JP2004085550A - Surveying system and method for selecting optimal image - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To simply obtain an image photographed by disposing a camera at an optically substantially equivalent position to a surveying instrument. <P>SOLUTION: Images of an object to be surveyed of J pieces are photographed, by changing the positions in the vicinity of installation site of a theodolite. Different surveying points P<SB>i</SB>on the object are surveyed by the theodolite. Image coordinates (X<SB>ji</SB>, Y<SB>ji</SB>) of the point P<SB>i</SB>of each image are obtained (S201, S204). Virtual three-dimensional coordinates (x<SB>i</SB>, y<SB>i</SB>, z<SB>i</SB>), which satisfy collinear conditions are calculated from a horizontal angle θ<SB>hi</SB>and an altitude angle θ<SB>pi</SB>of the surveyed point P<SB>i</SB>(S202). It is assumed that the position of the camera is the same as the position of the theodolite, and the optimum values of the inclination (α, β, γ) of the camera is calculated as unknown variables, by using the least-square method (S206-S209). When the position of the camera is (0, 0, 0) and the inclination is (α, β, γ), differences between the image coordinates of the point P<SB>i</SB>calculated, based on the coordinates (x<SB>i</SB>, y<SB>i</SB>, z<SB>i</SB>) and the image coordinates of an actual image are evaluated by a merit function Φ<SB>j</SB>. <P>COPYRIGHT: (C)2004,JPO

Description

すなわち、メリット関数Φ_ｊは、各測点Ｐ_ｉの画像ｊ上の実際の画像座標（Ｘ_ｊｉ，Ｙ_ｊｉ）と、画像ｊが視準原点Ｏ_Ｓ（０，０，０）において傾き（α_Ｇｊ，β_Ｇｊ，γ_Ｇｊ）で撮影されたと仮定したときに共線条件から算出される近似的な画像座標（Ｘ_Ｇｊｉ，Ｙ_Ｇｊｉ）との間のズレの大きさ表わす。
【００２６】
ステップＳ２０８では、ステップＳ２０６〜ステップＳ２０９の繰り返し処理において、メリット関数Φ_ｊが前回の値に対して変化しているか否かが判定される。例えば前回の処理におけるメリット関数の値がΦ_ｊ ^０であり、今回の処理での値がΦ_ｊ ^１であるとするとき、｜Φ_ｊ ^１−Φ_ｊ ^０｜の値が所定値以上であるか否かが判定される。
【００２７】
｜Φ_ｊ ^１−Φ_ｊ ^０｜Φ≧所定値であると判定された場合には、ステップＳ２０９において近似的に与えられた傾き（α_Ｇｊ，β_Ｇｊ，γ_Ｇｊ）に対する補正量（δα，δβ，δγ）が例えば最小二乗法により求められる。すなわち共線条件を近似値である（α_Ｇｊ，β_Ｇｊ，γ_Ｇｊ）の周りにテイラー展開し高次の項を省いて線形化し、補正量（δα，δβ，δγ）を未知量とする正規方程式を作成することにより適正な補正量（δα，δβ，δγ）が求められる。また、ステップＳ２０９では、算出された補正量（δα，δβ，δγ）に基づいて近似値である傾き（α_Ｇｊ，β_Ｇｊ，γ_Ｇｊ）の値が、それぞれ（α_Ｇｊ＋δα，β_Ｇｊ＋δβ，γ_Ｇｊ＋δγ）に更新される。その後処理はステップＳ２０６に戻り、ステップＳ２０８において｜Φ_ｊ ^１−Φ_ｊ ^０｜Φ＜所定値と判定されるまで、ステップＳ２０６〜ステップＳ２０９の処理が繰り返される。ステップＳ２０８において｜Φ_ｊ ^１−Φ_ｊ ^０｜Φ＜所定値と判定されると、処理はステップＳ２１０に進む。
【００２８】
ステップＳ２１０では、ステップＳ２０６〜ステップＳ２０９の繰り返し処理において、最後に求められたメリット関数Φ_ｊの値、及び最後の（α_Ｇｊ，β_Ｇｊ，γ_Ｇｊ）の値がＣＰＵ４１の記憶領域に格納される。ステップＳ２１１では、ｊ＝Ｊ（＝９）であるか否かが判定される。すなわち、画像１〜画像９全てに対してメリット関数Φ_ｊの値が算出されたか否かが判定される。ｊ＝Ｊでない、すなわちｊ＜Ｊ、と判定されるとステップＳ２１２においてパラメータｊの値が１インクリメントされ、処理はステップＳ２０４に戻る。
【００２９】
一方、ステップＳ２１１においてｊ＝Ｊと判定されると、ステップＳ２１３において画像ｊ（ｊ＝２，３，・・・，９）のうち、メリット関数Φ_ｊが最小となる画像が選別され、そのときの画像番号ｊと傾き（α_Ｇｊ，β_Ｇｊ，γ_Ｇｊ）が例えば記録媒体４２等に記録される。すなわち、メリット関数Φ_ｊが最小となる画像は、画像１〜画像９のうちで、電子セオドライト１０の視準原点Ｏ_Ｓに最も近い位置から撮影された画像である。以上により本実施形態の最適画像選別処理は終了する。なお、上記説明では、カメラ位置を水平面上の９点（位置▲１▼〜▲９▼）としたが、カメラ位置は、これらの位置に限定されるものではないことは言うまでもない。例えば平面上の縦３点、横３点（合計９点）に、上下３点を加え、合計２７点に対応する位置で撮影を行ってもよい。
【００３０】
次にステップＳ２０６における近似的な画像座標（Ｘ_Ｇｊｉ，Ｙ_Ｇｊｉ）の算出方法について説明する。
【００３１】
機械座標系の３次元座標（ｘ，ｙ，ｚ）は、カメラ座標系の原点が（ｘ_０，ｙ_０，ｚ_０）にあり、カメラ座標系がｘ軸、ｙ軸、ｚ軸周りに（α、β、γ）回転されているとき、次の（２）式によりカメラ座標系の３次元座標（ｃｘ，ｃｙ，ｃｚ）に変換される。
【数２】

