Perl Requires Chilkat v11.7.0+

Get the Modules of a QR Code (Bit Matrix)

See more QR Code Examples

Demonstrates getting the QR code itself, as a grid of dark and light modules, to draw with something other than the built-in PNG and SVG output: on a canvas, in a PDF, on a display, or with a label printer language. With output.includeModuleData the response has symbols[0].moduleData, a bit matrix with one bit per module, each row starting on a new byte, most significant bit first, 1 for dark. The quiet zone is not part of the matrix. The example prints the symbol using two characters per module. 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.

my $json = Chilkat2::JsonObject->new;
$json->UpdateString('payload.text', 'CHILKAT');
$json->UpdateBool('output.includeModuleData', 1);

my $fmt = Chilkat2::Formats->new;
my $jsonOut = Chilkat2::JsonObject->new;
my $success = $fmt->QrCode('generate', $json, $jsonOut);
if (!$success) {
    print $fmt->LastErrorText, "\n";
    exit;
}

my $width = $jsonOut->IntOf('symbols[0].moduleData.width');
my $height = $jsonOut->IntOf('symbols[0].moduleData.height');
my $rowBytes = $jsonOut->IntOf('symbols[0].moduleData.rowBytes');
print 'kind: ', $jsonOut->StringOf('symbols[0].moduleData.kind'), "\n";
print 'modules: ', $width, ' x ', $height, ', ', $rowBytes, " bytes per row\n";

# The matrix is height rows of rowBytes bytes.
my $bd = Chilkat2::BinData->new;
$success = $bd->AppendEncoded($jsonOut->StringOf('symbols[0].moduleData.bytesBase64'), 'base64');
if (!$success) {
    print $bd->LastErrorText, "\n";
    exit;
}

my $sbRow = Chilkat2::StringBuilder->new;
my $b = 0;
my $mask = 128;
for my $row (0 .. $height - 1) {
    $sbRow->Clear();
    for my $col (0 .. $width - 1) {
        # The module at (col,row) is a bit of the byte at (row * rowBytes) + (col / 8).
        # The leftmost module of each byte is its most significant bit.
        if (($col % 8) == 0) {
            $mask = 128;
        }

        $b = $bd->GetByte(($row * $rowBytes) + (int($col / 8)));
        if (((int($b / $mask)) % 2) == 1) {
            $sbRow->Append('##');
        } else {
            $sbRow->Append('  ');
        }

        $mask = int($mask / 2);
    }

    print $sbRow->GetAsString(), "\n";
}

# The same symbol as the PNG that the call also returned:

# 

# Sample output:

# kind: bitMatrix
# modules: 21 x 21, 3 bytes per row
# ##############              ##############
# ##          ##      ####    ##          ##
# ##  ######  ##  ##  ####    ##  ######  ##
# ##  ######  ##  ##          ##  ######  ##
# ##  ######  ##  ##  ##  ##  ##  ######  ##
# ##          ##  ####  ##    ##          ##
# ##############  ##  ##  ##  ##############
#                 ####
# ##  ##########      ####    ##########
#     ####          ##  ########    ######
# ####  ########    ####  ##  ####      ####
#       ##  ##      ############    ####  ##
#   ######  ####  ######  ##    ##  ##
#                 ##  ##  ##    ##  ##    ##
# ##############        ##  ##    ##      ##
# ##          ##  ##  ##        ######  ####
# ##  ######  ##  ####  ##  ##    ##
# ##  ######  ##  ##  ############    ##
# ##  ######  ##  ##      ##  ####  ##
# ##          ##    ##  ########          ##
# ##############  ##      ##      ######