Three Dimensional Reconstruction Strategies Using a Profilometrical Approach based on Fourier Transform

In the past 3 decades, there is an idea to extract the 3D information of a scene from its 2D images ant it has been a research interest in many fields. The main idea is to extract the useful depth information from an image or set of images in an efficient and automatic way. The result of the process (depth information) can be used to guide various tasks such as synthetic aperture radar (SAR), magnetic resonance imaging (MRI), automatic inspection, reverse engineering, 3D robot navigation, interferometry and so on. The obtained information can be used to guide various processes such as robotic manipulation, automatic inspection, inverse engineering, 3D depth map for navigation and virtual reality applications (Gokstorp, 1995). Depending on the application, a simple 3D description is necessary to understand the scene and perform the desired task, while in other cases a dense map or detailed information of the object’s shape is necessary. Furthermore, in some cases a complete 3D description of the object may be required. In 3D machine vision, the three-dimensional shape can be obtained by using two different methodologies; Active and Passive Methods, which are also classified as contact and non contact methods. The active methods project energy in the scene and detect the reflected energy; some examples of these methods are sonar, laser ranging, fringe projection and structured method. The fringe processing methods are widely used in non-destructive testing, optical metrology and 3D reconstruction systems. Some of the desired characteristics in these methods are high accuracy, noise-immunity and processing speed. In the spatial and temporal fringe pattern analysis, the main characteristics are the number of fringes, and the intensity variation due temporal and spatial measurements. A few commonly used fringe processing methods are well-known like Fourier Transform Profilometry (FTP) method (Malacara, 2006) and phase-shifting interferometry (Takeda et al., 1992). The main problem to overcome in these methods is the wrapped phase, where the depth information is included.