Synthetic Images
Particle Image Diameter
The particle image diameter variable controls the size of the particle images generated. Below is an example of the parameters from 1 to 10 (pixels).
Figure 1. The particle image diameter variable adjusted from 1 pixel (top left) to 10 pixels (bottom right).
The particle diameter is an important variable, and as is common with PIV relies on several trade-offs. As smaller particle images “take up” less of each interrogation region (allowing the user to capture more particles in each picture). However, the particles must remain large enough for the PIV algorithm to identify each particle image as a distinct particle (separate from other particles and background/camera noise). Generally, as shown in Figure 1, the balancing point is near a particle image diameter of 3-4 pixels, and increasing the particle image sizes from this point on is less likely to improve the estimation of the particle displacement in pixels.
Author: Jack Elliott
Date Published: June, 2022