mean.im
Mean and Median of Pixel Values in an Image
Calculates the mean or median of the pixel values in a pixel image.
Usage
## S3 method for class 'im'
## mean(x, trim=0, na.rm=TRUE, ...) ## S3 method for class 'im'
## median(x, na.rm=TRUE) [R < 3.4.0]
## median(x, na.rm=TRUE, ...) [R >= 3.4.0]
Arguments
- x
A pixel image (object of class
"im"
).- na.rm
Logical value indicating whether
NA
values should be stripped before the computation proceeds.- trim
The fraction (0 to 0.5) of pixel values to be trimmed from each end of their range, before the mean is computed.
- …
Ignored.
Details
These functions calculate the mean and median
of the pixel values in the image x
.
An object of class "im"
describes a pixel image. See im.object
)
for details of this class.
The function mean.im
is a method for the generic
function mean
for the class "im"
.
Similarly median.im
is a method for the generic
median
.
If the image x
is logical-valued, the mean value of x
is
the fraction of pixels that have the value TRUE
. The median is
not defined.
If the image x
is factor-valued, then the mean of x
is the mean of the integer codes of the pixel values. The median is
are not defined.
Other mathematical operations on images are supported by
Math.im
, Summary.im
and Complex.im
.
Other information about an image can be obtained using
summary.im
or quantile.im
.
Value
A single number.
See Also
Math.im
for other operations.
Examples
# NOT RUN {
X <- as.im(function(x,y) {x^2}, unit.square())
mean(X)
median(X)
mean(X, trim=0.05)
# }