ここで行列｛Ｔ_ｊｋ｝は回転行列であり、各成分Ｔ_ｊｋは例えば次式で表される。
Ｔ_１１＝ｃｏｓβ・ｃｏｓγ
Ｔ_１２＝ｃｏｓα・ｓｉｎγ＋ｓｉｎα・ｓｉｎβ・ｃｏｓγ
Ｔ_１３＝ｓｉｎα・ｓｉｎγ−ｃｏｓα・ｓｉｎβ・ｃｏｓγ
Ｔ_２１＝−ｃｏｓβ・ｓｉｎγ
Ｔ_２２＝ｃｏｓα・ｃｏｓγ−ｓｉｎα・ｓｉｎβ・ｓｉｎγ
Ｔ_２３＝ｓｉｎα・ｃｏｓγ＋ｃｏｓα・ｓｉｎβ・ｓｉｎγ
Ｔ_３１＝ｓｉｎβ
Ｔ_３２＝−ｓｉｎα・ｃｏｓβ
Ｔ_３３＝ｃｏｓα・ｃｏｓβ
【００３２】
また、カメラ座標系の原点をカメラの投影中心に一致させ、ｃｘ軸、ｃｙ軸をデジタルスチルカメラ２０の撮像素子の水平、垂直ラインに平行にし、ｃｚ軸を撮像面に垂直で、投影中心から像面の方向に向けて定義すると、カメラ座標系での３次元座標（ｃｘ、ｃｙ、ｃｚ）は、共線条件である次の（３）式により、撮像面上の２次元のスクリーン座標（ｓ、ｔ）に投影される。
【数３】

なお、スクリーン座標系は主点を原点とした撮像面上の２次元座標系であり、ｓ軸は撮像素子２１の水平ライン方向に、ｔ軸は垂直ライン方向に対応する。また、ここでｆは画面距離である。
【００３３】
（３）式ので得られるスクリーン座標（ｓ，ｔ）は、デジタルスチルカメラ２０の光学系のディスト−ション等による共線条件からのズレを考慮していない。補正されたスクリーン座標（ｓｃ、ｔｃ）は、次の（４）式により求められる。
【数４】

ここで、Ｄ_２、Ｄ_４、Ｄ_６はそれぞれディストーション２次成分、４次成分、６次成分であり、Ｎ_１、Ｎ_２はディストーション非対称成分、Ｘ_Ｃ、Ｙ_Ｃは主点の画像中心からのｓ軸方向、ｔ軸方向への偏心量である。
【００３４】
画像座標（Ｘ，Ｙ）は、次の（５）式に補正されたスクリーン座標（ｓｃ，ｔｃ）を代入することにより求められる。
【数５】

ここで、Ｐｘ、ＰｙはそれぞれＣＣＤの水平、垂直方向の画素ピッチであり、Ｗ、Ｈはそれぞれ画像の水平、垂直方向のピクセル数である。
【００３５】
以上の（２）式〜（５）式の変換により機械座標系の３次元座標は画像座標へ変換することができる。したがって、ステップＳ２０６において、（２）式にカメラ位置（０，０，０）、傾き（α_Ｇｊ，β_Ｇｊ，γ_Ｇｊ）、３次元座標（ｘ_ｉ，ｙ_ｉ，ｚ_ｉ）を代入することにより、画像ｊにおける測点Ｐ_ｉに対応する近似的な画像座標（Ｘ_Ｇｊｉ，Ｙ_Ｇｊｉ）が算出される。
【００３６】
次に、本実施形態におけるカメラのセオドライト設置台への装置方法及び、カメラ位置の調整方法について図６〜図９を参照して説明する。
【００３７】
図６は、電子セオドライト１０が三脚５０に取り付けられた状態が示されている。電子セオドライト１０は、視準望遠鏡１７を俯仰自在に支持するセオドライト本体１００と、水平目盛盤を備える水平目盛部１０１と、整準台１０２と、三脚５０に取り付けられる底板１０３とから概ねなる。本実施形態の電子セオドライト１０の本体及び水平目盛部１０１は、一体的に構成され、整準台１０２に着脱自在である。すなわち、本実施形態では、整準台１０２がセオドライト設置台としての機能を果たす。
【００３８】
図７は、本実施形態のカメラ装着装置の斜視図であり、図８は正面図、図９は図８のＡ−Ａ断面図である。
【００３９】
デジタルスチルカメラ２０は、カメラ装着装置２００を介して三脚５０に取り付けられたセオドライト設置台（整準台）１０２に装着される。セオドライト設置台１０２には、水平目盛り部１０１の代わりに円筒形の基台部２０１が取り付けられる。基台部２０１の底面には例えば３個の突起２０２が設けられており、突起２０２は、セオドライト設置台１０２の対応する窪みに嵌入され、基台部２０１をセオドライト設置台１０２に固定する。
【００４０】
基台部２０１の上面には、細長い扁平の板をコの字型に成形した水平回動部２０３が配置される。コの字型の水平回動部２０３は口の開いた方を上方に向け、基台部２０１の略中央にその中心が配置される。水平回動部２０３の基台部２０１の中央部に対応する位置には、回転軸部材２０４が貫入される軸穴２０３ｈが形成されている。また、これに対応して基台部２０１の中央には、底面から上面に達する軸穴２０１ｈが形成されている。軸穴２０３ｈ及び軸穴２０１ｈには回転軸部材２０４が貫入されてナット２０４ｎ等で固定される。これにより、水平回動部２０３は基台部２０１に対して鉛直軸Ｌｐ’周りに回動自在に保持される。
【００４１】
水平回動部２０３の内側には、水平回動部２０３と略同じ幅を持つが、水平回動部２０３よりも一回り小さいコの字型の俯仰部２０５が所定の間隔を隔てて配置される。水平回動部２０３及び俯仰部２０５の両者は、互いに左右の上端部において係合される。すなわち、水平回動部２０３と俯仰部２０５の両上端部にはそれぞれ回転軸部材２０６ａ、２０６ｂを挿通するための軸穴がそれぞれ設けられている。回転軸部材２０６ａは、水平回動部２０３と俯仰部２０５の正面図（図８）において右側の上端に設けられたそれぞれの軸穴にスペ−サ−２０６Ｃを介して回転自在に挿通される。一方、回転軸部材２０６ｂは、左側の上端に設けられたそれぞれの軸穴にスペ−サ−２０６Ｃを介して回転自在に挿通される。回転軸部材２０６ａ、２０６ｂは同軸Ｌｈ’上に配置され、軸Ｌｈ’は基台部２０１の中心を通る鉛直軸Ｌｐ’と直交する。すなわち俯仰部２０５は水平回動部２０３により、水平軸Ｌｈ’周りに回動自在に保持され、これによりカメラの俯仰動作が実現される。また、回転軸部材２０６ａの端部には、俯仰操作の固定を行うための摘み部２０７が取り付けられている。なお、水平軸Ｌｈ’と鉛直軸Ｌｐ’との交点は電子セオドライト１０が取り付けられたときの視準原点Ｏ_Ｓの位置に略対応する。
【００４２】
俯仰部２０５の横方向に延在する底板中央には、円柱部材２０８が底板に垂直に設けられる。すなわち、円柱部材２０８は、俯仰部２０５の両側板に平行に底板中央に取り付けられている。また、円柱部材２０８の上端側は、円管部材２０９に嵌入され、円管部材２０９は、円柱部材２０８に対して摺動自在である。円管部材２０９の位置は、円管部材２０９の下端よりに設けられた上下固定摘み部２０９ｄにより固定される。すなわち、円管部材２０９の下端よりには、円管の内側と外側を連通する穿孔が穿設されており、この穿孔には上下固定摘み部２０９ｄの雄ネジと螺合する雌ネジが穿刻されている。円管部材２０９の上下方向の運動は、上下固定摘み部２０９ｄを回転し、雄ネジを円管部材２０９の内の円柱部材２０８の側面に押し付けることにより規制される。なお、円筒部材２０８の側面には目盛２０８ｍが描かれており、作業者は目盛２０８ｍを参照して円管部材２０９の俯仰部２０５からの距離を知ることができる。
【００４３】
