.TH ppmchange 1 "3 December 1993"
.IX ppmchange
.SH NAME
ppmchange - change all pixels of one color to another in a portable pixmap
.SH SYNOPSIS
.B ppmchange
.I oldcolor newcolor [...]
.RI [ ppmfile ]
.SH DESCRIPTION
Reads a portable pixmap as input.
Changes all pixels of 
.I oldcolor 
to 
.IR newcolor , 
leaving all others unchanged.
Up to 256 colors may be replaced by specifying couples of colors on
the command line.  
.PP
The colors can be specified in five ways:
.IX "specifying colors"
.TP 
o
A name, assuming
that a pointer to an X11-style color names file was compiled in.
.TP 
o
An X11-style hexadecimal specifier: rgb:r/g/b, where r g and b are
each 1- to 4-digit hexadecimal numbers.
.TP 
o
An X11-style decimal specifier: rgbi:r/g/b, where r g and b are
floating point numbers between 0 and 1.
.TP 
o
For backwards compatibility, an old-X11-style hexadecimal
number: #rgb, #rrggbb, #rrrgggbbb, or #rrrrggggbbbb.
.TP 
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.)
.SH "SEE ALSO"
pgmtoppm(1), pbmplus(1)
.SH AUTHOR
Wilson H. Bent. Jr. (whb@usc.edu)
with modifications by Alberto Accomazzi (alberto@cfa.harvard.edu)