I have a bunch of third-party client logos in clashing colours. I would like to convert them to elegantly matching grayscale.
What I'm after is a set of identical grayscale images of the kind seen frequently on "our clients" pages, like this one.
Does anyone know an easy way to turn them into greyscale logos, all in exactly the same shade of grey? (I'm a programmer, so can handle a technical solution, but unfortunately know very little about graphic design.)
I'd like to do this using either Gimp, or even better, a web service designed to do just this :)
Thanks for your help.