HOW TO BLUR THE BACKGROUND OF A PHOTO WITHOUT FUZZY EDGES
Begin with a photo that looks like it could use a little depth.
Right click on the layer thumbnail and choose Convert To Smart Object
Choose Filter Blur Gallery>Field Blur
Set the blur to 15
Click to add a second blur point
To set it to zero Hold Cmd/Ctrl+Double click
Drag the points until the blur makes the background fall off in a realist way.
The result is a nice blur that looks like a more expensive lens than was used. Only problem, our person is blurred too. Let’s fix that now.
Click the eye icon to the left of the Smart Object to hide the smart blur. (A filter on a Smart object is called a Smart Filter because you can change its settings at any time).
Make selection around the person: Choose the selection brush and click select subject from the options bar. (If you are using an earlier Photoshop version, make the selection with the quick select brush, lasso or magic wand.)
Turn back on the Smart object and then choose the white mask under the layer
Press the D key to reset the foreground and background colors
Press Cmd/Ctrl+Backspace to fill the mask with black.
The person is now sharp because we masked away the filter where the selection is.
The only problem is that when you blur and mask, you will get a little bit of bleed. This means the edges are fuzzy because thats the overlap of the edges. I see this all the time in Photoshop work.
If you don’t mind, you are done. But if you are striving for perfection, read on.
I’m now going to show you how to get rid of that fuzz and make a perfect edge.
Duplicate the Layer (Cmd/Ctrl+J)
Turn it into a regular layer (no longer a Smart Object)
Right click on the layer thumbnail and choose Rasterize layer
Ctrl+Click on the White Layer mask on the original smart Object. This will load the selection of the person.
Press Cmd/Ctrl+J to copy the selected person to a new layer.
Hide or even delete the middle layer, its no longer needed.
Here I’m hiding the background just for a second, so you can see the cutout. You don’t need to do this.
Lets open the Smart Object Layer
Double click the thumbnail to open the Smart Object
Select our person again, by using the Select Subject like we did in step 9.
Choose Select>Modify>Feather and set it to 2 pixels, we are expanding beyond the edge so we get all of the person and don’t have any of the edges unselected.
Press Shift+Delete (Shift+ Backspace on Windows) for the fill dialog box
Choose Content Aware Fill for the Contents
Press ok and the person will be gone and filled somewhat with the surrounding image. It doesn’t have to be perfect for this.
Close the window that you were working in and choose YES when it asks to save.
Back in your main window with the top layer on, it should look like this.
Zoom in and see how nice the edges are now, no fuzzy edges anymore, just a realistic looking background blur what starts sharp and fades away naturally.