PHP Requires Chilkat v11.7.0+

PDF Object Streams: generate, preserve or disable

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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 PHP

<?php

use Chilkat2\FileAccess;
use Chilkat2\JsonObject;
use Chilkat2\Pdf;

// 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 = new FileAccess();
$json = new JsonObject();
$jsonOut = new JsonObject();

// generate: pack the objects (the default).
$pdf1 = new Pdf();
try {
    $pdf1->LoadFile('qa_data/pdf/grand_canyon_hiking_guide.pdf');

    $json->UpdateString('objectStreams', 'generate');
    $pdf1->Optimize('optimize', $json, $jsonOut);

    $pdf1->WriteFile('qa_output/grand_canyon_objstm_generate.pdf');
} catch (\Chilkat2\Exception $e) {
    echo $e->getMessage(), "\n";
    exit;
}

echo '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.
$pdf2 = new Pdf();
try {
    $pdf2->LoadFile('qa_data/pdf/grand_canyon_hiking_guide.pdf');

    $json->UpdateString('objectStreams', 'disable');
    $pdf2->Optimize('optimize', $json, $jsonOut);

    $pdf2->WriteFile('qa_output/grand_canyon_objstm_disable.pdf');
} catch (\Chilkat2\Exception $e) {
    echo $e->getMessage(), "\n";
    exit;
}

echo '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.
$pdf3 = new Pdf();
try {
    $pdf3->LoadFile('qa_data/pdf/grand_canyon_hiking_guide.pdf');

    $json->UpdateString('objectStreams', 'preserve');
    $pdf3->Optimize('optimize', $json, $jsonOut);

    $pdf3->WriteFile('qa_output/grand_canyon_objstm_preserve.pdf');
} catch (\Chilkat2\Exception $e) {
    echo $e->getMessage(), "\n";
    exit;
}

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