円管部材２０９の上部には、雲台部２１０が設けられている。雲台部２１０は、下から固定部２１１、左右移動部２１２、前後移動部２１３の３層構造をなす。固定部２１１は円管部材２０９に固着されており、固定部２１１は、水平面が正方形の扁平な直方体形状を略呈する。固定部２１１の上面には水平軸Ｌｈ’方向に沿った蟻ほぞ形状のキー溝が形成されている。左右移動部２１２も固定部２１１と略同型の直方体形状を呈し、その底面には、上記固定部２１１の上面に形成されたキー溝と噛合う蟻ほぞ形状のキーが形成されている。すなわち、左右移動部２１２は、固定部２１１に対して水平軸Ｌｈ’方向に摺動自在である。また、固定部２１１の正面側の側面中央には、固定部２１１の上面に形成されたキー溝に達する穿孔が設けられており、この穿孔には、左右調整摘み部２１１ｄが取り付けられている。すなわち、左右調整摘み部２１１ｄを回転させることにより左右移動部２１２を固定部２１１に対して左右方向（水平軸Ｌｈ’に沿って）に移動することができる。なお、固定部２１１、左右移動部２１２には、固定部２１１に対する左右移動部２１２の移動量を示す目盛２１１ｍが描かれている。
【００４４】
一方、左右移動部２１２の上面には水平軸Ｌｈ’と直交する方向に沿って、蟻ほぞ形状のキー溝が形成されており、左右移動部２１２と略同型の直方体形状を呈した前後移動部２１３の底面には、左右移動部２１２の上面に設けられたキー溝と噛合う蟻ほぞ形状のキーが形成されている。すなわち、前後移動部２１３は、左右移動部２１２に対して水平軸Ｌｈ’と直交する方向（前後方向）に沿って摺動自在である。また、左右移動部２１２の右側面中央には、左右移動部２１２の上面に形成されたキー溝に達する穿孔が設けられており、この穿孔には、前後調整摘み部２１２ｄが取り付けられている。すなわち、前後調整摘み部２１２ｄを回転させることにより、前後移動部２１３を左右移動部２１２に対して前後方向に移動することができる。なお、左右移動部２１２、前後移動部２１３には、左右移動部２１２に対する前後移動部２１３の移動量を示す目盛２１２ｍが描かれている。
【００４５】
前後移動部２１３の上面には、略正方形の凹部２１３ｃが形成されており、前後移動部２１３の正面側の側面中央には、凹部２１３ｃに達するネジ孔が形成されている。このネジ孔には、ボルト状のカメラ固定摘み部２１３ｄが装着される。凹部２１３ｃには、カメラ取付部２１４が嵌入される。カメラ取付部２１４は、略凹部２１３ｃと同型の直方体形状をしており、その底面中央には、底面から上面に貫通する穿孔が形成されており、取付ボルト２１４ｄが嵌挿されている。取付ボルト２１４ｄは、カメラ取付部２１４の上面から突出し、カメラ底面に設けられた、三脚取付孔に螺着され、カメラをカメラ取付部２１４に固定する。カメラ取付部２１４の正面側の側面には、カメラ取付部２１４を凹部２１３ｃ内に装着したときに、カメラ固定摘み部２１３ｄに対応する位置に例えば水平方向の溝が切られている。すなわち、カメラ固定摘み部２１３ｄを回転し、凹部２１３ｃ内に送り出すことにより、カメラ取付部２１４を雲台２１０の前後移動部２１３に固定することができる。
【００４６】
雲台２１０に装置されたカメラ２０は、固定摘み部２０９ｄを操作することにより上下の位置を、２つの調整摘み部２１１ｄ、２１２ｄを操作することにより前後左右の位置を調整することができる。カメラを雲台２１０に配置すると、その投影中心は、略水平軸Ｌｈ’と鉛直軸Ｌｐ’との交点（視準原点Ｏ_Ｓ）付近に配置される。通常作業者は、カメラの投影中心の位置を知ることはできないので、これを視準原点Ｏ_Ｓに正確に一致させることはできない。カメラ２０の位置は、固定摘み部２０９ｄ、左右調整摘み部２１１ｄ、前後調整摘み部２１２ｄを操作して視準原点Ｏ_Ｓの周囲の異なる位置（例えば位置▲１▼〜▲９▼）に配置することができるので、これらの各位置で撮影された画像に上記最適画像選別処理を適用することによりカメラの投影中心が測量機１０の視準原点Ｏ_Ｓに最も近い位置で撮影された画像を選別することができる。
【００４７】
以上のように本実施形態によれば、セオドライト等のように測点の方向のみを計測できる測量機であっても、測量機と光学的に略等価な位置に配置されたカメラで撮影された画像を簡単に選別することができる。また、本実施形態のカメラ装着装置を用いれば、測量機と光学的に略等価な位置と推定される複数の位置から画像を簡単に撮影することができる。さらに、等価な位置選択後には、その位置に固定することにより本条件を再現できる、よって本検出を再度行う必要がなくなり作業性を上げる事ができる。
【００４８】
なお、本実施形態では、電子セオドライトを測量機として用いたため、測量機に対する測点の方向を表わす角度情報（水平角、高度角）のみに基づいて最適画像選別処理を実行した。測点までの距離と角度情報が得られるトータルステーション等では、測点の３次元的な位置が特定できるので、各画像が撮影されたときのカメラの外部標定要素を各々算出することができる。この場合には、画像毎に算出されたカメラの位置（外部標定要素）のうち最も測量機の位置に近い位置で撮影された画像を選択すればよい。
【００４９】
本実施形態では、各測点の水平角、高度角から仮想的な（視準原点に対する方向を表わす）３次元座標を算出し、この３次元座標に対する共線条件から求められる画像座標を、各画像における実際の測点の画像座標と比べることにより最適な画像を選別しているが、実際の測点の画像座標から対応する仮想的な３次元座標を算出し、これを水平角、高度角から求められる３次元座標と比較してもよい。また更に、測点の画像座標から対応する水平角、高度角を算出し、これを実測された各測点の水平角、高度角と比較してもよい。
【００５０】
【発明の効果】
以上のように、本発明によれば、測量機と光学的に略等価な位置にカメラを配置して撮影された画像を簡便に得ることができる。更に本発明によれば、測量機の位置に近い位置から画像を撮影できるとともに、測量機に対する測点の方向のみ測定可能な測量機においても、その測量情報から撮影された画像のうち最も測量機に近い位置で撮影された画像を簡単に選別することができる。
【図面の簡単な説明】
【図１】本発明における第１の実施形態である測量システムの構成を概略的に示すブロック図である。
【図２】本実施形態の測量システムにおける全体の作業手順を示すフローチャートである。
【図３】測量物を前後・左右に異なる９個の位置から順次撮影した場合（Ｊ＝９）のカメラ位置▲１▼〜▲９▼を模式的に表わす。
【図４】図３で示される測量物の画像の撮影に続いて、測量物上の測点Ｐ_１〜Ｐ_３に対する測量を行うときの模式図である。
【図５】図２のステップＳ１０５における最適画像選別処理のフローチャートである。
【図６】電子セオドライトが三脚に取り付けられた状態を示す。
【図７】本実施形態のカメラ装着装置の斜視図である。
【図８】図８は図７に示したカメラ装着装置の正面図である。
【図９】図８のカメラ装着装置のＡ−Ａ断面図である。
【符号の説明】
１０　測量機
１２　測角部
２０　デジタルスチルカメラ
４０　コンピュータ
４１　ＣＰＵ
Ｌｈ　　水平軸
Ｌｐ　　鉛直軸[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a surveying system using a surveying instrument and a camera.
