If I own a copy of an old film that has been colorized, is it possible for me to make a copy of it with the color bled out? With individual images, I am familiar with using gimp or Photoshop to desaturate the image. Is there a way I could do that to an entire movie file?
Depending on the format of your movie, you can probably find a filter for VirtualDub that would do it for you. Have a look around in that area.