Created an attachment (id=19607)
Comparing HINT_NONE to HINT_SLIGHT
> I would guess this is because it is important for a PDF viewer to give an
> accurate reproduction of a printed page, and the purpose of hinting is to
> sacrifice accurate metrics and color for increased contrast.
>
> Since the legacy LCD filter (FC_LCD_LEGACY / FT_LCD_FILTER_LEGACY /
> CAIRO_LCD_FILTER_DEFAULT(!)) adds bad color fringing to unhinted text, it might
> be a good idea to also ensure that the LCD filter is FC_LCD_DEFAULT or
> FC_LCD_LIGHT.
>
This is interesting. I didn’t realize that Poppler disables hinting. It’s true that full hinting would alter the positioning due to the pixel snapping, but fortunately HINT_SLIGHT does not, because it only hints in the vertical axis to reduce smear on horizontal strokes.
Combined with the so called DEFAULT LCD filter HINT_SLIGHT gives really nice results -- without affecting the positioning. See the attachment.
Created an attachment (id=19607)
Comparing HINT_NONE to HINT_SLIGHT
> I would guess this is because it is important for a PDF viewer to give an FILTER_ LEGACY / FILTER_ DEFAULT( !)) adds bad color fringing to unhinted text, it might
> accurate reproduction of a printed page, and the purpose of hinting is to
> sacrifice accurate metrics and color for increased contrast.
>
> Since the legacy LCD filter (FC_LCD_LEGACY / FT_LCD_
> CAIRO_LCD_
> be a good idea to also ensure that the LCD filter is FC_LCD_DEFAULT or
> FC_LCD_LIGHT.
>
This is interesting. I didn’t realize that Poppler disables hinting. It’s true that full hinting would alter the positioning due to the pixel snapping, but fortunately HINT_SLIGHT does not, because it only hints in the vertical axis to reduce smear on horizontal strokes.
Combined with the so called DEFAULT LCD filter HINT_SLIGHT gives really nice results -- without affecting the positioning. See the attachment.