[0002]
[Prior art]
In a conventional survey, there is a case where a surrounding scenery including a point to be surveyed (a surveying point) is photographed as an overview image of a surveying site, and the photographed image is stored together with measurement data. Although it is preferable to take the overview image by arranging the projection center of the camera at a position optically equivalent to the rotation center of the surveying instrument, it is difficult to arrange a commercially available normal camera in this way.
[0003]
[Problems to be solved by the invention]
SUMMARY OF THE INVENTION It is an object of the present invention to easily obtain an image photographed by disposing a camera at a position optically substantially equivalent to a surveying instrument. In particular, the present invention can take an image from a position close to the position of the surveying instrument, and also in a surveying instrument that can measure only the direction of the surveying point with respect to the surveying instrument, the closest to the surveying instrument among the images taken from the surveying information The purpose is to easily select images taken at positions.
[0004]
[Means for Solving the Problems]
The surveying system according to the present invention includes image photographing means for photographing a plurality of images including survey points from a plurality of positions, survey information of the survey points measured by the survey means, and positional information of the survey points on each image. And an optimum image selection unit that selects an image taken from a position closest to the position where the surveying unit is installed among the plurality of images based on the plurality of images.
[0005]
The surveying system includes surveying means for performing surveying, and the surveying information relates to information such as an angle indicating a direction in which the surveying point exists, such as a horizontal angle and an altitude angle. The surveying means is rotatable around the first and second rotation axes that intersect, and the position where the surveying means is installed is defined as the intersection of the first and second rotation axes. At this time, the first and second rotation axes are preferably a horizontal axis and a vertical axis, respectively. The position where an image is captured is defined as the projection center of the optical system of the image capturing means.
[0006]
The surveying system includes input means for designating, on an image, a position of a measurement point measured by the surveying means. At this time, a first image of a plurality of images is measured by the input means. The position of the point is specified. On the other hand, it is preferable that the position of the measurement point with respect to the remaining images is determined by performing a matching process with the first image on each image. This makes it possible to automate a large part of the operation for designating the measurement point on the image, and the operation is greatly simplified.
[0007]
The optimal image selection means is a collinear condition based on survey information for the survey point when each image is taken at the position where the survey means is installed, and a collinear condition based on positional information on the image for the survey point. Based on the deviation, an image photographed at a position close to the position where the surveying means is installed is selected. This makes it possible to select an optimal image even when the survey information has only information on the direction of the survey point.
[0008]
In addition, the optimal image selection means is, for example, assuming that each image is photographed in a predetermined direction at the position where the surveying means is installed, and based on the collinear condition for the surveying information of the surveying point, an image corresponding to the surveying point is obtained. Image position calculating means for calculating the position of the image, and a shooting direction for calculating an image shooting direction in which the distance between the calculated position of the measuring point on the image and the actual position of the measuring point on the image is minimized for each image Calculation means. At this time, the selection of the image is performed based on the distance between the position on the image of the measurement point calculated based on the image capturing direction and the actual position of the measurement point in each image. This makes it possible to easily select the optimum image.
[0009]
Further, in the image selection system of the present invention, in a plurality of images including a survey point, position designation means for respectively designating a position on the image corresponding to the survey point, surveying information indicating a direction of the survey point with respect to a predetermined origin, and Image selection means for selecting an image in which the projection center of the optical system at the time of shooting is closest to a predetermined origin from among the images, from the position on the image of the measurement point designated by the position designation means. And
[0010]
For example, the image selection means, when assuming that each image was taken with the projection center placed at a predetermined origin, the position on the image of the measurement point calculated from the collinear condition using the survey information, Based on the deviation of the measuring point specified by the position specifying means from the position on the image, the image capturing direction that minimizes the deviation is calculated for each image, and the minimum deviation is compared between the images. By selecting the image with the smallest deviation, the image whose projection center at the time of shooting is closest to the predetermined origin is selected.
[0011]
Furthermore, the camera mounting device of the present invention, for a tripod for a surveying instrument, a base portion capable of fixing the position and orientation, a vertical rotating portion rotatably held on the base portion around a vertical axis, An elevating part that is rotatably held around a horizontal axis by a vertical rotating part, a camera head mounted with a camera and capable of moving the camera in first and second directions, A head support that communicates with and supports the head, the head support slidably supporting the head in a third direction that is linearly independent of the first and second directions, The axis and the horizontal axis intersect, and when the camera is mounted, the camera is mounted so that a point where the vertical axis and the horizontal axis intersect is included in the main body.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram schematically showing a surveying system using a surveying instrument and a camera according to a first embodiment of the present invention.
[0013]
The surveying instrument 10 is a goniometer, such as an electronic theodolite, and includes a collimating telescope 17 for collimating a measuring point. The collimating telescope 17 has a horizontal axis Lh for lowering the collimating telescope and a vertical axis Lp for rotating the collimating telescope in a horizontal plane, and is rotatable around these axes. The point O is between the horizontal axis Lh and the vertical axis Lp._S(Hereinafter the collimation origin O_SOptical axis (collimation line) LN of the collimating telescope 17_OIs the collimation origin O_SPass through.
[0014]
The angle measuring unit 12 is connected to the system control circuit 13 and detects an altitude angle θh around the horizontal axis Lh and a horizontal angle θp around the vertical axis Lp. That is, the angle measuring unit 12 constantly measures the angle, and sends a measured value to the system control circuit 13 in response to a request from the system control circuit 13. The measured values such as the detected altitude angle θh and horizontal angle θp are processed in the system control circuit 13. In addition, a switch group 14, a display 15 (for example, LCD), an interface circuit 16, and the like are connected to the system control circuit 13. The interface circuit 16 can be connected to a computer 40 such as a notebook personal computer or a peripheral device such as a data collector (not shown) via an interface cable.
