I think I agree that the rounding is necessary for raster backends, but is in the wrong place -- it should be in the backend itself.
It's needed for Agg to prevent "gaps" between the image and axes rectangle. The axes rectangle is always drawn pixel-aligned using "round", so if the image is drawn by truncation to integers, there will be small gaps for certain values. But yes, it makes sense to *not* do any rounding or truncation in the vector backends. I'll commit something for this -- on the trunk, because it feels a bit too pervasive for the branch. Mike Jouni K. Seppänen wrote: > Hi, > > Mike Fitzgerald reported bug #2832896 and has been investigating its > causes: > > https://sourceforge.net/tracker/?func=detail&aid=2832896&group_id=80706&atid=560720 > > 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? > > -- Michael Droettboom Science Software Branch Operations and Engineering Division Space Telescope Science Institute Operated by AURA for NASA ------------------------------------------------------------------------------ Let Crystal Reports handle the reporting - Free Crystal Reports 2008 30-Day trial. Simplify your report design, integration and deployment - and focus on what you do best, core application coding. Discover what's new with Crystal Reports now. http://p.sf.net/sfu/bobj-july _______________________________________________ Matplotlib-devel mailing list Matplotlib-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-devel
