Invert Normalmap axies?

I'm sorry if this has been asked before but I didn't find anything on that subject.

The question is simple: What tools are there to invert Normalmap axies? No matter if I'm missing a checkbox in unity or need an external tool. The thing is that any tangent-space normal I render out of Blender (object to object baking) is obviosly inverted.
I could create a normal inside unity from the displacement map but the quality is less than poor.
(See the atached image for what I exaclty mean)

So the thing is - I know that this is a problem of inverted normalmap axies. Yet I don't find a way to either invert the output from blender or the usage withng Unity. I asume it's something terribly simple - so any help is appreciated.

 

Have you tried "CrazyBump"?
http://crazybump.com/

 

Thank you for the quick answer.

I know crazybump and I also know xNormal and the NVidia Plugins for the Windows version of Photoshop. Unfortunately neither of those is an option ATM, as they are either windows versions or I don't want to spend money on extra software only for normalmpas.

Besides Blender I'm using Cinema4D - which still isn't able to handle tangent space baking (or even two UV layouts).

[edit] Allright. I got it.
I actually learned something basic about normalmaps today I should have known to begin with

Just in case anybody encounters the problem, too: If you want to invert the Axies of the X and/or Y channels you can of course also do so in Gimp or Photoshop by simply inverting the red and/or green channel.

 

I had the same problem!
Sollution:

open normalmap image in photoshop, select RED channel and invert it, do the same for the green channel... leave blue as it is.

should be ok now!

-wim wouters

 

wim wouters, you are awesome! Thanks for posting this 8 years ago.

 

You change value to -1 in material tab.