.TH BLIND-SET-LUMA 1 blind
.SH NAME
blind-set-luma - Multiply the luminosity of a video
.SH SYNOPSIS
.B blind-set-luma
.I luma-stream
.SH DESCRIPTION
.B blind-set-luma
reads a video from stdin and a mask video from
.IR luma-stream .
The video is printed to stdout, with the luminosity
of each pixel multiplied by the product of the
luminosity and the alpha value of the corresponding
pixel and frame in the mask video.
.P
If stdin is longer than
.IR luma-stream ,
the remainder or stdin is printed without any changes.
If stdin is shorter than
.IR luma-stream ,
the remainder of
.I luma-stream
is ignored but may be partially read.
.SH NOTES
In most cases, this is not what you want to use, instead
you probably want to use
.BR blind-arithm (1)
to multiple the X, Y and Z values on one value. This
produces the same affect as reducing the intensity of
the light sources, which is not what
.B blind-set-luma
does.
.SH AUTHORS
Mattias Andrée
.RI < maandree@kth.se >