What is investigated?
ESF ?x? ? LSF ?x? ? MTF ? f ?
(Bischof & Erhardt, Pelc)
To analyse the PTFE block we use a variation of the method proposed by Judy (references, slide 17) in which the Edge Spread Function is calculated. This is then differentiated to find the Line Spread Function and the absolute Fourier Transform of this gives us the MTF.
To analyse the wire the method proposed by independently by Bishof & Erhardt and Pelc is used, in which the absolute Fourier Transform of the 2D Point Spread Function is taken.
To analyse the CATPHAN we use the method proposed by Droege in which the Standard Deviation of a bar pattern is directly related to the MTF.