int pdf_open_image_file ( resource pdfdoc, string imagetype, string filename, string stringparam, int intparam )
Open an image file. Supported types are jpeg,
tiff, gif, and png.
stringparam is either empty,
mask, masked, or
page.
intparam is either 0, the image id
of the applied mask, or the page.
Parameters stringparam and
intparam were optional before PHP 5.
