Ruby Requires Chilkat v11.7.0+

PDF Object Streams: generate, preserve or disable

See more PDF Optimization Examples

Demonstrates the objectStreams option. An object stream packs many small objects (dictionaries, not stream data) into one compressed stream, which is usually a worthwhile saving in a document with many pages or tags. "generate" (the default) packs them and writes a cross-reference stream; "preserve" keeps the file as it is -- packed if it already was, not packed if it was not; "disable" writes every object on its own with a classic cross-reference table, which is what a PDF 1.4 reader needs. Object streams require PDF 1.5 and are skipped for PDF/A-1. 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 grand_canyon_hiking_guide.pdf

fac = Chilkat::CkFileAccess.new()
json = Chilkat::CkJsonObject.new()
jsonOut = Chilkat::CkJsonObject.new()

#  generate: pack the objects (the default).
pdf1 = Chilkat::CkPdf.new()
success = pdf1.LoadFile("qa_data/pdf/grand_canyon_hiking_guide.pdf")
if (success == false)
    print pdf1.lastErrorText() + "\n";
    exit
end

json.UpdateString("objectStreams","generate")
success = pdf1.Optimize("optimize",json,jsonOut)
if (success == false)
    print pdf1.lastErrorText() + "\n";
    exit
end

success = pdf1.WriteFile("qa_output/grand_canyon_objstm_generate.pdf")
if (success == false)
    print pdf1.lastErrorText() + "\n";
    exit
end

print "generate: " + fac.FileSize("qa_output/grand_canyon_objstm_generate.pdf").to_s() + " bytes, objects packed: " + jsonOut.IntOf("actions.objectStreams.count").to_s() + "\n";

#  disable: every object on its own, with a classic cross-reference table.
pdf2 = Chilkat::CkPdf.new()
success = pdf2.LoadFile("qa_data/pdf/grand_canyon_hiking_guide.pdf")
if (success == false)
    print pdf2.lastErrorText() + "\n";
    exit
end

json.UpdateString("objectStreams","disable")
success = pdf2.Optimize("optimize",json,jsonOut)
if (success == false)
    print pdf2.lastErrorText() + "\n";
    exit
end

success = pdf2.WriteFile("qa_output/grand_canyon_objstm_disable.pdf")
if (success == false)
    print pdf2.lastErrorText() + "\n";
    exit
end

print "disable:  " + fac.FileSize("qa_output/grand_canyon_objstm_disable.pdf").to_s() + " bytes" + "\n";

#  preserve: leave the file's own structure alone.  Use it when the output must stay readable by
#  whatever reads the input today.
pdf3 = Chilkat::CkPdf.new()
success = pdf3.LoadFile("qa_data/pdf/grand_canyon_hiking_guide.pdf")
if (success == false)
    print pdf3.lastErrorText() + "\n";
    exit
end

json.UpdateString("objectStreams","preserve")
success = pdf3.Optimize("optimize",json,jsonOut)
if (success == false)
    print pdf3.lastErrorText() + "\n";
    exit
end

success = pdf3.WriteFile("qa_output/grand_canyon_objstm_preserve.pdf")
if (success == false)
    print pdf3.lastErrorText() + "\n";
    exit
end

print "preserve: " + fac.FileSize("qa_output/grand_canyon_objstm_preserve.pdf").to_s() + " bytes" + "\n";