。
【００３２】
（３）被写体存在確認処理動作
追従信号処理回路１６は、自動追従処理手順ＲＴ１のステツプＳＰ５において被写体の映像が表示画面ＰＩＣ内にあるか否かの存在確認処理に入ると、以下に述べるような被写体存在確認処理サブルーチンを実行する。
【００３３】
（３−１）第１の実施例
図１１は、第１の実施例を示すもので、追従信号処理回路１６は被写体存在確認処理ルーチンＲＴ２に入ると、先ずステツプＳＰ１１に移つて表示画面ＰＩＣ内に被写体が存在するか否かの判断をし、肯定結果が得られることにより被写体の存在が確認できたとき（すなわち内容が「存在」の被写体存在検出情報が得られたとき）にはステツプＳＰ１２を通つてメインルーチン、すなわち図７の自動追従処理手順ＲＴ１のステツプＳＰ５にリターンして自動追従処理手順ＲＴ１の処理を続ける。
【００３４】
これに対して表示画面ＰＩＣ内に被写体が存在しない場合には、追従信号処理回路１６はステツプＳＰ１１において否定結果が得られることにより（すなわち内容が「不存在」の被写体検出情報が得られることにより）ステツプＳＰ１３に移つてタリーランプ駆動回路１３に駆動制御信号Ｓ６を送出することにより、タリーランプ９を点灯表示させる。
この実施例の場合図１２に示すように、タリーランプ９はテレビジヨンカメラ２５のケースの天板上に突出するように設けられており、かくして表示画面ＰＩＣに映出された視野映像内に被写体の映像が映出されない状態になつたとき、ユーザはこの被写体の不存在をタリーランプ９が点灯したことにより容易に知ることができる。
【００３５】
かくしてユーザは被写体が不存在の状態になつたときにはこれを放置せずに、例えば手でビデオカメラ２５をパン及びチルト操作することにより被写体の映像を表示画面ＰＩＣ内に捕捉し直すような処理を、必要に応じて直ちに実施することができる。
このようにしてユーザが手でビデオカメラ２５をパン及びチルト操作をすることにより、被写体の映像を表示画面内に捕捉し直した状態になると、追従信号処理回路１６はステツプＳＰ１１において肯定結果を得、これによりステツプＳＰ１３のタリーランプ９の点灯処理を実行することなく（従つてタリーランプ９を消灯して）ステツプＳＰ１２を通してメインルーチンに戻るような処理を実行する。
【００３６】
図１２において、２５Ａはパンニング／チルテイング駆動部、２５Ｂはレンズ系、２５Ｃはビユーフアインダ系、２５Ｄはマイクロホンである。
図１１及び図１２の構成によれば、表示画面ＰＩＣ内に被写体の映像が存在しなくなつたとき、この状態の発生をユーザに直ちに知らせることができ、その結果一段と使い易いビデオカメラシステムを容易に実現し得る。
【００３７】
（３−２）第２の実施例
図１３は第２の実施例を示すもので、この場合追従信号処理回路１６は被写体存在確認処理ルーチンＲＴ３に入ると、先ずステツプＳＰ２１において被写体が存在するか否かを判断し、肯定結果が得られたとき（すなわち「存在」の被写体検出情報が得られたとき）ステツプＳＰ２２を通つてメインルーチン、すなわち自動追従処理手順ＲＴ１のステツプＳＰ５にリターンし、これにより自動追従処理手順ＲＴ１の処理を続ける。
これに対してステツプＳＰ２１において否定結果が得られると（すなわち「不存在」の被写体検出情報が得られると）、このことは表示画面ＰＩＣ内に被写体の映像が存在しないことを意味し、そのとき追従信号処理回路１６はステツプＳＰ２３に移つて現在のレンズ２のズーム位置を内蔵のメモリに記憶した後、ステツプＳＰ２４において追従制御信号Ｓ５によつてズーミング駆動モータ１２Ｃを駆動することによりレンズ２をワイド方向に駆動する。
【００３８】
この実施例の場合、レンズ２はズーミング駆動モータ１２Ｃによつて駆動されるズームレンズを有し、このズームレンズと関連して動作するポテンシヨメータによつてズームレンズのズーム位置を表すズーム位置検出信号を追従信号処理回路１６に供給するようになされている。
この結果レンズブロツク部１のレンズ２に到来する撮像光ＬＡ２をＣＣＤ撮像素子４に取り込むことにより得られる映像の視野がズーム位置従つてズーム倍率をワイド方向に引くことにより拡大することができる。
続いて追従信号処理回路１６はステツプＳＰ２５に移つて被写体を発見できるか否かの判断を実行し、否定結果が得られたときにはステツプＳＰ２５において肯定結果が得られるまでステツプＳＰ２５の処理を続ける。
【００３９】
やがてステツプＳＰ２５において肯定結果が得られると、このことは表示画面ＰＩＣに映出された視野映像内に被写体が存在することにより自動追従処理をなし得る状態になつたことを意味し、このとき追従信号処理回路１６はステツプＳＰ２６に移つて被写体を表示画面ＰＩＣ内に補捉しながらズーミング駆動モータ１２Ｃを駆動することによりズーム位置をステツプＳＰ２３において記憶したズーム位置にまで復帰させた後、上述のステツプＳＰ２１に戻る。
かくして追従信号処理回路１６はレンズ２のズームレンズを元のズーム位置に戻した状態における表示画面ＰＩＣ内に被写体の映像が存在するような状態にレンズブロツク部１を自動的に制御し、その結果ステツプＳＰ２１における判断において肯定結果が得られることにより、ステツプＳＰ２２を通つてメインルーチン、すなわち自動追従処理手順ＲＴ１のステツプＳＰ５にリターンする。
【００４０】
図１３の構成において、追従信号処理回路１６は自動追従処理手順ＲＴ１を実行することにより表示画面ＰＩＣの中心位置に被写体の映像を映出する状態に自動追従動作している状態において、被写体を見失つて当該被写体の映像が画面内に存在しない状態になると、追従信号処理回路１６はこれを被写体存在確認処理ルーチンＲＴ３のステツプＳＰ２１において否定結果が得られることにより検出し、ステツプＳＰ２３においてレンズ２のズーム倍率をワイド側に引くことによつて撮像素子４に結像する映像内に被写体の映像を存在させるような状態にする。
この状態において追従信号処理回路１６は、ステツプＳＰ２４及びＳＰ２５によつて被写体を発見した後、被写体を画面内に捕捉しながらレンズ２のズーム倍率を元に戻してステツプＳＰ２１、ＳＰ２２を順次通つて自動追従処理手順ＲＴ１の処理に戻る。
【００４１】
かくして図１３の構成によれば、テレビジヨンカメラシステムが一旦被写体を見失つたような状態になつたときには、自動的に被写体を捕捉し直すようにレンズ２をズーミング制御するようにしたことにより、ビデオカメラシステムが被写体を見失つたような場合にもこれを直ちに検出すると共に、ユーザがその都度ビデオカメラ２５のそばまで来てパン及びチルト操作をし直すような煩雑な手間を不必要にできる分、一段と使い易いビデオカメラシステムが実現できる。
【００４２】
（３−３）第３の実施例
図１４は第３の実施例を示すもので、被写体を見失つたとき追従信号処理回路１６は先ず予測追尾処理を実行し、その結果被写体を発見できないとき次にスキヤン捕捉処理を実行する。
すなわち追従信号処理回路１６は被写体存在確認処理ルーチンＲＴ４に入ると、先ずステツプＳＰ３１において被写体が存在するか否かの判断をし、肯定結果が得られたとき（すなわち「存在」の被写体検出情報が得られたとき）ステツプＳＰ３２を通つてメインルーチン、すなわち自動追従処理手順ＲＴ１のステツプＳＰ５に戻つて画面の中央に被写体が来るような自動追尾処理を実行する。
【００４３】
これに対してステツプＳＰ３１において否定結果が得られる（すなわち「不存在」の被写体存在検出情報が得られる）と、このことはレンズブロツク部１が被写体を見失つたことを意味し、このとき追従信号処理回路１６はステツプＳＰ３３に移つて予測追尾処理をするか否かの判断をする。
追従信号処理回路１６はステツプＳＰ３３において肯定結果を得ると、ステツプＳＰ３４から予測追尾モードに入る。
ここで追従信号処理回路１６は、表示画面ＰＩＣから被写体を見失つたとき所定時間の間（例えば１画面分の表示時間の間）被写体を見失う前の制御量を用いて被写体の自動追尾処理を続ける。
【００４４】
かくしてビデオカメラシステムは、例えば被写体が物体の背後を通過した場合のように被写体を瞬時的に見失つたときに、当該被写体を見失う前のパン及びチルト駆動条件を用いて予測的に自動追尾処理を続けることができ、かくして被写体が物体の背後を移動し終つて同じ速度で移動して行くとき、ビデオカメラのパン及びチルト動作を連続的にかつ円滑に続行させることができる。
