Good luck documenting the diferences between the different ways to convert an image to grayscale:
https://graphicdesign.stackexchange.com/questions/69308/how-to-convert-color-images-to-black-white-in-gimp/69372#69372 On 6 June 2017 at 06:02, Lancer <for...@gimpusers.com> wrote: > I am a school teacher. One of the checks I ask students to do in order to test > the contrast of their graphics work, is to convert the images to grayscale and > see whether images are still clear. > > There are two methods students are using to convert their images to grayscale > for this test... > > > Method 1: flatten image, then Colors > Hue-Saturation => slide the saturation > slider down to zero. > Method 2: image => mode => grayscale > > Either of these methods results in a grayscale image, but the grays are not > exactly the same. > > For example, if I have absolute red (#FF0000) next to blue, the > grayscaled-blue > may match the grayscaled-red depending on the tone *and* the method used. > Method 1: Absolute red (#FF0000) will grayscale-match absolute blue (#0000FF) > Method 2: Absolute red (#FF0000) will grayscale-match a slightly lighter shade > of blue (#2626FF) > > Why are the two methods of grayscale having a different result? I would have > thought that conversion to grayscale would be the same process as dragging > down > the saturation of an image. > > ...and given that they are different, which is the better method to use in > terms > of testing for contrast in media assignments? > > -- > Lancer (via www.gimpusers.com/forums) > _______________________________________________ > gimp-user-list mailing list > List address: gimp-user-list@gnome.org > List membership: https://mail.gnome.org/mailman/listinfo/gimp-user-list > List archives: https://mail.gnome.org/archives/gimp-user-list _______________________________________________ gimp-user-list mailing list List address: gimp-user-list@gnome.org List membership: https://mail.gnome.org/mailman/listinfo/gimp-user-list List archives: https://mail.gnome.org/archives/gimp-user-list
