To use gegl:transform, you need to create the transformation matrix yourself. There are plenty of tutorials for learning how to create transformation matrices online.
Then, do this to set the node's property: 1. When you create your matrix, place it in a GeglMatrix3 struct. It contains one member named coeff, which is a 3x3 array of doubles for the matrix values. 2. Turn the matrix into a string with gchar* gegl_matrix3_to_string (GeglMatrix3 *matrix); 3. Set this string as the property "transform" on your gegl:transform node with gegl_node_set. 4. Free the string from (2) with g_free Anyway, I hope this helps! Feel free to ask if you have any issues. -- drawoc On Sun, Sep 29, 2013 at 6:06 AM, beee <gdb_1...@163.com> wrote: > Hi, > > I want to apply perspective effects on an image. But I can't find an > operation for it. I thought maybe I can do it with gegl:transform. But I > don't know which parameters should use. > > Please help. Thanks! > > Regards. > > > > > _______________________________________________ > gegl-developer-list mailing list > List address: gegl-developer-list@gnome.org > List membership: https://mail.gnome.org/mailman/listinfo/gegl-developer-list > > _______________________________________________ gegl-developer-list mailing list List address: gegl-developer-list@gnome.org List membership: https://mail.gnome.org/mailman/listinfo/gegl-developer-list
