Once refinement of the crystal orientation for one image is complete a final integration of the spots is performed
using profile fitting [27].
A calculated spot profile for every reflection is evaluated by averaging the
observed profiles of other strong reflections within a specified radius on the image. A constant symmetric
background 
is calculated for the reflection and the predicted profile 
is then normalised such
that 
, where
the sum is over all the pixels 
within the profile. The experimentally measured intensity 
in the th pixel is
defined as
such that the constant 
is a measure of the fitted integrated intensity calculated with knowledge
of only , and for any one pixel. The variance of 
is defined as [38]
The final profile fitted intensity 
is defined as the weighted average of all the individual intensity
estimates from each pixel:
