JBIGTOPNM(1)

💖 JBIGTOPNM 💖

okay so this is the manual page for jbigtopnm, bestie. it lives in the Netpbm family of tools and honestly? it's giving file-format-glow-up energy. 🌈 let's get into it.

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✨ NAME ✨

jbigtopnm — the JBIG to PNM image file converter. yes. that's the whole job. she converts. 💅

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✨ SYNOPSIS ✨

[output-file]]

a few lil quality-of-life things you can do with the options here:

• the minimum unique abbreviation of any option is totally acceptable — like, she'll know what you meant. 🫶
• you can use double hyphens instead of single hyphen to denote options. both are valid, no gatekeeping.
• you can use white space in place of the equals sign to separate an option name from its value. free yourself.

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✨ DESCRIPTION ✨

so first things first: this program is part of Netpbm(1). one of the family. 👑

jbigtopnm reads a JBIG bi-level image entity (BIE) from a file or from standard input, decompresses it, and outputs a PBM or PGM file. and which one do you get? here's the vibe check:

• if the input has one plane, or you choose just one plane of it → the output is PBM.
• otherwise → the output is PGM.

JBIG, for the uninitiated, is a highly effective lossless compression algorithm for bi-level images (that's one bit per pixel, bestie), and it's particularly suitable for scanned document pages. like, that's literally her moment. 📄✨

here's the structural tea: a JBIG encoded image can be stored in several resolutions in one or several BIEs. all of the resolution layers except the lowest one are stored efficiently as differences to the next lower resolution layer — iconic, efficient, no notes. 💅

you can use options -x and -y to stop the decompression at a specified maximal output image size. and the input file can consist of several concatenated BIEs which contain different increasing resolution layers of the same image. slay.

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✨ OPTIONS ✨

in addition to the options common to all programs based on libnetpbm (most notably -quiet, see Common Options), jbigtopnm recognizes the following command line options:

⏳ history lesson: before Netpbm 10.85 (December 2018), only single-character single-hyphen abbreviations of the options are accepted. so like, old-school era. we don't do that anymore.

• -xmax number — decode only up to the largest resolution layer which is still not more than number pixels wide. if no such resolution layer exists, then use the smallest one available. 🎀
• -ymax number — decode only up to the largest resolution layer which is still not more than number pixels high. if no such resolution layer exists, then use the smallest one available. you can also use options -x and -y together, which selects the largest layer that satisfies both limits. teamwork fr fr. 🤝
• -binary — use binary values instead of Gray code words in order to decode pixel values from multiple bitplanes. this option has effect only if the input has more than one bitplane and you don't select just one of those bitplanes. ⚠️ big note: the decoder has to be used in the same mode as the encoder, and it cannot determine from the BIE whether Gray or binary code words were used by the encoder. so, like, ask your encoder. 😭
• -diagnose — diagnose a BIE. with this option, jbigtopnm only prints a summary of the header information found in the input file and then exits. it's giving doctor's appointment. 🩺
• -plane number — if the input contains multiple bitplanes, then extract only the specified single plane as a PBM file. the first plane has number 0. zero-indexed, as the universe intended. ⭐

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✨ STANDARDS ✨

this program implements the JBIG image coding algorithm as specified in:

• ISO/IEC 11544:1993
• ITU-T T.82(1993)

certified. official. paperwork done. 📜✨

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✨ AUTHOR ✨

jbigtopnm is based on the JBIG library by Markus Kuhn, part of his JBIG-KIT package. the jbgtopbm program is part of the JBIG-KIT package too. (yes, that's jbgtopbm — no, that is not a typo, look at it very carefully, bestie. 👀)

and jbigtopnm is part of the Netpbm package of graphics tools. found family. 🫶

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✨ SEE ALSO ✨

• pnm(1)
• pnmtojbig(1)

go read those too, iykyk. 📚

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✨ LICENSE ✨

there was at one time concern about the need for patent licenses to use jbigtopnm, but any relevant patents expired by 2012. so we're free, we're clear, we're unbothered. 🕊️

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✨ DOCUMENT SOURCE ✨

this manual page was generated by the Netpbm tool 'makeman' from HTML source. the master documentation is at:

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🌈 and that's the whole page, bestie!! this manual page came to you straight from netpbm documentation, dated 28 July 2020, under the title Jbigtopnm User Manual(1). periodt. 💅💖