Perl Requires Chilkat v11.7.0+

Extract Text from a Two-Column PDF

See more PDF Text Extraction Examples

Demonstrates how multi-column pages are read. By default the columns are detected and each column is read top to bottom before the next ("columns": "auto"); "columns": "none" reads the full page width line by line, which interleaves the columns. The quality report tells how many columns were found. Perl

use chilkat();

$success = 0;

#  This example requires the Chilkat API to have been previously unlocked.
#  See Global Unlock Sample for sample code.

#  The two-column PDF used in this example is available at two_column_article.pdf

$pdf = chilkat::CkPdf->new();
$success = $pdf->LoadFile("qa_data/pdf/two_column_article.pdf");
if ($success == 0) {
    print $pdf->lastErrorText() . "\r\n";
    exit;
}

$json = chilkat::CkJsonObject->new();
$jsonOut = chilkat::CkJsonObject->new();

#  With the default options the columns are detected, and the text of the left column
#  comes before the text of the right column.
$success = $pdf->ExtractText("text",$json,$jsonOut);
if ($success == 0) {
    print $pdf->lastErrorText() . "\r\n";
    exit;
}

print "Columns detected: " . $jsonOut->IntOf("quality.pages[0].columns") . "\r\n";
print "Reading order: " . $jsonOut->stringOf("quality.pages[0].readingOrderSource") . "\r\n";
print $jsonOut->stringOf("text") . "\r\n";

#  "none" switches column detection off: the page is read across its full width, line by line,
#  so each output line holds a line of the left column followed by a line of the right column.
#  This is rarely wanted, but it shows what the detection does.
$json->UpdateString("columns","none");
$json->UpdateString("layout","lines");
$success = $pdf->ExtractText("text",$json,$jsonOut);
if ($success == 0) {
    print $pdf->lastErrorText() . "\r\n";
    exit;
}

print "---- columns: none ----" . "\r\n";
print $jsonOut->stringOf("text") . "\r\n";

#  Sample output (abbreviated):

#  Columns detected: 2
#  Reading order: visual
#  The Harbor Lighthouse, Season Two
#  
#  The harbor lighthouse was built in 1874 to mark the entrance to the inner channel. It operated continuously until 1968, ...
#  
#  The restoration society took ownership in 2021 with three goals: ...
#  ...
#  The lantern room frame was stripped, primed and repainted in the original dark green. ...
#  ...
#  ---- columns: none ----
#  The Harbor Lighthouse, Season Two
#  The harbor lighthouse was built in 1874 to The lantern room frame was stripped, primed
#  mark the entrance to the inner channel. It and repainted in the original dark green. New
#  ...