How to get the font pixel height using PIL's ImageFont class?

Question

I am using PIL' ImageFont module to load fonts to generate text images. I want the text to tightly bound to the edge, however, when using the ImageFont to get the font height, It seems that it includes the character's padding. As the red rectangle indicates.

c = 'A'
font = ImageFont.truetype(font_path, font_size)
width = font.getsize(c)[0]
height = font.getsize(c)[1]
im = Image.new("RGBA", (width, height), (0, 0, 0))
draw = ImageDraw.Draw(im)
draw.text((0, 0), 'A', (255, 255, 255), font=font)
im.show('charimg')

If I can get the actual height of the character, then I could skip the bounding rows in the bottom rectangle, could this info got from the font? Thank you.

Answer 1

Exact size depends on many factors. I'll just show you how to calculate different metrics of font.

font = ImageFont.truetype('arial.ttf', font_size)
ascent, descent = font.getmetrics()
(width, baseline), (offset_x, offset_y) = font.font.getsize(text)

• Height of red area: offset_y
• Height of green area: ascent - offset_y
• Height of blue area: descent
• Black rectangle: font.getmask(text).getbbox()

Hope it helps.