Thanks for reading the email! I am an algorithm engineer in image processing.Here I have some question to ask you (maybe about the history of these algorithm ) and I also download the free type source and simply read it.I also have some idea about the algorithm,or we can discuss it.
Background On the tradition screen,one pixel have R/G/B three sub pixel. Some algorithm like Microsoft ClearType.(Here some paper like displaced filtering for patterned display it calculate the minimum perceptual color error) .I think these algorithm designed for "font display". Here my job is to research the panel sub pixel arrangement and sub pixel rendering for oled screen.As we all know,Samsung have the Pentile arrangment in RGBG which one pixel have only two sub pixel. Question: 1.what does mac or apple system using for "font display".Is that the “truetype”？ 2.ClearType using 3 channel to calculate the rendering font.I can't understand it. I also see the freetype code doing like this.If you want get the result R'/G'/B",the basic filter is like this R' R coeff00 coeff01 coeff02 G' = [G] * [coeff10 coeff11 coeff22] B' B coeff20 coeff21 coeff22 Here each coeff is a filter,where coeff00 coeff11 coeff12 maybe the low-pass filter ,others may be the Hight-pass filter. but does it cause color fringing? If we calculate lick this: R' = R' * [coeff00 coeff01 coeff02] R' = R' * [coeff00 coeff01 coeff02] R' = R' * [coeff00 coeff01 coeff02] Here each coeff is only a digital number and sum(coeff00 + coeff01 + coeff02 = 1<<n) does it better? 3.Because the ClearType only do the horizontal so some Vertical Shape may have sawtooth？There are many reason：1. horizontal have three subpixel ;2.human visual system are sensitive to the horzontal direction. Cause I am not good at English. Thank you very much for discussing. Best regrads! NAME：ZeyuNiu TEL：+86-18665844648
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