getNeighborhoodAtVoxel: Get a hypercube neighborhood at a voxel

In stnava/ANTsR: ANTs in R: Quantification Tools for Biomedical Images

Get a hypercube neighborhood at a voxel

Description

Get the values in a local neighborhood of an antsImage.

Usage

getNeighborhoodAtVoxel(image, center, kernel, physical.coordinates = FALSE)

Arguments

image	Image object of S4 class antsImage to get values from.
center	array of indices for neighborhood center
kernel	either an array of values for neighborhood radius (in voxels) or a binary array of the same dimension as the image, specifying the shape of the neighborhood to extract
physical.coordinates	a logical indicating if voxel indices and offsets should be in voxel or physical coordinates

Value

a list

values

numeric vector of values

indices

matrix providing the coordinates for each value

Author(s)

Duda JT

Examples

img <- makeImage(c(10, 10), rnorm(100))
center <- dim(img) / 2
radius <- rep(3, 2)
nhlist <- getNeighborhoodAtVoxel(img, center, radius)
kernel <- 1 * (rnorm(49) > 0)
dim(kernel) <- c(7, 7)
randlist <- getNeighborhoodAtVoxel(img, center, kernel)
randlist <- getNeighborhoodAtVoxel(img, center, kernel,
  physical.coordinates = TRUE
)
arr <- as.array(img)
testthat::expect_error(getNeighborhoodAtVoxel(arr, center, kernel), "class")
testthat::expect_error(
  getNeighborhoodAtVoxel(img, as.character(center), kernel),
  "center must be"
)
testthat::expect_error(
  getNeighborhoodAtVoxel(img, center, c(radius, 3)),
  "kernel must have same"
)

stnava/ANTsR documentation built on April 13, 2025, 4:10 a.m.