Thursday, March 09, 2023

Sky Replacement Wars

 I consider this a relatively small digression in the Ai developments in photography. With the introduction of layers and masking in Adobe Photoshop, the ability to replace anything with something else, for example, a new sky has been possible. Albeit tedious. If the horizon was flat and only a few simple shapes against the sky made this easy. However bare deciduous trees, open foliage or fly-away hair and anything with a complex edge made this very time-consuming, especially when using the masking brush. This ability became an art form and photoshopping became a verb to describe this type of image manipulation.

I think it was Skylum's Luminar AI (a predecessor to Luminar Neo) that first added AI tools to make the sky masking fairly automatic and let you choose different skies from a library of beautiful skies. Further, it was heavily promoted, was popular and there was a lot of hype in the photo YouTube and podcast communities.

Other software developers quickly followed, some in a few weeks, with a variety of outcomes. So sky replacement became a very big issue comparing software offerings. How well the sky matched into the rest of the photo became important, as did being able to build and organize your own cloud image library.



The complexity of fiddly edges in the masking was helped as masking AI improvements where made. Also the methods applied to blend other aspects of the photo such as the reflection of the sky on water or wet surface or adding matching atmosphere effects.

In the illustrations here I have used simple “one-click” sky comparisons on two complex situations, the complex interconnecting lines of power cables and electricity transmission towers, and the bare tree branch silhouette. Comparing such sky replacement in current versions of Luminar Neo and On1 Photo RAW 2022, The results are good but not perfect. Both packages do offer other tools such as refining the mask edges and better colour balance etc.



The hype has faded but pretty well all the dominant software editing suites now offer AI assisted sky replacement.


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