Get bestseller products filter by category id

Get Only 10 Prodects Magento already uses bestseller products aggregation that can be checked under Admin > Reports > Products > Bestsellers. Thanks to this aggregated data we no longer need to determine the total of all the orders to see which products are sold the most. By the variety of aggregation data we are able to get the most popular products not only from the beginning, but for each specific day, month or year

$productCount = 10;  //insert how much prodect
    $storeId    = Mage::app()->getStore()->getId();      
    $collection = Mage::getResourceModel('reports/product_collection')
               	  ->setOrder('ordered_qty', 'desc')
  <?php foreach ($collection as $_product):  ?>
              get collection
  <?php endforeach; ?>