Here is a quick and easy technique to blur photo border using Photoshop. I found this is helpful in portraits to bring more emphasis to the subject matter similar to adding a vignette. It is also helpful diminish any distracting details that may be in the background or to blend an expanded canvas with the original photo.
1. In Photoshop, copy your Background Layer or click on the Background Layer to convert it to Layer 0.
2. You can use either the elliptical or rectangle tool to isolate the area you want in focus. Personally, I tend to use the elliptical tool more frequently. It seems to blend better for me.
3. Feather the area between 5 and 10 pixels. You may have to experiment with the amount depending on your subject and composition.
4. Invert your Selection by either using shortcut keys Shift/Command/I or the top toolbar Select > Inverse.
4. Create a Layer Mask by clicking on the Add Layer Mask icon on the bottom of the Layer’s Palette.
5. Create the blur using the Gaussian Blur filter. On the top tool bar select Filter > Blur > Gaussian Blur. You will also have to experiment with amount to get the your desired effect.
6. If the blur is too intense, use the Opacity Slider to decrease the amount on the Layer Pallete. If you would like to remove the blur from certain areas, use your brush tool on the Layer Mask and paint in black the areas you want to remove or in black for areas you want to add the blur.
As with much of Photoshop, there are many ways to do one task or effect and to blur photo border is no exception, so experiment with this technique and other Blur options available under the Filter Toolbar or also with the Blur Tool.
Thanks for reading and happy editing. Visit my gallery to view more of my work.