The Modulation Transfer Function
Shows us how well frequency information is transferred from object to image
ImPACT quote MTF 50% & MTF 10% values
With the objective methods our aim is to measure the Modulation Transfer Function of the algorithm used to reconstruct the image.
The MTF shows us how well frequency information is transferred from object to image, it is normalised to itís DC level (ie, the level at zero spatial frequency) and decreases with increasing spatial frequency.
Different points on the MTF can be used as a measure of spatial resolution, for example ImPACT quotes the MTF 50% & 10% values in itís publications.
These points are the spatial frequencies at which the MTF falls to 50% & 10% of itís value at zero spatial frequency.