Get particular category all product images

<?php

$cat_id = 513;  //category id
$category = Mage::getModel('catalog/category')->load($cat_id);
$collection = $category->getProductCollection()->addAttributeToSort('position');
Mage::getModel('catalog/layer')->prepareProductCollection($collection);
?>
<ul id="mycarousel" class="jcarousel-skin-tango">
<li>
<?php
foreach ($collection as $product) {
?>
   
<img src="<?php echo $this->helper('catalog/image')->init($product, 'small_image')->resize(150, 118); ?>"  alt="<?php echo $this->htmlEscape($product->getName()) ?>" />
 </li>
</ul>
<?php    
  
}

?>