Adding a background image to a row in Visual Composer is pretty easy.
- Click on the 'pen' icon at the end of the row to edit it.
- Next, click on the 'Design Options' tab.
- You can add an image under the 'Background' field.
- Ensure you set 'Cover' in the dropdown below it to make it fill the width of the row.
You can add a 'Parallax' effect to the row within the 'General' tab if you wish.