Makie consistency problem in iteratively saved png resolution

New to Julia
1

Hi all,

In the following MWE there is a problem of resolution consistency when saving iteratively png from a Makie scene:

using GLMakie,AbstractPlotting,ImageCore
function save_png(img, i)
    fn=string(i)*".png"
    scene = AbstractPlotting.image(rotr90(img), show_axis = false);
    AbstractPlotting.save(fn, scene; resolution = (1920,1088), px_per_unit = 72)
    close(GLMakie.global_gl_screen())
    nothing
end

function res_png(nf)
    nx,ny=1920,1088

    for i=1:nf
        img = rand(RGB{N0f8}, nx, ny)
        save_png(img,i)
        println("Saved png resolution :", size(load(string(i,".png"))))
    end
end
res_png(100)

I would like all the saved png to have the same resolution: 1920,1088 as specified when calling the save function. Any ideas?

Thanks in advance for the time you will take to help me.

2

I suspect you have some other packages loaded, the set of packages in your using statement does not provide a load method. Replacing ImageCore with Images produces:

Saved png resolution :(1088, 1920)
Saved png resolution :(1088, 1920)
Saved png resolution :(1088, 1920)
Saved png resolution :(1088, 1920)
Saved png resolution :(1088, 1920)
.
.
.

Which looks like it is working to me.

4

@contradict, I though it was resolved… But actually it’s not the case. I rewrote a MWE, this time with a video as it’s closer to what I would like to do.

using VideoIO, FileIO
using GLMakie,AbstractPlotting


function save_png(img, i,rota)
    fn=string(i)*".png"
    scene = AbstractPlotting.image(rotr90(img), show_axis = false);
    AbstractPlotting.rotate!(scene,-rota)
    AbstractPlotting.save(fn, scene; resolution = (1920,1088), px_per_unit = 72)
    close(GLMakie.global_gl_screen())
    nothing
end


function ext_frames(vid_name::String, rota)
    io = VideoIO.testvideo(vid_name) # for testing purposes
    f = VideoIO.openvideo(io); ## Open the video
    img = read(f); ## Take the first frame
    n = 1
    save_png(img,n,rota)

    while !eof(f) ## While the video is not finished
        next_img = read!(f, img); ## Take the next frame
        n = n + 1
        save_png(next_img,n,rota)
        println("Saved png resolution :", size(load(string(n,".png"))))
    end
    close(f)
end

ext_frames("annie_oakley", pi/67)

I tried 3 times in a row, each time destroying my REPL in between. The first time it worked well until the 611th frames, at this time 16 consecutive frames were saved with a resolution of 2176, 3840 (my screen). This happened again at the 704th frames. The 2nd try worked properly. However, the third time I had again the same problems, after the 524th, 618th and 611th frames the 16 next were saved with a different resolution than the 1088,1920 asked.

Why I have this changes in resolution and how to fix it? And how to speed up the process ? And why this is so random?

Thanks in advance for the time you will take to look into it.

5

What OS is this? This is likely some weird OS window manager problem. Do you get an open window? Is this in the VSCode/Atom repl?

6

I’m working on macOS Big Sur 11.1. Indeed when the script is running I have an open window (exe).
It’s on VSCode v1.52.1.

7

Sigh, MacOS of course…
Open window + MacOS + VSCode is probably the worst combination for this kind of problem :smiley:
Can you try a clean REPL, with a hidden window?
AbstractPlotting.inline!(true) in the beginning of the script should make save(scene, "..") not open any window.

8

Ohh that’s a bad news then…

Where exactly you want me to add AbstractPlotting.inline!(true) ?
I tried right after the using, but also as the first line of the save_png(), it’s not solving the problem at all. The window is still opening and the resolution problem is still there…

9

Like this:

using GLMakie,AbstractPlotting,ImageCore, FileIO
AbstractPlotting.inline!(true)

function save_png(img, i)
    fn="test/$(i).png"
    scene = AbstractPlotting.image(rotr90(img), show_axis = false);
    AbstractPlotting.save(fn, scene; resolution = (1920,1088), px_per_unit = 72)
    close(GLMakie.global_gl_screen())
    nothing
end
mkdir("test")
function res_png(nf)
    nx,ny=1920,1088

    for i=1:nf
        img = rand(RGB{N0f8}, nx, ny)
        save_png(img,i)
        println("Saved png resolution :", size(load("test/$(i).png")))
    end
end
res_png(100)

Just tried this, and window is hidden & resolutions stay the same… Sigh, looks like another unexplainable osx bug…
On what AbstractPlotting version are you?

10

Nop, I still have the same problem… The resolution changed at the 59th image and that for the 16 following ones and then come back to the asked resolution. That’s really weird !

I’m with AbstractPlotting v0.14.4