Method of determining the modulation transfer function
AssigneeAfga-Gevaert Aktiengesellschaft
InventorHans-Theo Buschmann
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Abstract
The invention relates to a method of determining the modulation transfer function of a recording support or of an optical system. In the context of the invention, an optical system includes any components with finite apertures which are required for forming an image of an object. A coherent-optically produced scatterer of known noise distribution or with a known spatial frequency spectrum is used for determining the required modulation transfer function. The modulation transfer function can be determined through the density of transparency distributions present on the recording support.
Claims10
In a method of determining the modulation transfer function of a recording system,
- the steps of
- illuminating a photographic plate with the coherent light of a laser beam through a diffuser and subsequent aperture, and then
- processing that exposed photographic plate to produce a scatterer of known noise distribution;
- the further steps of
- projecting the scatterer with incoherent light onto the recording system to be tested,
- then subjecting the recording system to photographic processing
- and then, scanning the image on the processed recording system with a microphotometer whose output signal is subjected to a correlation analysis.
Dependencies are inferred from the claim text.