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Diffstat (limited to 'LIBCOLOUR_YDBDR.7')
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diff --git a/LIBCOLOUR_YDBDR.7 b/LIBCOLOUR_YDBDR.7 new file mode 100644 index 0000000..6281813 --- /dev/null +++ b/LIBCOLOUR_YDBDR.7 @@ -0,0 +1,64 @@ +.TH LIBCOLOUR_YDBDR 7 libcolour +.SH NAME +LIBCOLOUR_YDBDR - YDbDr +.SH DESCRIPTION +YDbDr colours are presented with either of +.nf + + \fBtypedef struct libcolour_ydbdr_f libcolour_ydbdr_f_t;\fP + \fBtypedef struct libcolour_ydbdr_lf libcolour_ydbdr_lf_t;\fP + \fBtypedef struct libcolour_ydbdr_llf libcolour_ydbdr_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_ydbdr_f +is defined as +.nf + + \fBstruct libcolour_ydbdr_f {\fP + \fBenum libcolour_model\fP \fImodel\fP\fB;\fP + \fBfloat\fP \fIY\fP\fB;\fP + \fBfloat\fP \fIDb\fP\fB;\fP + \fBfloat\fP \fIDr\fP\fB;\fP + \fB};\fP + +.fi +.I .model +shall be set to +.BR LIBCOLOUR_YDBDR . +In +.BR union\ libcolour_colour_f , +.BR union\ libcolour_colour_lf , +and +.BR union\ libcolour_colour_llf , +.I .ydbdr +is used for YDbDr colours. +.P +.IR .Y , +.IR .Db , +and +.I .Dr +hold the Y (luma), Db, and Dr values, respectively. +.P +Y is 0 in black and 1 in white. +Db is the difference (with a factor) between Y and blue. +Dr is the difference (with a factor) between Y and red. +.P +YDbDr is additive, since it is linearly isomorphic +to CIE 1931 XYZ. It's white point is the +CIE Standard Illuminant D65. Additionally, conversion +between YDbDr and YUV is done with a diagonal matrix +multiplication. +.SH SEE ALSO +.BR libcolour (7) +.SH AUTHORS +Mattias Andrée +.RI < maandree@kth.se > |