Re: [Matplotlib-users] Best way to cycle through numpy images

[Benjamin R. <ben...@ou...>]

On Thu, Aug 11, 2011 at 11:19 AM, David Just <Jus...@ma...> wrote:

>  Sorry if this get’s re-posted,  my earlier e-mail didn’t seem to go
> through.
>
> I have an array of images stored as an array of numpy arrays.   I need to
> be able to efficiently scroll through that set of images.   My first attempt
> at doing this goes something like this:
>
> --init--
>
>         self.ax = pyplot.imshow(imgdta[0], interpolation='spline36',
> cmap=cm.gray, picker=True)      # draw the plot @UndefinedVariable
>         pyplot.axes().set_axis_off()
>         self.fig = self.ax.get_figure()
>         self.canvas = FigureCanvasGTKAgg(self.fig)
>
> --onscroll--
>         self.ax.set_array(imdta[n]) # 0 < n < num_images
>         self.canvas.draw()
>
>
> This method ends up re-interpolating the image on each scroll event (which
> takes SIGNIFICANT time).   What I’d like to do is pre-build the images and
> then just change what image is displayed on the canvas on each scroll event.
>  I cannot seem to figure out how to do this.  Can anybody give me a pointer
> in the right direction.
>
> Thanks,
> Dave.
>
>
You are doing it how I would do it for animations of imshow, which does not
result in re-interpolations.  I wonder if the on_scroll event is getting
called more often than it needs?  How big are these images?

Ben Root