.TH BLIND-INVERT-LUMA 1 blind
.SH NAME
blind-invert-luma - Invert the luminosity of a video
.SH SYNOPSIS
.B blind-invert-luma
[-iw]
.I mask-stream
.SH DESCRIPTION
.B blind-invert-luma
reads a video from stdin and a mask video from
.IR mask-stream .
The video is printed to stdout, with the luminosity
inverted where, in
.IR mask-stream ,
the product of the luminosity and the alpha value is
1, and unchanged where the product is 0. For other
products, the result is linearly interpolated or
linearly extrapolated.
.P
If stdin is longer than
.IR mask-stream ,
the remainder or stdin is printed without any changes.
If stdin is shorter than
.IR mask-stream ,
the remainder of
.I mask-stream
is ignored but may be partially read.
.SH OPTIONS
.TP
.B -i
Invert the luminosity in
.I mask-stream
before calculating the product of the luminosity and
the alpha value.
.TP
.B -w
Instead of using CIE Standard Illuminant D65 as the
whitepoint, use the X and Z from each pixel in
.I mask-stream
for the whitepoint.
.SH SEE ALSO
.BR blind (7),
.BR blind-single-colour (1),
.BR blind-arithm (1),
.BR blind-set-alpha (1),
.BR blind-set-luma (1),
.BR blind-set-saturation (1)
.SH AUTHORS
Mattias Andrée
.RI < maandree@kth.se >