🚀 go-pugleaf

Among several factors two important quantities affect the imaging when
scanning photographs or displaying images with pixels on a monitor: the
number of detectors/pixels per inch, and the size of them.

    The first quantity limits the "geometric imaging" through
    the Nyquist criterion. This means that an object with F0 [dpi]
    (F0/2 [lines/inch]) requires F0 detectors/pixels per inch for
    preserving the geometry.

    The second quantity limits the "modulation imaging" through
    the MTF of the detector/pixel (and optics etc). For a quadratic
    detector/pixel with the size 1/F0 [inch] the MTF will be
    sin(PI*V/F0)/(PI*V/F0), with V measured in [lines/inch]. The
    limiting spatial frequency will be 2*F0 [dpi] (F0 [lines/inch]).
    NOTE that the modulation will be 0 at this spatial frequency.

For a scanner/monitor with quadratic detectors/pixels mounted side by side
this means that resolving 300 [dpi] geometry and modulation require AT LEAST
300 detectors/pixels per inch. NOTE that the modulation will be damped with
a factor of about 0.6 for 300 detectors/pixels per inch, and 0.9 for 600
detectors/pixels per inch. In practice the damping will be even worse since
MTF of other components, such as optics and stray light, must be included.