adobe photoshop - How do I extend an image by adding blur to sides?

I need to make an image 1080 x 1920. But when I do, the image looks very distorted. Is there a way I can extend an image by adding this blur to the sides of it? Also, does anyone know what this is called? I use Gimp as my primary editor. Any feedback would be appreciated

Answer

These are steps with Gimp (or any other image processing software) to add a blurred border to an image.

1. Select all of the image (Select > All)


2. Shrink selection to desired size for paste below (7).



3. Feather selection to desired size for paste below (7).


4. Copy selection (Edit > Copy) to clipboard


5. Scale image to desired output size.


6. Blur the scaled image (here I just used a radial blur):

7. Paste the image from clipboard:

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From the set of G'MIC plugins we also have a preset filter for a simple blurred frame (Frames > Frame [blur]).

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In case the background of an image we want to extend is not blurred but has many details we can use the Heal Selection tool to fill the extended areas.

1. Crop-Extend source image to desired size:

2. Select the extended background to apply heal selection:

3. Add blur to hide the artifacts produced by heal selection: