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| author | giraffedata <giraffedata@9d0c8265-081b-0410-96cb-a4ca84ce46f8> | 2008-12-06 21:17:55 +0000 |
|---|---|---|
| committer | giraffedata <giraffedata@9d0c8265-081b-0410-96cb-a4ca84ce46f8> | 2008-12-06 21:17:55 +0000 |
| commit | 77bf1e7cd506979ca0679c48a9da3dcf0d948dbd (patch) | |
| tree | c9adbfcb316afc55d92c6c6d9597e52b1695206a /g3topbm.html | |
| parent | 670454c57475df3a8e79bf658b796ff2cae7611c (diff) | |
| download | netpbm-mirror-77bf1e7cd506979ca0679c48a9da3dcf0d948dbd.tar.gz netpbm-mirror-77bf1e7cd506979ca0679c48a9da3dcf0d948dbd.tar.xz netpbm-mirror-77bf1e7cd506979ca0679c48a9da3dcf0d948dbd.zip | |
"miscellaneous update"
git-svn-id: http://svn.code.sf.net/p/netpbm/code/userguide@784 9d0c8265-081b-0410-96cb-a4ca84ce46f8
Diffstat (limited to 'g3topbm.html')
| -rw-r--r-- | g3topbm.html | 34 |
1 files changed, 12 insertions, 22 deletions
diff --git a/g3topbm.html b/g3topbm.html index fbcacc6b..3ba61094 100644 --- a/g3topbm.html +++ b/g3topbm.html @@ -2,7 +2,7 @@ <HTML><HEAD><TITLE>G3topbm User Manual</TITLE></HEAD> <BODY> <H1>g3topbm</H1> -Updated: 28 February 2006 +Updated: 03 December 2008 <BR> <A HREF="#index">Table Of Contents</A> @@ -27,8 +27,8 @@ space in place of the equals sign to separate an option name from its value. <p>This program is part of <a href="index.html">Netpbm</a>. -<p><b>g3topbm</b> reads a Group 3 fax file as input and produces a PBM -image as output. +<p><b>g3topbm</b> reads a Group 3 fax file in MH format as input and produces +a PBM image as output. <p><b>g3topbm</b> tolerates various deviations from the standard, so as to recover some of the image if there was a transmission error. @@ -40,6 +40,12 @@ the right. It warns you when it does this. <p>You can use the <b>stop_error</b> option to make <b>g3topbm</b> insist on valid input. +<p>There is no Netpbm program that understands the other command fax +formats, MR and MMR. + +<p>There are subformats of TIFF that use the Group 3 fax encodings +inside. See <b>tifftopnm</b>. + <H2 id="options">OPTIONS</H2> <DL COMPACT> @@ -107,29 +113,14 @@ never failed when it encountered other problems. </DL> -<H2 id="g3">ABOUT G3</H2> - -<P>G3 is the near universal format used by fax machines. There is also -a newer, more capable G4. - -<p>The standard for Group 3 fax is defined in CCITT Recommendation T.4. -In the U.S., that is implemented by EIA standards EIA-465 and EIA-466. -These standards cover the layers below the image format (which are -irrelevant to <b>g3topbm</b> as well. - -<p>G3 faxes are 204 dots per inch (dpi) horizontally and 98 dpi (196 -dpi optionally, in fine-detail mode) vertically. Since G3 neither -assumes error free transmission nor retransmits when errors occur, the -encoding scheme used is differential only over small segments never -exceeding 2 lines at standard resolution or 4 lines for fine-detail. -(The incremental G3 encoding scheme is called two-dimensional and the -number of lines so encoded is specified by a parameter called k.) - <H2 id="seealso">SEE ALSO</H2> <A HREF="pbmtog3.html">pbmtog3</A>, +<A HREF="tifftopnm.html">tifftopnm</A>, <A HREF="pbm.html">pbm</A> +<A HREF="faxformat.html">fax formats</A> + <HR> <H2 id="index">Table Of Contents</H2> @@ -137,7 +128,6 @@ number of lines so encoded is specified by a parameter called k.) <LI><A HREF="#synopsis">SYNOPSIS</A> <LI><A HREF="#description">DESCRIPTION</A> <LI><A HREF="#options">OPTIONS</A> -<LI><A HREF="#g3">ABOUT G3</A> <LI><A HREF="#seealso">SEE ALSO</A> </UL> </BODY> |