How to use ps to add a filter to the background

1. Open the original image. In order not to destroy the original image, we need to copy the background layer (Ctrl+J) to copy it quickly.

2. Find the natural saturation brightness/contrast option and adjust the saturation, contrast and brightness of the image.

3. Select the Rectangular Marquee Tool and draw a rectangular Marquee on the layer.

4. We click Select-Modify-Smooth, and the size is 50.

5. Click Select-Modify-Feather Size 30.

6. Click Select-Reverse-Fill the background color (the background color here refers to the color bluer than the layer background)-and change the image blending mode to overlay.

7. Click Select-Reverse

8. Click Select-Modify-Shrink the size to 30.

9. Fill the foreground color-the blending mode is superposition, and the steps are the same as 6-deselect (CTRL+D)-reduce the opacity.