How to get full product image url in Magento
After you loaded your product using load()
you can use the following in your code:
Full size image:
$imageUrl = Mage::getBaseUrl(Mage_Core_Model_Store::URL_TYPE_MEDIA) . 'catalog/product' . $product->getImage();
Resized/Cached image:
$imageCacheUrl = Mage::helper('catalog/image')->init($product, 'image')->resize(135, 135);
If you need a different cache size, then use other numbers for the resize method.
You can try below code first of all call helper of catalog
echo Mage::helper('catalog/image')->init($product, 'thumbnail');
From this code you can get cache path also.
Try this
$product = Mage::getModel('catalog/product')->load($product_id);
$full_path_url = Mage::helper('catalog/image')->init($product, 'thumbnail');