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| author | Mattias Andrée <maandree@kth.se> | 2016-12-17 14:37:48 +0100 |
|---|---|---|
| committer | Mattias Andrée <maandree@kth.se> | 2016-12-17 14:37:48 +0100 |
| commit | c72ccb7d2cec01c8a614ef6746733dc8f66bb468 (patch) | |
| tree | 2dbd7cdd43fb42ba6d65e4bba88fb2f00f9f4135 | |
| parent | more direction conversions (diff) | |
| download | libcolour-c72ccb7d2cec01c8a614ef6746733dc8f66bb468.tar.gz libcolour-c72ccb7d2cec01c8a614ef6746733dc8f66bb468.tar.bz2 libcolour-c72ccb7d2cec01c8a614ef6746733dc8f66bb468.tar.xz | |
Implement OEFT HLG
Signed-off-by: Mattias Andrée <maandree@kth.se>
| -rw-r--r-- | src/libcolour.c | 27 |
1 files changed, 26 insertions, 1 deletions
diff --git a/src/libcolour.c b/src/libcolour.c index 60dab61..57f1e80 100644 --- a/src/libcolour.c +++ b/src/libcolour.c @@ -296,6 +296,28 @@ static double invtransfer_function_l_star(double t) return t * sign; } +static double transfer_function_oetf_hlg(double t) +{ + double sign = 1; + if (t < 0) { + t = -t; + sign = -1; + } + t = 12 * t <= 1 ? sqrt(3 * t) : 0.17883277 * log(t - 0.02372241) + 1.004293468902569985701234145381; + return t * sign; +} + +static double invtransfer_function_oetf_hlg(double t) +{ + double sign = 1; + if (t < 0) { + t = -t; + sign = -1; + } + t = t <= 0.5 ? t * t / 3 : exp(t - 1.004293468902569985701234145381) / 0.17883277 + 0.02372241; + return t * sign; +} + static void get_transfer_function(libcolour_colour_t* cs) { @@ -310,9 +332,12 @@ static void get_transfer_function(libcolour_colour_t* cs) case LIBCOLOUR_RGB_COLOUR_SPACE_ITU_R_BT_2100_OETF_PQ: case LIBCOLOUR_RGB_COLOUR_SPACE_ITU_R_BT_2100_EOTF_HLG: case LIBCOLOUR_RGB_COLOUR_SPACE_ITU_R_BT_2100_OOTF_HLG: - case LIBCOLOUR_RGB_COLOUR_SPACE_ITU_R_BT_2100_OETF_HLG: /* TODO http://www.itu.int/dms_pubrec/itu-r/rec/bt/R-REC-BT.2100-0-201607-I!!PDF-E.pdf */ break; + case LIBCOLOUR_RGB_COLOUR_SPACE_ITU_R_BT_2100_OETF_HLG: + cs->rgb.to_encoded_red = cs->rgb.to_encoded_green = cs->rgb.to_encoded_blue = transfer_function_oetf_hlg; + cs->rgb.to_decoded_red = cs->rgb.to_decoded_green = cs->rgb.to_decoded_blue = invtransfer_function_oetf_hlg; + break; default: break; } |