blind-chroma-key.1 (1247B)
1 .TH BLIND-CHROMA-KEY 1 blind 2 .SH NAME 3 blind-chroma-key - Replace a colour range with transparency 4 .SH SYNOPSIS 5 .B blind-chroma-key 6 .I key-stream 7 .SH DESCRIPTION 8 .B blind-chroma-key 9 reads a video from stdin and colours from 10 .IR key-stream . 11 Each frame in 12 .I key-stream 13 should contain exactly two pixels. The colour of 14 the first pixel, and all colours with a distance 15 from that colour upto the same distance the colour 16 of the second pixel has to that colour, will be 17 turned into transparency in the video from stdin, 18 and the resulting video will be printed to stdout. 19 .P 20 If the two colours in a frame from 21 .I key-stream 22 have the same alpha value, all matching colours 23 will be turned into full transparency. Otherwise, 24 the colours matching the first colour will be 25 given the transparency specified with the first 26 colour, all other matching colours will have 27 a transparency between to two specified alpha 28 values. However, if alpha value of the second 29 colour is less than the alpha value of the first 30 colour, twos alpha values are inverted. 31 .SH SEE ALSO 32 .BR blind (7), 33 .BR blind-from-text (1), 34 .BR blind-colour-ciexyz (1), 35 .BR blind-colour-srgb (1), 36 .BR blind-dual-key (1), 37 .BR blind-primary-key (1) 38 .SH AUTHORS 39 Mattias Andrée 40 .RI < maandree@kth.se >