Inset a closed vector shape or path in any graphics application

Question

I used a text vector only because I was too lazy to draw a vector shape on my own. But this is NOT about text; I want a general way that can be applied to any closed vector shape.

If I have a closed vector shape like the image below, is there any way to create an inset of that vector shape in any graphics application or utility, preferably a free one like Gimp? I mean, not just scaling down like the left image, but insetting in all directions of the closed vector like the right image.

If I just scale down a shape, like the red "A", it does not fit in the original shape. But I inset a shape in all directions, it will create a skeleton version of the original shape that fits inside of it, like the blue "A".

Answer 1

Try Inkscape. It has in its Path menu effect "Dynamic Offset". You drag one handle which moves the edge outwards or inwards. Apply that effect to a duplicate of your closed path.

Limitation: You have no control how much sharp corners will be rounded. Many fonts like your A will be virtually destroyed, it's not the same font any more. Better result is possible by inserting and subtracting a stroke or by converting to path and moving the nodes.

A working example:

The blueish shape isn't a stroke, it's a filled area. It's duplicated and the copy got the reddish fill color and effect Dynamic Offset. The only visible handle in the top right is the one which is adjusted with the node tool for the wanted offset.

The generated offset path can be converted to editable path by applying Object > Object to Path.

A not so well working example:

The "insert and subtract a stroke"-method":

1. the original

2. a stroke is inserted. It's half outside and half inside the shape.

3. The stroke is converted to path with Path > Stroke to Path

4. The converted stroke is placed and aligned on the original and Path > Difference is applied. The result = The original but the edges are moved half of the stroke width.

Answer 2

With Gimp:

Method #1:

• Select>From path
• Select>Shrink
• Select>To path

Method #2:

• Create new transparent layer, and Edit>Stroke path (line mode, twice the offset that you need)
• Layer>Transparency>Alpha to selection
• Select>To path
• Delete the outer stroke

Comparison:

• black: initial path
• blue: method #1
• red: method #2

Results are similar, method #2 is better at keeping sharp angles.