pbmtext(1) - phpMan

Pbmtext User Manual(0) Pbmtext User Manual(0)

NAME
pbmtext - render text into a PBM image

SYNOPSIS
pbmtext [-font fontfile] [-builtin fontname] [-space pixels] [-lspace pixels] [-nomargins]
[-width pixels] [text]

Minimum unique abbreviation of option is acceptable. You may use double hyphens instead
of single hyphen to denote options. You may use white space in place of the equals sign
to separate an option name from its value.

DESCRIPTION
This program is part of Netpbm(1).

pbmtext takes the specified text, either a single line from the command line or multiple
lines from standard input, and renders it into a PBM graphical image.

In the image, each line of input is a line of output. Formatting characters such as new-
line have no effect on the formatting; like any unprintable character, they turn into spa-
ces.

The image is just wide enough for the longest line of text, plus margins, and just high
enough to contain the lines of text, plus margins.

The left and right margins are twice the width of the widest character in the font; the
top and bottom margins are the height of the tallest character in the font. But if the
text is only one line, all the margins are half of this. You can use the -nomargins
option to eliminate the margins.

pbmtextps does the same thing as pbmtext, but uses Ghostscript to generate the characters,
which means you can use Postscript fonts. But it also means you have to have Ghostscript
installed and it isn't as fast. Also, pbmtextps generates only one line of text, whereas
pbmtext can create multiple lines.

pbmtext is meant for simple text. If you're working with a document, you would be better
off using a document formatting program to "print" to a Postscript file, then feeding that
Postscript to pstopnm.

OPTIONS
-font

-builtin
-builtin selects a font among those built into Netpbm.

-font selects a font that you supply yourself either as an X Window System BDF
(Bitmap Distribution Format) <http://xfree86.org/current/bdf.pdf> file or as a PBM
file in a special form.

The default is the built in font "bdf."

"bdf" is Times-Roman 15 pixels high. (That's about 14 point type printed at 75
dpi).

"fixed" is a built in fixed width font.

For information about other fonts, and how to make one of your own, see Fonts
<#fonts> below.

-space pixels
Add pixels pixels of space between characters. This is in addition to whatever
space surrounding characters is built into the font, which is usually enough to
produce a reasonable string of text.

pixels may be fractional, in which case the number of pixels added varies so as to
achieve the specified average. For example -space=1.5 causes half the spaces to be
1 pixel and half to be 2 pixels.

pixels may be negative to crowd text together, but the author has not put much
thought or testing into how this works in every possible case, so it might cause
disastrous results.

-lspace pixels
Add pixels pixels of space between lines. This is in addition to whatever space
above and below characters is built into the font, which is usually enough to pro-
duce a reasonable line spacing.

pixels must be a whole number.

pixels may be negative to crowd lines together, but the author has not put much
thought or testing into how this works in every possible case, so it might cause
disastrous results.

-nomargins
By default, pbmtext adds margins all around the image as described above. This
option causes pbmtext not to add any margins.

Note that there may still be space beyond the edges of the type because a character
itself may include space at its edges. To eliminate all surrounding background, so
the type touches all four edges of the image, use pnmcrop.

-width pixels
This specifies how much horizontal space the text is supposed to fit into.

If the input is one line, pbmtext breaks it into multiple lines as needed to fit
the specified width. It breaks it between characters, but does not pay attention
to white space; it may break in the middle of a word and a line may begin or end
with white space.

If the input is multiple lines, pbmtext assumes you already have line breaks where
they make sense, and pbmtext simply truncates each line as needed to fit the speci-
fied width.

USAGE
Often, you want to place text over another image. One way to do this is with ppmlabel.
For more flexible (but complex) drawing of text on an image, there is ppmdraw. These do
not give you the font options that pbmtext does, though.

Another way is to use pbmtext to create an image containing the text, then use pamcomp to
overlay the text image onto your base image. To make only the text (and not the entire
rectangle containing it) cover the base image, you will need to give pamcomp a mask, via
its -alpha option. You can just use the text image itself as the mask, as long as you
also specify the -invert option to pamcomp.

If you want to overlay colored text instead of black, just use ppmchange to change all
black pixels to the color of your choice before overlaying the text image. But still use
the original black and white image for the transparency mask.

If you want the text at an angle, use pnmrotate on the text image (and transparency mask)
before overlaying.

FONTS
There are three kinds of fonts you an use with pbmtext:

o built in

o BDF

o PBM

Built In Fonts
There are two built in fonts: bdf and fixed. You select these fonts with a -builtin
option.

bdf is the default when you specify no font information on the command line.

bdf is encoded in ISO 8859-1 (Latin 1, 8-bit). In addition to English it can handle most
West European languages (Spanish, French, German, Swedish ...) This set lacks the Euro
currency sign.

fixed is ASCII (7-bit) only.

BDF Font
BDF is an ancient font format that at one time was standard for the X Window System. Now,
you don't see it very often, but you can find some BDF fonts on the Xfree86
<http://cvsweb.xfree86.org/cvsweb/xc/fonts/bdf/> web site.

You can get the full package of the BDF fonts from XFree86 (see above) from the Netpbm web
site <http://netpbm.sourceforge.net/bdffont.tgz> .

PBM Font
To create a font as a PBM file (to use with the -font option), you just create a PBM image
of the text matrix below.

The first step is to display text matrix below on the screen, e.g. in an X11 window.

M ",/^_[`jpqy| M

/ !"#$%&'()*+ /
< ,-./01234567 <
> 89:;<=>?@ABC >
@ DEFGHIJKLMNO @
_ PQRSTUVWXYZ[ _
{ \]^_`abcdefg {
} hijklmnopqrs }
~ tuvwxyz{|}~ ~

M ",/^_[`jpqy| M

Make sure it's a fixed width font -- This should display as a perfect rectangle.

