ImageMagick (or other) for UTF-8 text to image

Question

I'm trying to create many single-character images using convert. The purpose is to provide a plastics specialist with images to print onto keyboard keycaps.

The ImageMagick documentation suggests something like this:

 printf "\u2318" | convert -size 100x100 label:@- -font unifont-Medium command.png

or

 echo ⌘ | convert -size 100x100 label:@- -font unifont-Medium command.png

or

 convert -size 100x100 label:'⌘' -font unifont-Medium command.png

which is supposed to print the place of interest symbol, but it instead produces a question mark.

I have confirmed (using charmap) that the unifont-Medium fontset actually includes this glyph. I know that other fonts on my system can also provide this glyph, because I could see it before installing unifont, but I've not been able to work out what their name is.

I also tried using LaTeX (e.g. TexLive with all the extras and the utf8x package) but none of the special characters are supported.

There are a lot of forum questions about printing chinese characters with imagemagick and other special characters... the following does work for me:

convert -background lightblue -fill blue -pointsize 32 \
      label:' é è à ù ç Ö ÿ ‘ ’ “ ” ° ² ³ € x ÷ '    label_i8n.gif

but it just doesn't work for the UTF-8 characters that are actually important to me.

How can I convert arbitrary unicode characters to images?

UPDATE: I gave up, looks like a bug. Instead, I created a bunch of scripts to generate and render SVG, open sourced here: kinesis-dvorak

Answer 1

I tried the same commands and got the same results.

$ printf "\u2318" | convert -size 100x100 label:@- \
        -font unifont-Medium command.png

                                                                           

Changing to the unicode for the letter G works fine though:

$ printf "\u0047" | convert -size 100x100 label:@- \
       -font unifont-Medium command.png

                                                                           

I would post this question to the ImageMagick Discourse site to see why this is occurring. I can assist if you're unsure how to do this or proceed.

Debugging convert

You can add the -debug annotate switch to see what convert's up to.