[0015]
The computer 40 mainly includes a CPU 41, a recording medium 42 such as a hard disk, a DVD, an MO, an IC card, an input device such as a mouse 43 and a keyboard 44, an image display device (monitor) 45 such as an LCD and a CRT, and an interface circuit 46. From roughly. The interface 46 can be connected to the interface circuit 16 of the surveying instrument 10 via the interface cable as described above. Further, the interface circuit 46 can be connected to the digital still camera 20, for example. That is, an image captured by the digital still camera 20 can be transmitted to the computer 40 as digital image data, and can be recorded on the recording medium 42, for example.
[0016]
Next, an overall operation procedure in the surveying system according to the first embodiment will be described with reference to FIGS.
[0017]
First, FIG. 2 is a flowchart showing an overall operation procedure in the surveying system of the present embodiment. In step S101, the operator mounts the digital still camera (DSC) 20 on the theodolite installation table. In step S102, a plurality of (for example, J) overview images of the survey site are taken while the camera position is slightly shifted up and down, left and right, or up and down. FIG. 3 schematically shows the camera positions (1) to (9) when the survey object is sequentially photographed from nine different positions in the front, rear, left, and right directions (J = 9). The method of installing the digital still camera 20 on the theodolite mounting table and the method of adjusting the camera position will be described later in detail.
[0018]
In step S103, the digital still camera 20 is removed from the theodolite installation base, and the electronic theodolite 10 is mounted. In step S104, a plurality of different points (for example, three points P₁, P₂, P₃Altitude angle θh_iAnd horizontal angle θp_iAre respectively measured. (Also, for θh and θp, given geographic data such as already measured values, survey information of the Geographical Survey Institute, commercially available geographic data, etc. may be used. However, in the present embodiment. If the coordinate system used in the above is different from the given geographic data and the coordinate system, it is necessary to convert the given geographic data into values of the coordinate system used in the present embodiment by coordinate conversion, and vice versa. The parameter i used as a subscript is for identifying each measurement point measured by the electronic theodolite 10, and in the case of the present embodiment, i = 1, 2, and 3. FIG. 4 schematically shows this survey. In step S105, the projection center of the camera in the images captured at the camera positions (1) to (9) is the collimation origin O of the electronic theodolite 10._SIs performed, and the surveying operation of the present embodiment ends. The optimal image selection processing will be described below with reference to the flowchart of FIG.
[0019]
FIG. 5 is a flowchart of the optimal image selection process in step S105. The optimal image selection processing is performed by using image data of nine images (images 1 to 9) photographed at positions (1) to (9) using the digital still camera 20 and three images measured by the electronic theodolite 10. Altitude angle θh of measuring points P1 to P3_i, Horizontal angle θp_iAfter transferring the survey data to the computer 40, the program is executed on the computer 40. The image data can be transferred to the computer 40 by connecting the digital still camera 20 and the computer 40 with an interface cable as shown in FIG. 1 or by using a removable memory such as a compact flash (registered trademark). May be performed via
[0020]
In step S201, for example, image 1 is displayed on monitor 45, and measurement point P is₁~ P₃Is specified on the image corresponding to the image coordinates (X₁₁, Y₁₁), (X₁₂, Y₁₂), (X_Thirteen, Y_Thirteen) Is obtained. In the following, the image coordinates (X_ji, Y_ji) Indicates that the first subscript j is the value of parameter j for identifying image 9 from image 1 and the second subscript is measurement point P₁From measurement point P₃Represents the value of a parameter i for identifying
[0021]
In step S202, the measurement point P_iVirtual three-dimensional coordinates (x representing (i = 1, 2, 3)_i, Y_i, Z_i) Indicates each measurement point P_iAltitude angle θh_i, Horizontal angle θp_iIs calculated from Coordinates (x_i, Y_i, Z_i) Is the collimation origin O_SExpressed in an arbitrary three-dimensional coordinate system having the origin as the collimation origin O_SAnd station P_iCorresponds to an arbitrary collinear vector on a straight line (collinear) connecting. As a three-dimensional coordinate system, for example, the altitude angle θh_i, Horizontal angle θp_iA left-handed coordinate system is used in which the direction of 0 is the y-axis, the x-axis is in the horizontal plane, and the vertically upward direction is the z-axis. At this time, assuming that the size of the collinear vector is r, the three-dimensional coordinates (x_i, Y_i, Z_i)
x_i= R · cos θh_i・ Cosθp_i
y_i= R · cos θh_i・ Sin θp_i
z_i= R · sin θh_i
Is represented by Hereinafter, this coordinate system is called a machine coordinate system.
[0022]
Next, in step S203, the parameter j is set to 2, and the processes in steps S204 to S212 are repeatedly executed for each image j until j = J. In step S204, the measurement point P on the image j_iImage coordinates (X_ji, Y_ji) Is required. In the present embodiment, matching processing is performed on the image 1 and the image j, and the image coordinates (X_1i, Y_1i) Corresponding to the image coordinates (X_ji, Y_ji) Are required, but the operator may specify each image using the mouse 43.
[0023]
In step S205, the approximate inclination (α) of the digital still camera 10 when the image j is captured is_Gj, Β_Gj, Γ_Gj) Is temporarily set to (0, 0, 0). Where the angle α_Gj, Β_Gj, Γ_GjAre rotation angles around the x-axis, y-axis, and z-axis, respectively, and any convention is used to define the rotation angle. In step S205, the merit function Φ for the image j_jIs initialized to 0. Hereinafter, the processing of steps S206 to S209 is repeated with the above set values as initial values. Note that the merit function Φ_jWill be described in the description of step S207.
[0024]
In step S206, the camera position at the time of capturing the image j is the collimation origin O_S(0, 0, 0) and the camera tilt at that time is (α_Gj, Β_Gj, Γ_Gj), The measurement point P_iThree-dimensional coordinates (x_i, Y_i, Z_i) Corresponding to the image coordinates (X_Gji, Y_Gji) Is calculated as approximate image coordinates using the collinear condition. The method of calculating the image coordinates will be described later in detail.
[0025]
In step S207, the merit function Φ_jIs calculated. Merit function Φ_jIs defined, for example, by equation (1).
(Equation 1)

That is, the merit function Φ_jIs the measurement point P_iActual image coordinates (X_ji, Y_ji) And the image j is the collimation origin O_SAt (0,0,0), the slope (α_Gj, Β_Gj, Γ_Gj), Approximate image coordinates (X_Gji, Y_Gji) Represents the magnitude of the deviation between
[0026]
In step S208, in the repetitive processing of steps S206 to S209, the merit function Φ_jIs determined whether or not has changed from the previous value. For example, the value of the merit function in the previous process is Φ_j ⁰And the value in this process is Φ_j ¹| Φ_j ¹−Φ_j ⁰It is determined whether or not the value of | is equal to or greater than a predetermined value.