かかる予測追尾モードの処理を実行した後、追従信号処理回路１６はステツプＳＰ３５に移つて被写体を発見できるか否かの判断をし、肯定結果が得られたとき上述のステツプＳＰ３１、ＳＰ３２を通つてメインルーチンに戻る。
【００４５】
これに対してステツプＳＰ３５において否定結果が得られると、このことは、ステツプＳＰ３４の予測追尾処理だけでは被写体を補捉し直すことができなかつたことを意味し、このとき追従信号処理回路１６は上述のステツプＳＰ３３に戻る。
ところがこの状態においては、予測追尾処理が既に終了しているので、追従信号処理回路１６はステツプＳＰ３３において否定結果を得ることになり、このとき追従信号処理回路１６はステツプＳＰ３６からスキヤン補捉モードに入る。
【００４６】
このステツプＳＰ３６はスキヤン処理をするか否かを判断するステツプで、追従信号処理回路１６はステツプＳＰ３３からＳＰ３６に移つたとき肯定結果を得ることによりステツプＳＰ３７においてレンズブロツク部１をスキヤン制御する。
この実施例の場合追従信号処理回路１６はスキヤン制御処理として、先ずズーミング駆動モータ１２Ｃを介してレンズ２を構成するズームレンズを所定のズーム位置にワイド方向にズーム動作させた後、パンニング駆動モータ１２Ａ及びチルテイング駆動モータ１２Ｂをパンニング方向及びチルテイング方向に１画面幅に相当する画面範囲に亘つて原画面の周囲をスキヤン駆動することにより、表示画面ＰＩＣに映出する視野映像の視野を拡大して見失つた被写体をビデオカメラ２５の表示画面ＰＩＣの視野映像内に映出させると共に、表示画面ＰＩＣ内に被写体が存在するか否かの判断をするような処理を実行する。
【００４７】
この実施例の場合、表示画面ＰＩＣに映出される視野映像は、左上位置から順次左右方向にほぼジグザグ状にカメラの視野を移動させることによりスキヤンされる。
これに続いて追従信号処理回路１６はステツプＳＰ３８に移つて被写体を発見したか否かの判断をし、肯定結果が得られたとき上述のステツプＳＰ３１、ＳＰ３２を通つてメインルーチンに戻る。
これに対して当該スキヤン動作を実行しても被写体を発見できないとき、追従信号処理回路１６はステツプＳＰ３６において否定結果を得てステツプＳＰ３９に移る。
【００４８】
このようにステツプＳＰ３６において否定結果が得られると、このことは予測追尾処理及びスキヤン捕捉処理をしたにもかかわらず、被写体を捕捉し直すことができなかつたことを意味し、このとき追従信号処理回路１６はステツプＳＰ３９において初期位置復帰モードに入つてパンニング駆動モータ１２Ａ及びチルテイング駆動モータ１２Ｂを予測追尾する前の初期位置に移動させる。
この状態において追従信号処理回路１６はステツプＳＰ４０において被写体が発見できたか否かの判断をし、否定結果が得られたとき、上述のステツプＳＰ３９に戻つて以後ステツプＳＰ３９−ＳＰ４０−ＳＰ３９のループの処理を実行することにより、被写体が発見できない限り初期位置にパンニング駆動モータ１２Ａ及びチルテイング駆動モータ１２Ｂを移動させた状態を維持する。
【００４９】
かくして被写体を見失つた状態になつた後、予測追尾処理及びスキヤン処理によつて被写体が発見できない状態が続くと、追従信号処理回路１６はその後ユーザが手でビデオカメラをパンニング及びチルテイング操作することにより被写体を画面内に捕捉する際に、初期位置から操作できることにより手での被写体の捕捉を一段と容易になし得る。
これに対して初期位置に移動したとき被写体を発見できれば、追従信号処理回路１６はステツプＳＰ４０において肯定結果が得られることによりステツプＳＰ３１、ＳＰ３２を通つてメインルーチンにリターンする。
【００５０】
図１４の構成によれば、被写体が例えば急激に加速することにより画面から逸脱した不存在状態になつたとき、追従信号処理回路１６がステツプＳＰ３３−ＳＰ３４−ＳＰ３５−ＳＰ３３のループによつて予測追尾処理を実行した後、ステツプＳＰ３６−ＳＰ３７−ＳＰ３８−ＳＰ３６のループのスキヤン捕捉処理を実行することにより、ビデオカメラシステムがたとえ被写体が急激な加速により画面から逸脱したような場合にも、その都度ユーザがカメラのそばに来てビデオカメラ位置を任意に設定する煩雑な手間を必要とすることなく、自動的に被写体を画面内に捕捉し直すような処理を実行できる。
かくして一段と使い易いビデオカメラシステムを得ることができる。
【００５１】
（４）他の実施例
上述の実施例においては、表示画面ＰＩＣを構成する画素情報をレンズブロツク部１において形成し、レンズブロツク部１をパンニング及びチルテイング動作させることにより表示画像を被写体の動きに追従させるようにしたが、これに代え、レンズブロツク部１から送出された映像出力信号Ｓ１を画像メモリ１５に記憶させ、当該画像をパンニング及びチルテイング処理することにより表示画面を形成するようにしても、上述の場合と同様の効果を得ることができる。
【００５２】
また上述の実施例においては、基準計測枠及び検出計測枠内の輝度信号及び色相信号の頻度特性データに基づいて被写体の位置を検出するようにした場合について述べたが、被写体の位置の検出手段としては、これに限らず、例えば赤外線センサ、超音波センサなどを用いて被写体位置を検出する自動追尾システムに本発明を適用するようにしても、上述の場合と同様の効果を得ることができる。
【００５３】
また図１４の実施例においては、スキヤン捕捉モードにおけるスキヤン動作として、視野映像を左上位置から順次左右方向にほぼジグザグ状に移動させるようにしたが、スキヤン動作はこれに限らず、例えば中心位置からうず巻状に外側に移動させて行く方法など、種々の方法を採用し得る。
【００５４】
さらに、図１４の実施例においては、スキヤン捕捉モードのスキヤン動作を、先ずズーミング手段によつて視野映像をズーム倍率を拡大する方向に引いた後、実行するようにしたが、これに代え、ズーム倍率を変更しないようにしても、上述の場合と同様の効果を得ることができる。
【００５５】
【発明の効果】
上述のように本発明によれば、例えば自動追尾制御動作をしている間に被写体を見失つたような場合には、これを直ちに検出してユーザに知らせるようにし、又は当該見失つた画像を、パンニング及びチルテイング、並びにズーミング駆動することによつて自動的に補捉し直すような処理を実行するようにしたことにより、例えば被写体が急激に加速したために自動追尾しきれなくなつたような場合にも、ユーザに過大な負担をかけることなく容易に対応処置をなし得るようにしたビオデオカメラシステムを実現できる。かくするにつき、輝度及び色相の類似度を表す情報の和に基づいて被写体の映像の位置を検出するようにしたことにより、光源の影響を受けずに自動追尾をなし得る。
【図面の簡単な説明】
【図１】従来の制御量算出方法を示す特性曲線図である。
【図２】本発明によるビデオカメラシステムの全体構成を示すブロツク図である。
【図３】視覚刺激を表すＨＬＳ色座標系の説明に供する略線図である。
【図４】基準計測枠ＦＭＲの説明に供する略線図である。
【図５】図４の基準計測枠ＦＭＲから得られる基準色相頻度特性を示す特性曲線図である。
【図６】図４の基準計測枠ＦＭＲから得られる基準輝度頻度特性を示す特性曲線図である。
【図７】自動追従処理手順を示すフローチヤートである。
【図８】検出計測枠によるスキヤン動作の説明に供する略線図である。
【図９】検出色相頻度特性を示す特性曲線図である。
【図１０】検出輝度頻度特性を示す特性曲線図である。
【図１１】第１の実施例における被写体存在確認処理ルーチンを示すフローチヤートである。
【図１２】警報表示を有するビデオカメラの外観を示す斜視図である。
【図１３】第２の実施例における被写体存在確認処理ルーチンを示すフローチヤートである。
【図１４】第３の実施例における被写体存在確認処理ルーチンを示すフローチヤートである。
【符号の説明】
