Why Doesn't This Work?

[Dysan]

I have the following code, that carries out the following in order to create a barcode on the fly. But for some strange reason, the barcodes doesn't scan once printed. Why is this? - How else are Code 39 Barcodes encoded?

 

Basically, the code converts an ASCII string into a Binary string.

The code then searches the Binary string and upon finding a 0 outputs a white bar (rectangle), and a black bar upon finding a 1.

 

<?php
$rectangle_width = 2;
$rectangle_height = 20;

$image = imagecreatetruecolor(500, 182);
$white = imagecolorallocate($image, 255, 255, 255);
$black = imagecolorallocate($image, 0, 0, 0);
imagefill($image, 0, 0, $white);

$find = array('0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '*');
$replace = array('00110000', '00110001', '00110010', '00110011', '00110100', '00110101', '00110110', '00110111', '00111000', '00111001', '00101010');

$string = '*1101*';
$textstring = str_replace($find, $replace, $string);

$j = 0;
$sarray = str_split($textstring, 1);
for($i = 0; $i < count($sarray); $i++)
{
    if($sarray[$i] ==  '0')
    {
        imagefilledrectangle($image, $rectangle_width * $j, 0, ($rectangle_width * $j) + $rectangle_width, $rectangle_height, $white);
        $j++;
        
    }
    elseif($sarray[$i] ==  '1')
    {
        imagefilledrectangle($image, $rectangle_width * $j, 0, ($rectangle_width * $j) + $rectangle_width, $rectangle_height, $black);
        $j++;
    }
} 

header("Content-type: image/jpeg");
imagejpeg($image);
imagedestroy($image);
?>

[Daukan]

Works for me. I just tried it on server.

[Dysan]

Yes it works on computer, but the barcode scanner doesn't scan it once printed. Why is this?

[revraz]

May have to ask the Barcode Reader company.

[Dysan]

What you think it looks OK? How come if you change the string *1101* to * the barcode for the * isn't the same as shown on the picture here:

 

http://www.codeproject.com/bitmap/barcode1.asp?df=100&forumid=4090&exp=0&select=1905375