In addition to the options common to all programs based on libnetpbm (most notably -quiet, see Common
Options ), pnmalias recognizes the following command line options:
-bgcolorcolorb sets the background color the colorb.
-fgcolorcolorf sets the foreground color to colorf.
Pixels with these values will be anti-aliased. By default, pnmalias takes the background color to be
black, and foreground color to be white.
Specify the color (color) as described for the argument of the pnm_parsecolor() library routine .
Note that even when dealing with PGMs, background and foreground colors need to be specified in the
fashion described above. In this case, pnmalias takes the background and foreground pixel values to be
the value of the red component for the specified color.
-bonly says to apply anti-aliasing only to the background pixels.
-fonly says to apply anti-aliasing only to the foreground pixels.
-balias says to apply anti-aliasing to all pixels surrounding background pixels.
-falias says to apply anti-aliasing to all pixels surrounding foreground pixels.
If you specify neither -balias nor -falias, pnmalias applies anti-aliasing only among neighboring
background and foreground pixels.
-weightw says to use w as the central weight for the aliasing filter. w must be a real number in the
range 0 < w < 1. The lower the value of w is, the "blurrier" the output image is. The default is w =
1/3.