Below are some successful and some less than successful examples
Step #1
Successful Examples
In these examples, some the algorithm did not successfully identify the location of Waldo. Instead it appears that it was unable to distinguish the red and white stripes of Waldo from the red and white stripes of another person or article of clothing. In the first example below, the algorithm identified a Waldo look-a-like, which other than some subtle differences in the face, is nearly identical to Waldo in terms of pixel coloration.
Step #1
Less than Successful Examples
Figure 1: Unsolved image.
Figure 2: Zoom in unsolved image.
For the second example below, there are several locations of red and white stripes and it seems that the algorithm identified a location where there are very clearly horizontal red and white stripes while missing the subtler stripes from Waldo hidden behind another figure.
Figure 3: Unsolved image.
Figure 4: Zoom in unsolved image.