1Pgmtopbm User Manual(0) Pgmtopbm User Manual(0)
2
3
4
6 pgmtopbm - convert a PGM image to PBM
7
8
10 pgmtopbm
11
12 [-floyd | -fs | -threshold | -hilbert | -dither8 | -d8 | -cluster3 |
13 -c3 | -cluster4 | -c4 | -cluster8 | -c8]
14
15 [-value val]
16
17 [-clump size]
18
19 [-randomseed integer]
20
21 [pgmfile]
22
23
25 This program is part of Netpbm(1).
26
27 This program is almost entirely obsolete since Netpbm 10.23 (July
28 2004). Use pamditherbw(1) to do what this program used to do.
29
30 pgmtopbm never was the simple converter it appeared to be. It was a
31 dithering program. Unfortunately, it didn't do the dithering properly
32 because it treated the PGM input samples as if they were directly pro‐
33 portional to light intensity, but they are actually gamma-adjusted.
34
35 pamditherbw is backward compatible with pgmtopbm except that it
36
37
38 · does the correct gamma adjustments.
39
40 · produces PAM output instead of PBM. (Modern Netpbm programs
41 that accept PBM input also accept PAM input, but if you need
42 actual PBM, you can use pamtopnm with pamditherbw).
43
44 So use the manual for pamditherbw for pgmtopbm, except ignore
45 anything that says it was added after Netpbm Release 10.23 and
46 ignore any options that are not shown in the synopsis above.
47
48 Although pgmtopbm is mostly obsolete, the simple threshold method
49 (specified by -threshold) is an exception. Unlike the other conversion
50 methods, gamma-adjustment is not an issue with simple thresholding and
51 pgmtopbm can produce PBM output directly. Note that even in this basic
52 mode of operation pgmtopbm may produce output which is slightly differ‐
53 ent from what pamditherbw does because of differences in internal cal‐
54 culation.
55
56 If you just want to convert a PGM image with maxval 1 to PBM, use pam‐
57 topnm(1).
58
59
61 pamditherbw(1), pamtopnm(1), pbmtopgm(1), pamthreshold(1), pbmre‐
62 duce(1), pgm(1), pbm(1)
63
64
66 Copyright (C) 1989 by Jef Poskanzer.
67
69 This manual page was generated by the Netpbm tool 'makeman' from HTML
70 source. The master documentation is at
71
72 http://netpbm.sourceforge.net/doc/pgmtopbm.html
73
74netpbm documentation 17 July 2020 Pgmtopbm User Manual(0)