" Input: {
string - string to convert to qr-code
(qr_level) - qr_level (default=3)
(image_size) - picture size (default=512)
(image_type) - picture type (default=PNG)
(web) - if 'yes', return as web output
(filename) - file to write (if not web) (default - qr-code.png)
}
Output: {
return - return code = 0, if successful
> 0, if error
(error) - error text if return > 0
full_filename - file with image
}
"