Blur filter в CSS

.parent{ 
  background-image:url("https://cdn.sstatic.net/Sites/stackoverflow/img/error-lolcat-problemz.jpg"); 
  background-position:center center; 
  background-repeat:no-repeat; 
  background-size:cover; 
  height:200px; 
  padding:50px 0; 
} 
.inner{ 
  overflow:hidden; 
} 
.blur{ 
  background-image:url("https://cdn.sstatic.net/Sites/stackoverflow/img/error-lolcat-problemz.jpg"); 
  background-position:center center; 
  background-repeat:no-repeat; 
  background-size:cover; 
  height:100px; 
  filter: blur(10px); 
}

<div class="parent"> 
  <div class="inner"><div class="blur"></div></div> 
</div>