Tcl 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. Tcl

load ./chilkat.dll

set 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

set pdf [new_CkPdf]

set success [CkPdf_LoadFile $pdf "qa_data/pdf/four_pages.pdf"]
if {$success == 0} then {
    puts [CkPdf_lastErrorText $pdf]
    delete_CkPdf $pdf
    exit
}

set json [new_CkJsonObject]

CkJsonObject_UpdateString $json "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");
CkJsonObject_UpdateString $json "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.
CkJsonObject_UpdateString $json "units" "in"
CkJsonObject_UpdateNumber $json "image.width" "1.5"

#  Bottom-right, half an inch in from the page edges.
CkJsonObject_UpdateString $json "position.align" "bottomRight"
CkJsonObject_UpdateNumber $json "position.margin" "0.5"
CkJsonObject_UpdateNumber $json "opacity" "0.85"
CkJsonObject_UpdateString $json "id" "logo"

set jsonOut [new_CkJsonObject]

set success [CkPdf_Watermark $pdf "add" $json $jsonOut]
if {$success == 0} then {
    puts [CkPdf_lastErrorText $pdf]
    delete_CkPdf $pdf
    delete_CkJsonObject $json
    delete_CkJsonObject $jsonOut
    exit
}

puts "id: [CkJsonObject_stringOf $jsonOut id] pages: [CkJsonObject_stringOf $jsonOut pages]"

set success [CkPdf_WriteFile $pdf "qa_output/four_pages_logo.pdf"]
if {$success == 0} then {
    puts [CkPdf_lastErrorText $pdf]
    delete_CkPdf $pdf
    delete_CkJsonObject $json
    delete_CkJsonObject $jsonOut
    exit
}

#  Sample output:

#  id: logo pages: 1-4

delete_CkPdf $pdf
delete_CkJsonObject $json
delete_CkJsonObject $jsonOut