Change one area and leave the rest alone
Paint over the part you want changed, describe it, and nothing else moves.
SamImageGenerator ·
The brush is what turns a generator into an editor. Paint over the part of the picture you want changed, write what should happen there, and the instruction sent to the model becomes "change only the marked area". Everything outside the mark is protected.
Why this is different from prompting a whole change
Without a mask, a request like "change the sky" is a suggestion about the whole frame, and the model is free to redraw the building, the road and the light while it is at it. With a mask, the scope is explicit: sky changes, building does not. That is the difference between one clean edit and three regenerations that each break something else.
Working with several areas
You can mark more than one region and give each its own note — "new sky" here, "remove this sign" there — and one pass handles both. Marks are numbered and each note is tied to its number, so short and specific beats long and descriptive: "remove", "make it red", "replace with a wooden chair".
| Job | Mark | Note |
|---|---|---|
| Replace a sky | The sky only | dramatic sunset sky |
| Remove an object | The object plus a little margin | remove, fill with the wall behind |
| Change a colour | The item | make the jacket dark green |
| Add something | The empty space | a potted plant on the floor |
When the mask is not the answer
If more than about half the frame is changing, generating a new image is usually faster and cleaner than masking most of the picture. And if what you want is the same content in another look, that is a restyle rather than a masked edit — see turning a photo into another style. Every path here costs one credit per image, so trying the cheap one first is rarely wasted.