XnView Software

Hi, After years of using XnViewMP for image viewing, I just realized it can also serve as a windowed slideshow! amazing! (i was using another software for that)

The suggestion is to add an "on the fly" blurred frame", to make the image more beautiful, than how would they appear with black bars.

Cheers!

do you have a screenshot for example?

Davinci Resolve has an effect called 'Blanking Fill' which is one option for how this might look.

One of the parameters in that effect is 'Blend Edges', which smudges from the image to the background. That might be something like OP is suggesting. See attached.