Removing Edge Halos Using Defringe

If you’re working with an object with no background and the edge contains a halo, you can use the Defringe command to remove it.

Go to Layer > Matting > Defringe and enter a value in pixels. Photoshop will then analyze the image and replace the color of the pixels around the object’s edge with the color of nearby pixels, thus removing the edge halo. Unfortunately this command does not work on masks.