
for 2-D images described in Chapters 9 and 10. In this method, connected voxels
along a straight line of N elements are segregated into three types: grid parallel,
square diagonal, and cube diagonal. The numbers of elements in each class
ðn
grid
, n
square
, n
cube
Þ are scaled using predefined weight coefficients a, b, gðÞto
determine the 3-D length as follows [99]
L ¼ an
grid
þ bn
square
þ gn
cube
(14:82)
Several different values for the weight parameters, such as a ¼ 0:9016,
b ¼ 1:289, g ¼ 1:615, have been published [100–102].
The second method for measuring length in 3-D is based on techniques from
stereology. This approach works best for long curves or on sets ...