.TH LIBCOLOUR_GET_RGB_COLOUR_SPACE 3 libcolour
.SH NAME
libcolour_get_rgb_colour_space - Select RGB colour space
.SH SYNOPSIS
.nf
#include <libcolour.h>

int \fBlibcolour_get_rgb_colour_space_f\fP(libcolour_rgb_f_t *\fIcolour\fP,
                                     libcolour_rgb_colour_space_t \fIspace\fP);
int \fBlibcolour_get_rgb_colour_space_lf\fP(libcolour_rgb_lf_t *\fIcolour\fP,
                                      libcolour_rgb_colour_space_t \fIspace\fP);
int \fBlibcolour_get_rgb_colour_space_llf\fP(libcolour_rgb_llf_t *\fIcolour\fP,
                                       libcolour_rgb_colour_space_t \fIspace\fP);

#define \fBlibcolour_get_rgb_colour_space\fP(\fIcolour\fP, \fIspace\fP)\\
	(_Generic((\fIcolour\fP),\\
	          libcolour_rgb_f_t *:   \fBlibcolour_get_rgb_colour_space_f\fP(\fIcolour\fP, \fIspace\fP),\\
	          libcolour_rgb_lf_t *:  \fBlibcolour_get_rgb_colour_space_lf\fP(\fIcolour\fP, \fIspace\fP),\\
	          libcolour_rgb_llf_t *: \fBlibcolour_get_rgb_colour_space_llf\fP(\fIcolour\fP, \fIspace\fP)))
	          /* list is incomplete */
.fi
.SH DESCRIPTION
.B libcolour_get_rgb_colour_space
Sets the members of
.I colour
that specifies the colour space and transfer
function according the specified RGB colour
.IR space .
.P
The recognised RGB colour spaces are:
.TP
.B LIBCOLOUR_RGB_COLOUR_SPACE_SRGB
The sRGB colour space.
.TP
.B LIBCOLOUR_RGB_COLOUR_SPACE_ADOBE_RGB
The Adobe RGB colour space.
.TP
.B LIBCOLOUR_RGB_COLOUR_SPACE_APPLE_RGB
The Apple RGB (1998) colour space.
.TP
.B LIBCOLOUR_RGB_COLOUR_SPACE_BEST_RGB
The Best RGB colour space.
.TP
.B LIBCOLOUR_RGB_COLOUR_SPACE_BETA_RGB
The Beta RGB colour space.
.TP
.B LIBCOLOUR_RGB_COLOUR_SPACE_BRUCE_RGB
The Bruce RGB colour space.
.TP
.B LIBCOLOUR_RGB_COLOUR_SPACE_CIE_RGB
The CIE 1931 RGB colour space.
.TP
.B LIBCOLOUR_RGB_COLOUR_SPACE_COLORMATCH_RGB
The ColorMatch RGB colour space.
.TP
.B LIBCOLOUR_RGB_COLOUR_SPACE_DCI_P3_D65
The DCI-P3 D65 colour space.
.TP
.B LIBCOLOUR_RGB_COLOUR_SPACE_DCI_P3_THEATER
The DCI-P3 Theater colour space.
.TP
.B LIBCOLOUR_RGB_COLOUR_SPACE_DON_RGB_4
The Don RGB 4 colour space.
.TP
.B LIBCOLOUR_RGB_COLOUR_SPACE_ECI_RGB
The ECI RGB colour space.
.TP
.B LIBCOLOUR_RGB_COLOUR_SPACE_ECI_RGB_V2
The ECI RGB v2 colour space.
.TP
.B LIBCOLOUR_RGB_COLOUR_SPACE_EKTA_SPACE_PS5
The Ekta Space PS5 colour space.
.TP
.B LIBCOLOUR_RGB_COLOUR_SPACE_ITU_R_BT_601_625_LINE
The ITU-R Recommendation BT.601, 625 line colour space.
.TP
.B LIBCOLOUR_RGB_COLOUR_SPACE_ITU_R_BT_601_525_LINE
The ITU-R Recommendation BT.601, 525 line colour space.
.TP
.B LIBCOLOUR_RGB_COLOUR_SPACE_ITU_R_BT_709
The ITU-R Recommendation BT.709 colour space.
.TP
.B LIBCOLOUR_RGB_COLOUR_SPACE_ITU_R_BT_2020
The ITU-R Recommendation BT.2020 colour space.
.TP
.B LIBCOLOUR_RGB_COLOUR_SPACE_ITU_R_BT_2100_EOTF_PQ
The ITU-R Recommendation BT.2100 colour space, using the
perceptual quantization (PQ) elctro-optical transfer function (EOTF).
.TP
.B LIBCOLOUR_RGB_COLOUR_SPACE_ITU_R_BT_2100_OOTF_PQ
The ITU-R Recommendation BT.2100 colour space, using the
perceptual quantization (PQ) opto-optical transfer function (OOTF).
.TP
.B LIBCOLOUR_RGB_COLOUR_SPACE_ITU_R_BT_2100_OETF_PQ
The ITU-R Recommendation BT.2100 colour space, using the
perceptual quantization (PQ) opto-electronic transfer function (OETF).
