I need to save the visualization of a sparse matrix. I believe the right function to call is Spy(), but when I try to save the image via "saveas(gcf,'Spy.png')" it's just completely blue.
When I open the preview in Matlab its fine . I would just take a screenshot of the preview but I don't want the grey background.
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Trying to experiment with MATLAB image filtering.
I take the image, use imshow(img), then apply a filter or some other transformation and call imshow(img) again.
For some reason, MATLAB seems to only display the image once, even if I call imshow or imagesc multiple times.
When I did this in Python, when I closed the image window, then the next image would appear. So I thought that until I closed the image window, code execution would halt. But that does not seem to be the case for MATLAB, as closing the image does nothing.
Anyone know why? Thank you.
I am asking for a solution to the blurred image I get when I use copy figure option in Matlab. For example, when I plot 3d figure in matlab I get the following image (It is the result of printscreen!)..
However, when I use the option copy figure I get a blurred image as the following image
.
How can I avoid this as I need to get high resolution image using copy figure option. Thank you in advance for any help you may lend.
By default, the figure is copied as an Enhanced Metafile (a color graphics format) which works for basic plots such as bar plots, line plots, and other 2D plots but may yield undesirable results for more complex plots as in your case. This is because the rendering of the Metafile content is controlled my Microsoft Word and it may render things differently than MATLAB.
If you need a high resolution image, I would recommend using the print command where you can specify the desired resolution (using the -r option). Then you can import the resulting image into Word
print(gcf, 'myfile.png', '-dpng', '-r300')
Alternately, you can use export_fig from the File Exchange which better preserves the appearance
Another option would be to change the format used by Copy Figure to tell it to use a bitmap instead
Or you can call Copy Figure programmatically and specify a different format (either a bitmap or PDF)
print(gcf, '-clipboard', '-dpdf')
I am trying to get better quality phase plots of complex functions made with the Complex Function Explorer of E. Wegert CFE. For this purpose I apply the Matlab anti-aliasing function myaa.m to the phase plots that are made with the CFEGUI.m. For the example screenshot of the result window below I used the setting myaa([8 8]) in the Matlab command window which means that the supersampling enlarge the figure 8x and then downscale it to 1/8 to get the original h x w.
As one can see the window of the figure has no operation icons or menu options for save or print. My question is what to do with such a figure (beside making screenshots)? Can I somehow use export-fig to save such a figure or load it in an image array and if yes, how?
It is also possible to use the setting myaa([8 1]) which results in a very large figure window that is larger than my screen (and has the unpleasant attribute that it can not be moved). It would be even better if such a whole figure could be saved (not only the visible part).
You can use getframe to grab current figure information in pixels.
However, while I do not know how this affects you, notice that MATLAB versions above 2014b (included) have already anti-aliasing. The code you linked seem to be from 2008, I am not 100% sure if it has become obsolete now.
In one GUI (viewer) I have an image that shows a 2D slice through a 3D image cube. A toolbar button opens a second GUI (z-profile) that plots a 2D graph showing the z-profile of one pixel in the image cube. What I want is to be able to update this plot dynamically when a different pixel is clicked in the original viewer GUI. I've looked in to linkdata but I'm not sure if that can be used to link across two GUIs. Is there a simple way to do this without re-creating the second GUI each time a new pixel is clicked and feeding in the new input location?
You can definitely doing it without recreating the second GUI every time.
Without knowing your specific code I would say that you should store a reference to the second GUI in the first GUI, then in a callback for clicking a pixel in the first GUI, change data in the second GUI via the stored reference (e.g. figure handle). You can store arbitrary data in a figure, for example by using function guidata. A bit of code.
...
figure2 = figure();
figure1 = figure('WindowButtonDownFcn',#myCallback);
guidata(figure1, figure2);
...
function myCallback(obj,eventdata)
figure2 = guidata(obj);
...
Even easier but a bit more error-prone would be to use global variables for storing the references.
I'm very new to Matlab, though I know a few other programming languages, so please forgive me if this is something simple. I have not been able to find any answers to this, either on StackOverflow or elsewhere.
I produce a figure using the following code:
figure(6),imageplot(P); drawnow;
Which looks like this:
I then save this image to my computer using the following commands:
imwrite(P, 'images/plot.png');
And the resulting image is tiny, and missing some of the color information:
If, however, I utilize the save function in the open figure (image #1) and save it manually, I get exactly what I want, which is that exact image stored on my computer.
How would I program that? I assumed that imwrite() would just write the image directly, but apparently I'm doing something wrong. Any advice? Perhaps it has something to do with the imageplot command? I cannot seem to get that to work in imwrite.
Update: Based on the comments below, I have begun using "imresize" with the "nearest" option. This scales the image properly, but the resulting image is still curiously darker (and therefore has less information) than if I hit the "save" button in the figure.
Image saved from figure:
Image using "imresize" with "nearest" option:
The MATLAB imwrite command saves exactly the number of pixels as specified in your image matrix. This is the actual result of your computation; the reason the output is "tiny" is because it is supposed to be. To make it larger, would be to simply scale/zoom it as required.
The save figure option however does something quite different: it rasterizes the the output you obtain in the figure window and gives you the option for saving it as an image. This is evident in the fact that when you do so, you obtain a white background in addition to your result which is really just the grey background you see before you save it; this can be adjusted by resizing the figure window before utilizing the save option.
If you're looking to simply make the output figure larger, I would recommend using something along the lines of the imresize command.
Say, if you want the default size to be twice the size of the real result, simply use:
imresize(P, 2.0);
For more options, try help imresize.
The command you need for the "Save As..." functionality of figures is called "print". I often use
print(gcf, '-dpng', 'some_filename.png')
or
print(gcf, '-depsc', 'some_filename.eps','-r0')
to save a figure as it is shown on screen. The format png offers a small filesize and excellent quality, and it is understood by most image viewers and browsers. The eps format is a vector format, which I use for printig. The '-r0' option specifies "use the same size as given by the screen resolution" for the vector format properties.