ＶＣＳ……ビデオカメラシステム、１……レンズブロツク部１、２……レンズ、３……アイリス、４……撮像素子、５……信号分離／自動利得調整回路部、７……デイジタルカメラ処理回路、１１……追従制御回路部、１２Ａ……パンニング駆動モータ、１２Ｂ……チルテイング駆動モータ、１２Ｃ……ズーミング駆動モータ、１３……タリーランプ駆動回路、１４……飽和度／色相検出回路、１５……画像メモリ、１６……追従信号処理回路、１７……アドレス発生回路、１８……ゲート回路、１９……色相ヒストグラム発生回路、２０……輝度ヒストグラム発生回路、ＲＴ１……自動追従処理手順、ＲＴ２〜ＲＴ４……被写体存在確認処理ルーチン。[0001]
【table of contents】
The present invention will be described in the following order.
Industrial applications
Conventional technology (Fig. 1)
Problems to be solved by the invention
Means for solving the problem (FIGS. 2 to 14)
Action (FIGS. 2 to 14)
Example
(1) Overall configuration (FIGS. 2 to 16)
(2) Automatic follow-up processing operation (FIGS. 7 to 10)
(3) Subject existence confirmation processing operation (FIGS. 11 to 14)
(4) Another embodiment
The invention's effect
[0002]
[Industrial applications]
The present invention relates to a video camera system, and is particularly suitable for application to a video camera subject tracking system in which a subject in the field of view of the video camera is always displayed at the center of the display screen.
[0003]
[Prior art]
2. Description of the Related Art Conventionally, a video camera system has been proposed in which a video camera is automatically followed by a video camera using a pan drive mechanism and a tilt drive mechanism, so that the subject is always displayed in the center of a display screen. Hei 4-322652).
In the control amount calculation unit of the conventional subject tracking system applied to this video camera system, the relationship between the displacement of the display position of the subject with respect to the center of the screen and the motor control amount is calculated as shown in FIG. On the other hand, a method is used in which the camera is tracked so that the subject is pulled back to the center of the screen by controlling the drive in the direction in which the motor is returned.
[0004]
[Problems to be solved by the invention]
However, when the automatic tracking control is performed so that the subject is always at the center of the screen using this conventional method, when the subject is lost and the subject cannot be projected on the screen, the center of the screen is The automatic tracking operation cannot be performed because the amount of displacement of the subject with respect to can not be calculated.
[0005]
Actually, in the conventional video camera system, a configuration is used in which the video camera is kept stopped by setting the control amount of the motor to 0 when such a state occurs.
Therefore, for example, when the subject passes through behind the object, the subject loses sight of the subject instantaneously, or when the subject accelerates rapidly and the video camera system can no longer track the subject. If the video camera deviates to the outside, the video camera may stop and cannot perform the tracking operation. In such a case, the user may entrust the movement of the subject and wait for the subject to be projected on the screen again, or go near the video camera position and perform the panning or tilting operation of the video camera by hand. There is a problem that the user has to perform a complicated operation of drawing the subject into the screen.
[0006]
The present invention has been made in consideration of the above points, and when the subject cannot be performed because the subject is not projected on the screen, the user can easily determine the operation state of the video camera system. An object of the present invention is to propose a video camera system that can be confirmed and that can automatically capture a subject that has gone out of the screen, thereby making the video camera system easier to use.
