Perl 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. Chilkat2 Perl

use strict;
use warnings;
use Chilkat2;

# 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

my $fac = Chilkat2::FileAccess->new;
my $json = Chilkat2::JsonObject->new;
my $jsonOut = Chilkat2::JsonObject->new;

# generate: pack the objects (the default).
my $pdf1 = Chilkat2::Pdf->new;
my $success = $pdf1->LoadFile('qa_data/pdf/grand_canyon_hiking_guide.pdf');
if (!$success) {
    print $pdf1->LastErrorText, "\n";
    exit;
}

$json->UpdateString('objectStreams', 'generate');
$success = $pdf1->Optimize('optimize', $json, $jsonOut);
if (!$success) {
    print $pdf1->LastErrorText, "\n";
    exit;
}

$success = $pdf1->WriteFile('qa_output/grand_canyon_objstm_generate.pdf');
if (!$success) {
    print $pdf1->LastErrorText, "\n";
    exit;
}

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

# disable: every object on its own, with a classic cross-reference table.
my $pdf2 = Chilkat2::Pdf->new;
$success = $pdf2->LoadFile('qa_data/pdf/grand_canyon_hiking_guide.pdf');
if (!$success) {
    print $pdf2->LastErrorText, "\n";
    exit;
}

$json->UpdateString('objectStreams', 'disable');
$success = $pdf2->Optimize('optimize', $json, $jsonOut);
if (!$success) {
    print $pdf2->LastErrorText, "\n";
    exit;
}

$success = $pdf2->WriteFile('qa_output/grand_canyon_objstm_disable.pdf');
if (!$success) {
    print $pdf2->LastErrorText, "\n";
    exit;
}

print 'disable:  ', $fac->FileSize('qa_output/grand_canyon_objstm_disable.pdf'), " bytes\n";

# preserve: leave the file's own structure alone.  Use it when the output must stay readable by
# whatever reads the input today.
my $pdf3 = Chilkat2::Pdf->new;
$success = $pdf3->LoadFile('qa_data/pdf/grand_canyon_hiking_guide.pdf');
if (!$success) {
    print $pdf3->LastErrorText, "\n";
    exit;
}

$json->UpdateString('objectStreams', 'preserve');
$success = $pdf3->Optimize('optimize', $json, $jsonOut);
if (!$success) {
    print $pdf3->LastErrorText, "\n";
    exit;
}

$success = $pdf3->WriteFile('qa_output/grand_canyon_objstm_preserve.pdf');
if (!$success) {
    print $pdf3->LastErrorText, "\n";
    exit;
}

print 'preserve: ', $fac->FileSize('qa_output/grand_canyon_objstm_preserve.pdf'), " bytes\n";