1Ppmtogif User Manual(0)                                Ppmtogif User Manual(0)
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NAME

6       ppmtogif was replaced in Netpbm 10.37 (December 2002) by pamtogif(1).
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SYNOPSIS

10       pamtogif is mostly backward compatible with ppmtogif.
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DESCRIPTION

14       One  way  pamtogif  is not backward compatible with ppmtogif is that to
15       specify a transparency (alpha)  mask  with  ppmtogif,  you  supply  the
16       transparency  as a separate pseudo-PGM image and use the -alpha option,
17       whereas with pamtogif, you supply an input image that  has  the  trans‐
18       parency integrated into it, and there is no -alpha option.
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20       ppmtogif still exists as a separate program for backward compatibility,
21       but it runs pamtogif to do the essential work.  The compatibility  ppm‐
22       togif interprets an -alpha option by reading the transparency image and
23       combining it with the input image, then feeding pamtogif  the  combined
24       image  it  expects.   Other  than that, the compatibility ppmtogif just
25       passes input and options directly to pamtogif.
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27       You should not make any new use of ppmtogif and if you modify an exist‐
28       ing use, you should upgrade to pamtogif.
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30       Unless you use the -alpha option, you can simply change the name of the
31       program.  If you use -alpha, here is how to upgrade:
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33         $ ppmtogif -alpha=myalpha.pgm myinput.ppm >myoutput.gif
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35       becomes
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37         $ pamstack -tupletype=RGB_ALPHA myinput.ppm myalpha.pgm |  \
38             pamtogif >myoutput.gif
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Original Ppmtogif

43       If you are using Netpbm before 10.37, pamtogif doesn't  exist,  so  you
44       use  ppmtogif.   You can use the pamtogif manual for ppmtogif, with the
45       following exceptions.
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47       The current documentation of pamtogif documents all  versions  of  that
48       program.  Use the information for Version 10.37 only.
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50       ppmtogif before Netpbm 10.31 does not accept PAM input at all.
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52       ppmtogif does not accept PAM input with transparency information in it.
53       Instead, ppmtogif has an -alpha option.
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55       The syntax of the option is -alpha=pgmfile.  ppmtogif treats  the  con‐
56       tents of the named PGM file the same as pamtogif treats the alpha plane
57       of a PAM.  The PGM image must have the same  dimensions  as  the  input
58       file.   But unlike the PAM case, the alpha image need not have the same
59       maxval as the input.  ppmtogif interprets  the  alpha  file  using  the
60       alpha file's maxval.
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62       You cannot specify both -transparent and -alpha.
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66netpbm documentation                                   Ppmtogif User Manual(0)