Adept AdeptSight User Guide - Manual (Page 316)

Intrinsic Inertia Results
Object Definition
Roundness The degree of similarity between the blob and a cir-
cle. Values are between 0 and 1, where 1 is a per-
fectly circular blob.
Convex Perimeter Calculated from the average projected diameter of
the blob and is more stable and accurate than the
raw perimeter for convex shapes, including rec-
tangular forms.
Convex perimeter is calculated using an approx-
imation of Crofton's theorem. The blob's diameter
is determined by projections made at four dif-
ferent orientations: 0, 45, 90 and 135 degrees.
The average diameter calculated from these pro-
jections is multiplied by PI to obtain the convex
perimeter.
Raw Perimeter The sum of the pixel edge lengths on the contour
of the blob. Because the raw perimeter is sensitive
to the orientation of the blob with respect to the
pixel grid, results may vary greatly. Unless blobs
are non-convex, convex perimeter results provide
greater accuracy.
Intrinsic Inertia Results
The intrinsic moments of inertia measure the inertial resistance of the blob to rotation about
its principal axes. Because their orientation depends on the coordinate system in which the
blob is represented, the principal axes, major and minor, are defined in the section on extrin-
sic blob properties.
Intrinsic Inertia Results
AdeptSight User's Guide, Version 3.2.x, Updated: 8/23/2012
Page 316