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Dfarr.1
Dfarr.1
Associate III
August 13, 2021
Question

Font Dither Adjustment

  • August 13, 2021
  • 1 reply
  • 1131 views

I am having a problem with on-screen fonts. The dither/font-smoothing applied to the fonts eats into thin segments of the characters too much. This causes them to be too dim on screen for my application.

I've managed to show that the problem clears up if I use the BOLD version of the same font when defining my typographies, so it seems related to how the dither algorithm behaves around thin sections of characters.

When BOLD, the dither doesn't touch the core of the character at all, its a bright, solid colour. When not bolded, there are lots of little tracks of dim pixels winding through the main body of the character.

I would prefer not to resort to using the BOLD typeface everywhere if possible.

Are there any settings I can adjust to "sharpen" the text or limit how much dither bleeds into the body of the character? I'm running 4.15.0.

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1 reply

Dfarr.1
Dfarr.1Author
Associate III
August 16, 2021

I may have found a possible cause.

My MX configuration had what seems like a random arrangement of LOW and VERY HIGH for the maximum output speed of the LTDC GPIO pins (this was auto-generated by MX, frustrating). This translates into low/high slew rates, some of which were on color bits, some on clocks! This was definitely causing stray pixels to appear beside the text. But it may also have caused other pixel color data to "drift east" on the display, leading to darker spots in the text as well as stray pixels to the right of the text.

Seems to agree with what I was seeing, but I still need to finish the numerical measurement of the character brightness to be certain. Will report back.

Seeing no responses yet, does that mean there are no adjustments that can be made to the font smoothing/dither?

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