.OUTPUT FILE: H_IMG032
[Enter the name of the output file.]
.OUTER & INNER RADII: 12.0
[Enter the radius of the mask circle, in pixels.]
.(D)ISK, (G)AUSSIAN EDGE, OR (T)RUE GAUSSIAN: D/G/T
[Enter 'D' for a sharp disk-profile cutoff, (for 2D image
only:) 'G' for a piece-wise mask (no modification inside
a circle with the specified radius, and Gaussian-shaped
falloff from this radius outwards), or 'T' for a true
Gaussian mask.]
.(A)V, (P)REC AV, (C)IRCUMF, OR (E)XTERNAL: P
[Enter 'A' if the background is to be the average of
the picture before masking; enter 'P' if the
background is to be the average after masking; or enter
'E' if the background is to be specified EXTERNALLY.
Enter 'C' if you want the background to be determined
by averaging along the circumference of the mask].