lighting reversal

[THoff]

If I understand you correctly, use the Color Balance filter and lower the contrast.

[zfa4ever]

I dont really want to invert the picture, I want the dark portion light, and the light portion dark

[THoff]

If you use the YUV filter and change the curves so they slope from the upper left to the lower right, you invert the image. Is that what you're after?

[Aristotelis]

try using the yuv filter... experiment with the first curve

[zfa4ever]

Right now I have a picture with a bright background and a dark subject, how would I reverse this situation?