blind-spectrum.1 - blind - suckless command-line video editing utility
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       blind-spectrum.1 (2266B)
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            1 .TH BLIND-SPECTRUM 1 blind
            2 .SH NAME
            3 blind-spectrum - Transform a gradient into a spectrum
            4 .SH SYNOPSIS
            5 .B blind-spectrum
            6 [-y]
            7 [-z
            8 .IR depth ]
            9 .I spectrum-stream
           10 .SH DESCRIPTION
           11 .B blind-spectrum
           12 reads a video from stdin, transforms it according
           13 to a colour table and prints the resulting video
           14 to stdout. The values of the colours, excluding
           15 the alpha channel, in stdin, are truncated to
           16 fit [0, 1]. The resulting values for each pixel
           17 is used to look up a colour in
           18 .I spectrum-stream
           19 for the same frame, with linear interpolation.
           20 That colour is used as the pixel's colour. The
           21 alpha values of the looked up colour and the
           22 pixel's original colour are multiplied, and the
           23 product is used as the pixel's alpha value.
           24 .P
           25 When looking up colours in
           26 .IR spectrum-stream ,
           27 the value of the first channel (the X channel)
           28 is multiplied by the width of the video in
           29 .I spectrum-stream
           30 less 1,
           31 the product is the column in
           32 .I spectrum-stream
           33 that will be used (using interpolation for
           34 none integer products), and the value of the first
           35 channel (the Y channel) is multiplied by the height
           36 of the video in
           37 .I spectrum-stream
           38 less 1, the product is the row in
           39 .I spectrum-stream
           40 that will be used.
           41 .SH OPTIONS
           42 .TP
           43 .B -y
           44 Rather than using the values of the three
           45 colour channels to look up a colour in a
           46 multidimensional table, the luma is used to
           47 look up a value in a singledimensional table.
           48 Which dimension is used does not matter; the
           49 result is unspecified if the colour table
           50 is multidimensional.
           51 .TP
           52 .BR -z \ \fIdepth\fP
           53 For each frame in stdin,
           54 .I depth
           55 frames are read from
           56 .IR spectrum-stream .
           57 When looking up colours in
           58 .IR spectrum-stream ,
           59 the value of the third channel (the > channel)
           60 is multiplied by
           61 .I depth
           62 less 1, the product is the frame
           63 in this set of
           64 .I depth
           65 frames from
           66 .I spectrum-stream
           67 that will be used.
           68 .SH SEE ALSO
           69 .BR blind (7),
           70 .BR blind-from-text (1),
           71 .BR blind-arithm (1),
           72 .BR blind-double-spectrum (1),
           73 .BR blind-round-wave (1),
           74 .BR blind-sawtooth-wave (1),
           75 .BR blind-sine-wave (1)
           76 .BR blind-sinc-wave (1),
           77 .BR blind-triangular-wave (1),
           78 .BR blind-cone-gradient (1),
           79 .BR blind-linear-gradient (1),
           80 .BR blind-radial-gradient (1),
           81 .BR blind-spiral-gradient (1),
           82 .BR blind-square-gradient (1)
           83 .SH AUTHORS
           84 Mattias Andrée
           85 .RI < maandree@kth.se >