Have you tried using guides to snap the handles? --- Leonard Evens <[EMAIL PROTECTED]> wrote:
> I don't see a way to specify the matrix used to perform a desired > perspective transformation manually. Of course, I can adjust it by > dragging handles, but it would be much easier for me to calculate what I > need and then enter the elements of the matrix by hand. > > Needless to say, a typical gimp user would not be able to do this, but I > am a mathematician who has taught geometry many times during my > professional life, so I know what to do. I don't need an explanation of > how the matrix is formed and what it does since I can work that out by > experimentation. > > The gimp manual is not helpful. It refers the reader to the section on > convolution filters, but that appears to have to do with modifying > pixels in place rather than moving the pixels---a rather misleading > reference. Perhaps something entirely different happens if you use the > full matrix, but the documentation is silent on that matter. > > Of course, I can try to produce what I want by moving the handles, but > for slight adjustments of large images, that is difficult if not > impossible. It helps if I increase the magnification enormously, but it > is still awkward. It would be a lot simpler to be able to enter the > matrix elements directly. > > > -- > Leonard Evens <[EMAIL PROTECTED]> > Mathematics Department, Northwestern University > > _______________________________________________ > Gimp-user mailing list > Gimp-user@lists.XCF.Berkeley.EDU > https://lists.XCF.Berkeley.EDU/mailman/listinfo/gimp-user > ____________________________________________________________________________________ Be a better friend, newshound, and know-it-all with Yahoo! Mobile. Try it now. http://mobile.yahoo.com/;_ylt=Ahu06i62sR8HDtDypao8Wcj9tAcJ _______________________________________________ Gimp-user mailing list Gimp-user@lists.XCF.Berkeley.EDU https://lists.XCF.Berkeley.EDU/mailman/listinfo/gimp-user
