Fringe analysis is a technique that uses interference patterns to measure the shape, deformation, or displacement of an object. It has applications in various fields such as optical metrology, biomedical imaging, and surface inspection. However, fringe analysis usually requires complex and expensive equipment and software, which limits its accessibility and usability.
A new mobile app called iFringe aims to change that by incorporating the fringe analysis algorithms into the smart mobile devices platform. iFringe is a fringe analysis application for mobile smart devices that was developed by researchers from Osaka University and Nanyang Technological University. It allows users to capture, process, and analyze fringe patterns using their smartphones or tablets.
iFringe implements two fundamental fringe analysis techniques: the Fourier transform fringe analysis method and the phase-shifting technique. These methods can extract the phase information from the fringe patterns and reconstruct the 3D shape of the object. iFringe also includes features such as discrete Fourier transform (DFT), quality-guided phase unwrapping, and windowed Fourier filtering to enhance the accuracy and robustness of the results.
iFringe is a novel and innovative app that demonstrates the feasibility and potential of using mobile devices for fringe analysis. It can provide a convenient and low-cost alternative to conventional fringe projection systems, as well as enable new applications that leverage the mobility and interactivity of mobile devices. iFringe is a first step towards modernizing and diversifying the optical processing field.
Source: [^1^] [^2^] [^3^]iFringe can be applied to various optical measurement systems that produce fringe patterns. Some examples of such systems are:
Interferometry: Interferometry is a technique that uses the interference of light waves to measure distances, displacements, refractive indices, surface profiles, and other physical quantities. Interferometry can produce different types of fringe patterns depending on the optical configuration and the object under test. For example, holographic interferometry can produce exponential phase fields, while phase-shifting interferometry can produce carrier fringe patterns. iFringe can be used to denoise, demodulate, and unwrap these fringe patterns to obtain the phase information and reconstruct the object shape or deformation [^1^] [^2^].
Fringe projection: Fringe projection is a technique that projects a series of sinusoidal fringe patterns onto an object and captures the deformed patterns using a camera. The deformation of the fringe patterns reflects the 3D shape of the object. Fringe projection can also be combined with phase-shifting or Fourier transform methods to improve the accuracy and resolution. iFringe can be used to filter out noise and background, extract the phase or frequency information, and calculate the phase derivatives for 3D shape measurement [^2^] [^3^].
Digital image correlation: Digital image correlation is a technique that compares two images of an object before and after deformation to measure the displacement and strain fields. The images are divided into small regions called subsets, and the correlation between the subsets is calculated to find the displacement vector. The subsets can be regarded as fringe patterns with random phase distributions. iFringe can be used to perform windowed correlation analysis and obtain sub-pixel accuracy and robustness [^2^] .
These are just some of the examples of how iFringe can be applied to optical measurement. There are many other potential applications that can benefit from the versatility and efficiency of iFringe. aa16f39245