Example

$ printf "\u2318" | convert -size 100x100 label:@- -font unifont-Medium -pointsize 40 -debug annotate command.png
2014-04-10T09:37:04-04:00 0:00.020 0.010u 6.7.8 Annotate convert[16619]: annotate.c/RenderFreetype/1220/Annotate
  Font /usr/share/fonts/msttcorefonts/arialbd.ttf; font-encoding none; text-encoding none; pointsize 12
2014-04-10T09:37:04-04:00 0:00.020 0.010u 6.7.8 Annotate convert[16619]: annotate.c/GetTypeMetrics/798/Annotate
  Metrics: text: ⌘; width: 6.375; height: 14; ascent: 11; descent: -3; max advance: 24; bounds: 0.625,0  6.78125,8; origin: 7,0; pixels per em: 12,12; underline position: -5.0625; underline thickness: 3.35938
2014-04-10T09:37:04-04:00 0:00.020 0.010u 6.7.8 Annotate convert[16619]: annotate.c/RenderFreetype/1220/Annotate
  Font /usr/share/fonts/msttcorefonts/arialbd.ttf; font-encoding none; text-encoding none; pointsize 12
2014-04-10T09:37:04-04:00 0:00.020 0.010u 6.7.8 Annotate convert[16619]: annotate.c/GetTypeMetrics/798/Annotate
  Metrics: text: ⌘; width: 6.375; height: 14; ascent: 11; descent: -3; max advance: 24; bounds: 0.625,0  6.78125,8; origin: 7,0; pixels per em: 12,12; underline position: -5.0625; underline thickness: 3.35938
2014-04-10T09:37:04-04:00 0:00.020 0.010u 6.7.8 Annotate convert[16619]: annotate.c/RenderFreetype/1220/Annotate
  Font /usr/share/fonts/msttcorefonts/arialbd.ttf; font-encoding none; text-encoding none; pointsize 24
2014-04-10T09:37:04-04:00 0:00.020 0.010u 6.7.8 Annotate convert[16619]: annotate.c/GetTypeMetrics/798/Annotate
  Metrics: text: ⌘; width: 12.75; height: 28; ascent: 22; descent: -5; max advance: 48; bounds: 1.25,0  13.5781,18; origin: 15,0; pixels per em: 24,24; underline position: -5.0625; underline thickness: 3.35938
2014-04-10T09:37:04-04:00 0:00.020 0.010u 6.7.8 Annotate convert[16619]: annotate.c/RenderFreetype/1220/Annotate
  Font /usr/share/fonts/msttcorefonts/arialbd.ttf; font-encoding none; text-encoding none; pointsize 48
2014-04-10T09:37:04-04:00 0:00.020 0.010u 6.7.8 Annotate convert[16619]: annotate.c/GetTypeMetrics/798/Annotate
  Metrics: text: ⌘; width: 25.5156; height: 55; ascent: 43; descent: -10; max advance: 96; bounds: 2.48438,0  27.1406,35.5; origin: 29,0; pixels per em: 48,48; underline position: -5.0625; underline thickness: 3.35938
2014-04-10T09:37:04-04:00 0:00.020 0.010u 6.7.8 Annotate convert[16619]: annotate.c/RenderFreetype/1220/Annotate
  Font /usr/share/fonts/msttcorefonts/arialbd.ttf; font-encoding none; text-encoding none; pointsize 96
2014-04-10T09:37:04-04:00 0:00.020 0.020u 6.7.8 Annotate convert[16619]: annotate.c/GetTypeMetrics/798/Annotate
  Metrics: text: ⌘; width: 53.0312; height: 110; ascent: 87; descent: -20; max advance: 192; bounds: 4.96875,0  54.2812,70; origin: 59,0; pixels per em: 96,96; underline position: -5.0625; underline thickness: 3.35938
2014-04-10T09:37:04-04:00 0:00.020 0.020u 6.7.8 Annotate convert[16619]: annotate.c/RenderFreetype/1220/Annotate
  Font /usr/share/fonts/msttcorefonts/arialbd.ttf; font-encoding none; text-encoding none; pointsize 96
2014-04-10T09:37:04-04:00 0:00.020 0.020u 6.7.8 Annotate convert[16619]: annotate.c/GetTypeMetrics/798/Annotate
  Metrics: text: ⌘; width: 53.0312; height: 110; ascent: 87; descent: -20; max advance: 192; bounds: 4.96875,0  54.2812,70; origin: 59,0; pixels per em: 96,96; underline position: -5.0625; underline thickness: 3.35938
2014-04-10T09:37:04-04:00 0:00.020 0.020u 6.7.8 Annotate convert[16619]: annotate.c/RenderFreetype/1220/Annotate
  Font /usr/share/fonts/msttcorefonts/arialbd.ttf; font-encoding none; text-encoding none; pointsize 95
2014-04-10T09:37:04-04:00 0:00.020 0.020u 6.7.8 Annotate convert[16619]: annotate.c/GetTypeMetrics/798/Annotate
  Metrics: text: ⌘; width: 52.0781; height: 109; ascent: 86; descent: -20; max advance: 190; bounds: 4.92188,0  53.7188,70; origin: 58,0; pixels per em: 95,95; underline position: -5.0625; underline thickness: 3.35938
2014-04-10T09:37:04-04:00 0:00.020 0.020u 6.7.8 Annotate convert[16619]: annotate.c/RenderFreetype/1220/Annotate
  Font /usr/share/fonts/msttcorefonts/arialbd.ttf; font-encoding none; text-encoding none; pointsize 94
2014-04-10T09:37:04-04:00 0:00.020 0.020u 6.7.8 Annotate convert[16619]: annotate.c/GetTypeMetrics/798/Annotate
  Metrics: text: ⌘; width: 51.1406; height: 108; ascent: 85; descent: -20; max advance: 188; bounds: 4.85938,0  53.1562,68; origin: 57,0; pixels per em: 94,94; underline position: -5.0625; underline thickness: 3.35938
2014-04-10T09:37:04-04:00 0:00.020 0.020u 6.7.8 Annotate convert[16619]: annotate.c/RenderFreetype/1220/Annotate
  Font /usr/share/fonts/msttcorefonts/arialbd.ttf; font-encoding none; text-encoding none; pointsize 93
2014-04-10T09:37:04-04:00 0:00.020 0.020u 6.7.8 Annotate convert[16619]: annotate.c/GetTypeMetrics/798/Annotate
