Three-dimensional capturing of underwater archeological sites or sunken shipwrecks can support important documentation purposes. In this study, a novel 3D scanning system based on structured illumination is introduced, which supports cultural heritage and measurement tasks in environments. The newly developed consists two monochrome cameras, projection unit that produces aperiodic sinusoidal fringe patterns, flashlights, color camera, an inertial (IMU), electronic control box. opportunities...

Next-best-view (NBV) planning is an important aspect for three-dimensional (3D) reconstruction within controlled environments, such as a camera mounted on robotic arm. NBV methods aim at purposive 3D sustaining predefined goals and limitations. Up to now, literature mainly presents range sensors, model-based approaches or algorithms that address the of finite set primitives. For this work, we use intensity without active illumination. We present novel combined online approach comprising...

Abstract A novel concept of camera modelling for underwater 3D measurements based on stereo utilisation is introduced. The geometrical description the ray course subject to refraction in cameras presented under assumption conditions, which are typically satisfied or can be achieved approximately. Possibilities simplification shown, allow an approximation by classical pinhole modelling. It shown how expected measurement errors estimated, as well its influence result. Final processing data...

Different concepts of correspondence findings in contactless optical three-dimensional (3-D) measurement systems using fringe projection are analyzed concerning the accuracy 3-D point calculation. These different kind performance triangulation procedure order to calculate resulting points and use geometric constraints versus second sequence. Triangulation may be alternatively performed between camera pixels phase origin projection, one pixel prior image corresponding measured value camera,...

Measuring systems using fringe projection provide the possibility of very accurate touchless measurements. For measurement small objects compact devices are possible. However, in case close distances between optical system and measuring object there is a considerable influence distance to lens distortion. This will lead errors if neglected. In typical cases our amount distortion may change by factor greater than two range difference few centimetres. Results dependence be given for lenses devices.

A new mobile optical 3D measurement system using phase correlation based fringe projection technique will be presented. The sensor consist of a digital unit and two cameras in stereo arrangement, whereby both are battery powered. data transfer to base station be done via WLAN. This gives the possibility to use complicate, remote situations, which are typical archaeology architecture. In procedure hand-held by user, illuminating object with sequence of less than 10 patterns, within time...

View planning for three-dimensional (3D) reconstruction and inspection solves the problem of finding an efficient sequence views allowing complete high quality complex objects. To fulfil this task, view methods need to deal with sensor limitations satisfy predefined goals. Our objective is jointly evaluate accuracy requirements coverage during planning, optimise procedure, as well explicitly take configuration space constraints into account. We present a novel model-based approach, which at...

Here a new set-up of 3D-scanning system for CAD/CAM in dental industry is proposed. The designed direct scanning the preparations within mouth. measuring process based on phase correlation technique combination with fast fringe projection stereo arrangement. novelty approach characterized by following features: A between values images two cameras used co-ordinate calculation. This works contrary to usage only (phasogrammetry) or classical triangulation (phase and camera image values)...

In this article an approach to a mobile 3-D handheld scanner with additional sensory information is proposed. It fully automatically builds multi-view scan. Conventionally complex post processing or expensive position trackers are used realize such process. Therefore combination of visual and inertial motion tracking system developed deal the tracking. Both sensors integrated into their data fused for robustness during swift movements long term stability. This presents overview over...

A new underwater 3D scanning device based on structured illumination and designed for continuous capture of object data in motion deep sea inspection applications is introduced. The sensor permanently captures the inspected surface generates a model real time. Sensor velocities up to 0.7 m/s are directly compensated while capturing camera images reconstruction pipeline. accuracy results static measurements special specimens water basin with clear show high potential scanner sub-millimeter...

For three-dimensional (3D) measurement of object surface and shape by pattern projection systems, we used a hybrid system, i.e., combination lens transmissive freeform to generate an aperiodic sinusoidal fringe pattern. Such effects light redistribution, thus leading effective low-loss projection, as it increases the total transmission intensity system has less power dissipation than classical systems. In this paper, present conception realization setup system. We compare characteristics...

In this study, we introduce a new calibration method for underwater optical stereo scanners. It uses air calibration, additional parameters, and extended camera modeling. The methodology can be applied to both passive photogrammetric structured light three-dimensional (3D) scanning systems. novel model variable principal distance depending on the radial point instead of two-dimensional distortion functions. This allows an initial improvement 3D reconstruction quality. second step, certain...

High-resolution contactless optical 3D measurements are well suited for determination of state and position gas turbine vane cooling-holes during maintenance rework. The air flow through the protects vanes from high temperatures. However, coating needs to be renewed repair vanes. renewal process can lead partially or completely filled cooling-holes. This paper describes a newly developed procedure automatically detect reopen such holes by laser-drilling an effective new process. is scanned...

Three different methods to realize point correspondences in 3D measurement systems based on fringe projection are described and compared concerning accuracy, sensitivity, handling. Advantages disadvantages of the three techniques discussed. A suggestion is made combine principles order achieve an improved completeness measurements. The principle a virtual image raster which basis combination explained. model describe random error for established described. Simulations real measurements...

3D measurement of the shape rough structures can be realised with structured light illumination techniques. Several problems arise while measuring complex object geometries these Complex objects are characterized, f.e. by deep holes, walls, concave and convex corner-like shaped surface structures. When illuminating object, one part "illuminate" another one, yielding locally spurious fringe patterns. Due to patterns phase values strongly distorted significantly increasing noise locally. Here...