Re: [Matplotlib-users] Is really matplotlib this slooow for displaying images ? (sorry again)

[Eric E. <ems...@ob...>]

Hi again,
thanks a lot for the fixing and comments on figimage. This looks much
much better now. Indeed a local matplotlib user had also pointed
out to me the time it spent on cmap.

By the way, the problem I have now is that I would like to have a quick
way of looking at my images (the 1600x1600) but being able to
size it INTO the actual opened window (so basically this calls for using 
imshow
and not figimage). Just to be clear here is what I usually do (e.g. with 
Midas):

1/ I create a display window with the size (and location on my desktop) 
I wish
2/ I ''load'' my big image in there. Depending on the size it will take 
the full window or not.
3/ then depending on the region I wish to look at I scale and recenter 
the image
   to e.g., have it all in the window or just zoom in some regions.
4/ then I can interact with the cursor to e.g. make a cut of the image 
(and display it
in another window) or get some coordinates

so this would look like this in Midas:

1/ create/disp   1 600,600  # create the display window number 1 with 
600x600 px
2/ load image.fits      # load the image: from a fits file
3/ load image.fits scale=-2 center=0,0 # center the image at coord 0,0 and
                                               # scale it down by a 
factor of 2, (- = down, + = up)
4/ get/curs                  #activate the cursor on the image so that a 
click
                                       # prints out the corresponding 
coordinates

By using imshow in matplotlib I think I can solve all these things
(and as soon as the .key fields are activated so I can use the keyboard
to interact with the display), but then it will show again its very slow 
behaviour
(interpolation, etc...) ? Would there be a way to have such a command
but with a much quicker loading / interacting? (note that the pan and zoom
things would probably do it - although it would need to keep the 
coordinates right
so there is no confusion there - , but at the moment this is not usable 
in imshow
with large images as it is much too slow)

Cheers,
Eric

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