[0007]
[Means for Solving the Problems]
In order to solve such a problem, in the present invention, the position of an image of a subject on a display screen is detected, and the subject is automatically tracked by panning and tilting driving of a visual field image. In the detection measurement frame, the position of the video of the subject is detected based on the sum of the information indicating the similarity between the luminance and the hue with respect to the reference measurement frame, and the content of the subject presence detection information indicates that the content is “absent”. When the object is present, the tracking means is driven to capture, and when the subject presence detection information indicates that the content is "absent", the zoom magnification of the zooming means is changed. When the content of the detection information indicates "absence", this is displayed on the subject absence display means to notify the user.
[0008]
[Action]
If the subject is lost while performing the automatic tracking control operation, this should be immediately detected and notified to the user, or the lost image should be panned and tilted and zoomed. , The user is overloaded when the subject cannot be automatically tracked due to, for example, rapid acceleration of the subject. Thus, it is possible to realize a video camera system capable of easily performing a corresponding action without using the video camera. In this way, by detecting the position of the image of the subject based on the sum of the information indicating the similarity between the luminance and the hue, automatic tracking can be performed without being affected by the light source.
[0009]
【Example】
An embodiment of the present invention will be described below in detail with reference to the drawings.
[0010]
(1) Overall configuration
In FIG. 2, VCS indicates a video camera system as a whole. An image pickup light LA coming from a subject passes through a lens 2 and an iris 3 of a lens block unit 1 and is received by an image pickup device 4 formed of, for example, a CCD (charge coupled device). An image pickup output signal S1 corresponding to a visual field image including a subject image is supplied to a signal separation / automatic gain adjustment circuit unit 5.
The signal separation / automatic gain adjustment circuit 5 samples and holds the imaging output signal S1 and controls the gain so that the imaging output signal S1 has a predetermined gain by a control signal from an auto iris (AE) (not shown). The imaging output signal S2 having the predetermined gain thus obtained is supplied to the digital camera processing circuit 7 via the analog / digital conversion circuit section 6.
[0011]
The digital camera processing circuit 7 forms a luminance signal Y and a chroma signal C based on the imaging output signal S2, and sends out the luminance signal Y and the chroma signal C via the digital / analog conversion circuit 8 as a video signal S3.
In addition, the digital camera processing circuit 7 supplies the luminance signal Y and the color difference signals RY and BY to the tracking control circuit section 11 as the subject tracking detection signal S4, and the tracking control circuit section 11 Based on the detection signal S4, a follow-up control signal S5 for a panning drive motor 12A, a tilting drive motor 12B, and a zooming drive motor 12C provided for the lens block unit 1 is generated, and attached to the outer housing of the lens block unit 1. A drive control signal S6 is generated for the alarm display means provided, for example, the tally lamp drive circuit 13 for driving the display of the tally lamp 9.
[0012]
The tracking control circuit unit 11 supplies the color difference signals RY and BY to the saturation / hue detection circuit 14 to form a hue (Hue) signal HUE and a saturation (Saturation) signal SAT. For example, the image data is stored for each pixel in the image memory 15 constituted by a field memory.
The saturation / hue detection circuit 14 forms the hue signal HUE and the saturation signal SAT by transforming the color difference signals RY and BY into rectangular coordinates / polar coordinates, and thus the luminance signal Y, the hue signal HUE and the saturation signal. The SAT recognizes the subject based on a visual stimulus that can be perceived by a human.
[0013]
In general, a visual stimulus that can be perceived by humans is represented by a color coordinate system called an HLS system having an L axis and an SH plane orthogonal to the L axis, as shown in FIG.
The L axis represents brightness (Lightness) and corresponds to the luminance signal Y. The SH plane is represented by polar coordinates orthogonal to the L axis. In the SH plane, S represents a saturation (Saturation) and is represented by a distance from the L axis. H represents a hue (Hue), and is represented by an angle when the direction of the color difference signal RY is 0 °.
[0014]
In this HLS-based solid, when the light source becomes brighter, the color coordinates, that is, the SH plane goes upward along the L axis and all colors become white. At that time, the degree of saturation S decreases. On the other hand, when the light source becomes dark, the color coordinates, that is, the SH plane goes downward along the L axis, and all colors become black. At this time, the saturation S also decreases at the same time.
Based on such features of the HLS color coordinate system, it can be seen that the saturation S and the brightness Y are easily affected by the brightness of the light source, and therefore are not optimal as parameters representing the feature amount of the subject. . On the contrary, it can be seen that the hue H represents the characteristic amount unique to the subject and is hardly affected by the light source.
[0015]
However, even if it is said that, when the color of the subject is in the vicinity on the L axis, that is, in the case of white, black and gray, the signal of the hue H has no meaning as information, and the worst case In this case, it can be seen that an image having a poor S / N ratio may have various hue H vectors despite being white.
The tracking control circuit section 11 utilizes the properties of the HLS color coordinate system to extract the features of the subject, and drives the panning drive motor 12A and the tilting drive motor 12B so as to follow a change in the feature when it occurs. As a result, it is possible to obtain, as the video signal S3, a video signal that adapts to the movement of the subject and always displays the video at the center position of the display screen.
[0016]
That is, the pixel information constituting the subject tracking detection signal S4 stored in the image memory 15 is obtained by applying a block designating signal S6 sent from a microprocessor-based tracking signal processing circuit 16 to an address generation circuit 17, as shown in FIG. As shown in FIG. 4, an address signal for substantially dividing the display screen PIC formed in the image memory 15 into blocks each having a small area AR having a predetermined size based on xy orthogonal coordinates (x, y). S7 is supplied from the address circuit 17 to the image memory 15.
Thus, the data of each pixel constituting the display screen PIC of the image memory 15 is read out for each small area AR and processed as one block image information for each small area AR.
[0017]
In the case of this embodiment, the display screen PIC is divided into 16 small areas AR in the x direction and the y direction, and thus the coordinates of the rectangular coordinates (x, y) for 16 × 16 (= 256) small areas AR. By specifying x = i, y = j (for example, coordinates of the upper left corner), reading image information I (x = i, y = j) obtained from pixels included in the specified small area AR Can be.
The hue signal HUE component of the image information I (x = i, y = j) read out from the image memory 15 for each small area AR is supplied to the hue histogram generation circuit 19 through the gate circuit 18. , The luminance signal Y component is directly supplied to the luminance histogram generation circuit 20.
[0018]
As shown in FIG. 5, the hue histogram generation circuit 19 generates a pixel having a hue angle of 0 ° to 359 ° with respect to the hue of the pixel in the reference measurement frame FMR set on the center position of the display screen PIC. The hue frequency characteristic HuStd (i) representing the distribution of the number of pixels (i.e., frequency distribution) is obtained, and is sent to the follow-up signal processing circuit 16 as the hue histogram signal S11.
Thus, the hue histogram generation circuit 19 converts the hue characteristic of the image in the reference measurement frame FMR into a hue characteristic pattern represented by the hue frequency characteristic HuStd (i), and sends it to the tracking signal processing circuit 16. Will be supplied.
