.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 alpha-stream , the remainder or stdin is printed without any changes. If stdin is shorter than .IR alpha-stream , the remainder of .I alpha-stream is ignored but may be partially read. .SH AUTHORS Mattias Andree .RI < maandree@kth.se >