spatstat (version 1.18-1)

mean.im: Mean, Median and Range of Pixel Values in an Image

Description

Calculates the mean, median or range of the pixel values in a pixel image.

Usage

## S3 method for class 'im':
mean(x, \dots)
  ## S3 method for class 'im':
median(x, \dots)
  ## S3 method for class 'im':
range(x, \dots)

Arguments

x

A pixel image (object of class "im").

...

Arguments passed to mean.default.

Value

• A single number.

Details

These functions calculate the mean, median and range 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 and range.im is a method for range. 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 and range are not defined.

Any arguments in ... are passed to the default method, for example mean.default. In particular, using the argument trim will compute the trimmed mean, as explained in the help for mean.default.

Other information about an image can be obtained using summary.im or quantile.im.

See Also

mean, median, range, mean.default, median.default, range.default, quantile.im, im.object, summary.im.

Examples

X <- as.im(function(x,y) {x^2}, unit.square())
  mean(X)
  median(X)
  range(X)

  mean(X, trim=0.05)