Perl Requires Chilkat v11.7.0+

Clipped, Off-Page and White-on-White Text in PDF Extraction

See more PDF Text Extraction Examples

Demonstrates the "clippedText", "offPageText" and "obscuredText" filters. Text that a reader never sees - hidden by a clipping path, outside the crop box, or drawn in the same color as the box beneath it - is excluded by default, and the quality report notes what was skipped. Each kind can be included. 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 hidden_text.pdf

my $pdf = Chilkat2::Pdf->new;
my $success = $pdf->LoadFile('qa_data/pdf/hidden_text.pdf');
if (!$success) {
    print $pdf->LastErrorText, "\n";
    exit;
}

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

# The page has a visible paragraph plus three hidden lines: one drawn outside its clipping
# rectangle, one below the crop box, and one in white on a white box.
$success = $pdf->ExtractText('text', $json, $jsonOut);
if (!$success) {
    print $pdf->LastErrorText, "\n";
    exit;
}

print "---- default ----\n";
print $jsonOut->StringOf('text'), "\n";

# The quality report says what was left out.
my $i = 0;
my $count_i = $jsonOut->SizeOfArray('quality.pages[0].issues');
while ($i < $count_i) {
    $jsonOut->I($i);
    print 'issue: ', $jsonOut->StringOf('quality.pages[0].issues[i].code'), "\n";
    $i = $i + 1;
}

# Include everything.
$json->UpdateString('clippedText', 'include');
$json->UpdateString('offPageText', 'include');
$json->UpdateString('obscuredText', 'include');
$success = $pdf->ExtractText('text', $json, $jsonOut);
if (!$success) {
    print $pdf->LastErrorText, "\n";
    exit;
}

print "---- clippedText, offPageText, obscuredText: include ----\n";
print $jsonOut->StringOf('text'), "\n";

# Sample output:

# ---- default ----
# Visible Text
#
# This paragraph is visible. The page also carries three kinds of text a reader never sees.
#
# End of the visible text.
# issue: obscuredTextSkipped
# issue: clippedTextSkipped
# ---- clippedText, offPageText, obscuredText: include ----
# Visible Text
#
# This paragraph is visible. The page also carries three kinds of text a reader never sees.
#
# CLIPPED: this line is drawn outside its clipping rectangle.
#
# OBSCURED: this line is white on a white box.
#
# End of the visible text.
#
# OFFPAGE: this line sits below the crop box.