Outpainting

The edge is the only clue it has

Outpainting starts by setting the original photo down on a bigger, empty canvas. The spot the original sits on stays fixed, and only the empty space around it gets built. At every step, the original's spot gets pasted back over from the source, so the photo itself never drifts. The method is the same one used to fix something on the inside — the only difference is whether you're working inward or outward.

The hard part is that the clue only comes from one side. Fill something on the inside and you get pattern and color from every direction; fill the outside and there's just that one strip of original edge to build the rest from. A clear line running through it — a horizon, a wall corner, a road — stitches on well. A messy edge gives a messy result.

Widen a little at a time

Double the canvas in one pass and the outer half sits too far from the original to guess well, so it drifts into a scene with nothing to do with the source. Widen a hand's width at a time instead, and what you just built becomes the next pass's clue, so the flow keeps going.

Pick one direction at a time, too. Stretch left-right and up-down together and the four corners have no clear clue to follow, so they blur out. Widen left first, finish it, then widen up — now the corners have an already-built neighbor to follow.

Even done gradually, a slow drift creeps in over several passes: colors fade a little, the same pattern repeats, light shifts direction. Every few passes, it helps to look the whole thing over and fix whatever's drifted.

You can say what fills the new space

Leave the sentence field blank and the tool just keeps going with whatever the original was doing — an alley photo gets more alley, a field photo gets more field.

Write a sentence and you decide what shows up in the new space. Describe both the original scene and what you want to appear outside it — describe only the outside and you'll get a scene with a different feel stitched on next to the original, and the seam will show.

Where it's useful

The most common use is changing the aspect ratio. A photo shot tall that needs to fill a wide frame gets widened on the sides instead of cropped, so nothing from the original gets thrown away.

There's a place to be careful, too. Asking it to redraw the rest of a person or object that got cut off at the frame's edge tends to look off — limbs and posts are shapes your eye tracks closely, and the smallest mismatch stands out. It's usually faster to widen first and then repaint just the awkward part.

It's also handy for opening up space for text. Building a banner or a cover and need room up top? Widen upward only and let the sky extend. The same trick adds a bit of extra margin outside a print job's trim line.