[0019]
Further, based on the luminance signal Y for the pixels in the reference measurement frame FMR set on the display screen PIC in the same manner, the luminance histogram generation circuit 20 performs each luminance for luminance levels 0 to 255 as shown in FIG. A luminance frequency characteristic YStd (i) representing the distribution of the number of pixels having a level (that is, a frequency distribution) is obtained, and this is supplied to the follow-up signal processing circuit 16 as a luminance histogram signal S12.
Thus, the luminance histogram generation circuit 20 converts the luminance characteristic of the image in the reference measurement frame FMR into a luminance characteristic pattern represented by the luminance frequency characteristic YStd (i), and sends the luminance characteristic pattern to the tracking signal processing circuit 16. Will be supplied.
[0020]
In the case of this embodiment, a hue noise gate signal forming circuit 25 having a comparator configuration is provided for the gate circuit 18, and a saturation signal SAT read out from the image memory 15 for each pixel is sent out from the tracking signal processing circuit 16. The hue signal HUE of the pixel is supplied to the hue histogram generation circuit 19 by providing the gate signal S15 for closing the gate circuit 18 when the saturation signal SAT is equal to or lower than the predetermined level to the gate circuit 18 in comparison with the noise determination signal S14. It is made not to input.
When the saturation signal SAT detected by the saturation / hue detection circuit 14 is in the vicinity of the L axis (FIG. 3), this is because the hue signal HUE is buried in noise because the saturation is small, and is used as information. Therefore, the hue signal HUE having no such meaning is removed by the gate circuit 18.
[0021]
(2) Automatic tracking processing operation
In the above configuration, the tracking signal processing circuit 16 executes the automatic tracking processing procedure RT1 shown in FIG. 7 so that even if the subject moves within the field of view of the camera, the tracking signal processing circuit 16 The lens block unit 1 is adaptively controlled in accordance with the movement of the subject so that the image having the highest similarity can always be displayed in the reference measurement frame FMR.
When the tracking signal processing circuit 16 enters the automatic tracking processing procedure RT1, first in step SP1, the frame number FN is initialized to FN = 0, and the recording pause state is released by the user operating the recording pause button RECPAUSE. It is in a state of waiting for.
[0022]
When the user starts recording in this state, the follow-up signal processing circuit 16 proceeds to step SP2, and the reference measurement frame FMR at the center of the display screen PIC is sent to the address generation circuit 17 as described above with reference to FIGS. Then, the luminance signal Y and the hue signal HUE corresponding to the pixel in the reference measurement frame FMR are sent to the luminance histogram generation circuit 20 and the hue histogram generation circuit 19, and thereby the reference luminance frequency characteristic YStd (i) ( Processing such as recording is performed using a luminance histogram signal S12 and a hue histogram signal S11 using the reference hue frequency characteristic HuStd (i) (FIG. 5) and the reference hue frequency characteristics HueStd (i) (FIG. 5) as reference characteristic patterns.
[0023]
Subsequently, the follow-up signal processing circuit 16 proceeds to step SP3, in which the frame number FN is stepped up to FN + 1 first, and secondly, as shown in FIG. By scanning the position, the image information on the display screen PIC is extracted in units of the detection measurement frame FMD by the detection measurement frame FMD.
In the case of this embodiment, the detection measurement frame FMD is composed of 4 × 4 small areas AR similarly to the reference measurement frame FMR, and the address generation circuit 17 sets the small area address at the upper left corner of the detection measurement frame FMD to the left. The scan is performed by sequentially designating from right to right and from top to bottom.
As a result, the detection / measurement frame FMD has addresses (x, y) = (0, 0), (1, 0)... (12, 0), (0, 1), (1, 1). ),..., (0, 12), (1, 12)... (12, 12).
[0024]
During such a scan, the tracking signal processing circuit 16 shown in FIGS. 9 and 10 based on the hue information and the luminance information of the image of the detection measurement frame FMD moved to the address (x, y) position. Such a detected hue frequency characteristic Hue (x, y) (i) and a detected luminance frequency characteristic Y (x, y) (i) are obtained.
Here, the detected hue frequency characteristic Hue (x, y) (i) is based on the frequency of occurrence of the pixel having the hue angle y = 0 ° to 359 ° that all the pixels included in the detection measurement frame FMD have. 4 shows an FMD hue detection pattern.
On the other hand, the detected luminance frequency characteristic Y (x, y) (i) is based on the detected characteristic pattern based on the frequency of occurrence of the pixels of the luminance level = 0 to 255 belonging to all the pixels included in the detection measurement frame FMD. Is represented.
[0025]
Subsequently, in step SP4, the tracking signal processing circuit 16 calculates the following equation for the luminance signal.
(Equation 1)

For the detection measurement frame FMD, the absolute value of the difference between the detected luminance frequency characteristic Y (x, y) (i) and the reference luminance frequency characteristic YStd (i) is summed for luminance levels y = 0 to 255. As a result, the Euclidean distance J1 (x, y) is obtained, and this is used as information representing the similarity of the luminance information in the detection measurement frame FMD at the address (x, y) position with respect to the luminance information of the image in the reference measurement frame FMR. obtain.
[0026]
For the hue information of the detection measurement frame FMD, the tracking signal processing circuit 16 calculates
(Equation 2)

The absolute value of the difference between the detected hue frequency characteristic Hue (x, y) (i) of the detection measurement frame FMD at the address (x, y) position and the reference hue frequency characteristic HueStd (i) is The Euclidean distance J2 (x, y) is obtained by summing the angles i = 0 ° to 359 °, and is located at the position (x, y) with respect to the reference hue pattern of the image of the reference measurement frame FMR. Information indicating the degree of similarity of the image included in the detection measurement frame FMD to the detection feature pattern is formed.
[0027]
Based on the Euclidean distances J1 (x, y) and J2 (x, y) thus obtained for the luminance and the hue, the following signal processing circuit 16 calculates
[Equation 3]

The evaluation value J (x, y) is obtained by calculating the sum of
[0028]
Thus, the tracking signal processing circuit 16 evaluates the evaluation values of all the detection measurement frames FMD at the scan positions (x, y) (x = 0, 1,... 12, y = 0, 1,... 12) of the detection measurement frame FMD. In a state where J (x, y) (x = 0, 1,..., Y = 0, 1,..., 12) is obtained, the process proceeds to the next step SP5, and the evaluation value J (x, y) is minimized. The position of the detection measurement frame FMD is determined to be the position of the subject at the time of the current measurement, and the minimum evaluation value J (x, y) is equal to or less than the non-existence confirmation threshold level. After confirming that an image of the subject exists in the screen PIC, in the next step SP6, the center position (x, y) of the new subject is set to the reference measurement frame FMR (FIG. 4) position set at the center position of the screen. Panning drive the following control signal S5 It gives the chromatography data 12A and tilting drive motor 12B.
