Remove a background
How to Remove a Background in Photasium
A product on a table, a person against a wall, or a logo on a coloured card often needs the subject on its own. In Photasium that happens in the tab: the file never goes to a server.
A cut around the subject
Remove background finds the subject on the active raster layer and builds a mask from it. Edge shift moves that edge in or out, from -20 to 20 pixels, and starts at 0. Edge softness feathers the edge, from 0 to 20 pixels, and starts at 0.
Fill floods one connected colour, which suits a flat wall. Wand selects matching colour, and Delete clears those pixels. Remove background looks for the subject on a busier photo, then you choose whether to erase, mask, cut out, or select it.
The subject on a plain field
A story often wants the person or the product on a plain field, or sitting over type. Erase the background, then fill a layer underneath, or drop another photo on the canvas.
Duplicate the raster first if you want the original pixels still in the stack. Layers keeps that copy. Put the cutout on a new layer keeps it too: the new layer takes the source name with cutout on the end, and the source is hidden.
A listing wants the product on white or on a clear field. Erase the background, then export PNG so the clear pixels stay clear. JPEG fills those areas with white.
A screenshot of a dialog can keep the window and drop the desktop around it. If the cut takes a thin border, move Edge shift toward the positive side before you apply, so the edge sits a little outside the subject.
A scan of a drawing on coloured paper can drop the paper and keep the line. A few pixels of Edge softness rounds a hard ink edge. A layer mask hides the paper and leaves the pixels in place, so you can paint the mask later if a corner needs to come back.
Removing a background in Photasium
Open a photo
Open the editor, then File → Open, or drop an image on the canvas. Select a raster layer.
Choose Remove background
Open Image → Remove background. The dialog looks for the subject, and Apply stays disabled until the subject is found. The first time, the editor downloads a segmentation model of about 25 MB from Hugging Face, and its runtime from jsDelivr, then keeps a copy in this browser’s cache. Later cuts use that copy. The photo stays on this device. Privacy covers that download.
Set the edge
Edge shift runs from -20 to 20 and starts at 0. A negative value pulls the edge in and drops a leftover halo. A positive value pushes it out and keeps more hair and fine detail. Edge softness runs from 0 to 20 and starts at 0, and feathers the edge by that many pixels. The preview updates as you move either slider. Reset puts both back to 0.
Apply
Pick a result, then click Apply. Erase the background clears those pixels on the raster. Put the cutout on a new layer adds a layer above the source, named with cutout on the end, and hides the source. Hide the background with a layer mask keeps the pixels and hides the background. The mask thumbnail is selected, so Brush and Eraser paint the mask until you click the layer thumbnail. Select the subject makes a selection and leaves the pixels as they were. Cancel, Escape, or a click on the dimmed page closes the dialog without a change.
Remove background needs a raster layer. A text layer, a group, or a locked layer does not open the dialog: rasterize type from the layer menu, open a raster inside the group, or unlock the layer. If a selection is active, erase, the new layer, and the mask change only the pixels inside it, and pixels outside stay as they were. Select the subject replaces the selection with the subject. Undo brings back an erase, a mask, or the source under a cutout layer. If the layer changes while the subject is being found, the dialog closes and asks you to try again.
The subject on its own
The cut sits on the raster you chose, nothing was uploaded, and undo brings the previous pixels back. If the edge cut into the hair, undo, push Edge shift outward, and apply again.
Download PNG if you need the clear pixels, or JPEG or WebP if a flat file is enough. Come back later and the document is still listed under the editor, until this browser’s storage is cleared. Remove background sits with the other photo editing tools: fill a wall, select a region, and export a listing.