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| author | giraffedata <giraffedata@9d0c8265-081b-0410-96cb-a4ca84ce46f8> | 2023-07-03 00:54:42 +0000 |
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| committer | giraffedata <giraffedata@9d0c8265-081b-0410-96cb-a4ca84ce46f8> | 2023-07-03 00:54:42 +0000 |
| commit | f9352b40e5733cfc65607a846ccdeba38d679e21 (patch) | |
| tree | 4509a8a5aab92e70d3e5f4cd0a1f2606b3fdf080 | |
| parent | 4baaad4b0a1b5bbac8914ac004029841780e4da7 (diff) | |
| download | netpbm-mirror-f9352b40e5733cfc65607a846ccdeba38d679e21.tar.gz netpbm-mirror-f9352b40e5733cfc65607a846ccdeba38d679e21.tar.xz netpbm-mirror-f9352b40e5733cfc65607a846ccdeba38d679e21.zip | |
miscellaneous update
git-svn-id: http://svn.code.sf.net/p/netpbm/code/userguide@4565 9d0c8265-081b-0410-96cb-a4ca84ce46f8
| -rw-r--r-- | g3topbm.html | 44 |
1 files changed, 37 insertions, 7 deletions
diff --git a/g3topbm.html b/g3topbm.html index 048235c8..1c0f438d 100644 --- a/g3topbm.html +++ b/g3topbm.html @@ -2,7 +2,7 @@ <html><head><title>G3topbm User Manual</title></head> <body> <h1>g3topbm</h1> -Updated: 03 December 2008 +Updated: 02 July 2023 <br> <a href="#index">Table Of Contents</a> @@ -12,11 +12,12 @@ g3topbm - convert a Group 3 fax file into a PBM image <h2 id="synopsis">SYNOPSIS</h2> <b>g3topbm</b> -[<b>-kludge</b>] [<b>-reversebits</b>] [<b>-stretch</b>] [<b>-width=</b><i>pixels</i> | paper_size={A3|A4|A5|A6|B4}] [<b>-stop_error</b>] +[<b>-correctlong</b>] +[<b>-kludge</b>] [<i>g3file</i>] <p>Minimum unique abbreviation of option is acceptable. You may use double @@ -64,11 +65,6 @@ Common Options</a>), <b>g3topbm</b> recognizes the following command line options: <dl compact> -<dt><b>-kludge</b> - -<dd>Tells <b>g3topbm</b> to ignore the first few lines of the file; -sometimes fax files have some junk at the beginning. - <dt><b>-reversebits</b> <dd>Tells <b>g3topbm</b> to interpret bits least-significant first, @@ -126,6 +122,40 @@ input errors. <b>g3topbm</b> always failed when it encountered premature EOF and never failed when it encountered other problems. +<dd><b>-correctlong</b> + +<p>This option helps with certain corrupted input files. Faxes often are +corrupted because of communication line errors. A particularly annoying +corruption causes a line to be much longer than it is supposed to be. One way +that can happen is where an End of Line marker is missing, so two consecutive +lines turn into one. + +<p>Without this option, <b>g3topbm</b> faithfully renders the document as +coded, so the output PBM image simply contains that long line. This is an +especially problematic corruption because it makes the entire out image about +twice as wide as it is supposed to be. But with <b>-correctlong</b>, +<b>g3topbm</b> truncates that line so the overall effect of the input +corruption is that a line is missing rather than that the image is twice as +wide as it is supposed to be. + +<p>Specifically, with <b>-correctlong</b>, the program looks at the lengths of +all the lines (which would all be the same length in an uncorrupted G3 image) +and considers the line length that occurs the most to be the intended image +width. It truncates every line that is longer than that. + +<p>The program warns you when corruption has causes the input image to have +lines of more than one length, whether you specify <b>-correctlong</b> or not. + +<p>Note that there is no point to specifying <b>-correctlong</b> if you also +specify <b>-stop_error</b>. + +<P>This option was new in Netpbm 11.04 (September 2023). + +<dt><b>-kludge</b> + +<dd>Tells <b>g3topbm</b> to ignore the first few lines of the file; sometimes +fax files have some junk at the beginning. + </dl> |