  Metrics: text: ⌘; width: 51.1875; height: 107; ascent: 84; descent: -20; max advance: 186; bounds: 4.8125,0  52.5781,67; origin: 57,0; pixels per em: 93,93; underline position: -5.0625; underline thickness: 3.35938
2014-04-10T09:37:04-04:00 0:00.020 0.020u 6.7.8 Annotate convert[16619]: annotate.c/RenderFreetype/1220/Annotate
  Font /usr/share/fonts/msttcorefonts/arialbd.ttf; font-encoding none; text-encoding none; pointsize 92
2014-04-10T09:37:04-04:00 0:00.020 0.020u 6.7.8 Annotate convert[16619]: annotate.c/GetTypeMetrics/798/Annotate
  Metrics: text: ⌘; width: 50.2344; height: 106; ascent: 83; descent: -19; max advance: 184; bounds: 4.76562,0  52.0156,67; origin: 56,0; pixels per em: 92,92; underline position: -5.0625; underline thickness: 3.35938
2014-04-10T09:37:04-04:00 0:00.020 0.020u 6.7.8 Annotate convert[16619]: annotate.c/RenderFreetype/1220/Annotate
  Font /usr/share/fonts/msttcorefonts/arialbd.ttf; font-encoding none; text-encoding none; pointsize 91
2014-04-10T09:37:04-04:00 0:00.030 0.020u 6.7.8 Annotate convert[16619]: annotate.c/GetTypeMetrics/798/Annotate
  Metrics: text: ⌘; width: 50.2969; height: 105; ascent: 82; descent: -19; max advance: 182; bounds: 4.70312,0  51.4531,65.4688; origin: 56,0; pixels per em: 91,91; underline position: -5.0625; underline thickness: 3.35938
2014-04-10T09:37:04-04:00 0:00.030 0.020u 6.7.8 Annotate convert[16619]: annotate.c/RenderFreetype/1220/Annotate
  Font /usr/share/fonts/msttcorefonts/arialbd.ttf; font-encoding none; text-encoding none; pointsize 90
2014-04-10T09:37:04-04:00 0:00.030 0.020u 6.7.8 Annotate convert[16619]: annotate.c/GetTypeMetrics/798/Annotate
  Metrics: text: ⌘; width: 49.3438; height: 103; ascent: 81; descent: -19; max advance: 180; bounds: 4.65625,0  50.8906,65.4688; origin: 55,0; pixels per em: 90,90; underline position: -5.0625; underline thickness: 3.35938
2014-04-10T09:37:04-04:00 0:00.030 0.020u 6.7.8 Annotate convert[16619]: annotate.c/RenderFreetype/1220/Annotate
  Font /usr/share/fonts/msttcorefonts/arialbd.ttf; font-encoding none; text-encoding none; pointsize 89
2014-04-10T09:37:04-04:00 0:00.030 0.020u 6.7.8 Annotate convert[16619]: annotate.c/GetTypeMetrics/798/Annotate
  Metrics: text: ⌘; width: 48.3906; height: 102; ascent: 81; descent: -19; max advance: 178; bounds: 4.60938,0  50.3281,64; origin: 54,0; pixels per em: 89,89; underline position: -5.0625; underline thickness: 3.35938
2014-04-10T09:37:04-04:00 0:00.030 0.020u 6.7.8 Annotate convert[16619]: annotate.c/RenderFreetype/1220/Annotate
  Font /usr/share/fonts/msttcorefonts/arialbd.ttf; font-encoding none; text-encoding none; pointsize 88
2014-04-10T09:37:04-04:00 0:00.030 0.020u 6.7.8 Annotate convert[16619]: annotate.c/GetTypeMetrics/798/Annotate
  Metrics: text: ⌘; width: 48.4375; height: 101; ascent: 80; descent: -19; max advance: 176; bounds: 4.5625,0  49.7656,64; origin: 54,0; pixels per em: 88,88; underline position: -5.0625; underline thickness: 3.35938
2014-04-10T09:37:04-04:00 0:00.030 0.020u 6.7.8 Annotate convert[16619]: annotate.c/RenderFreetype/1220/Annotate
  Font /usr/share/fonts/msttcorefonts/arialbd.ttf; font-encoding none; text-encoding none; pointsize 87
2014-04-10T09:37:04-04:00 0:00.030 0.020u 6.7.8 Annotate convert[16619]: annotate.c/GetTypeMetrics/798/Annotate
  Metrics: text: ⌘; width: 47.5; height: 100; ascent: 79; descent: -18; max advance: 174; bounds: 4.5,0  49.1875,63; origin: 53,0; pixels per em: 87,87; underline position: -5.0625; underline thickness: 3.35938
2014-04-10T09:37:04-04:00 0:00.030 0.020u 6.7.8 Annotate convert[16619]: annotate.c/RenderFreetype/1220/Annotate
  Font /usr/share/fonts/msttcorefonts/arialbd.ttf; font-encoding none; text-encoding none; pointsize 86
2014-04-10T09:37:04-04:00 0:00.030 0.020u 6.7.8 Annotate convert[16619]: annotate.c/GetTypeMetrics/798/Annotate
  Metrics: text: ⌘; width: 47.5469; height: 99; ascent: 78; descent: -18; max advance: 172; bounds: 4.45312,0  48.625,63; origin: 53,0; pixels per em: 86,86; underline position: -5.0625; underline thickness: 3.35938
2014-04-10T09:37:04-04:00 0:00.030 0.020u 6.7.8 Annotate convert[16619]: annotate.c/RenderFreetype/1220/Annotate
  Font /usr/share/fonts/msttcorefonts/arialbd.ttf; font-encoding none; text-encoding none; pointsize 86
2014-04-10T09:37:04-04:00 0:00.030 0.020u 6.7.8 Annotate convert[16619]: annotate.c/GetTypeMetrics/798/Annotate
  Metrics: text: ⌘; width: 47.5469; height: 99; ascent: 78; descent: -18; max advance: 172; bounds: 4.45312,0  48.625,63; origin: 53,0; pixels per em: 86,86; underline position: -5.0625; underline thickness: 3.35938
2014-04-10T09:37:04-04:00 0:00.030 0.020u 6.7.8 Annotate convert[16619]: annotate.c/RenderFreetype/1220/Annotate
  Font /usr/share/fonts/msttcorefonts/arialbd.ttf; font-encoding none; text-encoding none; pointsize 86

