On Thursday 25 October 2007 10:18, norman wrote: > I would like to be able to produce a black and white negative image > from an ordinary colour image. The effect I would like to produce > would be to imitate what one would get if you took a colour, > positive transparency and made a contact print on to either > orthographic or lithographic film. Thus, blue would be black and > red would be clear and transparent. Have you any suggestions how to > approach this using the Gimp, please. >
Colors->Components->Decompose (elseqwhee if you are on gimp 2.2, b ut still "decompose") and pick only the "Hue" channel. You cna tehn use colors->curves, or colors-->levels to equate your previous blue to black and your previous red to white. js -><- > Norman > > _______________________________________________ > Gimp-user mailing list > Gimp-user@lists.XCF.Berkeley.EDU > https://lists.XCF.Berkeley.EDU/mailman/listinfo/gimp-user _______________________________________________ Gimp-user mailing list Gimp-user@lists.XCF.Berkeley.EDU https://lists.XCF.Berkeley.EDU/mailman/listinfo/gimp-user