How I can load a font file with PIL.ImageFont.truetype without specifying the absolute path?

To me worked this on xubuntu:

from PIL import Image,ImageDraw,ImageFont

# sample text and font
unicode_text = u"Hello World!"
font = ImageFont.truetype("/usr/share/fonts/truetype/freefont/FreeMono.ttf", 28, encoding="unic")

# get the line size
text_width, text_height = font.getsize(unicode_text)

# create a blank canvas with extra space between lines
canvas = Image.new('RGB', (text_width + 10, text_height + 10), "orange")

# draw the text onto the text canvas, and use black as the text color
draw = ImageDraw.Draw(canvas)
draw.text((5,5), u'Hello World!', 'blue', font)

# save the blank canvas to a file
canvas.save("unicode-text.png", "PNG")
canvas.show()

Windows version

from PIL import Image, ImageDraw, ImageFont

unicode_text = u"Hello World!"
font = ImageFont.truetype("arial.ttf", 28, encoding="unic")
text_width, text_height = font.getsize(unicode_text)
canvas = Image.new('RGB', (text_width + 10, text_height + 10), "orange")
draw = ImageDraw.Draw(canvas)
draw.text((5, 5), u'Hello World!', 'blue', font)
canvas.save("unicode-text.png", "PNG")
canvas.show()

The output is the same as above

According to the PIL documentation, only Windows font directory is searched:

On Windows, if the given file name does not exist, the loader also looks in Windows fonts directory.

http://effbot.org/imagingbook/imagefont.htm

So you need to write your own code to search for the full path on Linux.

However, Pillow, the PIL fork, currently has a PR to search a Linux directory. It's not exactly clear yet which directories to search for all Linux variants, but you can see the code here and perhaps contribute to the PR:

https://github.com/python-pillow/Pillow/pull/682

On mac, I simply copy the font file Arial.ttf to the project directory and everything works.