Perl Requires Chilkat v11.7.0+

Add an Image (Logo) Watermark to a PDF

See more PDF Watermark Examples

Demonstrates an image watermark placed in a corner of every page. The image is a PNG or JPEG given either by path ("image.path") or, as here, as base64 in the JSON itself ("image.base64"), which suits a server that keeps its logo in a database rather than on disk. PNG transparency is kept. Giving only a width keeps the aspect ratio, and the units member says those numbers are inches rather than points. Perl

use chilkat();

$success = 0;

#  This example requires the Chilkat API to have been previously unlocked.
#  See Global Unlock Sample for sample code.

#  The PDF used in this example is available at four_pages.pdf

$pdf = chilkat::CkPdf->new();
$success = $pdf->LoadFile("qa_data/pdf/four_pages.pdf");
if ($success == 0) {
    print $pdf->lastErrorText() . "\r\n";
    exit;
}

$json = chilkat::CkJsonObject->new();
$json->UpdateString("type","image");

#  A small PNG logo, base64 encoded.  Use "image.path" instead to name a PNG or JPEG file:
#     ignore = json.UpdateString("image.path","logo.png");
$json->UpdateString("image.base64","iVBORw0KGgoAAAANSUhEUgAAAGAAAAAgCAYAAADtwH1UAAAApElEQVR42u3a7QmAIBgAYTdpo/ZphhZti6IBylLrlXoO/G3cIeFHSgAAFDKM08rCy8Jzg6Ug8UJ0JF+EDuSXRGgxX8+jufxlTk0nFuCCiF360aidXICMiDP5uQgCXAxQI782ggAHEu7IP4sgQOcBIMA35ItgBQhQEqBmtbX6xl//hAUI3gcIELwTFiD4LEiA4NNQAYLvA+BGzJ0wvIrwLggA8DgbwPbrr8c7+lkAAAAASUVORK5CYII=");

#  The size to draw it at.  Give only the width and the height follows the aspect ratio.
$json->UpdateString("units","in");
$json->UpdateNumber("image.width","1.5");

#  Bottom-right, half an inch in from the page edges.
$json->UpdateString("position.align","bottomRight");
$json->UpdateNumber("position.margin","0.5");
$json->UpdateNumber("opacity","0.85");
$json->UpdateString("id","logo");

$jsonOut = chilkat::CkJsonObject->new();
$success = $pdf->Watermark("add",$json,$jsonOut);
if ($success == 0) {
    print $pdf->lastErrorText() . "\r\n";
    exit;
}

print "id: " . $jsonOut->stringOf("id") . " pages: " . $jsonOut->stringOf("pages") . "\r\n";

$success = $pdf->WriteFile("qa_output/four_pages_logo.pdf");
if ($success == 0) {
    print $pdf->lastErrorText() . "\r\n";
    exit;
}

#  Sample output:

#  id: logo pages: 1-4