Render string in X11 bitmap font - linux

Question

How do I render a string in an ancient X11 bitmap font? I mean something like
-*-lucida-medium-r-normal-*-34-*-*-*-*-*-*-*
which I can find with xfontsel. I just need a command line tool etc. that displays a given string in that font. A similar TrueType font won't work, since it has to be pixel-perfect (I'm trying to get images of each letter to OCR an image in that font).

Answer 1

I'm not sure if there is a command line tool. But you can always roll your own with Xlib and C.
Somebody seems to have written a simple X11 C program that displays a string using Xlib. Changing a couple of lines and compiling with:
gcc -lX11 -o xrenderstring xrenderstring.c
.. should do it for you.
I've reproduced the entire program in this gist (in case it vanishes from the original source), modified to take two arguments: 1. fontname, 2. string to be rendered.
So you'd call it like (after compiling of course):
./xrenderstring "-*-lucida-medium-r-normal-*-34-*-*-*-*-*-*-*" "Quick brown fox"

Answer 2

To just render characters in that font:
xfd -fn '-*-lucida-medium-r-normal-*-34-*-*-*-*-*-*-*'
xfontsel -pattern '-*-lucida-medium-r-normal-*-34-*-*-*-*-*-*-*'
To render a specific string:
xfontsel -pattern '-*-lucida-medium-r-normal-*-34-*-*-*-*-*-*-*' -sample 'The quick brown fox jumps the shark'

Answer 3

Found a hackish way. Add the following to ~/.Xdefaults:
xedit*editWindow*font: -*-lucida-medium-r-normal-*-36-*-*-*-*-*-*-*
and then run
$ xrdb -merge ~/.Xdefaults
$ xedit
Then I typed the string in, took a screenshot, and compared it in gimp.
(Turns out the X11 font was not quite the right one after all. My source used Lucida Sans 36 pt (ttf), but without antialiasing and probably wierd hinting.)

Answer 4

You can use ImageMagick.
Added benefits:
can render old-fashioned (fixed) or TTF or other fonts
can render to screen or to image file (PNG, whatever)
Simple
For short text
echo "The quick brown fox jumps over the lazy dog." \
| convert \
-font '-*-fixed-*-*-*-*-18-*-*-*-*-*-iso8859-*' \
TEXT:- -trim fox.png
To render to screen:
echo "The quick brown fox jumps over the lazy dog." \
| convert \
-font '-*-fixed-*-*-*-*-18-*-*-*-*-*-iso8859-*' \
TEXT:- -trim MIFF:- | display MIFF:-
Remove -trim to see that ImageMagick uses a canvas to draw.
More control
Canvas size. To avoid two-step computations, create a canvas larger than needed and trim it afterwards.
Control background and foreground colors.
Control PNG parameters (one bit per pixel)
convert -size 2000x20 xc:black \
-font '-*-fixed-*-*-*-*-18-*-*-*-*-*-iso8859-*' \
-fill white \
-draw "text 0,15 'The quick brown fox jumps over the lazy dog.'" \
-trim +dither -depth 1 fox.png
The resulting image below weighs 592 bytes:
To get independently framed characters (for later composition)
You could put only one character in line above, but applying to several characters independently would cause the resulting images to no longer have a same size nor same common baseline.
for CHAR in H e l o ' ' W r d
do
convert -size 9x13 xc:black \
-font '-*-fixed-*-*-*-*-18-*-*-*-*-*-iso8859-*' \
-fill white -stroke none \
-draw "text 0,10 '${CHAR}'" \
+dither -depth 2 fixed_char_${CHAR}.png
done
The command below produces a PNG showing that individually framed images keep their common alignment:
montage -mode concatenate -tile x1 fixed_char_H.png fixed_char_e.png \
fixed_char_l.png fixed_char_l.png fixed_char_o.png fixed_char_\ .png \
fixed_char_W.png fixed_char_o.png fixed_char_r.png fixed_char_l.png \
fixed_char_d.png helloworld.png