On Mon, Apr 07, 2014 at 07:56:34PM +0200, Werner LEMBERG wrote:
http://en.wikipedia.org/wiki/Subpixel_rendering#Patents
It is very often confused with bytecode interpreter patent.
As far as I know, this only affects the colour filter. Sub-pixel rendering itself can't be patented since it is prior art.
Thanks Werner for poiting it out. I would like to now more, could you please elaborate? 'Technical' point of view. What is colour filter and how it can be chosen? By FT_LCD_FILTER_*? Which is actually harmless one? Legal point of view. How that corresponds to "Due to PATENTS covering subpixel rendering, this function doesn't do anything except returning ‘FT_Err_Unimplemented_Feature’ if the configuration macro FT_CONFIG_OPTION_SUBPIXEL_RENDERING is not defined in your build of the library, which should correspond to all default builds of FreeType." from FreeType2 manual? Why FT_CONFIG_OPTION_SUBPIXEL_RENDERING is off by default? Where we can read more? Thanks for any pointers! Petr