feConvolveMatrix(input = NA, order = 3, kernelMatrix = matrix(), divisor = 1, bias = 0, targetX = 1, targetY = 1, edgeMode = c("duplicate", "wrap", "none"), kernelUnitLength = NA, preserveAlpha = FALSE, ...)
filterInputs
.
kernelMatrix
. The values provided must be
integers greater than zero. The first number (orderX), indicates the
number of columns in the matrix. The second number (orderY),
indicates the number of rows in the matrix. If this is a vector of
length one then the number of rows is assumed to be same as the
number of columns specified.
order
.
kernelMatrix
to the input image to yield a
number, that number is divided by divisor
to yield the final
destination colour value. A divisor that is the sum of all the
matrix values tends to have an evening effect on the overall colour
intensity of the result. It is an error to specify a divisor of
zero. The default value is the sum of all values in kernelMatrix,
with the exception that if the sum is zero, then the divisor is set
to 1.
kernelMatrix
to the input image to yield a
number and applying the divisor
, the bias
attribute is
added to each component. One application of bias
is when it
is desirable to have 0.5 gray value be the zero response of the
filter. The bias property shifts the range of the filter. This
allows representation of values that would otherwise be clamped to 0
or 1.
"duplicate"
indicates that the input image is
extended along each of its borders as necessary by duplicating the
colour values at the given edge of the input image.
"wrap"
indicates that the input image is extended by
taking the colour values from the opposite edge of the image.
"none"
indicates that the input image is extended
with pixel values of zero for R, G, B and A.
dx
value. The second number is the
dy
value. If the dy
value is not specified, it
defaults to the same value as dx
. Indicates the intended
distance in current filter units (i.e., units as determined by the
value of the filter effect container's primitiveUnits
)
between successive columns and rows, respectively, in the
kernelMatrix
. By specifying value(s) for
kernelUnitLength
, the kernel becomes defined in a scalable,
abstract coordinate system. If kernelUnitLength
is not
specified, the default value is one pixel in the offscreen bitmap,
which is a pixel-based coordinate system, and thus potentially not
scalable.
FALSE
indicates that the convolution will apply to
all channels, including the alpha channel. A value of TRUE
indicates that the convolution will only
apply to the colour channels. In this case, the filter will
temporarily unpremultiply the colour component values, apply the
kernel, and then re-premultiply at the end.
fe
.
fe.convolve.matrix
object.
filterEffect
, fe
.