[0027]
│Φ_j ¹−Φ_j ⁰If it is determined that | Φ ≧ predetermined value, the gradient (α) approximately given in step S209_Gj, Β_Gj, Γ_Gj) Are obtained by, for example, the least squares method. That is, the collinear condition is an approximate value (α_Gj, Β_Gj, Γ_Gj), Linearize it by omitting higher-order terms, and create a normal equation with the correction amounts (δα, δβ, δγ) as unknowns, so that appropriate correction amounts (δα, δβ, δγ) Desired. In step S209, the gradient (α) which is an approximate value is calculated based on the calculated correction amounts (δα, δβ, δγ)._Gj, Β_Gj, Γ_Gj) Is (α_Gj+ Δα, β_Gj+ Δβ, γ_Gj+ Δγ). Thereafter, the process returns to step S206, and | Φ in step S208._j ¹−Φ_j ⁰Steps S206 to S209 are repeated until it is determined that | Φ <predetermined value. In step S208, | Φ_j ¹−Φ_j ⁰If it is determined that | Φ <the predetermined value, the process proceeds to step S210.
[0028]
In step S210, in the repetitive processing of steps S206 to S209, the last calculated merit function Φ_jAnd the last (α_Gj, Β_Gj, Γ_GjIs stored in the storage area of the CPU 41. In step S211, it is determined whether or not j = J (= 9). That is, the merit function Φ for all the images 1 to 9_jIt is determined whether or not the value has been calculated. If it is determined that j is not j = J, that is, j <J, the value of the parameter j is incremented by 1 in step S212, and the process returns to step S204.
[0029]
On the other hand, if j = J is determined in step S211, the merit function Φ of the image j (j = 2, 3,..., 9) in step S213_jIs minimized, and the image number j and the inclination (α_Gj, Β_Gj, Γ_Gj) Is recorded on the recording medium 42 or the like, for example. That is, the merit function Φ_jIs the smallest collimation origin O of the electronic theodolite 10 among the images 1 to 9._SIs an image taken from a position closest to. Thus, the optimal image selection processing according to the present embodiment ends. In the above description, the camera positions are nine points on the horizontal plane (positions (1) to (9)), but it is needless to say that the camera positions are not limited to these positions. For example, shooting may be performed at a position corresponding to a total of 27 points by adding 3 points vertically and 3 points horizontally and 3 points horizontally (9 points in total) on the plane.
[0030]
Next, the approximate image coordinates (X_Gji, Y_Gji) Will be described.
[0031]
In the three-dimensional coordinates (x, y, z) of the machine coordinate system, the origin of the camera coordinate system is (x₀, Y₀, Z₀), And the camera coordinate system is rotated (α, β, γ) around the x-axis, y-axis, and z-axis, the three-dimensional coordinates (cx, cy, cy, cz).
(Equation 2)

Where the matrix ｛T_jk｝ Is a rotation matrix, and each component T_jkIs represented, for example, by the following equation.
T₁₁＝ cosβ ・ cosγ
T₁₂= Cosα · sinγ + sinα · sinβ · cosγ
T_Thirteen= Sinα · sinγ−cosα · sinβ · cosγ
T₂₁= -Cosβ · sinγ
T₂₂＝ cosα ・ cosγ-sinα ・ sinβ ・ sinγ
T₂₃＝ sinα ・ cosγ + cosα ・ sinβ ・ sinγ
T₃₁= Sinβ
T₃₂= −sinα · cosβ
T₃₃＝ cosα ・ cosβ
[0032]
Also, the origin of the camera coordinate system is made coincident with the projection center of the camera, the cx axis and the cy axis are made parallel to the horizontal and vertical lines of the image sensor of the digital still camera 20, and the cz axis is made perpendicular to the imaging surface and from the projection center. When defined in the direction of the image plane, the three-dimensional coordinates (cx, cy, cz) in the camera coordinate system are represented by two-dimensional screen coordinates ( s, t).
(Equation 3)

The screen coordinate system is a two-dimensional coordinate system on the imaging surface with the principal point as the origin, and the s axis corresponds to the horizontal line direction of the image sensor 21 and the t axis corresponds to the vertical line direction. Here, f is the screen distance.
[0033]
The screen coordinates (s, t) obtained from the equation (3) do not take into account deviation from the collinear condition due to the distortion of the optical system of the digital still camera 20 or the like. The corrected screen coordinates (sc, tc) are obtained by the following equation (4).
(Equation 4)

Where D₂, D₄, D₆Are the second-, fourth-, and sixth-order distortion components, respectively, and N₁, N₂Is the distortion asymmetric component, X_C, Y_CIs the amount of eccentricity of the principal point in the s-axis direction and the t-axis direction from the image center.
[0034]
The image coordinates (X, Y) are obtained by substituting the corrected screen coordinates (sc, tc) into the following equation (5).
(Equation 5)

Here, Px and Py are the horizontal and vertical pixel pitches of the CCD, respectively, and W and H are the number of horizontal and vertical pixels of the image, respectively.
[0035]
The three-dimensional coordinates in the machine coordinate system can be converted into image coordinates by the above conversions of Expressions (2) to (5). Therefore, in step S206, the camera position (0, 0, 0) and the inclination (α_Gj, Β_Gj, Γ_Gj), Three-dimensional coordinates (x_i, Y_i, Z_i) Is substituted into the measurement point P in the image j._iApproximate image coordinates (X_Gji, Y_Gji) Is calculated.
[0036]
Next, a method for installing the camera on the theodolite mounting table and a method for adjusting the camera position according to the present embodiment will be described with reference to FIGS.
[0037]
FIG. 6 shows a state in which the electronic theodolite 10 is attached to a tripod 50. The electronic theodolite 10 generally includes a theodolite main body 100 that supports the collimating telescope 17 so as to be able to ascend and descend, a horizontal scale section 101 having a horizontal scale, a leveling table 102, and a bottom plate 103 attached to a tripod 50. The main body and the horizontal scale 101 of the electronic theodolite 10 of the present embodiment are integrally formed, and are detachable from the leveling table 102. That is, in the present embodiment, the leveling table 102 functions as a theodolite installation table.
[0038]
7 is a perspective view of the camera mounting device of the present embodiment, FIG. 8 is a front view, and FIG. 9 is a cross-sectional view taken along the line AA of FIG.
[0039]
The digital still camera 20 is mounted on a theodolite mounting table (leveling table) 102 mounted on a tripod 50 via a camera mounting device 200. A cylindrical base 201 is attached to the theodolite mounting table 102 instead of the horizontal scale section 101. For example, three projections 202 are provided on the bottom surface of the base 201, and the projections 202 are fitted into corresponding depressions of the theodolite installation base 102, and fix the base 201 to the theodolite installation base 102.
[0040]
On the upper surface of the base part 201, a horizontal rotating part 203 formed by forming a slender flat plate into a U-shape is disposed. The U-shaped horizontal rotating part 203 is arranged at the approximate center of the base part 201 with its mouth open upward. A shaft hole 203h into which the rotating shaft member 204 penetrates is formed at a position corresponding to the center of the base portion 201 of the horizontal rotating portion 203. Correspondingly, a shaft hole 201h extending from the bottom surface to the top surface is formed in the center of the base 201. The rotating shaft member 204 penetrates the shaft hole 203h and the shaft hole 201h, and is fixed with a nut 204n or the like. Thereby, the horizontal rotation unit 203 is held rotatably around the vertical axis Lp ′ with respect to the base unit 201.
