Extract PDF pages as PNG images

pdf_decompose.R

pdf_decompose <- function(input_file, output_folder, pages = NA){
  
  pdf_length <- as.integer(pdftools::pdf_info(input_file)$pages)
  
  if(is.na(pages[1])){pages <- seq(1, pdf_length, 1)}
  
  if(!all(purrr::map_lgl(pages, is.numeric))){
    stop("pages must be a numeric vector")
    }
  
  pages <- pages[pages <= pdf_length]
  
  for (i in seq_along(pages)){
    img <- magick::image_read_pdf(
      path = input_file,
      pages = pages[i]
    )
    
    magick::image_write(
      img,
      path = paste0(output_folder, "decomposed_", pages[i], ".png"),
      format = "png",
      quality = 100
    )
  }
}