Prediction of Settling Velocity of Nonspherical Soil Particles Using Digital Image Processing

Table 2

Description of shape properties of soil particles.

Shape properties	Description
Area	The area of the particle
Aspect	The ratio between the major axis and the minor axis of the ellipse equivalent to the particle
Major axis	The length of the main axis of the ellipse equivalent to the particle
Minor axis	The length of the minor axis of the ellipse equivalent to the particle
Maximum diameter	The length of the longest line joining two outline points and passing through the centroid
Minimum diameter	The length of the shortest line joining two outline points and passing through the centroid
Mean diameter	The average length of the diameters measured at two degree intervals joining two outline points and passing through the centroid
Maximum radius	The maximum distance between particle’s centroid pixel position and its perimeter
Minimum radius	The minimum distance between particle’s centroid pixel position and its perimeter
Perimeter	The length of particle’s outline
Radius ratio	The ratio between maximum radius and minimum radius for each particle, as determined by maximum radius/minimum radius
Roundness	The roundness of each particle, as determined by (4 ∗ pi ∗ area)/(perimeter^2)
Fractal dimension	The fractal dimension of the particle’s outline