[0029]
Here, if the minimum evaluation value is large, this means that the position J (x, y) of the new subject detected from the detection measurement frame is located far from the center of the display screen PIC. Accordingly, when the minimum evaluation value is equal to or higher than the predetermined absence confirmation threshold level, the tracking signal processing circuit 16 places the image of the subject outside the display screen PIC (accordingly, the image of the subject). Does not exist on the display screen PIC).
[0030]
Subsequently, the tracking signal processing circuit 16 proceeds to step SP7 and updates the reference frequency characteristic data (FIGS. 5 and 6) of the luminance signal and the hue signal of the image newly coming to the reference measurement frame FMR as the reference characteristic pattern. After that, the process returns to the above-mentioned step SP3 to enter the next measurement cycle.
Thus, when the subject moves relative to the television camera, the tracking signal processing circuit 16 determines the position of the detection measurement frame FMD having the image information having the highest similarity to the image information of the reference measurement frame FMR for the entire display screen PIC. When the subject moves by performing panning and tilting control of the lens block 1 of the television camera so that the image of the detection measurement frame FMD having the highest similarity comes to the position of the reference measurement frame FMR. In response, the video camera system VCS can be adaptively operated to return the image of the subject to the center position of the display screen PIC.
[0031]
On the other hand, when the subject at the reference measurement frame FMR position does not move, the detection feature pattern obtained from the detection measurement frame FMD at the same position as the reference measurement frame FMR is the most suitable for the reference feature pattern. Since the evaluation that the similarity is large can be obtained in step SP4, the tracking signal processing circuit 16 uses the tracking control signal S5 to maintain the state where the new subject is still in the detection measurement frame FMR. Control.
According to the automatic follow-up processing procedure shown in FIG. 7, as long as the user operates the camera so that the subject first enters the reference measurement frame FMR at the center of the screen and then starts recording, the image of the subject is thereafter displayed on the display screen PIC. Even if the movement is performed, the tracking signal processing circuit 16 reliably detects the movement position by comparing the detection characteristic pattern obtained based on the frequency characteristic data of the luminance signal and the hue signal with the reference detection pattern. The automatic tracking can be performed while the video camera system operates adaptively to the movement of the subject.
[0032]
(3) Subject existence confirmation processing operation
When the tracking signal processing circuit 16 enters the existence confirmation processing as to whether or not the image of the subject is in the display screen PIC in step SP5 of the automatic following processing procedure RT1, the following signal processing subroutine is executed. .
[0033]
(3-1) First embodiment
FIG. 11 shows the first embodiment. When the tracking signal processing circuit 16 enters the subject existence confirmation processing routine RT2, it first proceeds to step SP11 to determine whether or not a subject exists in the display screen PIC. When a positive result is obtained and the presence of the subject can be confirmed (that is, when the subject presence detection information having the content “exist” is obtained), the main routine, that is, FIG. The process returns to step SP5 of the automatic following procedure RT1 to continue the processing of the automatic following procedure RT1.
[0034]
On the other hand, when the subject does not exist in the display screen PIC, the follow-up signal processing circuit 16 obtains a negative result in step SP11 (that is, obtains subject detection information whose content is "absent"). The tally lamp 9 is turned on by transmitting the drive control signal S6 to the tally lamp drive circuit 13 at step SP13.
In the case of this embodiment, as shown in FIG. 12, the tally lamp 9 is provided so as to protrude above the top plate of the case of the television camera 25, so that the subject is included in the visual field image projected on the display screen PIC. The user can easily know that the subject is absent by turning on the tally lamp 9 when the video is not projected.
[0035]
Thus, the user does not leave the subject in the non-existent state, but performs a process of re-capturing the image of the subject in the display screen PIC by, for example, panning and tilting the video camera 25 by hand. Can be implemented immediately if necessary.
When the user performs a pan and tilt operation on the video camera 25 by hand in this manner, and the image of the subject is re-captured in the display screen, the tracking signal processing circuit 16 obtains a positive result in step SP11. Thus, a process of returning to the main routine through step SP12 is executed without executing the lighting process of the tally lamp 9 in step SP13 (accordingly, turning off the tally lamp 9).
[0036]
In FIG. 12, 25A is a panning / tilting drive unit, 25B is a lens system, 25C is a view finder system, and 25D is a microphone.
According to the configurations shown in FIGS. 11 and 12, when the image of the subject no longer exists in the display screen PIC, the occurrence of this state can be immediately notified to the user, and as a result, a video camera system that is easier to use can be easily provided. Can be realized.
[0037]
(3-2) Second embodiment
FIG. 13 shows a second embodiment. In this case, when the tracking signal processing circuit 16 enters the subject existence confirmation processing routine RT3, it first determines in step SP21 whether or not a subject exists, and a positive result is obtained. When it is determined (that is, when the subject detection information of "existence" is obtained), the processing returns to the main routine through step SP22, that is, step SP5 of the automatic tracking processing procedure RT1, thereby continuing the processing of the automatic tracking processing procedure RT1. .
On the other hand, if a negative result is obtained in step SP21 (that is, if "non-existent" subject detection information is obtained), this means that there is no image of the subject in the display screen PIC. The follow-up signal processing circuit 16 moves to step SP23, stores the current zoom position of the lens 2 in a built-in memory, and drives the zooming drive motor 12C by the follow-up control signal S5 in step SP24 to widen the lens 2. Drive in the direction.
[0038]
In this embodiment, the lens 2 has a zoom lens driven by a zooming drive motor 12C, and a potentiometer operating in conjunction with the zoom lens detects a zoom position of the zoom lens. The signal is supplied to the tracking signal processing circuit 16.
As a result, the field of view of an image obtained by capturing the imaging light LA2 arriving at the lens 2 of the lens block unit 1 into the CCD imaging device 4 can be enlarged by pulling the zoom magnification according to the zoom position in the wide direction.
Subsequently, the follow-up signal processing circuit 16 proceeds to step SP25 to determine whether or not the subject can be found. If a negative result is obtained, the processing of step SP25 is continued until a positive result is obtained in step SP25.
[0039]
When a positive result is finally obtained in step SP25, this means that the automatic tracking process can be performed due to the presence of the subject in the visual field image displayed on the display screen PIC. The signal processing circuit 16 returns to the step SP26 to return the zoom position to the zoom position stored in the step SP23 by driving the zooming drive motor 12C while capturing the subject in the display screen PIC, and then returning to the above-described step. Return to SP21.
Thus, the follow-up signal processing circuit 16 automatically controls the lens block unit 1 so that the image of the subject exists in the display screen PIC in a state where the zoom lens of the lens 2 is returned to the original zoom position, and as a result, When a positive result is obtained in the determination in step SP21, the process returns to the main routine, that is, step SP5 of the automatic following procedure RT1 through step SP22.
