B4X 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. B4X

Dim success As Boolean = False

'  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

Dim pdf As ChilkatPdf
pdf.Initialize("pdf")
success = pdf.LoadFile("qa_data/pdf/four_pages.pdf")
If success = False Then
    Log(pdf.LastErrorText)
    Return
End If


Dim json As ChilkatJsonObject
json.Initialize
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")

Dim jsonOut As ChilkatJsonObject
jsonOut.Initialize
success = pdf.Watermark("add", json, jsonOut)
If success = False Then
    Log(pdf.LastErrorText)
    Return
End If

Log("id: " & jsonOut.StringOf("id") & " pages: " & jsonOut.StringOf("pages"))

success = pdf.WriteFile("qa_output/four_pages_logo.pdf")
If success = False Then
    Log(pdf.LastErrorText)
    Return
End If


'  Sample output:

'  id: logo pages: 1-4