On the Personal IAS, is the graininess and mottle computation according to the ISO-13660 standard and methodology?
The Personal IAS does use the ISO-13660 methodology, but there are two small differences. Firstly, ISO-13660 requires mottle tile size of 1270m x 1270m but the Personal IAS uses a 250m x 250m tile size. In reality, mottle can occur on many different size scales and there is no “right” tile size. The 250m tile size for the Personal IAS was chosen because it was empirically found to work well. Secondly, the ISO-13660 standard requires the reporting of mottle and graininess in density units rather than reflectance units. However, since the density scale has a highly nonlinear behavior for dark patches, the Personal IAS uses the reflectance scale to provide results that are more consistent.
Related Questions
- On the Personal IAS, what color filter and density standard should be used when measuring graininess and mottle of different color patches?
- On the Personal IAS, how are graininess and mottle computed? What is the methodology employed?
- On the Personal IAS, what are the measurement units of graininess and mottle?
