imager: crop.borders – R documentation

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crop.borders

Crop the outer margins of an image

Description

This function crops pixels on each side of an image. This function is a kind of inverse (centred) padding, and is useful e.g. when you want to get only the valid part of a convolution

Usage

crop.borders(im, nx = 0, ny = 0, nz = 0, nPix)

Arguments

`im`	an image
`nx`	number of pixels to crop along horizontal axis
`ny`	number of pixels to crop along vertical axis
`nz`	number of pixels to crop along depth axis
`nPix`	optional: crop the same number of pixels along all dimensions

Value

an image

Author(s)

Simon Barthelme

Examples

#These two versions are equivalent
imfill(10,10) %>% crop.borders(nx=1,ny=1)
imfill(10,10) %>% crop.borders(nPix=1)

#Filter, keep valid part
correlate(boats,imfill(3,3)) %>% crop.borders(nPix=2)

imager

Image Processing Library Based on 'CImg'

v0.42.10

LGPL-3

Authors

Simon Barthelme [aut], David Tschumperle [ctb], Jan Wijffels [ctb], Haz Edine Assemlal [ctb], Shota Ochi [cre]

Initial release