If the particles are non-aggregating, each outline correspond the 2D projection of a particle and the particle characteristics, such as the particle area, perimeter, aspect ratio, or orientation, can be automatically calculated [19].
Particle size was characterized by image processing to calculate size and shape descriptors including area, perimeter, aspect ratio, and roundness.
Shape parameters, including area, perimeter, circularity, aspect ratio, major axis length, and minor axis length, were measured from the test digital images using ImageJ software (ver. 1.47q).
Therefore, to obtain the most effective size of digital images for shape analysis, we examined the errors in basic shape parameters, including area, perimeter, and aspect ratio, using ImageJ software.
Quantitative pore network descriptors including porosity, pore body and throat sizes, coordination number (number of throats per pore), shape factor (pore area to perimeter ratio), aspect ratio (pore body to throat size ratio), and their distributions are determined from SEM-based images of thin sections at multiple resolutions as well as physical core measurements.
Circularity = 4 π × Area Perimeter 2 Aspect ratio was calculated as the ratio of the major and minor axes of the best-fitting ellipse.
b d Particle aspect ratio, perimeter, and inclination angle from initial orientation, respectively, as a function of frame number.
See the supplemental Code 1. Figure 5b, c, and d depicts, respectively, the particle's aspect ratio, perimeter, and rotation from the initial orientation as functions of time.
All measurements describing the morphology (area, perimeter, shape factor and aspect ratio) of nuclei were analyzed from maximum intensity projections of Z-stack images of teased muscle fibers or cells using ImageJ or Zeiss ZEN software.
Yearly fire perimeters, topographic attributes (slope, aspect and elevation) and the forest territory limits were incorporated to, and analyzed by means of, a raster-based GIS.
Shape descriptors (area, perimeter, circularity, Feret's diameter, aspect ratio, and solidity) were quantified on 179 × 133 μm fields (A).
