Why EDID is not trustworthy for DPI

[Bruno Wolff III]

On Thu, Oct 06, 2011 at 12:00:36 -0400,
  Simo Sorce <simo at redhat.com> wrote:
> 
> My main use case here is video projectors, and in that case there is no
> way on earth you'll ever know the DPI as it depends on the distance from
> the wall, and again even if you knew the distance from the wall you'd
> know nothing because the optimal DPI will also depend on the distance of
> the crowd from the wall.

What you really want to know is the resolution per angle or arc. And that
would be relatively constant for a project regardless of distance from
the surface it is projecting on.