min_width and min_height for the upload class?

[eluser]chefnelone[/eluser]
[quote author="teampoop" date="1291246123"]There are configuration parameters for the file upload library. Check out CI/user_guide/libraries/file_uploading.html for more details.

Code:

$config['upload_path'] = './uploads/';
$config['allowed_types'] = 'gif|jpg|png';
$config['max_size']    = '100';
$config['max_width'] = '1024';
$config['max_height'] = '768';

$this->load->library('upload', $config);

// Alternately you can set preferences by calling the initialize function. Useful if you auto-load the class:
$this->upload->initialize($config);

[/quote]

I checked the user guide. But min_width and min_height are not include as parameter in the upload class. This http://ellislab.com/forums/viewthread/143418/#730179 shows a way to include these parameters... but it isn't working for me.