[Scribus] quality images for press (digital camera?

[Peter Nermander]

As someone mentioned, viewing distance is a MAJOR factor when considering
resolution needed. Viewing distance will tell you how many PPI you will need on
the print media. For example those large advertising boards next to the highway
are printed with something like 30 PPI (yes, THIRTY).

I don't recall the exact figure, but what you need to look at is the angular
resolution of the eye. I think it is is the proximity of 2 mrad, then you can
use trigonometry to figure out the resolution needed for a certain viewing
distance.

But then there is also the matter of interpolation. You do interpolation to keep
the image from looking jagged. Of course it will not bring more detail, but most
people judge image quality from wheter they can see the pixels or not (and don't
care whether they see details or not). Interpolation will change that limit.

This also means that frequency rasterisation (as opposed to grid rasterisation)
will make images look "better" in the eyes of many viewer (although the
resolution does not change, the pixels will be less visible).

/Peter