Image in binary form

[varunkumar31]

How to get image in binary form from controller ?
I used below code in controller but Image is not correct ?
$this->load->library('ciqrcode');
//$qrCodeObj = new Ciqrcode();
$params['data'] = 'VON';
$params['level'] = 'H';
$params['size'] = 10;
$filename = rand(100, 20000).'.png';
//$params['savename'] = '';
ob_start();
$this->ciqrcode->generate($params);
$imageString = base64_encode( ob_get_contents() );
ob_end_clean();
//use $imageString for further use
This code working without codeIgnitor using (phpqrcode library) but in codeIgnitor its not working. Please suggest how to get binary image data using this library.