Incorrect behavior of text=str.upper() in ImageDraw.Draw.text #5993

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1. radarhere

   changed the title [-]incorrect behavior of `text=str.upper()` in ImageDraw.Draw.text[/-] [+]Incorrect behavior of `text=str.upper()` in ImageDraw.Draw.text[/+] on Jan 27, 2022
2. radarhere commented on Jan 27, 2022

   

   radarhere

   on Jan 27, 2022

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   Hi. What font are you using?
3. radarhere

   added

   Font Rendering

   on Jan 27, 2022
4. chiboreache commented on Jan 27, 2022

   

   chiboreache

   on Jan 27, 2022

   Last edited by radarhere

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   I found similar behaviour in many fonts Code2000, DejaVuSans, DejaVuSerif, FreeSerif, FreeMonoBold ...
5. radarhere commented on Jan 27, 2022

   

   radarhere

   on Jan 27, 2022

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   As with #5948, it is important to understand that fonts do not automatically support every character you might try.

   Starting with code from https://stackoverflow.com/questions/4458696/finding-out-what-characters-a-given-font-supports and making changes, here is code (using fonttools rather than Pillow) that checks if the characters you are trying to draw are supported by the font.

   from itertools import chain
   from fontTools.ttLib import TTFont
   ttf = TTFont("Code2000.ttf", 0, allowVID=0, ignoreDecompileErrors=True, fontNumber=-1)
   chars = []
   for x in ttf["cmap"].tables:
       chars += [y[0] for y in x.cmap.items()]
   ttf.close()
   
   print("original string")
   text = 'ქართული'
   for letter in text:
       if ord(letter) in chars:
           print(letter, ord(letter), "is in font")
       else:
           print(letter, ord(letter), "is missing from font", ord(letter))
   
   print()
   print("uppercase string")
   text = text.upper()
   for letter in text:
       if ord(letter) in chars:
           print(letter, ord(letter), "is in font")
       else:
           print(letter, ord(letter), "is missing from font")

   Running the code, I get

   original string
   ქ 4325 is in font
   ა 4304 is in font
   რ 4320 is in font
   თ 4311 is in font
   უ 4323 is in font
   ლ 4314 is in font
   ი 4312 is in font
   
   uppercase string
   Ქ 7333 is missing from font
   Ა 7312 is missing from font
   Რ 7328 is missing from font
   Თ 7319 is missing from font
   Უ 7331 is missing from font
   Ლ 7322 is missing from font
   Ი 7320 is missing from font
   

   So I conclude that the font is missing the 'upper' version of your characters.
   For example, https://www.compart.com/en/unicode/U+10E5 is supported by Code2000, but https://www.compart.com/en/unicode/U+1CA5 is not.

   👍React with 👍1Reacted by chiboreache

   🚀React with 🚀1Reacted by chiboreache
6. chiboreache commented on Jan 27, 2022

   

   chiboreache

   on Jan 27, 2022

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   it would be nice to have built in char checker, but whatever, thank you @radarhere !
7. chiboreache

   closed this as completedon Jan 27, 2022