Level 2 Help for SBOXFLT

INFILE is the input dataset

OUTFILE is the input dataset

WIDTH is the width in pixels of the box filter.  It must be less than
twice the image width in pixels and defaults to 3.

LENGTH is the length in lines of the box filter.  It must be less than
twice the image length in pixels and defaults to 3.

FILTER=HIGHPASS specifies that the output is to be the high-pass, rather than
the low-pass, version of the input, i.e., OUT = IN - LOW + DCLEVEL.
The default is high-pass filtering.