[0041]
Inside the horizontal rotation unit 203, a U-shaped elevating unit 205 having substantially the same width as the horizontal rotation unit 203 but slightly smaller than the horizontal rotation unit 203 is arranged at a predetermined interval. You. Both the horizontal turning part 203 and the elevating part 205 are engaged with each other at the left and right upper ends. That is, shaft holes for inserting the rotation shaft members 206a and 206b are provided at both upper end portions of the horizontal rotation unit 203 and the elevation unit 205, respectively. The rotary shaft member 206a is rotatably inserted through a shaft hole provided at the upper end on the right side in the front view (FIG. 8) of the horizontal rotating portion 203 and the elevating portion 205 via a spacer 206C. On the other hand, the rotating shaft member 206b is rotatably inserted into each shaft hole provided at the upper end on the left side via a spacer 206C. The rotating shaft members 206a and 206b are arranged on the same axis Lh ', and the axis Lh' is orthogonal to the vertical axis Lp 'passing through the center of the base 201. That is, the elevating unit 205 is rotatably held around the horizontal axis Lh 'by the horizontal rotating unit 203, whereby the elevating operation of the camera is realized. Further, a knob 207 for fixing the elevating operation is attached to an end of the rotating shaft member 206a. Note that the intersection of the horizontal axis Lh 'and the vertical axis Lp' is the collimation origin O when the electronic theodolite 10 is attached._SRoughly corresponds to the position of.
[0042]
At the center of the bottom plate extending in the lateral direction of the elevating portion 205, a columnar member 208 is provided perpendicular to the bottom plate. That is, the columnar member 208 is attached to the center of the bottom plate in parallel with both side plates of the elevating portion 205. The upper end of the cylindrical member 208 is fitted into the cylindrical member 209, and the cylindrical member 209 is slidable with respect to the cylindrical member 208. The position of the tubular member 209 is fixed by a vertically fixed knob 209d provided from the lower end of the tubular member 209. That is, a perforation communicating between the inside and the outside of the circular tube is formed from the lower end of the circular tube member 209, and a female screw screwed with the male screw of the upper and lower fixed knob 209d is formed in the perforation. Have been. The vertical movement of the cylindrical member 209 is regulated by rotating the vertical fixing knob 209d and pressing a male screw against the side surface of the cylindrical member 208 in the cylindrical member 209. A scale 208m is drawn on the side surface of the cylindrical member 208, and the operator can know the distance from the elevation portion 205 of the circular pipe member 209 by referring to the scale 208m.
[0043]
A camera platform 210 is provided above the circular tube member 209. The head section 210 has a three-layer structure of a fixed section 211, a left-right moving section 212, and a front-rear moving section 213 from below. The fixing part 211 is fixed to the circular pipe member 209, and the fixing part 211 substantially has a flat rectangular parallelepiped shape having a square horizontal surface. A dovetail key groove is formed on the upper surface of the fixing portion 211 along the horizontal axis Lh 'direction. The left and right moving part 212 also has a rectangular parallelepiped shape substantially the same shape as the fixed part 211, and a dovetail key having a key groove formed on the upper surface of the fixed part 211 is formed on the bottom surface thereof. That is, the left / right moving unit 212 is slidable in the horizontal axis Lh ′ direction with respect to the fixed unit 211. Further, in the center of the side surface on the front side of the fixing portion 211, a hole reaching the key groove formed on the upper surface of the fixing portion 211 is provided. That is, by rotating the left and right adjustment knob 211d, the left and right moving part 212 can be moved in the left and right direction (along the horizontal axis Lh ') with respect to the fixed part 211. Note that a scale 211 m indicating the amount of movement of the left and right moving unit 212 with respect to the fixed unit 211 is drawn on the fixed unit 211 and the left and right moving unit 212.
[0044]
On the other hand, a dovetail-shaped key groove is formed on the upper surface of the left / right moving part 212 along a direction orthogonal to the horizontal axis Lh ′, and the front / rear moving part has a rectangular parallelepiped shape substantially the same as the left / right moving part 212. On the bottom surface of the 213, a dovetail key is formed which meshes with a key groove provided on the upper surface of the left / right moving part 212. That is, the front-rear moving unit 213 is slidable with respect to the left-right moving unit 212 along a direction (front-rear direction) orthogonal to the horizontal axis Lh ′. In the center of the right side surface of the left and right moving unit 212, a hole is formed which reaches a key groove formed on the upper surface of the left and right moving unit 212, and a front and rear adjustment knob 212d is attached to this hole. That is, by rotating the front and rear adjustment knob 212d, the front and rear moving unit 213 can be moved in the front and rear direction with respect to the left and right moving unit 212. It should be noted that a scale 212 m indicating the amount of movement of the front / rear moving unit 213 with respect to the left / right moving unit 212 is drawn on the left / right moving unit 212 and the front / back moving unit 213.
[0045]
A substantially square concave portion 213c is formed on the upper surface of the front / rear moving portion 213, and a screw hole reaching the concave portion 213c is formed in the center of the front side surface of the front / rear moving portion 213. A bolt-shaped camera fixing knob 213d is attached to the screw hole. The camera mounting portion 214 is fitted into the concave portion 213c. The camera mounting portion 214 has a rectangular parallelepiped shape having the same shape as the substantially concave portion 213c, and has a bottom center formed with a hole penetrating from the bottom surface to the top surface, and a mounting bolt 214d is fitted therein. The mounting bolt 214d protrudes from the upper surface of the camera mounting portion 214, is screwed into a tripod mounting hole provided on the bottom surface of the camera, and fixes the camera to the camera mounting portion 214. On the front side surface of the camera mounting portion 214, for example, a horizontal groove is cut at a position corresponding to the camera fixing knob 213d when the camera mounting portion 214 is mounted in the concave portion 213c. That is, by rotating the camera fixing knob 213d and sending it out into the concave portion 213c, the camera mounting portion 214 can be fixed to the front-rear moving portion 213 of the camera platform 210.
[0046]
The camera 20 mounted on the camera platform 210 can adjust the vertical position by operating the fixed knob 209d, and can adjust the front, rear, left and right positions by operating the two adjustment knobs 211d and 212d. When the camera is placed on the camera platform 210, the projection center is at the intersection of the substantially horizontal axis Lh 'and the vertical axis Lp' (the collimation origin O)._S). Usually, the worker cannot know the position of the projection center of the camera,_SCannot be matched exactly. The position of the camera 20 is adjusted by operating the fixed knob 209d, the left / right adjustment knob 211d, and the front / rear adjustment knob 212d._SCan be arranged at different positions (for example, positions {circle around (1)} to {circle around (9)}), by applying the above-described optimal image selection processing to the images photographed at these positions, the projection center of the camera can be measured. Collimation origin O of machine 10_SCan be sorted out.
