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toggle roi type: "roin:" vs. "roiup:" (native vs. upsample)
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keyboard equiv: <none>

This entry has two different states, "roin:" (3D
label, *native* resolution) and "roiup:" (3D
label, *upsampled* to structural resolution).

On startup, the default stat is "roiup:", which
is used to read ("R" button) and write ("W"
button) upsampled-resolution 3D labels.  These
are typically short (2-byte) files generated
within tkmedit by fill operations on the smoothed
upsampled data.  Rawdata timecourses from this
label can be dumped ("T" button).

Clicking on the label "roiup:" (bold to indicate
it is button-like) swaps in the "roin:" entry,
which is used to read ("R" button) a native
resolution 3D ROI label (same dimensions as
rawdata), register it to the structural underlay,
and upsample it to structural resolution.

Clicking again toggles back to "roiup:"
