How to change the background of a photo

Change a photo background in seven steps

1. 1

   Open the subject photo

   At lilcactus.app, choose File› then Open… (Ctrl+O or ⌘O) or open the portrait sample from this page. It becomes the Background layer.

   To follow along, download the café terrace background too. Both samples are 1536 × 1024 pixels, so the replacement fills the same canvas without resizing.

2. 2

   Select the person

   Choose Select› then Subject. Wait for the dotted selection outline around the woman. The first use downloads the AI model; the selection itself is processed on your device.

   Check the hair, shoulders and sleeves. If part of the subject is missing, right-click the selection-tool group and choose Quick Selection. Paint over the missing area to add it; hold Alt or ⌥ while painting to subtract unwanted background.

   

   

3. 3

   Refine the edge and keep an editable mask

   Choose Select› then Refine Edge… Keep Adapt to edge checked, Maximum edge recovery at 8 px and Remove background color at 100% for the sample. Edge recovery searches a band around the outline for fine detail; removing background color reduces the old street color in partially transparent hair.

   Set Zoom to 100% and compare Preview on White and Black. Look for a bright fringe, stray street pixels or missing hair. Leave Output on New layer with editable mask and click Apply.

   The new Background cut-out layer has a black-and-white mask beside its image thumbnail. White shows the subject; black hides the street. The original Background layer is switched off underneath. Double-click the new layer’s name, type Portrait and press Enter or ↩.

   

   

   

4. 4

   Place the new background in this document

   Choose File› then Place Image as Layer… and select sunlit-terrace.jpg. A layer called sunlit-terrace appears above Portrait. It covers the woman for now because it is higher in the stack.

   Use Place rather than Open for this step: Open makes a separate document, while Place adds the photo to the document you are editing.

   

5. 5

   Put the new background below the portrait

   In Layers, drag the sunlit-terrace row to just below Portrait, above the hidden original Background. Release over the lower half of the Portrait row. The woman reappears over the terrace.

   For the samples, leave both photos in their original positions. The tables stay to the left and the woman fills the open space at right center. Check that the replacement covers the whole canvas.

   Tip If your background is smaller or a different shape, use the sizing instructions below before continuing.

   

   

6. 6

   Match the light and color

   Click the image thumbnail for Portrait, not its mask, and choose Layer› then New Adjustment Layer› then Brightness/Contrast… For these samples, start with Brightness −10 and Contrast +8, leaving Use Legacy off. These changes darken the portrait slightly and deepen its shadows for the warm sunlit setting. Click Apply.

   With the new adjustment selected, choose Layer› then Create/Release Clipping Mask. A bent arrow appears beside its thumbnail. This restricts the adjustment to Portrait, so the café returns to its original light.

   To warm the portrait’s midtones, add Layer› then New Adjustment Layer› then Color Balance… above that adjustment. In Midtones, set Cyan – Red to +12 and Yellow – Blue to −16. Leave Magenta – Green at 0 and enable Preserve Luminosity. Click Apply and use Create/Release Clipping Mask for this layer too.

   For your own photos, start at 0 and move one control at a time. Compare skin, white clothing and shadows with the setting. Click an adjustment’s eye to compare before and after; stop before the skin looks gray or the highlights lose their shape.

   

   

   

   

   

7. 7

   Export the picture and save the layers

   Choose File› then Export› then JPEG…, name the copy portrait-cafe.jpg and click Export. The copy combines the visible layers. JPEG suits a photo with a filled background; use PNG if you need transparent areas.

   Choose File› then Save As› then Lil Cactus Project… to keep the background, mask and adjustments editable. After saving as a project, File› then Save saves that project. For an opened image, Save writes back in its own format: JPEG and PNG stay flat, while PSD keeps its supported layers. For an image opened from this page, or any JPEG, the first Save opens the Save Image dialog. Export always writes a new file.

   

   

Fit a background that is a different size

Select the replacement photo’s image thumbnail in Layers, then choose Edit› then Free Transform. Keep the chain link after H on so scaling preserves proportions. Drag a corner to enlarge the background until it covers every canvas edge. Drag inside the frame to position it, then click Commit transform on the options bar or press Enter or ↩.

Fill the canvas by letting the background extend beyond its edges. Stretching width and height separately makes doors, people or furniture look distorted. Enlarging a small photo cannot recover missing detail; choose a larger background when the result looks soft.

Make the two photos look like one scene

• Light direction: compare the bright side of the face with bright edges in the setting. Choose a background lit from the same side.
• Camera height: a portrait taken at eye level fits a setting photographed at a similar height. An overhead view of a room will make a standing person look out of place.
• Scale: compare the person with nearby doors, tables or chairs. Keep a waist-up portrait reaching the canvas edge; moving it upward exposes its abruptly cut lower edge.
• Sharpness: a close portrait can sit against a softer distant background. Avoid pairing a blurry subject with a sharply detailed setting.
• Contact: a full-length person or product needs a convincing point of contact with the ground. Keep an existing compatible shadow where possible, or choose a composition that does not show the feet. The sample ends at the waist, so no ground shadow is needed.

Use a plain color instead of another photo

Choose Layer› then New Fill Layer› then Solid Color…, pick the color and apply it. Drag the fill layer below Portrait. To use white, choose white in the fill layer; this keeps the background color editable in the project.

If you only need a transparent cut-out, leave the replacement and fill layers hidden and export PNG. Follow how to remove a photo background for the shorter workflow.

Repair the edge against the new background

Inspect the hair, shoulders and clothing at 100%. Click Portrait’s mask thumbnail, choose the Brush (B) and press D for black and white. Paint black to hide remaining street pixels and white to reveal missing parts of the cut-out; X swaps the colors. Use small strokes and undo a stroke if it removes too much.

For a colored fringe in fine hair, see the Refine Edge instructions.

For larger repairs, follow how to paint and edit a layer mask.

Fix common problems

The new background covers the person

It is above Portrait in Layers. Drag it below the cut-out. Check that Portrait’s eye is on.

The old street is still visible

Keep the original Background layer switched off. If the street appears only along an edge, repair the cut-out’s mask rather than hiding the replacement.

My color adjustment changes the café too

Select the adjustment and use Layer › Create/Release Clipping Mask. Check for the bent arrow and keep the adjustment directly above Portrait or its other clipped adjustments.

There is a white strip in the JPEG

The background does not cover that part of the canvas. Select it and use Free Transform to fill the frame; JPEG fills remaining transparency with white.

I cannot change the background in my exported JPG

The exported copy is one flat picture. Open the Lil Cactus Project to change the separate background layer.

Finish the new portrait

• Set the output dimensions: resize the image.
• Meet an upload limit: compress the photo.
• Soften a busy setting: blur the background.
• Add a headline: make a YouTube thumbnail.

Coming from another editor

Photoshop

Select › Subject and a layer mask in Layers; File › Place Embedded adds the replacement photo. Layer › Create Clipping Mask restricts an adjustment to the cut-out below it.

GIMP

Tools › Selection Tools › Foreground Select for the subject, Layer › Mask › Add Layer Masks…, then File › Open as Layers… for the replacement background.

Changing photo backgrounds: questions and answers