Challenge 1: Raising PPI Without Resampling — Solution Walkthrough

What actually happens:

Per this chapter's own warning box, simply changing the PPI value from
72 to 300 without resampling doesn't add any real pixel detail at all
— the underlying 3000x2000 pixel data stays exactly the same. What
actually changes is the image's own calculated print SIZE: at 72 PPI,
that pixel count prints much larger physically; at 300 PPI, the exact
same pixel data prints much smaller. If the photographer keeps the
print at the same physical size while changing the PPI number alone,
nothing about the image's actual sharpness or detail changes at all —
only the metadata describing intended print size has changed.

Why the photographer's expectation is wrong:

The expectation assumes PPI is some kind of quality dial that adds
detail when increased. Per this chapter, PPI combined with pixel
dimensions determines print size — it doesn't independently add or
remove pixel information. Since no resampling occurred, no new pixel
data was created at all; the file's actual resolution capability is
unchanged.

What would actually be needed:

To genuinely add more detail, the image would need to be resampled
(upsampled) to a higher pixel count, which invents new pixel data
through interpolation — a real process with its own real quality
limits, not the simple metadata change described in this scenario.

WHY THIS WORKS AS AN ANSWER
------------------------------
This exercise is a direct, concrete application of this chapter's own
warning box to the exact scenario it was written to address —
correctly distinguishing a metadata-only PPI change from an actual
resampling operation that adds real pixel data.