You can use regex to extract only background image or background:url format
$str="
<div class="thumb">
<a href="http://goruzont.blogspot.com/2017/04/blog-post_6440.html" style="background:url(https://1.bp.blogspot.com/-6vpIH5iqPYs/WPzlNdxsRpI/AAAAAAAAntU/d7U_Ch_6FiIPwosNL4tWwqBeXw8qwo2nACLcB/s1600/1424051.jpg) no-repeat center center;background-size:cover">
<span class="thumb-overlay"></span></a>
</div>";
preg_match_all('~\bbackground(-image)?\s*:(.*?)\(\s*(\'|")?(?<image>.*?)\3?\s*\)~i',$str,$matches);
$images = $matches['image'];
foreach($images as $img){
echo $img;
}
# https://1.bp.blogspot.com/-6vpIH5iqPYs/WPzlNdxsRpI/AAAAAAAAntU/d7U_Ch_6FiIPwosNL4tWwqBeXw8qwo2nACLcB/s1600/1424051.jpg
3
solved Web scraping photo in PHP