Companding technique for high dynamic range measurements using   gafchromic films
  We propose a methodology to perform dose measurements using gafchromic films which can span several decades of dose levels. The technique is based on a rescaling approach using different films irradiated at different dose levels. This is combined with a registration protocol correcting positioning and scaling factors for each film. 
Frank Van den Heuvel, Wouter Crijns, Gilles Defraene
physics.med-ph physics.ins-det