UPDATE #1 - Debugging further

This issue was irking me so I think I've finally figured it out. The issue is the selection of the font, and it not being able to display that particular glyph.

1. First off you can use this command to see which fonts you have available within convert. So let's start there.

   $ convert -list font | head -8
   
   Path: /etc/ImageMagick/type-ghostscript.xml
     Font: AvantGarde-Book
       family: AvantGarde
       style: Normal
       stretch: Normal
       weight: 400
       glyphs: /usr/share/fonts/default/Type1/a010013l.pfb
       ...
   

   The above shows a sample, every font has lines similar to the above. Incidentally, running this command shows we have several hundred fonts:

   $ convert -list font | grep Font | wc -l
   262
   

2. Next we're going to go through the task of encoding our character, \u2318 using every font we have. This sounds complicated but is fairly trivial with some well thought out one liners via Bash.

   $ for i in $(convert -list font | grep Font | awk '{print $2}'); \
       do convert -font $i -pointsize 36 label:⌘  ${i}.gif;done
   

   This snippet will use a for loop to run through each font, running a modified version of your convert command.

3. Now we look through the results. Many of the fonts could not display this particular glyph but several could, which would seem to indicate that it's not necessarily a bug in ImageMagick, but rather a limitation of the fonts themselves. Here's a list of the fonts that I had that could display this glyph.

