multipart/form-data php curl

I am using the OCR Service of i2ocr.com to convert an image to text..

In my project, I need to do this work automatically so I am using PHP to get the text of the image.

In the OCR website the postdata is contained in the form of multipart/form-data

Like this:

-----------------------------32642708628732\r\n
Content-Disposition: form-data; name="i2ocr_options"\r\n
\r\n
url\r\n
-----------------------------32642708628732\r\n
Content-Disposition: form-data; name="i2ocr_uploadedfile"\r\n
\r\n
\r\n
-----------------------------32642708629732\r\n
Content-Disposition: form-data; name="i2ocr_url"\r\n
\r\n
http://www.murraydata.co.uk/wp-content/uploads/2013/02/ocr-font-500x220.jpg\r\n
-----------------------------32642708628732\r\n
Content-Disposition: form-data; name="i2ocr_languages"\r\n
\r\n
gb,eng\r\n
-----------------------------32642708628732--\r\n

In PHP I am using

$ch = curl_init();
$dt = array();
$dt['i2ocr_options'] = 'url';
$dt['i2ocr_uploadedfile'] = '';
$dt['i2ocr_url'] = 'http://www.murraydata.co.uk/wp-content/uploads/2013/02/ocr-font-500x220.jpg';
$dt['i2ocr_languages'] = 'gb,eng';


    curl_setopt($ch, CURLOPT_URL,"http://www.i2ocr.com/process_form");    
    curl_setopt($ch, CURLOPT_USERAGENT, "Mozilla/5.0 (Windows NT 6.1; rv:23.0) Gecko/20100101 Firefox/23.0");
    curl_setopt($ch,CURLOPT_ENCODING,"gzip,deflate");
    curl_setopt($ch, CURLOPT_HTTPHEADER, Array("Content-Type: multipart/form-data; boundary=---------------------------32642708628732"));
    curl_setopt($ch, CURLOPT_COOKIEJAR, $cookie);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
    curl_setopt($ch, CURLOPT_REFERER, "http://www.i2ocr.com/");
    curl_setopt($ch, CURLOPT_AUTOREFERER, 1);
    curl_setopt($ch, CURLOPT_POST, 1);
    curl_setopt($ch, CURLOPT_POSTFIELDS, "$dt");
    $html=curl_exec($ch);

    print_r($html);

This code does not generate any errors, but I do not get any output either.

I need help getting the output from this curl request.

Like this:

<?php
function get($url, $refer, $ch)
{
        curl_setopt ($ch, CURLOPT_URL,$url); 
        curl_setopt ($ch, CURLOPT_POST, 0);  
        curl_setopt ($ch, CURLOPT_COOKIEJAR, realpath('cookie.txt')); // cookie.txt 
        curl_setopt ($ch, CURLOPT_COOKIEFILE, realpath('cookie.txt'));
    curl_setopt ($ch, CURLOPT_FOLLOWLOCATION, 1);
    curl_setopt ($ch, CURLOPT_RETURNTRANSFER, 1);
    curl_setopt ($ch, CURLOPT_USERAGENT, 'Mozilla/5.0 (X11; U; Linux i586; de; rv:5.0)         Gecko/20100101 Firefox/5.0');
    curl_setopt ($ch, CURLOPT_REFERER, $refer);
    $result= curl_exec($ch);
    return $result;                 
}
function post($url, $refer, $parametros, $ch)
{
    curl_setopt ($ch, CURLOPT_URL,$url); 
    curl_setopt ($ch, CURLOPT_POST, 1); 
    curl_setopt ($ch, CURLOPT_POSTFIELDS, $parametros); 
    curl_setopt ($ch, CURLOPT_COOKIEJAR, realpath('cookie.txt')); // cookie.txt 
    curl_setopt ($ch, CURLOPT_COOKIEFILE, realpath('cookie.txt'));
    curl_setopt ($ch, CURLOPT_FOLLOWLOCATION, 1);
    curl_setopt ($ch, CURLOPT_RETURNTRANSFER, 1);
    curl_setopt ($ch, CURLOPT_USERAGENT, 'Mozilla/5.0 (X11; U; Linux i586; de; rv:5.0) Gecko/20100101 Firefox/5.0');
    curl_setopt ($ch, CURLOPT_REFERER, $refer);
    $result= curl_exec($ch);
    return $result;                 
}
function hazlo() {
$ch = curl_init();
/* STEP 1. visito la primera pagina para coger sus cookies */
get ("http://www.i2ocr.com/", "http://www.i2ocr.com/", $ch);

//STEP 2. Creo un array con los datos del post
$data = array(
'i2ocr_options' => 'url',
'i2ocr_uploadedfile' => '',
'i2ocr_url' => 'http://www.murraydata.co.uk/wp-content/uploads/2013/02/ocr-font-    500x220.jpg',
'i2ocr_languages' => 'gb,eng'
);
$data2 = http_build_query($data);

//STEP 3. Enviamos el el array en post
echo post ("http://www.i2ocr.com/process_form", "http://www.i2ocr.com/", $data2, $ch);
}
hazlo();
?>

use view source to see the response html, you can see the text of the image (sorry for my english). Works 100% :)