maxWidth for RessourceType

Have you tried adding another in config.php? (assuming your using php)
$config['_RESOURCE_FOLDER_'] = Array(
'maxWidth' => 150,
'maxHeight' => 150,
'quality' => 80);

Oli

I assume that you would like to set different

$config['Images'] = Array(
      'maxWidth' => 1600,
      'maxHeight' => 1200,
      'quality' => 80);

for each resource type?

It is not implemented in CKFinder, however because config file is a server side script, you can actually easily do it by checking the query string.

Sample change for PHP version of CKFinder:

// Set different values for the "Files" resource type
if (!empty($_GET['type']) && $_GET['type']=='Files') {
   $config['Images'] = Array(
      'maxWidth' => 1600,
      'maxHeight' => 1200,
      'quality' => 80);
}
// default values for other resource types
else {
   $config['Images'] = Array(
      'maxWidth' => 300,
      'maxHeight' => 250,
      'quality' => 80);
}

The solution suggested by olirav will not work.