The method of adding a signature to a photo with ps is:

1. Sign on the white paper with a pen.

2. Use a camera or scanner to form a signed digital photo, as shown below:

3. Open the picture in PS.

4. Select-Color Range-Select Red-Parameter 200, as shown in the following figure:

5. Copy and paste.

6. Open the photo.

7. Pull the signature into the photo, as shown below: