crop.borders: Crop the outer margins of an image

In imager: Image Processing Library Based on 'CImg'

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 documentation built on Aug. 8, 2025, 7:35 p.m.