The edge-based Spatial Frequency Response (e-SFR) method is well established and has been included in the ISO 12233 standard since the first version in 2000. A new 4th edition of the standard is proceeding, with additions and changes that are intended to broaden its application and improve reliability. We report on results for advanced edge-fitting which, although reported before, was not previously included in the standard. The application of the e-SFR method to a range of edge-feature angles is enhanced by the inclusion of an angle-based correction, and use of a new test chart. We present examples of the testing completed for a wider range of edge test features than previously addressed by ISO 12233, for near-zero- and -45-degree orientations. Various smoothing windows were compared, including the Hamming and Tukey forms. We also describe a correction for image non-uniformity, and the computing of an image sharpness measure (acutance) that will be included in the updated standard.
Peter D. Burns, Kenichiro Masaoka, Kenneth Parulski, Dietmar Wueller, "Updated Camera Spatial Frequency Response for ISO 12233" in Proc. IS&T Int’l. Symp. on Electronic Imaging: Image Quality and System Performance, 2022, pp 357-1 - 357-6, https://doi.org/10.2352/EI.2022.34.9.IQSP-357