Render a PDF page directly to a PNG file — pdf_render_to

Convenience wrapper that calls pdf_render_page() and writes the result via png::writePNG(). The png package is required at runtime (it's a Suggests dependency).

Usage

pdf_render_to_png(
  page,
  file,
  page_num = 1L,
  dpi = 72,
  background = "white",
  annotations = FALSE,
  rotation = 0L
)

Arguments

page: A pdfium_page from pdf_page_load(), or a pdfium_doc (the page given by page_num will be loaded and closed internally).
file: Output file path.
page_num: One-based page index. Only used when page is a pdfium_doc. Ignored otherwise.
dpi: Render resolution in dots per inch (default 72, meaning one pixel per PDF point). Higher values give larger, sharper output at proportional memory cost.
background: Background color drawn behind the page content before rendering. Accepts any string grDevices::col2rgb() understands (named color, "#RRGGBB", "#RRGGBBAA"), or NA for a fully transparent background. Defaults to "white".
annotations: Logical; render annotation appearance streams on top of the page content. Defaults to FALSE.
rotation: Extra rotation in degrees applied on top of the page's own /Rotate attribute. One of 0, 90, 180, 270. Note: PDFium's rotation is clockwise; e.g. 90 means rotate the page 90° clockwise from its on-page orientation.

Value

Invisibly returns file.

Examples

fixture <- system.file("extdata", "fixtures", "shapes.pdf",
  package = "pdfium"
)
if (nzchar(fixture) && requireNamespace("png", quietly = TRUE)) {
  out <- tempfile(fileext = ".png")
  pdf_render_to_png(pdf_doc_open(fixture), file = out, dpi = 96)
  file.exists(out)
}
#> [1] TRUE