Package: netpbm
Version: 2:10.0-8sarge3.1
Severity: wishlist
Tags: patch
I was experiencing a problem with my Debian machine receiving
faxes. Every so often a very wide one would come though, which
when scaled & printed would cause the printed fax to be
impossibly small.
Turned out is was caused by the end-of-line markers in the
fax data being corrupted which in turn causes several lines
to be run together. Thus the G3 fax image ended up being
several times wider than it should, and when this was scaled
to fit onto the fax page the writing on the fax became too
small to read. Corruption is not uncommon in fax data.
The attached patch overcomes this by adding a -crop option
to g3topbm. -crop causes the image width to be cropped to
the most common line width. All lines should be the same
width, so this causes the outliners to be ignored.
-- System Information:
Debian Release: 3.1
Architecture: i386 (i686)
Kernel: Linux 2.6.17-8.1-lube-686-smp
Locale: LANG=en_AU, LC_CTYPE=en_AU (charmap=ISO-8859-1)
Versions of packages netpbm depends on:
ii bc 1.06-15 The GNU bc arbitrary precision cal
ii libc6 2.3.2.ds1-22sarge6 GNU C Library: Shared libraries an
ii libjpeg62 6b-10 The Independent JPEG Group's JPEG
ii libnetpbm10 2:10.0-8sarge3.1 Shared libraries for netpbm
ii libpng12-0 1.2.8rel-1 PNG library - runtime
ii libtiff4 3.7.2-7 Tag Image File Format (TIFF) libra
ii zlib1g 1:1.2.2-4.sarge.2 compression library - runtime
-- no debconf information
diff -Nur netpbm-free-10.0/pbm/g3topbm.1 netpbm-free-10.0-new/pbm/g3topbm.1
--- netpbm-free-10.0/pbm/g3topbm.1 2003-08-13 04:23:03.000000000 +1000
+++ netpbm-free-10.0-new/pbm/g3topbm.1 2007-06-20 16:17:03.000000000 +1000
@@ -4,6 +4,7 @@
g3topbm - convert a Group 3 fax file into a portable bitmap
.SH SYNOPSIS
.B g3topbm
+.RB [ -crop ]
.RB [ -kludge ]
.RB [ -reversebits ]
.RB [ -stretch ]
@@ -14,6 +15,12 @@
.IX fax
Produces a portable bitmap as output.
.SH OPTIONS
+.TP
+.B -crop
+Tells
+.I g3topbm
+to crop the picture at the most common column width.
+Without this corrupted end-of-line markers cause wide faxes.
.TP
.B -kludge
Tells
diff -Nur netpbm-free-10.0/pbm/g3topbm.c netpbm-free-10.0-new/pbm/g3topbm.c
--- netpbm-free-10.0/pbm/g3topbm.c 2007-06-20 16:01:44.000000000 +1000
+++ netpbm-free-10.0-new/pbm/g3topbm.c 2007-06-20 16:14:25.000000000 +1000
@@ -17,6 +17,7 @@
#define MAXCOLS 10800
#define MAXROWS 14400 /* up to two pages long */
+static int crop;
static int endoffile = 0;
static int eols;
static int rawzeros;
@@ -42,6 +43,7 @@
static int rawgetbit ARGS(( FILE* file ));
static bit* bits[MAXROWS];
+static int col_widthcount[MAXCOLS];
int
main( argc, argv )
@@ -50,12 +52,13 @@
{
FILE* ifp;
int argn, rows, cols, row, col, i;
- char* usage = "[-kludge][-reversebits][-stretch] [g3file]";
+ char* usage = "[-crop][-kludge][-reversebits][-stretch] [g3file]";
pbm_init( &argc, argv );
argn = 1;
+ crop = 0;
kludge = 0;
reversebits = 0;
stretch = 0;
@@ -65,6 +68,8 @@
{
if ( pm_keymatch( argv[argn], "-kludge", 2 ) )
kludge = 1;
+ else if ( pm_keymatch( argv[argn], "-crop", 2 ) )
+ crop = 1;
else if ( pm_keymatch( argv[argn], "-reversebits", 2 ) )
reversebits = 1;
else if ( pm_keymatch( argv[argn], "-stretch", 2 ) )
@@ -109,7 +114,8 @@
{
bits[rows] = pbm_allocrow( MAXCOLS );
col = getfaxrow( ifp, rows, bits[rows] );
- fprintf(stderr, "row=%d cols=%d\n", rows, col);
+ if (col < MAXCOLS)
+ col_widthcount[col] += 1;
if ( endoffile )
break;
if ( !col)
@@ -128,6 +134,16 @@
pm_close( ifp );
+ if (crop)
+ {
+ cols = 0;
+ for (col = 0; col < MAXCOLS; col += 1)
+ {
+ if (col_widthcount[col] > col_widthcount[cols])
+ cols = col;
+ }
+ }
+
pbm_writepbminit( stdout, cols, rows, 0 );
for ( row = 0; row < rows; ++row )
pbm_writepbmrow( stdout, bits[row], cols, 0 );
