| Morphological Parameters | Definition |
| Measures of size | |
| Area or projected area (A) | The area of projection of a 3-dimentional object into a 2-dimentional image. This is often represented by the sum of pixel values within the region specified by the selected object and given by:  . A is the selected object, and (i,j) є A, all pixel locations within A. The area is expressed as an actual area by multiplying by a calibration constant squared. |
| Distance | Distances are line lengths in general, with the simplest of all distance measurements being that between two specified pixels. There are several ways in which distances can be defined or approximated, as in the case of curved lines. |
| Perimeter (P) | Boundary lengths of objects. Since pixels lie on a rectilinear grid, it is necessary to include diagonal inter-pixel distances where appropriate. |
| Convex perimeter (Pc) | The length of the perimeter obtained by joining the outer points of an object, i.e. by filling in all the concavities in an object. |
| Length (L) | The length of a rectangular object having the same area and perimeter as the measured object. It is estimated from area and perimeter by  .The maximum Feret diameter (Feret diameter = the diameter measured using a pair of calipers) is one definition of the Length of an object, which may alternatively be specified as  . |
| Width (W) | The width of a rectangular object having the same area and perimeter as the measured object. It is estimated from area and perimeter by  .Alternatively it can be defined as the range of columns the object covers, i.e.  , or as the Feret diameter at angle θ = 0o. |
| Equivalent circular diameter (D) | This is the diameter of a circle having the same area as the measured feature. It is estimated from area by  . |
| Height | This is the range of rows the object covers, i.e.  . It is the Feret diameter at angle θ = 90o. |
| Measures of shape | |
| Circularity (C) | A shape factor that describes the deviation of an object in an image from a true circle. It is estimated from area and perimeter by  . The value of 1 corresponds to a circle, while larger values to shapes having a higher ratio of perimeter to area. |
| Compactness or Fullness (F) | Defined as the ratio of the area of an object to the area of a circle with the same perimeter. It is estimated by  . It is probably the most commonly used shape statistic and it is used to characterize the structure of mycelial clumps and pellets. A pellet without hairy regions has  while a loose clump has F<1. |
| Roughness (R) | A measure of the irregularity of the perimeter of an object obtained from the circularity measurement around an object boundary. |
| Convexivity | Convexivity can be obtained by forming the ratio of the perimeter of an object’s hull to the perimeter of the object itself. |
| Object count | |
| Number of objects | Number of objects per field of view and cumulative counts for a sample. |
| Hyphal tips | Number of tips per hypha, mean number of tips per hypha for a sample. |
