.TH BLIND-KERNEL 1 blind
.SH NAME
blind-kernel - Create a convolution matrix
.SH SYNOPSIS
.B blind-kernel
[-xyza]
.I kernel
.RI [ parameter ]\ ...
.SH DESCRIPTION
.B blind-kernel
creates a convolution matrix that can be applied to
a video using
.BR blind-apply-kernel (1).
The convolution matrix is created from a set
of standard formulae. The formula is selected
using the
.I kernel
argument and is tuned with
.IR kernel -specific
.IR parameter s.
.SH KERNELS
.TP
.RI ' \fBbox\ blur\fP '\ [-w\  weight ]\ [ spread \ |\  x-spread \  y-spread ]
Creates a box blur kernel. Unless
.B -w
is used, the kernel is unweighted, otherwise it has the specified
.IR weight .
The kernel will have the spread 1, the specified
.IR spread ,
or
.I x-spread
as the horizontal spread and
.I y-spread
as the vertical spread.
.TP
.BR emboss \ [\fIdirection\fP]
Create an emboss kernel with the specified
.IR direction .
The
.I direction
must be
.BR N ;
.BR NW
or
.BR WN ;
.BR W ;
.BR SW
or
.BR WS ;
.BR S ;
.BR SE
or
.BR ES ;
.BR E ;
.BR NE
or
.BR EN .
If no
.I direction
is specified,
.B SE
is used.
.TP
.RI \fBgaussian\fP\ [-s\  spread ]\ [-u]\  standard-deviation
Creates a Gaussian blur kernel with the standard deviation
.IR standard-deviation .
If
.B -u
is used, the a Gaussian unsharpen kernel is created. If
.B -s
is specified, the specified
.I spread
will be used, otherwise the spread will be selected automatically.
.TP
.BI gradient\  direction
Create a gradient detection kernel with the specified
.IR direction .
The
.I direction
must be
.BR N ;
.BR NW
or
.BR WN ;
.BR W ;
.BR SW
or
.BR WS ;
.BR S
or
.BR H ;
.BR SE
or
.BR ES ;
.BR E
or
.BR V ;
.BR NE
or
.BR EN .
.TP
.BI kirsch\  direction
Create a Kirsch kernel with the specified
.IR direction .
The
.I direction
must be
.B 1
or
.BR N ;
.BR 2 ,
.BR NW ,
or
.BR WN ;
.BR 3
or
.BR W ;
.BR 4 ,
.BR SW ,
or
.BR WS ;
.BR 5
or
.BR S ;
.BR 6 ,
.BR SE ,
or
.BR ES ;
.BR 7
or
.BR E ;
or
.BR 8 ,
.BR NE ,
or
.BR EN .
.TP
.BR sharpen \ [-i]
Creates a sharpen kernel. If
.B -i
is used, an intensified sharpen kernel is created.
.TP
.BI sobel\  direction
Create a Sobel operator kernel with the specified
.IR direction .
The
.I direction
must be
.BR N
or
.BR H ;
.BR NW
or
.BR WN ;
.BR W
or
.BR V ;
.BR SW
or
.BR WS ;
.BR S ;
.BR SE
or
.BR ES ;
.BR E ;
.BR NE
or
.BR EN .
.SH OPTIONS
.TP
.B -a
Apply the values to the alpha channel, set the
values for all unselected channels to zero.
.TP
.B -x
Apply the values to the X channel, set the values
for all unselected channels to zero.
.TP
.B -y
Apply the values to the Y channel, set the values
for all unselected channels to zero.
.TP
.B -z
Apply the values to the Z channel, set the values
for all unselected channels to zero.
.SH NOTES
.B blind-make-kernel
Create a single frame, to that it can be stored to
disc. When applying it to a video, you want to use
.BR blind-repeat (1).
.SH SEE ALSO
.BR blind (7),
.BR blind-apply-kernel (1),
.BR blind-kernel (1),
.BR blind-repeat (1)
.SH AUTHORS
Mattias Andrée
.RI < maandree@kth.se >