Error while using while generating barcode

First:

I'm using the function below and I'm implementing a chile.

Reason: I need to generate several codes, for example: 1 2 3 4 5 .... 98 99 100, follow code:

<?php
 $i = 1;
while ($i <= 100) {

    function geraCodigoBarra($numero){
        $fino = 1;
        $largo = 3;
        $altura = 70;

        $barcodes[0] = '00110';
        $barcodes[1] = '10001';
        $barcodes[2] = '01001';
        $barcodes[3] = '11000';
        $barcodes[4] = '00101';
        $barcodes[5] = '10100';
        $barcodes[6] = '01100';
        $barcodes[7] = '00011';
        $barcodes[8] = '10010';
        $barcodes[9] = '01010';

        for($f1 = 9; $f1 >= 0; $f1--){
            for($f2 = 9; $f2 >= 0; $f2--){
                $f = ($f1*10)+$f2;
                $texto = '';
                for($i = 1; $i < 6; $i++){
                    $texto .= substr($barcodes[$f1], ($i-1), 1).substr($barcodes[$f2] ,($i-1), 1);
                }
                $barcodes[$f] = $texto;
            }
        }

        echo '<img src="imagens/p.gif" width="'.$fino.'" height="'.$altura.'" border="0" />';
        echo '<img src="imagens/b.gif" width="'.$fino.'" height="'.$altura.'" border="0" />';
        echo '<img src="imagens/p.gif" width="'.$fino.'" height="'.$altura.'" border="0" />';
        echo '<img src="imagens/b.gif" width="'.$fino.'" height="'.$altura.'" border="0" />';

        echo '<img ';

        $texto = $numero;

        if((strlen($texto) % 2) <> 0){
            $texto = '0'.$texto;
        }

        while(strlen($texto) > 0){
            $i = round(substr($texto, 0, 2));
            $texto = substr($texto, strlen($texto)-(strlen($texto)-2), (strlen($texto)-2));

            if(isset($barcodes[$i])){
                $f = $barcodes[$i];
            }

            for($i = 1; $i < 11; $i+=2){
                if(substr($f, ($i-1), 1) == '0'){
                    $f1 = $fino ;
                }else{
                    $f1 = $largo ;
                }

                echo 'src="imagens/p.gif" width="'.$f1.'" height="'.$altura.'" border="0">';
                echo '<img ';

                if(substr($f, $i, 1) == '0'){
                    $f2 = $fino ;
                }else{
                    $f2 = $largo ;
                }

                echo 'src="imagens/b.gif" width="'.$f2.'" height="'.$altura.'" border="0">';
                echo '<img ';
            }
        }
        echo 'src="imagens/p.gif" width="'.$largo.'" height="'.$altura.'" border="0" />';
        echo '<img src="imagens/b.gif" width="'.$fino.'" height="'.$altura.'" border="0" />';
        echo '<img src="imagens/p.gif" width="1" height="'.$altura.'" border="0" />';
        echo'<br>';
        echo'<br>';
        echo"EAN: $i";
    }

    geraCodigoBarra('$i');

    echo $i++;

    }
?>

Follow-up:

  

EAN: 111 Fatal error: Can not redeclare geraCodeBar () (previously   declared in C: \ xampp \ htdocs \ cb \ index.php: 10) in   C: \ xampp \ htdocs \ cb \ index.php on line 10

Second:  After generating these codes, you can export them separately to .jpg? For a given folder? If so how could you do it?

To finish:  

I need the code to be 13 numbers, as an em- ployment in my code to add zeros and transform, for example: 1 to 0000000000001