exportgraphics streches images whily saving if 'visible' is 'off' - bug?

Hello,

I stumbled upon what might be a bug, or I am just overseeing some features...

When you run this code, the two saved PDFs should be the same because they only differ in their "visible" value. But if the figure's visibility is 'off', the saved PDF is distorted: The white space at the bottom is missing, and the content is streched to the bottom end.

Is this a bug?

clear all; close all;

%% on

f1 = figure('Visible','on');

heatmap(rand(10,5))

exportgraphics(f1,'test_on.pdf','ContentType','image');

%% off

f2 = figure('Visible','off');

heatmap(rand(10,5))

exportgraphics(f2,'test_off.pdf','ContentType','image');

edit: what is odd is, that this behavior is only seen when 'ContentType' is 'image'. Saving 'vector' graphics everything is ok.

[Richard Quist]

Does the behavior change if you place a call to drawnow before the exportgraphics call?

f2 = figure('Visible','off');
heatmap(rand(10,5))
drawnow;
exportgraphics(f2,'test_off.pdf','ContentType','image');

[Adam Zabicki]

no, the 'drawnow' command does not change the output PDF.

Answer 1

[Walter Roberson]

Figure layout including axes layout (including xlim and ylim) is not performed until the figure visibility is turned on.

[Adam Zabicki]

Hi,

thanks for your reply. May i have to add, that if you define the 'ContentType' to 'vector', both PDFs saved are identical. So it is the 'image' case only when the figure layout is not performed? Seems odd to me...

Answer 2

[yanqi liu]

clear all; close all;
data = rand(10,5);
%% on
f1 = figure('Visible','on');
h1=heatmap(data); 
exportgraphics(f1,'test_on.pdf','ContentType','image');

fa1 = getframe(f1);
%% off
f2 = figure('Visible','off');
h2=heatmap(data); 
exportgraphics(f2,'test_off.pdf','ContentType','image');
fa2 = getframe(f2);
%% compare
figure; 
subplot(1,2,1); imshow(frame2im(fa1));
subplot(1,2,2); imshow(frame2im(fa2));

yes，sir，now we can see the image is same，but export pdf when visible off is different，may be the axis do not set to equal in the code

[Adam Zabicki]

sorry, I am not sure what you are suggesting? Which axis?

[yanqi liu]

yes，sir，may be figure display can make the image x、y axis equal，if not display，then the x、y axis not equal，so when get pdf print，it is mismatch

[Adam Zabicki]

But it works if 'ContentType' is set to 'vector'...