The function pdf_open_image_file() reads an image of format format from the file filename. Possible formats are 'png', 'tiff', 'jpeg' and 'gif'. The function returns a pdf image identifier.
See also pdf_close_image(), pdf_open_jpeg(), pdf_open_gif(), pdf_open_tiff(), pdf_open_png(), pdf_execute_image(), pdf_place_image(), pdf_put_image().