Blur part of an image with CSS

Question

I have a problem with an image. I tried to blur a part of an image, but my solution deosn't work. Please, take a look at this code:

HTML file

<div id="image">
    <div class="blur"></div>
</div>

CSS file

#image {
    width: 940px;
    height: 360px;
    background-image: url('../img/photo.png');
}

#image .blur {
    background-image: url('../img/photo.png');
    background-position: center right;
    -webkit-filter: blur(3px);
    -moz-filter: blur(3px);
    -o-filter: blur(3px);
    -ms-filter: blur(3px);
    filter: blur(3px);
    filter: blur(3px);
    float: right;
    height: 100%;
    width: 360px;
}

It's possible in CSS?

Answer 1

I have set the overflow property of the outer div to hidden and the margin-right of the inner one to -1 and it worked like a charm.

#image {
    ...
    overflow: hidden;
}

#image .blur {
    ...
    margin-right: -1px;
}

Here is the working example in JSFiddle.

#image {
    width: 940px;
    height: 360px;
    overflow: hidden;
    background-image: url('https://upload.wikimedia.org/wikipedia/commons/thumb/e/e3/Nuvola_wikipedia_icon.png/240px-Nuvola_wikipedia_icon.png');
}

#image .blur {
    background-image: url('https://upload.wikimedia.org/wikipedia/commons/thumb/e/e3/Nuvola_wikipedia_icon.png/240px-Nuvola_wikipedia_icon.png');
    background-position: center right;
    -webkit-filter: blur(3px);
    -moz-filter: blur(3px);
    -o-filter: blur(3px);
    -ms-filter: blur(3px);
    filter: blur(3px);
    filter: blur(3px);
    float: right;
    height: 100%;
    width: 360px;
    margin-right: -1px;
}

<div id="image">
    <div class="blur"></div>
</div>

Answer 2

You choose a suitable background-position for the outer div.

Make inner div position:absolute. This is where the blur appears. Apply blur to the :before selector.

JSFiddle Demo