Hi,
I have written a quick'n'dirty image segmentation algorithm. It seems to work
fine. However, I am interested in getting contours of the segments
(essentially, (x,y) pairs of the edges of each segment). I can plot the
contours with MPL (pylab.contour()), but I'd like to have the locations of
the edges, so that I can actually do something with them.
Does anyone have any hints on how to go on about this?
Thanks!
Jose
Jos� G�mez-Dans wrote:
Hi,
I have written a quick'n'dirty image segmentation algorithm. It seems to work fine. However, I am interested in getting contours of the segments (essentially, (x,y) pairs of the edges of each segment). I can plot the contours with MPL (pylab.contour()), but I'd like to have the locations of the edges, so that I can actually do something with them.Does anyone have any hints on how to go on about this?
cs = contour(Z)
for lev, col in zip(cs.levels, cs.collections):
s = col._segments
s will be a list of numpy arrays, each containing the (x,y) vertices defining a contour line at level lev.
This illustrates a shortcoming of the contour and/or LineCollection code; to get what I think you want, you have to use a private attribute, _segments. It should be part of the public API. After some other changes and reorganizations in mpl have settled down, I will fix this. Feel free to send me a reminder in a month.
Eric