I'm having trouble displaying high dpi images in an Android WebView.

Firstly, I'm using this directive in my HTML:

```
<meta name="viewport" content="width=device-width" />

```

Background images are being specified as follows in my CSS:

```
.button {
    width: 100px;
    height: 50px;
    /* button.png is really 200x100 */
    background: url('../img/button.png') no-repeat 50% 50%;
    background-size: contain;
}

```

On Chrome for Android, this image appears very crisp. However in a WebView the image is blurry - as though it was 72dpi being upscaled.

Oddly, if I specify:

```
<meta name='viewport' content='target-densitydpi=device-dpi'>

```

then the image appears crisp, albeit the rest of the page is at half resolution too.

I've added things like `android:hardwareAccelerated="true"` and `android:anyDensity="true"` to my `AndroidManifest.xml` but none seem to make any difference.

Has anyone got any ideas?