Re: [julia-users] ImageView very slow

[Tom Breloff]

You're looking for "heatmap". You should read the docs if you want to learn
more.

On Wednesday, October 26, 2016, Paul B.  wrote:

> Tim:  Thank you, that works great.
>
> Josef:  I can plot 2D matrices with GR (which is what I want) but your
> code example doesn't work.  GR looks pretty impressive, I'll have to check
> it out.  A bit disappointed there's no interface to zoom in/out with the
> mouse and for some reason the window won't close.
>
> Tom:  Works for images but not readily clear how to plot something like
> rand(100,100) as a bitmap instead of a 100 lines.  Do I have to convert it
> to an image structure for plot to figure out that it's a bitmap?
>
> Thanks, all!
>

[julia-users] ImageView very slow

[Paul B.]

Hello, all.  Starting out with Julia.

I need to display some pseudo-color images so I'm playing around with the 
ImageView package.  It seems to be running very slowly.  Displaying one of 
the images from TestImages can take nearly a minute:
img = testimage( "cameraman" )
Gray Images.Image with:
  data: 512×512 Array{ColorTypes.Gray{FixedPointNumbers.UFixed{UInt8,8}},2}
  properties:
colorspace: Gray
spatialorder:  x y

julia> tic(); ImageView.view( img ); toc();
elapsed time: 50.552471225 seconds
Zooming and other interaction with the mouse is similarly sluggish.

I didn't expect this for a 512x512 grayscale image.  I am running Julia 
version 0.5.1-pre+2 and ImageView is running into some issues with 
deprecated functionality and namespace conflicts.  However, the above did 
not generate any warnings at all but still took 50 seconds to display.  
This is all under Linux.  Any ideas why this is happening or if I could be 
doing something wrong?