Ruby Requires Chilkat v11.7.0+

Audit a PDF First, Optimize Only If It Is Worth It

See more PDF Optimization Examples

Demonstrates deciding whether to rewrite a PDF at all. "audit" costs a fraction of a second and changes nothing, so a batch job can audit every file and optimize only those where enough would be saved. Here the threshold is a tenth of the file; a file already as small as it can be is left alone. Ruby

require 'chilkat'

success = 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

pdf = Chilkat::CkPdf.new()
success = pdf.LoadFile("qa_data/pdf/watersense_accomplishments.pdf")
if (success == false)
    print pdf.lastErrorText() + "\n";
    exit
end

json = Chilkat::CkJsonObject.new()
jsonOut = Chilkat::CkJsonObject.new()
success = pdf.Optimize("audit",json,jsonOut)
if (success == false)
    print pdf.lastErrorText() + "\n";
    exit
end

fileSize = jsonOut.IntOf("fileSize")
estimated = jsonOut.IntOf("estimatedSavings.total")
print "fileSize:  " + fileSize.to_s() + "\n";
print "estimated: " + estimated.to_s() + "\n";

#  Only bother when at least a tenth of the file would go.
if (estimated > (fileSize / 10))
    print "Worth optimizing." + "\n";
    success = pdf.Optimize("optimize",json,jsonOut)
    if (success == false)
        print pdf.lastErrorText() + "\n";
        exit
    end

    success = pdf.WriteFile("qa_output/watersense_optimized.pdf")
    if (success == false)
        print pdf.lastErrorText() + "\n";
        exit
    end

    print "bytesSaved: " + jsonOut.IntOf("bytesSaved").to_s() + "\n";
else
    print "Already small enough; left as it is." + "\n";
end