adjusting brightness and contrast of photos

[justask]

Hello!

I have some projects with B&W and colour photos (each photo is a layer in the project). It is some kind of collage. These photos' (layers) brightness and contrast are different (some are too dark/light). How can I adjust the brightness/contrast of photos to the same level before printing the collage? Is there any automatic mode to this?

Thanks

[Antonio]

I think automatic mode is not possible, it is better to adjust manually because each photo has different level...