R/antsImageClone.R

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

#' Clone an \code{antsImage}.
#'
#' Clone an image object of S4 class \code{antsImage}. N.B.: You cannot use
#' \code{a <- img} because the R assignment operator does not deal with the underlying
#' C++ pointers.
#'
#' @param in_image image object of S4 class \code{antsImage} to be cloned.
#' @param out_pixeltype C++ datatype to be used to represent the pixels in the
#' output image. Allowed values: \code{double}, \code{float},
#' \code{unsigned int}, \code{unsigned char}.
#' @return object of class \code{antsImage}
#' @author Shrinidhi KL
#' @examples
#'
#' img <- antsImageRead(getANTsRData("r16"), 2)
#' img2 <- antsImageClone(img)
#' img.int <- antsImageClone(img, "unsigned int")
#' multi <- antsImageRead(getANTsRData("multi_component_image"))
#' img <- antsImageRead(getANTsRData("r16"), 2)
#' m2 <- antsImageClone(multi)
#'
#' @export antsImageClone
antsImageClone <- function(in_image, out_pixeltype = in_image@pixeltype) {
  # this condition I believe is impossible
  # if in_image = NULL, then first condition is FALSE (it's 0, not 1)
  # if in_image is vector, still condition false
  if (length(dim(in_image)) == 1) {
    if (dim(in_image)[1] == 1) {
      return(NULL)
    }
  }

  if (in_image@components > 1) {
    mychanns <- splitChannels(in_image)
    for (k in 1:length(mychanns))
    {
      img_clone <- ANTsRCore::antsImageClone(mychanns[[k]], out_pixeltype)
      mychanns[[k]] <- img_clone
    }
    return(mergeChannels(mychanns))
  }

  ANTsRCore::antsImageClone(in_image, out_pixeltype)
}