234
P. Drap et al.
Fig. 14.9 On the right, one of the 64 digital photographs taken (photo Olivier Bianchimani, all
rights reserved), on the left, the point cloud automatically computed by the Furukawa method
14.4.2 Large Scale Detail by Photogrammetry
We also tested as part of this mission approach automatic mapping proposed by
Furukawa and Ponce (Furukawa and Ponce 2010). We tested this approach on largescale details, Gorgonaria whose ends were slightly in motion because of the current,
see figure below (Fig. 14.9).
One camera was used and sixty photographs were taken for each of the tests that
follow. The study of the accuracy and the percentage of coverage was not yet done,
that the study dating from April 2011.
14.4.3 The “Liban” Wreck
The Liban is a ship built in 1882 in Glasgow (Scotland), measuring 91 m long and
11 wide. It was equipped with a steam engine. On June 7, 1903 at noon, the Liban
left the port of Marseille and less than 1 h later sunk after a big collision with another
ship.
Today, the Liban is a very attractive dive site close to Marseilles at 25 m deep. We
chose to survey the bow in order to develop and test our approach. Three dives and
almost 2,000 photos were necessary to obtain the 3D point cloud visible in the next
figure (Fig. 14.10 and 14.11).
P. Drap et al.
Fig. 14.9 On the right, one of the 64 digital photographs taken (photo Olivier Bianchimani, all
rights reserved), on the left, the point cloud automatically computed by the Furukawa method
14.4.2 Large Scale Detail by Photogrammetry
We also tested as part of this mission approach automatic mapping proposed by
Furukawa and Ponce (Furukawa and Ponce 2010). We tested this approach on largescale details, Gorgonaria whose ends were slightly in motion because of the current,
see figure below (Fig. 14.9).
One camera was used and sixty photographs were taken for each of the tests that
follow. The study of the accuracy and the percentage of coverage was not yet done,
that the study dating from April 2011.
14.4.3 The “Liban” Wreck
The Liban is a ship built in 1882 in Glasgow (Scotland), measuring 91 m long and
11 wide. It was equipped with a steam engine. On June 7, 1903 at noon, the Liban
left the port of Marseille and less than 1 h later sunk after a big collision with another
ship.
Today, the Liban is a very attractive dive site close to Marseilles at 25 m deep. We
chose to survey the bow in order to develop and test our approach. Three dives and
almost 2,000 photos were necessary to obtain the 3D point cloud visible in the next
figure (Fig. 14.10 and 14.11).