Image Comparison

Images can be compared statistically. Three measurements can be calculated by CTSim. They are taken from the standard measurements used by Herman[1]. They are:

d The normalized root mean squared distance measure.
r The normalized mean absolute distance measure.
e The worst case distance measure over a 2 x 2 pixel area.

These measurements are defined in equations through . In these equations, p denotes the phantom image, r denotes the reconstruction image, and denotes the average pixel value of p. Each of the images have a size of m TIMES n. In equation [n/2] and [m/2] denote the largest integers less than n/2 and m/2, respectively.

These formulas are shown in the print documentation of CTSim.