On Mon, Aug 3, 2015 at 3:55 PM, Sturla Molden <sturla.mol...@gmail.com> wrote: > Juan Nunez-Iglesias <jni.s...@gmail.com> wrote: > >> The short version is that you'll save yourself a lot of pain by starting to >> think of your images as (plane, row, column) instead of (x, y, z). > > There are several things to consider here. > > 1. The vertices in computer graphics (OpenGL) are (x,y,z). > > 2. OpenGL rotation matrices and projection matrice are stored in column > major order. > > 3. OpenGL frame buffers are indexed (x,y) in column major order with (0,0) > being lower left. > > 4. ITK and VTK depends on OpenGL and are thus using column major order. > > 5. Those who use Matlab or Fortran in addition to Python prefer column > major order. > > 6. BLAS and LAPACK use column major order. > > 7. The common notation in image prorcessing (as opposed to computer > graphics in geberal) is indexing (row, column), in row major order, with > (0,0) being upper left. > > All in all, this is a strong case for prefering column major order and the > common mathematical notation (x,y,z). > > Also notice how the ususal notation in image pricessing differs from > OpenGL.
Sure, but to avoid confusion, maybe move the discussion of image indexing order to another thread? I think this thread is about memory layout, which is a different issue. Cheers, Matthew _______________________________________________ NumPy-Discussion mailing list NumPy-Discussion@scipy.org http://mail.scipy.org/mailman/listinfo/numpy-discussion
