1. Open the image file with official seal in photoshop.

2. Press CTRL+J to copy the background layer to get the layer 1.

3. Execute "Select-Color Range" and click the red official seal with a straw. If the red color is not enough for the first time, click the "+"straw on the right, then enlarge the red range, and watch the preview in the middle while sucking until it is suitable.

4. Press CTRL+J to copy the image in the selection to a new layer to get layer 2.

5. Click Layer 1 to create a new layer, and get Layer 3, which is filled with white. Placed between layers 1 and 2.

Dig official seal

The outline of the official seal is probably taken out, and further color processing is needed to repair the circle at the lower right of the official seal.

6. Now that the official seal dug out by PS is very weak, just use one trick, click on Layer 2, press CTRL+J repeatedly, and copy Layer 2 to get N layers. Finally, these layers are combined to make the outline of the official seal clearer.

7. Create a new hue saturation adjustment layer, select red, and make the adjustment as shown below. At this point, the color of the official seal has been corrected.

8. In the final details, some places with mottled colors or missing official seal details will be repaired with imitation seals or repair tools. Ps, this is the end of the official seal step.