   • DejaVu-Sans-Bold
   • DejaVu-Sans-Bold-Oblique
   • DejaVu-Sans-Book
   • DejaVu-Sans-Condensed-Bold
   • DejaVu-Sans-Condensed-Bold-Oblique
   • DejaVu-Sans-Condensed
   • DejaVu-Sans-Condensed-Oblique
   • DejaVu-Sans-Mono-Bold
   • DejaVu-Sans-Mono-Bold-Oblique
   • DejaVu-Sans-Mono-Book
   • DejaVu-Sans-Mono-Oblique
   • DejaVu-Sans-Oblique
   • DejaVu-Serif-Bold
   • DejaVu-Serif-Bold-Italic
   • DejaVu-Serif-Book
   • DejaVu-Serif-Condensed-Bold
   • DejaVu-Serif-Condensed-Bold-Italic
   • DejaVu-Serif-Condensed
   • DejaVu-Serif-Condensed-Italic
   • DejaVu-Serif-Italic
   • FreeMono-Regular
   • FreeSerif-Regular
   • STIX-Math-Regular
   • STIX-Regular
   • VL-Gothic-regular

   I visually went through the entire ~260 resulting .gif files to determine which worked and which didn't. Here's a sample of a few of the ones that worked just so you can see them.

                                                           

References

• Unicode character table
• UTF-8 Gentoo Wiki
• Unicode Charts

Answer 2

Short answer: Pango

Use pango:⌘ instead of label:⌘. Pango uses fontconfig to find an appropriate font for each glyph.

convert -pointsize 128 pango:⌘ command.png

Explanation

Pango is a library for rendering text which ImageMagick can use. It has advantages and disadvantages compared to ImageMagick's label and -draw text. If a glyph does not exist in the chosen font, it will fallback to a different one. Pango uses fontconfig to choose an appropriate font.

Note that, instead of pasting in the desired glyph, one can specify the hexadecimal Unicode number using the $'\uXXXX' syntax available in Bash and other modern shells:

convert -pointsize 128 pango:$'\u2318' command.png

Fontconfig

Fontconfig can list which fonts can render a specific glyph by specifying a single Unicode character code as the character set:

