How to Blur the Background in a Photo Already Taken With iPhotoby Steven J. MillerUpdated September 22, 2017
Apple operating systems come standard with iPhoto. This application allows you to organize, manipulate and edit your photos using simple commands located within the program. Blurring the background of a photo requires you to use the "Edge Blur" command. The level of blur that you want will depend on your needs. The command has several different levels that will allow you to customize the level of blur you would like to use on the photo.
Open iPhoto and drag your photo into the main window to import the image file. If the image file is already there, you do not need to complete this step. Just find the photo in the preview pane of iPhoto.
Select the photo and right-click the photo to open the drop-down menu. From the menu, select the "Edit" option that fits your preference. You can edit in full-screen mode or regular mode in which the picture does not take up the entire screen.
Click the "Effects" menu at the bottom of the screen. Select the "Edge Blur" option from the list of options. This will blue the background level. You can select a blur level of 1 to 11 depending on how much blur you want.