E xample plots are included in this section, which attempts
to illustrate the general aims and add some context. We are investigating
plots which depict a certain measure versus the extent of mean
pixel displacement. These plots typically reflect on some measure
of 'goodness' as data is degraded.
Mean pixel displacement is closely-related to the degree of mis-registration
in the set of images under investigation. In simple terms, as we move
rightwards in the plots, the overlap (or correspondence) among
the images is made worse. We expect our measure to be able to
detect these overlap changes, preferably with a linear response too,
which implies robustness. Below are 2 blended figures which practically
visualise that. In the former case, overlap between label in the images
is used as our measure, whereas model-based measures are used in the
latter.
It is worth noticing that all curves are sampled at 8 separate points.
Each such point corresponds to one particular value of mean pixel
displacement. The value measured, namely , is calculated over
10 instantiations of an image set, from which the average has been
derived. This repeatability factor will later enable us to argue that
the methods work consistently, so no handpicking or fluke are involved.
We are interested in two separate 'sources' of error (uncertainty):