Create consistent greyscale icons from a set of third-party logos?

Question

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.

Answer 1

From the sound of it, there is probably a smallish set of images, presumably with the web as a final destination. You can batch convert (copy to new folder) all to greyscale png, tile them up using a script such as php to get as many on the screen as once, and identify any that seem too dark or too light. adjust the contrast or balance on that subset.

This will get the main job done and provide you with a convenient way to quickly narrow the search space for ones that look out of range.