You can use a photo as background picture on the page. The easiest way is to select a layout with the photo as a background. Then delete the smaller frames on top of it. (Click on each of the smaller frame and then click on the "X" to clear/delete frame.)
Here is a screenshot as an example. Then you can click on Properties to apply a filter or change its opacity, brightness, etc.

Here is a screenshot as an example. Then you can click on Properties to apply a filter or change its opacity, brightness, etc.