[0040]
In the configuration of FIG. 13, the tracking signal processing circuit 16 executes the automatic tracking processing procedure RT1 to detect the subject in the state where the image of the subject is being projected at the center position of the display screen PIC. When the image of the subject is lost in the screen due to loss, the following signal processing circuit 16 detects this by obtaining a negative result in step SP21 of the subject existence confirmation processing routine RT3, and in step SP23, the following signal is detected. By pulling the zoom magnification to the wide side, the image of the subject is made to exist in the image formed on the image sensor 4.
In this state, the tracking signal processing circuit 16 finds the subject in steps SP24 and SP25, returns the zoom magnification of the lens 2 to the original while capturing the subject on the screen, and automatically passes through the steps SP21 and SP22. It returns to the process of the follow-up process procedure RT1.
[0041]
Thus, according to the configuration of FIG. 13, when the television camera system once loses sight of the subject, zooming control of the lens 2 is performed so that the subject is automatically captured again. Even if the video camera system loses sight of the subject, this can be immediately detected, and the troublesome work of the user coming to the vicinity of the video camera 25 and performing the pan and tilt operations each time can be eliminated. A video camera system that is easier to use can be realized.
[0042]
(3-3) Third embodiment
FIG. 14 shows a third embodiment. When the subject is lost, the tracking signal processing circuit 16 first executes a predictive tracking process, and when the subject is not found as a result, then executes a scan capturing process.
That is, when the tracking signal processing circuit 16 enters the subject existence confirmation processing routine RT4, first, in step SP31, it is determined whether or not the subject exists, and when a positive result is obtained (that is, the subject detection information of "existence" is detected). When it is obtained), the process returns to the main routine, that is, the step SP5 of the automatic tracking processing procedure RT1 through the step SP32 to execute the automatic tracking processing such that the subject comes to the center of the screen.
[0043]
On the other hand, if a negative result is obtained in step SP31 (that is, "non-existent" object presence detection information is obtained), this means that the lens block unit 1 has lost sight of the object, The signal processing circuit 16 proceeds to step SP33 to determine whether or not to perform prediction tracking processing.
When the tracking signal processing circuit 16 obtains a positive result in step SP33, the tracking signal processing circuit 16 enters the prediction tracking mode from step SP34.
Here, the tracking signal processing circuit 16 performs the automatic tracking processing of the subject by using the control amount before losing the subject for a predetermined time (for example, during the display time for one screen) when the subject is lost from the display screen PIC. to continue.
[0044]
Thus, when a video camera system loses sight of an object instantaneously, for example, when the object passes behind the object, the video camera system performs a predictive automatic tracking process using the pan and tilt drive conditions before losing the object. Thus, when the subject moves behind the object and ends and moves at the same speed, the panning and tilting operations of the video camera can be continuously and smoothly continued.
After executing the processing in the prediction tracking mode, the tracking signal processing circuit 16 proceeds to step SP35 to determine whether or not the subject can be found, and when an affirmative result is obtained, passes through the above-described steps SP31 and SP32. Return to the main routine.
[0045]
On the other hand, if a negative result is obtained in step SP35, this means that the subject cannot be recaptured only by the prediction tracking processing of step SP34, and the tracking signal processing circuit 16 The process returns to step SP33.
However, in this state, since the prediction tracking processing has already been completed, the tracking signal processing circuit 16 obtains a negative result in step SP33. At this time, the tracking signal processing circuit 16 switches from step SP36 to the scan capture mode. enter.
[0046]
This step SP36 determines whether or not to perform the scan processing. The tracking signal processing circuit 16 obtains an affirmative result when the processing proceeds from step SP33 to SP36, and performs the scan control of the lens block unit 1 in step SP37.
In the case of this embodiment, the follow-up signal processing circuit 16 performs a scan control process by first causing the zoom lens constituting the lens 2 to perform a zoom operation in the wide direction to a predetermined zoom position via the zooming drive motor 12C, and then the panning drive motor 12A. By driving the tilting drive motor 12B in the panning direction and the tilting direction around the original screen over a screen area corresponding to one screen width, the visual field of the visual field image projected on the display screen PIC is enlarged. The lost object is displayed in the visual field image of the display screen PIC of the video camera 25, and a process of determining whether or not the object exists in the display screen PIC is executed.
[0047]
In the case of this embodiment, the visual field image projected on the display screen PIC is scanned by sequentially moving the visual field of the camera substantially zigzag from the upper left position in the left-right direction.
Subsequently, the follow-up signal processing circuit 16 proceeds to step SP38 to determine whether or not the subject has been found. If an affirmative result is obtained, the process returns to the main routine through the above-described steps SP31 and SP32.
On the other hand, if the subject cannot be found even after executing the scan operation, the tracking signal processing circuit 16 obtains a negative result in step SP36 and proceeds to step SP39.
[0048]
If a negative result is obtained in step SP36 in this way, this means that the subject could not be captured again despite the prediction tracking processing and the scan capturing processing. The circuit 16 enters the initial position return mode in step SP39, and moves the panning drive motor 12A and the tilting drive motor 12B to the initial positions before predictive tracking.
In this state, the follow-up signal processing circuit 16 determines whether or not the subject has been found in step SP40. If a negative result is obtained, the process returns to step SP39, and the loop processing of steps SP39-SP40-SP39 is performed thereafter. Is executed, the panning drive motor 12A and the tilting drive motor 12B are kept at the initial positions unless the subject is found.
[0049]
Thus, after the subject has been lost, if the subject cannot be found due to the prediction tracking process and the scan process, the tracking signal processing circuit 16 causes the user to subsequently perform the panning and tilting operations of the video camera by hand. Thus, when the subject is captured on the screen, the operation can be performed from the initial position, so that the subject can be more easily captured by hand.
On the other hand, if the subject can be found when moving to the initial position, the tracking signal processing circuit 16 returns to the main routine through steps SP31 and SP32 because a positive result is obtained in step SP40.
[0050]
According to the configuration of FIG. 14, when the subject is in an absent state deviating from the screen due to, for example, rapid acceleration, the tracking signal processing circuit 16 predicts and tracks by a loop of steps SP33-SP34-SP35-SP33. After executing the processing, the loop camera of step SP36-SP37-SP38-SP36 is executed so that the video camera system can execute the user every time even if the subject deviates from the screen due to rapid acceleration. Can automatically execute the process of re-capturing the subject on the screen without the need for complicated work of coming to the side of the camera and arbitrarily setting the position of the video camera.
Thus, a video camera system that is easier to use can be obtained.
[0051]
(4) Another embodiment
In the above-described embodiment, the pixel information forming the display screen PIC is formed in the lens block unit 1, and the display image follows the movement of the subject by performing the panning and tilting operations of the lens block unit 1. Alternatively, the image output signal S1 sent from the lens block unit 1 may be stored in the image memory 15 and the image may be panned and tilted to form a display screen. The effect can be obtained.
[0052]
Further, in the above-described embodiment, the case has been described where the position of the subject is detected based on the frequency characteristic data of the luminance signal and the hue signal in the reference measurement frame and the detection measurement frame. However, the present invention is not limited to this. For example, even if the present invention is applied to an automatic tracking system that detects a subject position using an infrared sensor, an ultrasonic sensor, or the like, the same effects as those described above can be obtained. .
