A manual technique for keeping part of a photo's original background as real photography while letting AI generate the rest. After running Remove Background to cut the subject onto a layer mask, duplicate that layer and re-run Remove Background on the duplicate. Use the Rectangular Marquee tool to select the region that must stay unedited (e.g. the floor a subject is standing on), target the layer mask, and fill the selection with white — this restores the original pixels in that region on the mask (see Active Selection Auto-Loads as New Layer Mask). Then generate a new background for the rest of the scene via Generate Background-style prompting; only the unselected area receives AI content. Finish with Upscale to sharpen the generated portion.
Gives a controllable boundary between 'real' and 'AI-generated' pixels within a single layer mask — useful whenever part of a shot (product, floor, hands) must stay literal while the rest of the scene is reimagined.