Level 2 Help for ASCHIST

STRING
The input VICAR image.  This may be a PICSUM'd image.

STRING
The output histogram table file.  This is a ASCII tab-delimitted text file
containing two columns (with optional text headers).  Column 1 is the 
DN level (from RANGE(1) to RANGE(2)).  Column 2 is the population of the
levels.

If the input was PICSUM'd, the data are scaled down by the PICSCALE scale 
factor prior the the histogram generation.

INTEGER - COUNT=2 - OPTIONAL
The range of DN values to be included in the output histogram.
The default for byte data is (0,255).  For halfword data, the default is
(0,4096).

KEYWORD - OPTIONAL - Valid=(HEADER,NOHEADER)
Specifies whether to generate column headers.  The default is to generate 
the column headers.

KEYWORD - OPTIONAL - Valid=(NODN,DN) - Default=DN
Specifies whether to generate the column of DN values.  The default is 
to generate both DN and population columns.