shift.im: Apply Vector Translation To Pixel Image

Description

Applies a vector shift to a pixel image

Usage

## S3 method for class 'im':
shift(X, vec=c(0,0), ..., origin=NULL)

Arguments

Pixel image (object of class "im").

vec

Vector of length 2 representing a translation.

...

Ignored

origin

Character string determining a location that will be shifted to the origin. Options are "centroid", "midpoint" and "bottomleft". Partially matched.

Value

Another pixel image (of class "im") representing the result of applying the vector shift.

Details

The spatial location of each pixel in the image is translated by the vector vec. This is a method for the generic function shift.

If origin is given, then it should be one of the character strings "centroid", "midpoint" or "bottomleft". The argument vec will be ignored; instead the shift will be performed so that the specified geometric location is shifted to the origin. If origin="centroid" then the centroid of the image window will be shifted to the origin. If origin="midpoint" then the centre of the bounding rectangle of the image will be shifted to the origin. If origin="bottomleft" then the bottom left corner of the bounding rectangle of the image will be shifted to the origin.

Examples

Run this code

# make up an image
 X <- setcov(unit.square())
 plot(X)

 Y <- shift(X, c(10,10))
 plot(Y)
 # no discernible difference except coordinates are different

 shift(X, origin="mid")

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