- the only subsea scanning operator to provide all 3D subsea laser scanning technologies AND photogrammetry. Since 2003.
What is photogrammetry?
Subsea scanning, optical metrology, 3D optical reconstruction, photogrammetry, videogrammetry, structure from video, 3D motion capture, Video odometry, structure through motion, self-localisation and mapping, stereo-imaging, trinocular and multi-view imaging are all related technologies and Savante excels in the subsea application of all of them. Whether you want your data collected live, real-time or post-processed our solutions have been optimised for performance, precision and accuracy.
The basic principal of photogrammetry is that images of an object are processed in order to look for and find a very particular set of numerical features; each with a particular set of skills and properties. These features can be detected reliably by a computer even when the camera is slightly defocussed (essential for when the camera moves out of perfect alignment) at different scales (because things get bigger as you approach them) and also when the camera rotates through any range of angles (because ROVs roll, pitch and yaw in practise).
Once those features have been identified, clever things such as 3D reconstruction of the object and working out the location of the camera used to collect the photographs from frame-to-frame can be determined by matching those features from frame-to-frame of a video feed, tracking their motion and the application of simple triangulation.
Savante Subsea 3D Scanning Toolbox
3D Machine vision
3D optical reconstruction
Structure from Video,
3D motion capture,
Structure through motion,
Self-Localisation And Mapping,
3D Laser scanning
When should I look to laser scan?
Photogrammetry is an exceptionally powerful and flexible 3D modelling tool and Savante is a world leader and pioneer in the application of subsea image metrology software and hardware. The main issue with photogrammetry is that it relies on the presence of multiple distinct optical reference markers on the asset for the tool to self localise and 3D map (SLAM). Markers provided by the object itself; corrosion and discoloration features are often excellent choices.
HOWEVER, Under dynamic conditions the object being scanned can actually change shape. This is particularly relevant if it has been coated in thick marine growth. This can break down the principals under which 3D photogrammetry, SLAM, video odometry and structure through motion operate; at the best it degrades the resolution and precision of the measurement - at worst it can cause issues in “closing the loop” creating an almost unwrapped, warped model of the subject.
Whilst Savante uses AI to provide object classification (i.e we identify objects which are not static and eliminate them from consideration) sometimes it’s just better to change the measurement technology.