PDF_get_value()

(PHP 4 >= 4.0.1, PECL pdflib >= 1.0.0)

Get numerical parameter

说明

PDF_get_value(resource $p,string $key,float $modifier):float

Gets the value of some PDFlib parameter with numerical type.

If you're trying to get the version of the installed library, you can study this example:
<?php
$p=pdf_new();
echo pdf_get_value($p, 'major', 0).".";
echo pdf_get_value($p, 'minor', 0).".";
echo pdf_get_value($p, 'revision', 0);
?>
Outputs something like 
9.0.7

See the main PDF manual page (the "PDF" link to the left) for the magic words that this function accepts.

Note:
imagewidth and imageheigh do not return the actual width and height. Instead they are 2 times the actual width and height. I don't understand why, but this seems to be the case with multi page tiffs (and maybe other images). In order to insert a multi page tiff into a PDF without out of control extra space do the following:
<?php
$pdf = pdf_new();
pdf_set_parameter($pdf, "licensefile", "/etc/pdflib/licensekeys.txt");
pdf_open_file($pdf, "/tmp/tifftest.pdf");
for ($i=1; $i<=4; $i++) {
$image = pdf_open_image_file($pdf, "tiff", "/tmp/test.tif", "page", $i);
$w = pdf_get_value($pdf, "imagewidth", $image);
$h = pdf_get_value($pdf, "imageheight", $image);
// $w and $h are at this point 2*width and 2*height!!
// To place the image without having lots of extra space:
pdf_begin_page($pdf, $w/2, $h/2);
pdf_place_image($pdf, $image, 0, 0, 0.5);
pdf_close_image($pdf, $image);
pdf_end_page($pdf);
}
 
pdf_close($pdf);
?>

There should be many more. For example I found this in the manual, wich was very helpfull for me:
$textx = pdf_get_value($p, "textx", 0);
$texty = pdf_get_value($p, "texty", 0);
These will extract the current textposition in the document.

The Magic keywords are:
 IMAGEWIDTH,  IMAGEHEIGHT,  RESX, RESY,
 CAPHEIGHT, ASCENDER, DESCENDER, FONT
I looked in the sourcecode ...

To get the current font size, use something like this:
<?php $fontheight = PDF_get_value($pdf, "fontsize"); ?>

$width = PDF_get_value($p, "imagewidth", $image);