imager: pixel.grid – R documentation

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pixel.grid

Return the pixel grid for an image

Description

The pixel grid for image im gives the (x,y,z,c) coordinates of each successive pixel as a data.frame. The c coordinate has been renamed 'cc' to avoid conflicts with R's c function. NB: coordinates start at (x=1,y=1), corresponding to the top left corner of the image, unless standardise == TRUE, in which case we use the usual Cartesian coordinates with origin at the center of the image and scaled such that x varies between -.5 and .5, and a y arrow pointing up

Usage

pixel.grid(im, standardise = FALSE, drop.unused = TRUE, dim = NULL)

Arguments

`im`	an image
`standardise`	If TRUE use a centered, scaled coordinate system. If FALSE use standard image coordinates (default FALSE)
`drop.unused`	if TRUE ignore empty dimensions, if FALSE include them anyway (default TRUE)
`dim`	a vector of image dimensions (optional, may be used instead of "im")

Value

a data.frame

Examples

im <- as.cimg(array(0,c(10,10))) #A 10x10 image
pixel.grid(im) %>% head
pixel.grid(dim=dim(im)) %>% head #Same as above
pixel.grid(dim=c(10,10,3,2)) %>% head 
pixel.grid(im,standardise=TRUE) %>% head
pixel.grid(im,drop.unused=FALSE) %>% head

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