I am currently learning about lightmap baking and found that Blender doesn’t denoise the baked texture*. So I had to find an other way, and since Photoshop apparently can’t handle denoising for a 32 bit OpenEXR, I had to look for something else. I then found out about GIMP, which actually CAN do this.
The only problem I have right now is that I don’t know how to export properly from GIMP into Blender. I have tried exporting TIFF, PSD en OpenEXR, but after importing in Blender I keep getting slightly shifted colors.
What’s your way of exporting a 32 bit image out of GIMP into Blender? Any tips? 
*Not without paid addons, anyway.