Also, try to use a simple display program. Pbmtext divides this into a matrix of cells,
all the same size, each containing one character, so it is important that whatever you use
to display it display with uniform horizontal and vertical spacing. Fancy word processing
programs sometimes stretch characters in both directions to fit certain dimensions, and
that won't work. Sometimes a display program scales a font to show a character larger or
smaller than its natural size. That too won't often work because the rounding involved in
such scaling causes non-uniform distances between characters.

If you display the text matrix improperly, the usual symptom is that when you try to use
the font, pbmtext fails with an error message telling you that the number of lines in the
font isn't divisible by 11, or it can't find the blank band around the inner rectangle.
Sometimes the symptom is that one of the characters displays with a piece of the character
that is next to it in the matrix. For example, "l" might display with a little piece of
the "m" attached on its right.

Do a screen grab or window dump of that text, using for instance xwd, xgrabsc, or screen-
dump. Convert the result into a pbm file. If necessary, use pamcut to remove anything
you grabbed in addition to the text pictured above (or be a wimp and use a graphical edi-
tor such as Gimp). Finally, run it through pnmcrop to make sure the edges are right up
against the text. pbmtext can figure out the sizes and spacings from that.

There are some historical computer fonts, such as that used by the original IBM PC, in the
form that you can screen-grab and turn into a PBM font file available from Stewart C Rus-
sell" (1). There are fonts with various duodecimal digit glyphs at
treisara.deviantart.com <http://treisaran.deviantart.com/gallery/38695571/NetPBM-Fonts> .

NON-ENGLISH TEXT
pbmtext does little to accommodate the special needs of non-English text.

pbmtext reads input in byte units. Unicode (utf-7, utf-8, utf-16, etc.) text which con-
tains multibyte characters does not work.

pbmtext can handle 7-bit and 8-bit character sets. Examples are ASCII, ISO 8859 family,
koi8-r/u and VISCII. It is up to the user to supply a BDF file covering the necessary
glyphs with the "-font" option. The font file must be in the right encoding.

pbmtext does not recognize locale. It ignores the associated environment variables.

pbmtext cannot render vertically or right to left.

TIPS
If you get garbled output, check whether the font file encoding corresponds to the input
text encoding. Also make sure that your input is not in utf-* or any other multi-byte
format.

To dump characters in a BDF font file run this command:

$ awk 'BEGIN { for (i=1; i<=255; i++) \
{ printf("%c%s",i,i%16==15 ? "\n":""); } }' |\
pbmtext -f font.bdf > dump.pbm

If you need only ASCII, change the for statement to:

for (i=32; i<=127; i++)

To check the encoding of a BDF file, examine the CHARSET_REGISTRY line and the next line,
which should be CHARSET_ENCODING:

$ grep -A1 CHARSET_REGISTRY font-a.bdf
CHARSET_REGISTRY "ISO8859"
CHARSET_ENCODING "1"

$ grep -A1 CHARSET_REGISTRY font-b.bdf
CHARSET_REGISTRY "ISO10646"
CHARSET_ENCODING "1"

The latter is Unicode. BDF files coded in ISO 16046-1 usually work for Western European
languages, because ISO 16046-1 expands ISO 8859-1 (also called "Latin-1") while maintain-
ing the first 256 code points. ISO 8859-1 itself is a superset of ASCII. Run the above
command and verify the necessary glyphs are present.

It may sound strange that pbmtext accepts font files encoded in Unicode but not input text
in Unicode. This is because Unicode provides several "numbering schemes".

When rendering text in character sets other than ISO 8859-1, one often has to produce a
BDF file in the given encoding from a master BDF file encoded in ISO 10646-1.

In particular, 75% of the BDF files in the font collection available from the Netpbm
website <http://netpbm.sourceforge.net/bdffont.tgz> are in ISO 10646-1. Many have the
Euro sign, Greek letters, etc, but they are placed in code points beyond what pbmtext
sees.

There are several programs that perform BDF encoding conversion. If you have the X Window
System installed, first look for ucs2any. If you don't, you can download ucs2any.pl from
Unicode fonts and tools for X11" (1). This website has much useful information on fonts.

Another converter is trbdf, included in the "trscripts" package, available in some
GNU/Linux distributions.

BDF files encoded in ISO 8859-2, ISO 8859-7, koi8-r, etc. are available from ISO 8859
Alphabet Soup" (1) and its sister page The Cyrillic Charset Soup" (1). Though the infor-
mation is dated, these pages give a good overview of 8-bit character sets.

To convert OTF or TTF font files to BDF, use
otf2bdf by Mike Leisher <http://www.math.nmsu.edu/~mleisher/Software/otf2bdf> .

SEE ALSO
pbmtextps(1), pamcut(1), pnmcrop(1), pamcomp(1), ppmchange(1), pnmrotate(1), ppmlabel(1),
ppmdraw(1), pstopnm(1), pbm(1), Pango <http://www.pango.org> , Cairo
<http://cairographics.org>

DOCUMENT SOURCE
This manual page was generated by the Netpbm tool 'makeman' from HTML source. The master
documentation is at

http://netpbm.sourceforge.net/doc/pbmtext.html

netpbm documentation 14 June 2010 Pbmtext User Manual(0)

Generated by $Id: phpMan.php,v 4.55 2007/09/05 04:42:51 chedong Exp $ Author: Che Dong
On Apache
Under GNU General Public License
2024-04-18 18:19 @3.145.115.195 CrawledBy claudebot