Pit Pattern Classification in Colonoscopy using Wavelets - WaveLab

5 Results
If I have a thousand ideas and only one turns
out to be good, I am satisfied.
- Alfred Nobel
In the previous chapter the methods implemented for this thesis have been presented. In this
chapter we will now present the used test setup and the obtained classification results.
5.1 Test setup
5.1.1 Test images
In our experiments with the different methods from the previous chapter we used two different
sets of images.
First of all, as already mentioned in the first chapter, we used 364 endoscopic color images
of size 256 × 256 pixel, which were acquired in 2005 at the Department of Gastroenterology
and Hepatology (Medical University of Vienna) with a zoom-colonoscope (Olympus Evis
Exera CF-Q160ZI/L) which produced images 150-fold magnified. These images haven been
histopathologically classified, which resulted in the classification results shown in table 5.1,
which are used as ground truth for our experiments.
Pit Pattern I II III-S III-L IV V
2 classes 156 208
6 classes 99 57 12 59 112 25
Table 5.1: Histopathological classification of the images acquired
As can been seen in table 5.1 the number of images for the different pit pattern types
available for our tests significantly differs from class to class. Especially in the 6-class case
we had only a very few images for types III-S and V to test our algorithms with.
Figure 5.1 shows for each pit pattern type five different examples images from our test set
of endoscopic images.
61