Quite frequently I will come into the need to add a border around a non-square type shape. If it's square, it's easy to do: crop the image at it's boundaries, set the proper background color, and expand the canvas such that the newer area gets filled in with the color giving a nice symmetric boundary.
When I am trying to add boundaries to more complex shapes, however, such as circles, triangles, etc. I am at a complete loss. If I do it the same as with the box (crop the image to it's minimal size then expand the canvas) the resulting border only covers the perimeter as follows:
(A very crude example.)
As you can see I was able to shrink the square (border) boundary then increase the canvas size but this is clearly not what I want.
What I am hoping for is so somehow use like the Magic wand to draw a boundary around the circle, invert the selection, then "grow" the selection outwards (or inwards if the case may require) then fill in the added space with a color. The effect of growing the selection would be to maintain the spherical selection and all it to grow by N pixels from the center-line, or in the case of more complex shapes, grown by N pixels from the nearest boundary tangent.
Is there a way in Paint.NET to make a selection around an arbitrary object, invert the selection, then grown or shrink it, and finally fill the grown selection with a color using the Paint brush?
Thank you,
Jan