AutoIt Requires Chilkat v11.7.0+

Remove PDF Objects Nothing Refers To

See more PDF Optimization Examples

Demonstrates removeUnreferenced. When a page, an image or a whole section is replaced in an editor, the objects it used often stay in the file with nothing pointing at them any more. They are not old revisions -- they are in the current revision, simply unreachable -- so only a reachability walk from the document catalog finds them. In a publication assembled over several editing passes this is frequently the largest single saving. AutoIt

Local $bSuccess = 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 watersense_accomplishments.pdf

$oPdf = ObjCreate("Chilkat.Pdf")
$bSuccess = $oPdf.LoadFile("qa_data/pdf/watersense_accomplishments.pdf")
If ($bSuccess = False) Then
    ConsoleWrite($oPdf.LastErrorText & @CRLF)
    Exit
EndIf

$oJson = ObjCreate("Chilkat.JsonObject")
$oJsonOut = ObjCreate("Chilkat.JsonObject")
$bSuccess = $oPdf.Optimize("audit",$oJson,$oJsonOut)
If ($bSuccess = False) Then
    ConsoleWrite($oPdf.LastErrorText & @CRLF)
    Exit
EndIf

ConsoleWrite("fileSize: " & $oJsonOut.IntOf("fileSize") & @CRLF)
ConsoleWrite("removeUnreferenced would save: " & $oJsonOut.IntOf("estimatedSavings.removeUnreferenced") & @CRLF)

;  Optimize with the defaults and see how many objects were actually dropped.
$bSuccess = $oPdf.Optimize("optimize",$oJson,$oJsonOut)
If ($bSuccess = False) Then
    ConsoleWrite($oPdf.LastErrorText & @CRLF)
    Exit
EndIf

$bSuccess = $oPdf.WriteFile("qa_output/watersense_optimized.pdf")
If ($bSuccess = False) Then
    ConsoleWrite($oPdf.LastErrorText & @CRLF)
    Exit
EndIf

ConsoleWrite("objects removed: " & $oJsonOut.IntOf("actions.removeUnreferenced.count") & @CRLF)
ConsoleWrite("bytes saved:     " & $oJsonOut.IntOf("actions.removeUnreferenced.bytesSaved") & @CRLF)

;  Nothing a page needs is ever removed: the walk starts at the document catalog and follows every
;  reference, including the ones in annotations, the structure tree, named destinations and the
;  optional-content configuration.
ConsoleWrite("pages after: " & $oPdf.NumPages & @CRLF)