1.PS After opening the picture, you can see that the edge has been jagged because of the small resolution of the picture itself. Click the "Image" button in the toolbar above;

2. In the "Image" drop-down list, select the "Image Size" item;

3. In the "Image Size" window that pops up, select the value after "Resolution" and change it. Because the resolution is improved, the changed value here only needs to be greater than the original value. The original value here is 120, and the changed value should be greater than120;

4. After the resolution value is increased, click "resample" below to expand the list;

5. Select the "Quadratic Cube (Smooth Gradient)" option in the sampling list;

6. After the setting is completed, click [OK] to complete the setting;

7. The effect is shown in the figure.