g32pbm(1)

💖 g32pbm — bestie edition 💖

okay so this is the page for g32pbm(1) from the mgetty+sendfax manual, and bestie it is SO useful, let me tell you everything 🫶

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✨ NAME ✨

g32pbm — turns a Group 3 fax file into a portable bitmap. that's it, that's the whole job, and she does it 💅

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🌸 SYNOPSIS 🌸

g32pbm [-reversebits] [-stretch] [g3file]

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🦋 DESCRIPTION 🦋

So basically: it reads a Group 3 fax file (raw or digifax, she's not picky) as input. If you don't hand her a filename, she'll just read from stdin like the chill queen she is. Then she produces a portable bitmap as output. iconic behavior, no notes ✨

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💅 OPTIONS 💅

• -r — tells g32pbm to read the bits least-significant first instead of the default most-significant first. (yes, this is the -reversebits one, iykyk.) the thing is, some fax modems do it one way and some do it the other way, and nobody's ever gonna agree 🙄. so if you're getting a whole bunch of invalid code messages — like, nearly one per line, that's the vibe check failing — just try this flag. it'll probably fix it. fr fr.
• -s — doubles each horizontal row of the fax file in the pbm file (this is the -stretch one 🎀). why would you want that? to adjust the aspect ratio of a "normal resolution" fax file so it matches a "fine resolution" one. and yes, it might not seem like it belongs here, but bestie it is so much faster than doing pnmscale|pgmtopbm later. no cap. also lowkey: -s gets activated automatically if the file is specified on the command line and its name starts with fn... (fax/normal). she just knows 👑
• -l(aserjet) — instead of a portable bitmap (PBM), output HP laserjet files, suitable for direct printing on a HP laserjet or desjket. printer girlies rise up 🖨️
• -d <dpi> — scale output to <dpi> dots per inch before printing. normal FAX resolution is 204x196 dpi (fine mode), or 204x98 dpi (normal mode). and heads up bestie — in LaerJet mode, only the values 75, 150 and 300 are allowed for <dpi>. those three, periodt. don't try to get cute with other numbers 💀
• -t — turn image by 90 degrees clockwise. and the way multiple -t commands increase the angle?? so -t -t will turn it upside down, and so on. keep going and who even knows where you'll end up 🙈
• -? — print a short command syntax. the classic "help me pls" move 💜

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⭐ REFERENCES ⭐

the standard for Group 3 fax is defined in CCITT Recommendation T.4. that's the lore 📖

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💀 BUGS 💀

okay so we gotta be honest here, no gatekeeping:

• g32pbm could be smarter about the image width. at the moment, the maximum width is 1728 pixels, and the maximum height is 4300 lines. everything bigger is just cut off. gone. bye ✂️
• only 'raw' pbm files are created. that's the whole menu.
• scaling is too slow. 😭
• turning is too slow (and not yet fully implemented either). so like, double slow. tragic.

fr fr read the bugs section before you come for her, she's doing her best 💖

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🌈 SEE ALSO 🌈

pbm2g3(1), pbm(5), g3cat(1), sendfax(8), mgetty(1)

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👑 AUTHOR 👑

g32pbm is Copyright (C) 1993 by Gert Doering, <gert@greenie.muc.de>. she's similar to the g3topbm program in Jef Poskanzers pbmplus package, but she's a complete re-write — no code is copied. original main character energy only ✨

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and that's the whole page bestie!! 🎀 this one came out of greenie, dated 27 Oct 93, and it's the g32pbm(1) page, mwah 💋 go convert some faxes, you got this 🦋💜