ff-frhs.1

.Dd 2024-05-07
.Dt FF-FRHS 1
.Os farbfeld-utils
.Sh NAME
.Nm ff-frhs
.Nd farbfeld filter that converts HSV colours to RGB
.Sh SYNOPSIS
.Nm
<mode>
.Sh DESCRIPTION
.Nm
reads HSV colour information from stdin, converts it to
.Xr farbfeld 5
RGB and writes the result to stdout.
.Pp
HSV is short for hue, saturation and value.
.Pp
See
.Xr ff-tohs 1
for how to convert RGB colours to HSV.
.Pp
It may not be the intended usage, but you can try passing a normal image
through this filter for interesting effects.
.Pp
In case of an error
.Nm
writes a diagnostic message to stderr.
.Sh EXIT STATUS
.Bl -tag -width Ds
.It 0
Image processed successfully.
.It 1
An error occurred.
.El
.Sh OPTIONS
The filter takes exactly one argument which is the mode.

The available modes are:
   i --
   l --
   v --
   - -- no mode (do not use any of the above modes)

The modes affect how the HSV input is converted to RGB.
.Sh REFERENCES
https://en.wikipedia.org/wiki/HSL_and_HSV
.Sh EXAMPLES
$
.Nm
< hsv.dat > rgb.ff
.Pp
$
.Nm
< image.ff > image-hsv.ff
.Sh SEE ALSO
.Xr ff-tohs 1 ,
.Xr farbfeld 5 ,
.Xr farbfeld-utils 7