Features › Background replace
The subject is usually fine. The room behind it is the problem: cluttered, dim, or just dull. Upload the shot, say what should be behind it instead, and the scene gets rebuilt with the lighting following the new background rather than being pasted over it.
A photo of you, a product, a screenshot, whatever the subject is.
A place, a colour field, a gradient, a scene. Say how it should be lit.
The subject is kept, the surroundings are rebuilt, and the light on the subject is matched to the new scene.
Not exactly. Rather than cutting the subject out and dropping it on a new layer, the image is generated again with the subject kept and the scene rebuilt, so the lighting matches.
Yes, and for text-heavy thumbnails a flat or gradient background is usually the stronger choice.