This does not answer your question but might help your friend. The command matrix_plot (eg, "sage: matrix_plot(random_matrix(GF(389), 10), cmap='Oranges')") might be a simpler function to use if he just wants to test how good the linear code works on an "image".
BTW, since you are the author of the SAGE search function http://www.google.com/coop/cse?cx=017384562579735769466:s27byrlaffu here is an interesting experiment: type "matrix plot" (without the quotes) and see what you get. I think there are more hits on the plot of the movie The Matrix than on the command matrix_plot, which is strange since it should be SAGE specific. Maybe the wikipedia hits should have a lower weight somehow? On Thu, Apr 17, 2008 at 8:07 AM, Harald Schilly <[EMAIL PROTECTED]> wrote: > > Hi > > A friend of mine want's to manipulate pictures (bitmap, in color). > Basically, he want's to load and then represent them as a binary > vector in Sage and then encode them using linear codes -> > manipulations (errors) -> then back to an image and see how good the > code worked. > The one thing I don't know is what's the best and easiest way to get a > binary representation of an image to be able to work with - a > bijection from picture to binary vector in GF(2) and back. Maybe in > different versions (each color channel separate or other methods). > > Harald > > > --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~----------~----~----~----~------~----~------~--~---