Open the photo in an editor
Duplicate the image layer
Select the side you want to blur
Feather the selection
Apply a blur filter
Adjust blur strength
Refine the edge if needed
Save the edited photo
Open the photo in an editor
Duplicate the image layer
Select the side you want to blur
Feather the selection
Apply a blur filter
Adjust blur strength
Refine the edge if needed
Save the edited photo