Selections
How to Use Selections in Photasium
A sky, a face, or a rectangle you want to isolate can sit inside a selection, so the edit only touches those pixels. In Photasium that happens in the tab: the file never goes to a server.
Choosing which pixels to edit
A selection is a mask that says where the edit applies. Brush, Fill, Adjustments, and Delete work only inside the marching ants. Marquee draws a rectangle or an ellipse. Wand picks matching colour. Lasso traces a shape.
New replaces the current selection. Add joins it with the existing one. Subtract cuts a hole. Those modes sit in the options bar. Deselect clears the mask.
Isolate one part
A post can need the background replaced or the sky lifted. Wand selects that colour in one click if the area is connected and even. Raise tolerance if the selection stops short.
Fill or Adjustments inside a selection changes only those pixels. The rest of the photo stays as it was.
A listing photo often wants the product sharp and the background softened. Wand the backdrop, invert the selection, then apply a Sharpen. Or select the background and blur it.
A name or a number on a screenshot can sit inside a Marquee rectangle. Delete clears those pixels. Fill replaces them with a colour sampled from the interface.
A print that needs a vignette can have the corners selected with an ellipse. Invert so the middle is masked, then Adjustments lifts the centre without touching the edges.
Using selections in Photasium
Open a photo
Open the editor, then File → Open, or drop an image on the canvas.
Choose a selection tool
Click Marquee in the toolbar, or press M. Wand is W. Lasso is L. Rectangle and ellipse are in the options bar for Marquee.
Draw or click a selection
Drag a rectangle or ellipse with Marquee. Hold Shift to constrain the shape. Hold Option to draw from the centre. Click a colour with Wand, and connected pixels within the tolerance are selected. Drag with Lasso to trace a freehand shape, or click points in polygon mode.
Add or subtract
New, Add, and Subtract sit in the options bar. Shift-click with Wand adds to the selection. Option-click subtracts. Drag another Marquee shape with Add or Subtract to join or cut.
Edit inside
Brush, Eraser, Fill, Heal, Blur, and Smudge work only inside the selection. Adjustments apply to the selected raster. Delete clears the pixels. Option-Delete fills with the foreground, ⌘⌫ fills with the background.
Invert reverses the selection so the unselected pixels are now inside. Deselect clears the mask. A selection stays active when you switch tools, but opening a new document drops it. Select All (⌘A) selects the whole canvas.
The mask stays in the editor
The selection is just a mask, nothing was uploaded, and you can add to it or clear it. If the edge is too loose, undo the edit, adjust the tolerance or the shape, and try again.
Download PNG, JPEG, or WebP if you need a file to send. Come back later and the document is still listed under the editor, until this browser’s storage is cleared. Selections sit with the other photo editing tools: isolate the sky, fill a shape, export a listing.