4 ways to get Variable Blurs in GIMP

[RobA]

Over in my Not so Random Coastline Tutorial I suggested using a variable blur to control the randomness of the coastline. I had a few pm's asking how to do this, so I will give you four ways (in four posts).

#1 - Feathered Selection, Bigger Blur
Start with your base shape:
vb_fs00001.png

Blur it the lesser amount (20 px here):
vb_fs00002.png

Use the lasso tool to make a selection around the area you want to have a larger blur. Set it to a 100px feather. Leave lots of space:
vb_fs00003.png

Blur it again, with the greater amount (100px here):
vb_fs00004.png

The result:
vb_fs00005.png

-Rob A>