With the advent of the ISO standard 16067-1 Spatial Frequency Response for Electronic Desktop Scanners it becomes useful to compare established methods, such as Modulation Transfer Function or Contrast Transfer Function (MTF/CTF) to the new standard method. This facilitates communication between companies, vendors, OEM suppliers and end users as to the actual performance being provided or specified. However, when making a change in measurement method in an established field, it is important to understand the relationship between prior measurement methods and the one being adopted. This is required to provide clear migration paths for vendors, manufacturers and reviewers from the old method to the new, while preserving the knowledge inherent in the body of data available from prior measurements. This paper reports comparisons and conversion methods between the ISO 16067-1 SFR and a common MTF/CTF method and how to relate measurements made using the two methods. A number of consumer class desktop scanners with different optical systems are compared when operated at the optical sampling rate (ppi) as well as lower and higher sample rates (ppi). Preliminary results indicate a good correlation is found between the methods though different conversion factors must be used for different sampling rates.

Troy D. Strausbaugh

Papers

Migration from Contrast Transfer Function to ISO 16067-1 Spatial Frequency Response.