[0047]
As described above, according to the present embodiment, even with a surveying instrument such as a theodolite that can measure only the direction of a surveying point, an image was taken with a camera disposed at a position optically substantially equivalent to the surveying instrument. Images can be easily sorted. Further, by using the camera mounting device of the present embodiment, it is possible to easily capture images from a plurality of positions that are presumed to be optically substantially equivalent to the surveying instrument. Further, after selecting an equivalent position, the present condition can be reproduced by fixing the position, so that it is not necessary to perform the main detection again, and the workability can be improved.
[0048]
In the present embodiment, since the electronic theodolite is used as the surveying instrument, the optimum image selecting process is executed based only on the angle information (horizontal angle, altitude angle) indicating the direction of the measuring point with respect to the surveying instrument. In a total station or the like from which information on the distance to the measurement point and the angle can be obtained, the three-dimensional position of the measurement point can be specified, so that the external orientation elements of the camera when each image is captured can be calculated. In this case, an image captured at a position closest to the position of the surveying instrument may be selected from the camera positions (external orientation elements) calculated for each image.
[0049]
In the present embodiment, virtual three-dimensional coordinates (representing the direction with respect to the collimation origin) are calculated from the horizontal angle and the elevation angle of each measurement point, and the image coordinates obtained from the collinear condition for the three-dimensional coordinates are calculated as The most suitable image is selected by comparing the image coordinates of the actual measurement points in the image, but the corresponding virtual three-dimensional coordinates are calculated from the image coordinates of the actual measurement points, and are calculated by using the horizontal angle and the elevation angle. May be compared with the three-dimensional coordinates obtained from. Furthermore, the corresponding horizontal angle and altitude angle may be calculated from the image coordinates of the measurement point, and may be compared with the actually measured horizontal angle and altitude angle of each measurement point.
[0050]
【The invention's effect】
As described above, according to the present invention, it is possible to easily obtain an image photographed by disposing a camera at a position optically substantially equivalent to a surveying instrument. Further, according to the present invention, an image can be taken from a position close to the position of the surveying instrument, and even in a surveying instrument capable of measuring only the direction of the surveying point with respect to the surveying instrument, the most It is possible to easily select an image shot at a position close to.
[Brief description of the drawings]
FIG. 1 is a block diagram schematically showing a configuration of a survey system according to a first embodiment of the present invention.
FIG. 2 is a flowchart showing an overall work procedure in the surveying system of the present embodiment.
FIG. 3 schematically shows camera positions (1) to (9) when a survey object is sequentially photographed from nine different positions in front, rear, left and right (J = 9).
FIG. 4 is a diagram showing a survey point P on the survey object following photographing of the survey object image shown in FIG. 3;₁~ P₃It is a schematic diagram when performing survey with respect to.
FIG. 5 is a flowchart of an optimal image selection process in step S105 of FIG. 2;
FIG. 6 shows a state where the electronic theodolite is attached to a tripod.
FIG. 7 is a perspective view of the camera mounting device of the embodiment.
FIG. 8 is a front view of the camera mounting device shown in FIG. 7;
9 is a cross-sectional view of the camera mounting device taken along line AA of FIG. 8;
[Explanation of symbols]
10 surveying instrument
12 angle measuring unit
20 digital still camera
40 computer
41 CPU
Lh horizontal axis
Lp vertical shaft

Claims (15)

Image photographing means for photographing a plurality of images including a measuring point from a plurality of positions;
Based on the survey information of the survey point and the position information of the survey point on each of the images, an image photographed from a position closest to the position where the surveying means is installed is selected from the plurality of images. A surveying system comprising: an optimal image selection unit. The surveying system according to claim 1, further comprising surveying means for performing surveying. The surveying system according to claim 1, wherein the surveying information relates to a direction in which the surveying point exists. The surveying system according to claim 3, wherein the direction is indicated by an angle. The surveying system according to claim 4, wherein the angles are a horizontal angle and an altitude angle of the survey point. The surveying means is rotatable around first and second rotation axes that intersect, and a position where the surveying means is installed is an intersection of the first and second rotation axes. The surveying system according to claim 2, characterized in that: The surveying system according to claim 6, wherein the first and second rotation axes are a horizontal axis and a vertical axis, respectively. 2. The surveying system according to claim 1, wherein a projection center of the optical system of the image photographing unit is a position where the image is photographed. The surveying system according to claim 1, further comprising an input unit configured to specify a position of the survey point on the image. The position of the measurement point is designated by the input means with respect to a first image of the plurality of images, and the position of the measurement point with respect to the remaining images is subjected to matching processing with the first image for each image. The surveying system according to claim 9, wherein the surveying system is determined by performing the following. The optimal image selection means is configured to share a collinear condition based on the survey information when each of the images is photographed at a position where the survey means is installed, and a collinear condition based on positional information on the image with respect to the survey point. The surveying system according to claim 2, wherein an image photographed at a position close to a position where the surveying means is installed is selected based on a deviation from a line condition. The optimal image selecting unit assumes that each of the images is photographed in a predetermined direction at the position where the surveying unit is installed, and corresponds to the surveying point from the collinear condition for the surveying information of the surveying point. Image position calculating means for calculating a position on an image, and an image capturing direction in which the distance between the calculated position of the measurement point on the image and the actual position of the measurement point on the image is minimized for each image And a photographing direction calculating means for calculating the image, wherein the selection of the image is performed by comparing the position of the measuring point on the image calculated based on the image photographing direction with the actual position of the measuring point in each image. The surveying system according to claim 1, wherein the survey is performed based on a distance between the two. In a plurality of images including a measurement point, position specification means for specifying a position on the image corresponding to the measurement point,
From the surveying information indicating the direction of the measurement point with respect to a predetermined origin and the position on the image of the measurement point specified by the position specifying means, the projection center of the optical system at the time of shooting in the respective images is determined by the predetermined value. An image selection unit for selecting an image closest to the origin of the image. The image selecting means, when assuming that each of the images was photographed with the projection center placed at the predetermined origin, on the image of the survey point calculated from the collinear condition using the survey information And selecting an image whose projection center at the time of photographing is closest to the predetermined origin based on a deviation between the position of the measurement point and the position on the image designated by the position designation means. Item 14. The image sorting system according to Item 13. For a tripod for a surveying instrument, a base that can fix the position and orientation,
A vertical rotating portion that is rotatably held on the base portion around a vertical axis,
An elevating part that is held by the vertical rotating part so as to be rotatable around a horizontal axis,
A head mounted with a camera and capable of moving the camera in first and second directions;
A head support unit that communicates with the head unit and supports the head unit,
The head support section slidably supports the head section in a third direction that is linearly independent of the first and second directions, the vertical axis and the horizontal axis intersect, The camera mounting apparatus according to claim 1, wherein the camera is mounted such that a point at which the vertical axis and the horizontal axis intersect is included in the main body when the camera is mounted.

Images