.TP
.B LIBCOLOUR_RGB_COLOUR_SPACE_ITU_R_BT_2100_EOTF_HLG
The ITU-R Recommendation BT.2100 colour space, using the
Hybrid Log-Gamma (HLG) elctro-optical transfer function (EOTF).
.TP
.B LIBCOLOUR_RGB_COLOUR_SPACE_ITU_R_BT_2100_OOTF_HLG
The ITU-R Recommendation BT.2100 colour space, using the
Hybrid Log-Gamma (HLG) opto-optical transfer function (OOTF).
.TP
.B LIBCOLOUR_RGB_COLOUR_SPACE_ITU_R_BT_2100_OETF_HLG
The ITU-R Recommendation BT.2100 colour space, using the
Hybrid Log-Gamma (HLG) opto-electronic transfer function (OETF).
.TP
.B LIBCOLOUR_RGB_COLOUR_SPACE_LIGHTROOM_RGB
The Lightroom RGB colour space.
.TP
.B LIBCOLOUR_RGB_COLOUR_SPACE_NTSC_RGB
The NTSC RGB colour space.
.TP
.B LIBCOLOUR_RGB_COLOUR_SPACE_PAL_SECAM_RGB
The PAL/SECAM RGB colour space.
.TP
.B LIBCOLOUR_RGB_COLOUR_SPACE_PROPHOTO_RGB
The ProPhoto RGB colour space.
.TP
.B LIBCOLOUR_RGB_COLOUR_SPACE_SGI_RGB
The SGI RGB colour space.
.TP
.B LIBCOLOUR_RGB_COLOUR_SPACE_SMPTE_240M_RGB
The SMPTE 240M RGB colour space.
.TP
.B LIBCOLOUR_RGB_COLOUR_SPACE_SMPTE_C_RGB
The SMPTE C RGB colour space.
.TP
.B LIBCOLOUR_RGB_COLOUR_SPACE_WIDE_GAMUT_RGB
The wide-gamut RGB colour space, also known as Adobe Wide Gamut RGB.
.P
Additionally, it is possible to select a custom RGB
colour space by setting
.I space
to one of the following values:
.TP
.B LIBCOLOUR_RGB_COLOUR_SPACE_CUSTOM_FROM_MEASUREMENTS
The colour space is derived from the values of
.IR colour->red ,
.IR colour->green ,
.IR colour->blue ,
.IR colour->white ,
.IR colour->white_r ,
.IR colour->white_g ,
and
.IR colour->white_b .
The transfer functions, and parameters, must be set
manually.
.I colour->colour_space
must be set to any negative value,
.B LIBCOLOUR_RGB_COLOUR_SPACE_CUSTOM_FROM_MEASUREMENTS
(zero),
.BR LIBCOLOUR_RGB_COLOUR_SPACE_CUSTOM_FROM_MATRIX ,
or
.BR LIBCOLOUR_RGB_COLOUR_SPACE_CUSTOM_FROM_INV_MATRIX .
.IR colour->red.Y ,
.IR colour->green.Y ,
.IR colour->blue.Y
can be any value, the function will set them to
the correct value.
.TP
.B LIBCOLOUR_RGB_COLOUR_SPACE_CUSTOM_FROM_MATRIX
The colour space is derived from the values of
.IR colour->M ,
.IR colour->white_r ,
.IR colour->white_g ,
and
.IR colour->white_b .
The transfer functions, and parameters, must be set
manually.
.I colour->colour_space
must be set to any negative value,
.B LIBCOLOUR_RGB_COLOUR_SPACE_CUSTOM_FROM_MEASUREMENTS
(zero),
.BR LIBCOLOUR_RGB_COLOUR_SPACE_CUSTOM_FROM_MATRIX ,
or
.BR LIBCOLOUR_RGB_COLOUR_SPACE_CUSTOM_FROM_INV_MATRIX .
.TP
.B LIBCOLOUR_RGB_COLOUR_SPACE_CUSTOM_FROM_INV_MATRIX
The colour space is derived from the values of
.IR colour->Minv ,
.IR colour->white_r ,
.IR colour->white_g ,
and
.IR colour->white_b .
The transfer functions, and parameters, must be set
manually.
.I colour->colour_space
must be set to any negative value,
.B LIBCOLOUR_RGB_COLOUR_SPACE_CUSTOM_FROM_MEASUREMENTS
(zero),
.BR LIBCOLOUR_RGB_COLOUR_SPACE_CUSTOM_FROM_MATRIX ,
or
.BR LIBCOLOUR_RGB_COLOUR_SPACE_CUSTOM_FROM_INV_MATRIX .
.SH RETURN VALUES
Upon successful completion, the functions returns 0.
Otherwise the function return -1 with
.I errno
set to indicate the error.
.SH ERRORS
.TP
.B EDOM
The function tried to invert an non-invertable matrix.
.TP
.B EINVAL
.I space
does not refer to a recognised RGB colour space.
.SH SEE ALSO
.BR libcolour (7),
.BR LIBCOLOUR_RGB (7)
.SH AUTHORS
Mattias Andrée
.RI < maandree@kth.se >