Mike Fitzgerald reported bug #2832896 and has been investigating its
The problem is that images are not drawn at exactly the same coordinates
as other artists, so markers drawn on top of images are slightly off in
pdf and eps output. Apparently this can be fixed, at least to some
degree, by removing the round(...) operations from
renderer.draw_image(gc, round(l), round(b), im)
in _AxesImageBase.draw and making a slightly more involved change in
AxesImage.make_image (the details are in the bug report). I haven't had
time to investigate what this does to other backends, but I imagine the
rounding would be necessary for raster backends.
Can someone who is more familiar with the image machinery comment on the
matter? Do we need some kind of vector/raster indication in the backends,
in addition to the get_image_magnification method?
Jouni K. Sepp�nen