Re: [matplotlib-devel] blurry images at native resolution with images.BboxImage: patch to fix

[Daniel H. <dh...@gm...>]

>
>
> imshow() does take an "interpolation" kwarg, where you can specify
> "nearest" for pre v1.1.0 versions and "none" (not None) in the recent
> release.  "nearest" would be close to what you want, while "none" is exactly
> what you want.
>
> Personally, I don't think it would be a good idea to automatically turn
> interpolation off on such a specific set of conditions, but I could be
> wrong.  I would rather have the user explicitly state their interpolation
> intentions.
>
> Ben Root


Hello Ben,

Isn't the purpose of interpolation to handle situations where the image is
being displayed at a different size than its native resolution?  It seems
appropriate to me to turn interpolation off in such a case.

Just some context of what I was up to when I ran into this one....I'm trying
to allow the user to paste images (either from file or clipboard) onto a
matplotlib canvas and be able to drag and resize them, very similar to the
way powerpoint works.  So I wanted to work with the appropriate image object
in matplotlib, and BboxImage was the best I found after digging in the code
for a bit; imshow() is too tied to the axis....these are supposed to be just
free floating images.

What I ran into was that, on initial paste (where I am sizing the BboxImage
the same width/height as the incoming picture), the image was very blurry
(because of the interpolation).  I still want the interpolation on so that
the image looks nice when it is resized by the user with the grab handles,
but in the specific case where no interpolation is needed, this patch turns
it off.

The pasting/dragging/resizing has actually turned out pretty well...once I
get it cleaned up and working how I want it to, I'll submit it to you guys
for inclusion into matplotlib if you want it.  I was hoping to formulate it
as a mixin that will work for any artist (not just BboxImage) within
reasonable limits.






-- 
Daniel Hyams
dh...@gm...