1Ppmtogif User Manual(0) Ppmtogif User Manual(0)
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6 ppmtogif - replaced by pamtogif
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8 This program is part of Netpbm(1).
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12 ppmtogif was replaced in Netpbm 10.37 (December 2006) by pamtogif(1).
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14 pamtogif is mostly backward compatible with ppmtogif.
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18 One way pamtogif is not backward compatible with ppmtogif is that to
19 specify a transparency (alpha) mask with ppmtogif, you supply the
20 transparency as a separate pseudo-PGM image and use the -alpha option,
21 whereas with pamtogif, you supply an input image that has the transpar‐
22 ency integrated into it, and there is no -alpha option.
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24 ppmtogif still exists as a separate program for backward compatibility,
25 but it runs pamtogif to do the essential work. The compatibility ppm‐
26 togif interprets an -alpha option by reading the transparency image and
27 combining it with the input image, then feeding pamtogif the combined
28 image it expects. Other than that, the compatibility ppmtogif just
29 passes input and options directly to pamtogif.
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31 You should not make any new use of ppmtogif and if you modify an exist‐
32 ing use, you should upgrade to pamtogif. But note that if you write a
33 program that might have to be used with old Netpbm, ppmtogif is the
34 only way to do that.
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36 Unless you use the -alpha option, you can simply change the name of the
37 program. If you use -alpha, here is how to upgrade:
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39 $ ppmtogif -alpha=myalpha.pgm myinput.ppm >myoutput.gif
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42 becomes
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44 $ pamstack -tupletype=RGB_ALPHA myinput.ppm myalpha.pgm | \
45 pamtogif >myoutput.gif
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51 If you are using Netpbm before 10.37, pamtogif doesn't exist, so you
52 use ppmtogif. You can use the pamtogif manual for ppmtogif, with the
53 following exceptions.
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55 The current documentation of pamtogif documents all versions of that
56 program. Use the information for Version 10.37 only.
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58 ppmtogif before Netpbm 10.31 does not accept PAM input at all.
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60 ppmtogif does not accept PAM input with transparency information in it.
61 Instead, ppmtogif has an -alpha option.
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63 The syntax of the option is -alpha=pgmfile. ppmtogif treats the con‐
64 tents of the named PGM file the same as pamtogif treats the alpha plane
65 of a PAM. The PGM image must have the same dimensions as the input
66 file. But unlike the PAM case, the alpha image need not have the same
67 maxval as the input. ppmtogif interprets the alpha file using the al‐
68 pha file's maxval.
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70 You cannot specify both -transparent and -alpha.
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73 This manual page was generated by the Netpbm tool 'makeman' from HTML
74 source. The master documentation is at
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76 http://netpbm.sourceforge.net/doc/ppmtogif.html
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78netpbm documentation Ppmtogif User Manual(0)