R/imRead.R

In xRing: Identify and Measure Tree Rings on X-Ray Micro-Density Profiles

#' @export
#' @title Load Image From a File
#' @description Load an image using the \link{load.image} function from \link{imager} package
#' @param file path to file
#' @return an object of class "\link{cimg}"
#' @seealso
#' \link{load.image}
#' @examples
#' if (interactive()) {
#'   file_path <- system.file("img", "AFO1046.1200dpi.png", package = "xRing")
#'   im <- imRead(file_path)
#'   imDisplay(im)
#' }
#'
imRead <- function(file) {
  on.exit(gc())
  im <- load.image(file)
  if (dim(im)[4] > 1) {
    im <- grayscale(im)
  }
  # max_image <- max(im)
  max_image <- max(im[sample(1:nrow(im), 10), sample(1:ncol(im), 10), , ]) # faster
  if (max_image <= 1) {
    im <- im * 255
  }
  if (max_image <= 2^8) {
    im <- im * 255
  }
  storage.mode(im) <- "integer"
  im
}