Result and Discussion - Segmentation of Hand Bone for Bone Age Assessment - page 105

4.3 Segmentation Evaluation
The segmentation evaluations methods can be categorized into analytical evalua-
tion methods and empirical evaluation methods [ 3 ]. Which method is to be used
in the segmentation evaluation depends on the segmentation algorithms that are
to be evaluated. For example, if an enhanced version of a particular segmentation
algorithm has been designed by changing one of its parameters, or the selection
method for that particular parameter, then empirical evaluation method is more
suitable because both segmentation methods contain the same amounts of param-
eters and thus it is possible to set all the other parameters of the particular segmen-
tation as constant variables, the performance of segmentation as response variable
and the modified parameter as manipulated variable. Thus, empirical segmentation
evaluation can examine the effect of the particular modified parameter.
If segmentation algorithms are to be compared from different categories that
are significantly different from each other in terms of number of parameters, type
of parameters, parameters selection, number of inputs, types of inputs, and funda-
mental concept, then analytical methods that analyzes the, properties, applicability,
limitations, utilities, computational complexity, and principles of those segmentation
algorithms were more suitable. Besides being more suitable, the analytical evalua-
tion methods require less concrete realization of algorithm implementations and this
prevents the confrontation of experimental errors associate with setting up the exper-
iments as in empirical evaluation methods. The analytical evaluation methods, none-
theless, has limitation because not all segmentation methods is analytically evaluable
due to the scarcity of general segmentation theory.
In this chapter, comparison is made between the segmentation framework and
the state-of-the-art AAM which is the well-known deformable model developed
from ASM that have gained much attention in the image processing community.
This technique has been specifically applied in hand bone segmentation and is still
actively being applied at the moment. Both the details of ASM and AAM in the
chapter of literature review have been explained. The second reason to compare with
this method due to the fact that this is the latest segmentation method adopted by the
only commercialized computer-aided skeletal age scoring system corporate known
as 'BoneXpert' in the world thus far recently, to the best of knowledge. Besides,
unlike other arbitrarily found techniques in literatures, the authors have included
relatively substantial amounts of details of the techniques that would increase the
reliability and the repeatability of the comparison and conducted experiments.
4.3.1 User-Specified Parameters
Segmentation algorithms are examined and compared using both analytical and
empirical evaluation methods. In analytical evaluation, the listed properties of
segmentation algorithms that are critical to practical usage of segmentation in