Filmage Editor can help you add background to a video easily. 1. Open a video project and click the video which is on the track and you want to add a background to; 2. Click the “Add Background”;
3. And the box of adding a background will appear at the upper right of the interface;
4. Then you can choose the color you’d like to fill in the background. You can also modify blurriness of the background by the tab of “Fuzzy”. Click “Fuzzy”, and the box of adding background blur will appear.