Online PSUsing selections: edit only part of an image
By default, color changes and filters apply to the whole layer. To work on just a part, box that part in with a selection first.
Making a selection
- Pick the Selection tool in the toolbox (the dashed box icon);
- Drag on the canvas; the dashed box is the selection;
- "Edit → Select All" (
Ctrl + A) selects the whole layer at once.
What you can do with it
- Delete Selection (
Del): makes the boxed content transparent; - Copy Selection: copies the boxed content into a new layer and leaves the original alone, handy for working on a detail;
- Copy to Clipboard (
Ctrl + C): paste it into another app or another image; - New from Selection (Layer menu): like Copy Selection, a new layer with just the selected content.
Filters on part of an image
Filters in the Effects menu always apply to the whole current layer. To process only a part, first "Edit → Copy Selection" to make it a layer of its own, then apply the filter to that new layer. That's how hiding details in a screenshot works.
Tip: a zoomed-in detail
- Box in the detail and "Edit → Copy Selection" to get a new layer;
- Drag the new layer's corners with the Select object tool to enlarge it;
- Move it into place for a magnified-detail picture.