Level 2 Help for CONCOMP1

In order to determine which DNs to change, concomp1 applies a test to each
pixel in the input image.  The test involves looking at a 3 by 3 (pixel) window
centered around the pixel being tested. The number of OTHER pixels in the
window with the same value is the 'connectivity factor'.  If the connectivity
factor is less than the THRESH parameter, the central pixel is replaced either
by a user specified value or by the mode of the distribution within the window.
The default value for THRESH is 1.  Valid values for THRESH are integers from
0 to 8, inclusive.

Specify either REPLACE or MODE as the method for determining the new DN value 
for pixels that are to be replaced.  If REPLACE is specified, the new value 
is just the value specified for the REPLACE parameter.  The default value
for REPLACE is 255.  This default is used if neither REPLACE or MODE is
specified.

Specify either REPLACE or MODE as the method for determining the new DN value
for pixels that are to be replaced.  If MODE is specified, the new value is
generally the mode of the DN distribution within the window.  More precisely,
if MODE is specified, the new DN is the most frequent DN in the window that
lies in the range of DNs specified for the RANGE parameter.  In case of a tie
in determining the most frequent DN, the lowest of the DNs in the tie is used. 
If no DN in the specified range occurs in the window, the DN of the pixel
tested is not changed.  REPLACE is the default.

The RANGE parameter is used only when MODE is selected. This parameter is
entered in the form RANGE=(LO,HI) where LO and HI are selected by the user. 
This defines a range from a DN of LO to a DN of HI, inclusive.  When a pixel is
changed, the new DN is the most frequent DN in the window that lies in the
range of DNs specified for the RANGE parameter. The range is commonly set
according to the range of DNs for the regions of the image.  The range should
be made as small as the input image allows in order to reduce execution time. 
RANGE=(0,255) is the default.