Super User is a question and answer site for computer enthusiasts and power users. It's 100% free, no registration required.

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

Is it possible to blur/smudge only one colour in

e.g. blurring a red box with a thick black border so that the red blurs into the black but the outside of the border remains sharp?

share|improve this question
up vote 4 down vote accepted

magic wand the red (possibly with global as opposed to contiguous flood mode - that's the lightbulb on the top bar), copy, paste in new a layer, then run some kind of blurring filter on the red on the new filter. reduce the opacity of the layer to taste.

share|improve this answer
is it possible to do this for ALL the red boxes in an image? i have over 100 – GreyCloud Jun 28 '11 at 13:06
yes. magic wand, then switch flood mode to global - it will select all areas of the same colour, or close enough based off your tolerance level. – Journeyman Geek Jun 28 '11 at 13:07
thanks, thats got the selecting. However when i select blur it only blurs within the selection. How can i blur with big black border of the red box? I want to make the black border smaller and the red bit bigger. hope that makes sense – GreyCloud Jun 28 '11 at 13:33
select the area. copy it. paste it in a new layer. blur the NEW layer. that way you'll blur the whole thing, but only the red bits. – Journeyman Geek Jun 28 '11 at 13:36
thanks that's a neat trick :) – GreyCloud Jun 28 '11 at 13:59

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.