Can you “grow” a selection?

Prior to discovering Acorn, I used Gimp for most of my image editing. One of the things I find myself doing with some regularity is adding a border to something I’ve selected, which I accomplished in Gimp by choosing Select → Grow… and entering a number of pixels to grow the selection by. This feature creates a new selection based on the current one by taking an x pixel long line segment, putting one end on the current selection, making it exactly perpendicular to the path of the current selection at any particular point, and then sweeping it around the whole selection edge. At the end of the operation, the other end of the line segment has traced a new selection that is larger and has rounded corners. (Of course, this happens instantaneously in Gimp, I’m just describing it like this so that you all have some idea of what I mean if you’ve never used it before.)

Is it possible to do this in Acorn? I looked through the menus, but I didn’t see anything that did exactly what I was looking for. Using “Selection to shape” got me sort of close, but when I scale the resulting shape up, it doesn’t have rounded corners.


There’s nothing that’ll extend the selection and round the corners at the same time.

You can extend the selection though. When you’ve got a selection on the canvas, and have one of the selection tools active, you can hold down the option key and press one of the arrow keys for the direction you’d like the selection to grow. So if you want it to grow to the right, you’d hold down the option key and press the right arrow key. If you want it to jump in 10 pixel increments, you can hold down the shift key.

Neat, I didn’t know that!

I think I’m going to have to keep using Gimp for this particular edge case, though, since the grown selection doesn’t quite have the shape I’m looking for.

Thanks again!