Special purpose computer for digital holographic particle tracking velocimetry

Holographic particle-streak velocimetry.

We present a way to measure the positions and instantaneous velocities of micrometer-scale colloidal spheres using a single holographic snapshot obtained through in-line holographic video microscopy. This method builds on previous quantitative analyses of colloidal holograms by accounting for blurring that occurs as a sphere moves during the camera's exposure time. The angular variance of a blu...

Digital Holography Based Particle Tracking Velocimetry

Digital holography appears to be the next-generation technology for holographic diagnostics of particle fields and has been applied to holographic particle tracking flow measurements. In the digital holography, the Fresnel or Fourier holograms are recorded directly by the CCD or CMOS cameras and stored digitally. No film material involving wet-chemical or other processing is necessary as in opt...

Digital Particle Image Velocimetry: a challenge for feature based tracking

A variational approach for particle tracking velocimetry

We introduce a novel variational approach for evaluating PTV image pairs and sequences in two and three dimensions. We combine a discrete non-differentiable particle matching term with a continuous regularization term. An advanced mathematical method guarantees convergence to a local minimum. The experimental evaluation shows that our variational method competes with three alternative approache...

Som Based Particle Matching for Volumetric Particle Tracking Velocimetry

Novel 3D image analysis and particle matching techniques for the use in the volumetric particle tracking velocimetry have been developed and tested by using synthetic images and experimental images of unsteady 3D flows. A tomography based particle reconstruction scheme along with the subsequent process of individual particle detection and validation was used. The detected particles in the two t...