You can modify the pictures in the gallery. Take Huawei Glory 8 mobile phone as an example. The method is as follows:

1. Open the gallery app, as shown below.

2. Open the photo album and find the photos that need matting, as shown below.

3. Select to open the photo, as shown in the figure below.

4. Select the following editing options, as shown in the figure below.

You can decorate the picture by choosing the following options.