[0053]
In the embodiment of FIG. 14, as the scan operation in the scan capture mode, the visual field image is sequentially moved in a zigzag manner in the left-right direction sequentially from the upper left position. However, the scan operation is not limited to this. Various methods can be adopted, such as a method of moving the outer side in a spiral shape.
[0054]
Further, in the embodiment of FIG. 14, the scan operation in the scan capture mode is executed after the visual field image is first pulled in the direction of increasing the zoom magnification by the zooming means. Even if the magnification is not changed, the same effect as in the above case can be obtained.
[0055]
【The invention's effect】
According to the present invention as described above, for example, in the case where the subject is lost while performing the automatic tracking control operation, this is immediately detected and the user is notified, or the lost image is detected. Is automatically recaptured by performing panning, tilting, and zooming driving, so that, for example, when the subject is rapidly accelerated, it cannot be automatically tracked. Also in such a case, it is possible to realize a video camera system capable of easily performing a corresponding measure without imposing an excessive burden on a user. In this way, by detecting the position of the image of the subject based on the sum of the information indicating the similarity between the luminance and the hue, automatic tracking can be performed without being affected by the light source.
[Brief description of the drawings]
FIG. 1 is a characteristic curve diagram showing a conventional control amount calculation method.
FIG. 2 is a block diagram showing the overall configuration of a video camera system according to the present invention.
FIG. 3 is a schematic diagram illustrating an HLS color coordinate system representing a visual stimulus;
FIG. 4 is a schematic diagram used for describing a reference measurement frame FMR.
FIG. 5 is a characteristic curve diagram showing reference hue frequency characteristics obtained from the reference measurement frame FMR of FIG. 4;
FIG. 6 is a characteristic curve diagram showing reference luminance frequency characteristics obtained from the reference measurement frame FMR of FIG.
FIG. 7 is a flowchart showing an automatic follow-up processing procedure.
FIG. 8 is a schematic diagram for describing a scan operation by a detection measurement frame.
FIG. 9 is a characteristic curve diagram showing a detected hue frequency characteristic.
FIG. 10 is a characteristic curve diagram showing a detected luminance frequency characteristic.
FIG. 11 is a flowchart showing a subject presence confirmation processing routine in the first embodiment.
FIG. 12 is a perspective view showing the appearance of a video camera having an alarm display.
FIG. 13 is a flowchart showing a subject presence confirmation processing routine in a second embodiment.
FIG. 14 is a flowchart showing a subject existence confirmation processing routine in a third embodiment.
[Explanation of symbols]
VCS: video camera system, 1: lens block 1, 2, lens 3, iris 4, imaging device 5, signal separation / automatic gain adjustment circuit 7, digital camera processing circuit , 11 ... follow-up control circuit unit, 12A ... panning drive motor, 12B ... tilting drive motor, 12C ... zooming drive motor, 13 ... tally lamp drive circuit, 14 ... saturation / hue detection circuit, 15 ... ... image memory, 16 ... tracking signal processing circuit, 17 ... address generation circuit, 18 ... gate circuit, 19 ... hue histogram generation circuit, 20 ... brightness histogram generation circuit, RT1 ... automatic tracking processing procedure, RT2 RT4 ... Subject existence confirmation processing routine.

Claims (5)

Obtain information indicating the similarity of luminance and hue with respect to the reference measurement frame for the detection measurement frame, and calculate the sum to obtain an evaluation value, thereby detecting the position of the image of the subject projected on the display screen by detecting the subject position. Means,
Tracking drive amount calculation means for obtaining panning and tilting tracking drive amount information based on the detection position information of the subject position detection means;
Tracking means for automatically tracking a subject by performing panning and tilting driving on a visual field image in the display screen by an amount corresponding to the panning and tilting tracking drive amount information,
Subject presence detection means for detecting whether or not a video of the subject is present in the display screen to obtain subject presence detection information, wherein the subject presence detection information is obtained based on the subject presence detection information of the subject presence detection means. A video commanding that the tracking means should be driven so as to capture an image of a subject as a visual field image in the display screen when the content indicates "absence". Camera system. further,
When the content of the subject presence detection information is “absent” based on the subject presence detection information of the subject presence detection means, the panning immediately before entering the prediction tracking mode for a predetermined time after entering the prediction tracking mode Predicted tracking command means for performing the predicted tracking operation of the tracking means using the tilting tracking drive amount information, and
As a result of performing the predictive tracking operation of the tracking means by the predictive tracking command means, when the content of the subject presence detection information is still “absent”, the apparatus enters the scan capture mode and moves the tracking means to a predetermined range. Scan capturing command means for performing a scan capturing operation so as to perform panning and tilting driving over
As a result of performing the scan capturing operation of the tracking means by the scan capturing command means, if the content of the subject presence detection information is still "absent", the apparatus enters the initial position return mode and performs the prediction. 2. The video camera system according to claim 1, further comprising an initial position return instructing unit for returning to an initial position immediately before entering the tracking mode. Subject position detecting means for detecting the position of the image of the subject projected on the display screen;
Tracking drive amount calculation means for obtaining panning and tilting tracking drive amount information based on the detection position information of the subject position detection means;
Tracking means for automatically tracking a subject by performing panning and tilting driving on a visual field image in the display screen by an amount corresponding to the panning and tilting tracking drive amount information,
The apparatus further comprises: a subject presence detecting unit that detects whether or not a subject image is present in a display screen to obtain subject presence detection information; and a zooming unit that changes a zoom magnification of a visual field image projected on the display screen. When the content of the subject presence detection information indicates “absence” based on the subject presence detection information of the subject presence detection means, the subject image is captured as a visual field image in the display screen. A video camera system, wherein the zoom magnification of the zooming means is changed. further,
When the content of the subject presence detection information indicates "absence", the field of view of the field of view image in the display screen is expanded by controlling the zooming means so as to decrease the zoom magnification in a wide direction. Means for expanding the field of view,
In the state where the field of view is enlarged, when the content of the object presence detection information indicates “existence”, before the object is automatically tracked by the tracking means, the field of view at the zoom magnification is enlarged. 4. A video camera system according to claim 3, further comprising subject capturing means for returning to a value of: Subject position detecting means for detecting the position of the image of the subject projected on the display screen;
Tracking drive amount calculation means for obtaining panning and tilting tracking drive amount information based on the detection position information of the subject position detection means;
Tracking means for automatically tracking the subject by driving the panning and tilting of the visual field image in the display screen by an amount corresponding to the panning and tilting tracking drive amount information,
Subject presence detecting means for detecting whether or not the image of the subject exists in the display screen to obtain subject presence detection information,
A video camera comprising: a subject-absence display means for displaying, when the content of the subject-presence detection information of the subject-presence detection means is "absent", to indicate this to the user. system.

Images