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Diffstat (limited to 'LIBCOLOUR_YIQ.7')
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diff --git a/LIBCOLOUR_YIQ.7 b/LIBCOLOUR_YIQ.7 new file mode 100644 index 0000000..e618217 --- /dev/null +++ b/LIBCOLOUR_YIQ.7 @@ -0,0 +1,65 @@ +.TH LIBCOLOUR_YIQ 7 libcolour +.SH NAME +LIBCOLOUR_YIQ - YIQ +.SH DESCRIPTION +YIQ colours are presented with either of +.nf + + \fBtypedef struct libcolour_yiq_f libcolour_yiq_f_t;\fP + \fBtypedef struct libcolour_yiq_lf libcolour_yiq_lf_t;\fP + \fBtypedef struct libcolour_yiq_llf libcolour_yiq_llf_t;\fP + +.fi +These +.BR struct s +use +.BR float , +.BR double , +and +.BR long\ double , +respecitively, for the values stored in them, +and are otherwise identical. +.B struct libcolour_yiq_f +is defined as +.nf + + \fBstruct libcolour_yiq_f {\fP + \fBenum libcolour_model\fP \fImodel\fP\fB;\fP + \fBfloat\fP \fIY\fP\fB;\fP + \fBfloat\fP \fII\fP\fB;\fP + \fBfloat\fP \fIQ\fP\fB;\fP + \fB};\fP + +.fi +.I .model +shall be set to +.BR LIBCOLOUR_YIQ . +In +.BR union\ libcolour_colour_f , +.BR union\ libcolour_colour_lf , +and +.BR union\ libcolour_colour_llf , +.I .yiq +is used for YIQ colours. +.P +.IR .Y , +.IR .I , +and +.I .Q +hold the Y (luma), I (in-phase), and +Q (quadrature) values, respectively. +.P +Y is 0 in black and 1 in white. +Negative I values are blue, +positive I values are orange. +Negative Q values are green, +positive Q values are purple. +.P +YIQ is additive, since it is linearly isomorphic +to CIE 1931 XYZ. It's white point is the +CIE Standard Illuminant D65. +.SH SEE ALSO +.BR libcolour (7) +.SH AUTHORS +Mattias Andrée +.RI < maandree@kth.se > |