How can I smooth out an image but keep the detail ?

I have an image of different exposures, and there are clear boundaries between the exposures. How could I remove the boundaries and keep the detail. Right now I’m using Gaussian filter to smooth it out but the image is left blurred.

Answer 1

[Image Analyst]

You'd have to somehow identify the boundary/interface region and compute the exposure on each side of the interface. Then replace one of them with a version that is brighter or darker such that it's interface region will now match the brightness of the other region in that area. It may be difficult to get it to match around every pixel along the boundary if you have an image pasted onto another.