Server side Validation for image upload

[eluser]MASS MASS[/eluser]
I am using upload library to upload image........

$config['allowed_types'] = 'gif|png|jpg';
$config['max_size'] = '10000';
$config['max_width'] = '200';
$config['max_heigth'] = '200';
$config['upload_path'] = './uploads/'
$this->load->library('upload', $config);


while user uploading image........user should upload minimum widht and minimum height

for this how to do.........

CI have only max_width and max_heigth.........