pnmalias - antialias a portable anyumap.
pnmalias [-bgcolor color] [-fgcolor
color] [-bonly] [-fonly] [-balias]
[-falias] [-weight w] [pnmfile]
Reads a portable anymap as input, and applies anti-aliasing to
background and foreground pixels. If the input file is a portable bitmap,
the output anti-aliased image is promoted to a graymap, and a message is
printed informing the user of the change in format.
-bgcolor colorb, -fgcolor colorf
set the background color to
colorb, and the
foreground to color to
colorf. Pixels with these values will be
anti-aliased. by default, the background color is taken to be black, and
foreground color is assumed to be white. The colors can be specified in five
ways:
- o
- A name, assuming that a pointer to an X11-style color names file was
compiled in.
- o
- An X11-style hexadecimal specifier: rgb:r/g/b, where r g and b are each 1-
to 4-digit hexadecimal numbers.
- o
- An X11-style decimal specifier: rgbi:r/g/b, where r g and b are floating
point numbers between 0 and 1.
- o
- For backwards compatibility, an old-X11-style hexadecimal number: #rgb,
#rrggbb, #rrrgggbbb, or #rrrrggggbbbb.
- o
- For backwards compatibility, a triplet of numbers separated by commas:
r,g,b, where r g and b are floating point numbers between 0 and 1. (This
style was added before MIT came up with the similar rgbi style.)
Note that even when dealing with graymaps, background and
foreground colors need to be specified in the fashion described above. In
this case, background and foreground pixel values are taken to be the value
of the red component for the given color.
-bonly, -fonly
Apply anti-aliasing only to background (-bonly),
or foreground (-fonly) pixels.
-balias, -falias
Apply anti-aliasing to all pixels surrounding background
(-balias), or foreground (-falias) pixels. By default,
anti-aliasing takes place only among neighboring background and foreground
pixels.
-weight w
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.
Copyright (C) 1992 by Alberto Accomazzi, Smithsonian Astrophysical
Observatory.