\
.\" This man page was generated by the Netpbm tool 'makeman' from HTML source.
.\" Do not hand-hack it!  If you have bug fixes or improvements, please find
.\" the corresponding HTML page on the Netpbm website, generate a patch
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.TH "Ppmtogif User Manual" 0 "" "netpbm documentation"

.SH NAME
.PP
ppmtogif - replaced by pamtogif
.PP
This program is part of
.BR "Netpbm" (1)\c
\&.

.SH SYNOPSIS
.PP
\fBppmtogif\fP was replaced in Netpbm 10.37 (December 2006) by
.BR "pamtogif" (1)\c
\&.
.PP
\fBpamtogif\fP is mostly backward compatible with \fBppmtogif\fP.

.SH DESCRIPTION
.PP
One way \fBpamtogif\fP is not backward compatible with \fBppmtogif\fP
is that to specify a transparency (alpha) mask with \fBppmtogif\fP, you
supply the transparency as a separate pseudo-PGM image and use the
\fB-alpha\fP option, whereas with \fBpamtogif\fP, you supply an input
image that has the transparency integrated into it, and there is no
\fB-alpha\fP option.
.PP
\fBppmtogif\fP still exists as a separate program for backward 
compatibility, but it runs \fBpamtogif\fP to do the essential work.
The compatibility \fBppmtogif\fP interprets an \fB-alpha\fP option
by reading the transparency image and combining it with the input
image, then feeding \fBpamtogif\fP the combined image it expects.
Other than that, the compatibility \fBppmtogif\fP just passes input and
options directly to \fBpamtogif\fP.
.PP
You should not make any new use of \fBppmtogif\fP and if you modify an
existing use, you should upgrade to \fBpamtogif\fP.  But note that if you
write a program that might have to be used with old Netpbm, \fBppmtogif\fP is
the only way to do that.
.PP
Unless you use the \fB-alpha\fP option, you can simply change the name
of the program.  If you use \fB-alpha\fP, here is how to upgrade:

.nf
\f(CW
  $ ppmtogif -alpha=myalpha.pgm myinput.ppm >myoutput.gif
\fP

.fi

becomes

.nf
\f(CW
  $ pamstack -tupletype=RGB_ALPHA myinput.ppm myalpha.pgm |  \e
      pamtogif >myoutput.gif
\fP

.fi


.SH Original Ppmtogif
.PP
If you are using Netpbm before 10.37, \fBpamtogif\fP doesn't exist,
so you use \fBppmtogif\fP.  You can use the \fBpamtogif\fP manual
for \fBppmtogif\fP, with the following exceptions.
.PP
The current documentation of \fBpamtogif\fP documents all versions
of that program.  Use the information for Version 10.37 only.
.PP
\fBppmtogif\fP before Netpbm 10.31 does not accept PAM input at all.
.PP
\fBppmtogif\fP does not accept PAM input with transparency information
in it.  Instead, \fBppmtogif\fP has an \fB-alpha\fP option.
.PP
The syntax of the option is \fB-alpha=\fP\fIpgmfile\fP.
\fBppmtogif\fP treats the contents of the named PGM file the same as
\fBpamtogif\fP treats the alpha plane of a PAM.  The PGM image must
have the same dimensions as the input file.  But unlike the PAM case,
the alpha image need not have the same maxval as the input.
\fBppmtogif\fP interprets the alpha file using the alpha file's
maxval.
.PP
You cannot specify both \fB-transparent\fP and \fB-alpha\fP.
.SH DOCUMENT SOURCE
This manual page was generated by the Netpbm tool 'makeman' from HTML
source.  The master documentation is at
.IP
.B http://netpbm.sourceforge.net/doc/ppmtogif.html
.PP