$ fc-list :charset=2318


/usr/share/fonts/truetype/dejavu/DejaVuSerif-Bold.ttf: DejaVu Serif:style=Bold
/home/b9/.local/share/fonts/DaxlinePro-Light.otf: DaxlinePro,DaxlinePro\-Light:style=Light,Regular
/usr/share/fonts/truetype/dejavu/DejaVuSansMono.ttf: DejaVu Sans Mono:style=Book
/usr/share/fonts/truetype/dejavu/DejaVuSansCondensed-Oblique.ttf: DejaVu Sans,DejaVu Sans Condensed:style=Condensed Oblique,Oblique
/usr/share/fonts/truetype/dejavu/DejaVuSerifCondensed-BoldItalic.ttf: DejaVu Serif,DejaVu Serif Condensed:style=Condensed Bold Italic,Bold Italic
/usr/share/fonts/truetype/dejavu/DejaVuSans.ttf: DejaVu Sans:style=Book
/home/b9/.local/share/fonts/DaxlinePro-ExtraBold.otf: DaxlinePro,DaxlinePro\-ExtraBold:style=ExtraBold,Regular
/home/b9/.local/share/fonts/DaxlinePro-Bold.otf: DaxlinePro,DaxlinePro\-Bold:style=Bold,Regular
/usr/share/fonts/truetype/dejavu/DejaVuSerifCondensed.ttf: DejaVu Serif,DejaVu Serif Condensed:style=Condensed,Book
/usr/share/fonts/truetype/dejavu/DejaVuSerifCondensed-Italic.ttf: DejaVu Serif,DejaVu Serif Condensed:style=Condensed Italic,Italic
/home/b9/.local/share/fonts/DaxlinePro-Black.otf: DaxlinePro,DaxlinePro\-Black:style=Black,Regular
/usr/share/fonts/truetype/dejavu/DejaVuSerif-BoldItalic.ttf: DejaVu Serif:style=Bold Italic
/usr/share/fonts/truetype/dejavu/DejaVuSansMono-Oblique.ttf: DejaVu Sans Mono:style=Oblique
/usr/share/fonts/truetype/dejavu/DejaVuSerifCondensed-Bold.ttf: DejaVu Serif,DejaVu Serif Condensed:style=Condensed Bold,Bold
/usr/share/fonts/truetype/dejavu/DejaVuSans-Bold.ttf: DejaVu Sans:style=Bold
/usr/share/fonts/truetype/dejavu/DejaVuSansMono-BoldOblique.ttf: DejaVu Sans Mono:style=Bold Oblique
/usr/share/fonts/truetype/ancient-scripts/Symbola_hint.ttf: Symbola:style=Regular
/usr/share/fonts/truetype/dejavu/DejaVuSansCondensed-BoldOblique.ttf: DejaVu Sans,DejaVu Sans Condensed:style=Condensed Bold Oblique,Bold Oblique
/usr/share/fonts/truetype/dejavu/DejaVuSansCondensed.ttf: DejaVu Sans,DejaVu Sans Condensed:style=Condensed,Book
/usr/share/fonts/truetype/freefont/FreeSerif.ttf: FreeSerif:style=Regular,нормален,normal,obyčejné,Mittel,µεσαία,Normaali,Normál,Normale,Gemiddeld,odmiana zwykła,Обычный,Normálne,ปกติ,menengah,прямій,Navadno,vidējs,normalusis,عادی,vừa,Arrunta,सामान्य
/usr/share/fonts/opentype/freefont/FreeMono.otf: FreeMono:style=Regular,нормален,normal,obyčejné,Standard,µεσαία,Normaali,Normál,Normale,Standaard,Normalny,Обычный,Normálne,menengah,прямій,navadno,vidējs,normalusis,thường,Arrunta,सामान्य
/usr/share/fonts/truetype/dejavu/DejaVuSansCondensed-Bold.ttf: DejaVu Sans,DejaVu Sans Condensed:style=Condensed Bold,Bold
/usr/share/fonts/truetype/dejavu/DejaVuSansMono-Bold.ttf: DejaVu Sans Mono:style=Bold
/usr/share/fonts/truetype/dejavu/DejaVuSans-Oblique.ttf: DejaVu Sans:style=Oblique
/home/b9/.local/share/fonts/DaxlinePro-Regular.otf: DaxlinePro,DaxlinePro\-Regular:style=Regular
/home/b9/.local/share/fonts/DaxlinePro-Thin.otf: DaxlinePro,DaxlinePro\-Thin:style=Thin,Regular
/usr/share/fonts/truetype/dejavu/DejaVuSerif-Italic.ttf: DejaVu Serif:style=Italic
/usr/share/fonts/opentype/freefont/FreeSerif.otf: FreeSerif:style=Regular,нормален,normal,obyčejné,Mittel,µεσαία,Normaali,Normál,Normale,Gemiddeld,odmiana zwykła,Обычный,Normálne,ปกติ,menengah,прямій,Navadno,vidējs,normalusis,عادی,vừa,Arrunta,सामान्य
/home/b9/.local/share/fonts/DaxlinePro-Medium.otf: DaxlinePro,DaxlinePro\-Medium:style=Medium,Regular
/usr/share/fonts/truetype/unifont/unifont.ttf: Unifont:style=Regular
/usr/share/fonts/truetype/freefont/FreeMono.ttf: FreeMono:style=Regular,нормален,normal,obyčejné,Standard,µεσαία,Normaali,Normál,Normale,Standaard,Normalny,Обычный,Normálne,menengah,прямій,navadno,vidējs,normalusis,thường,Arrunta,सामान्य
/usr/share/fonts/truetype/dejavu/DejaVuSerif.ttf: DejaVu Serif:style=Book
/home/b9/.local/share/fonts/boecklinsuniverse/BoecklinsUniverse.ttf: Boecklins Universe:style=Regular
/usr/share/fonts/truetype/dejavu/DejaVuSans-BoldOblique.ttf: DejaVu Sans:style=Bold Oblique

One could use that information to try various fonts with ImageMagick to see how they look. For example,

convert -font Unifont -pointsize 128 pango:⌘ command.png

Ugrep (name subject to change)

For convenience, you may wish to use a script I wrote called ugrep (name subject to change) that lists which installed fonts contain a specific character using -l:

$ ugrep -l command key 
   ⌘    U+2318  PLACE OF INTEREST SIGN (command key)
                FreeMono 
                Unifont 
                Symbola 
                FreeSerif 
                DaxlinePro 
                Boecklins Universe 

Ugrep can also show a rendering of the character in each font, if your terminal supports sixel graphics, by using -Ln:

ugrep -L2 command key