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. Perl

use chilkat();

$success = 0;

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

$json = chilkat::CkJsonObject->new();
$json->UpdateString("payload.text","CHILKAT");
$json->UpdateBool("output.includeModuleData",1);

$fmt = chilkat::CkFormats->new();
$jsonOut = chilkat::CkJsonObject->new();
$success = $fmt->QrCode("generate",$json,$jsonOut);
if ($success == 0) {
    print $fmt->lastErrorText() . "\r\n";
    exit;
}

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

#  The matrix is height rows of rowBytes bytes.
$bd = chilkat::CkBinData->new();
$success = $bd->AppendEncoded($jsonOut->stringOf("symbols[0].moduleData.bytesBase64"),"base64");
if ($success == 0) {
    print $bd->lastErrorText() . "\r\n";
    exit;
}

$sbRow = chilkat::CkStringBuilder->new();

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

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

        $mask = $mask / 2;
    }

    print $sbRow->getAsString() . "\r\n";
}

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

#  

#  Sample output:

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