Is it possible to make a blur of an item which is behind another item?

Example: blur a part of image (like in qml - parent.centerIn: image)

![Blur example](https://i.stack.imgur.com/1ijs3.png)

I want something like: 

```
Image { id: img
    anchors.fill: parent
    source: "bug.png"

    Item { id: info
        anchors.centerIn: parent
        height: 200
        width: 200

        Text {
            text: "HAMMER TIME"
            color: "white"
        }

        /* BLUR CODE HERE TO BLUR BACKGROUND OF THIS ITEM */
        /* which is a part of "bug.png" image with 200x200 size */
        /* and offset equals to "info.x" and "info.y" */
    }
}

```

This question affects any `shader effect` because official docs dont have an answer for the question and all of my attempts are unsuccessfull - it is only possible to blur *WHOLE ITEM* but not a part of it.