Create contour plot + Image without calling figure() - matlab

Have an existing image in which I am overlaying a contour as per below
imshow(I), title(sprintf('contour')), hold on, contour (thresI,'w');
Would it be possible to overlay the contour on the image without calling figure? Would like to export the resulting image (into png/jpg) without calling figure()/imshow if possible.

Simply put: no. What you probably want though, is to save the figure without plotting. Use the 'visible' switch:
figure;
set(gcf,'visible', 'off');
Imshow(I)
(..) more of your plots

You could call the figure window so that it's not on the screen:
scrsz = get(groot,'ScreenSize');
figure('Position',[-scrsz(4)/2 -scrsz(4)/2 scrsz(3)/2 scrsz(4)/2])
so no one will (probably) see it
An other Option is of course imwrite

Related

Displaying whole image by clicking on a subplot

I croped some parts of images and displayed them in one figure with subplots. Number of subplots are not certain. I read images from a file then crop them. My aim is that when I click or double click on an subplot, I want to see whole image in new figure.
I want to give an example just to make clear my question. if I click on first subplot, I want to see whole cameraman image in new figure.
Is it possible? If it is possible, What is the way?
The example uses the ButtonDownFcn that can be added to most matlab plot commands.
Just copy both functions into one file and run the "interactivePlot" function.
The list_of_images contains all matrices that shall be plotted.
The number of matrices is flexible. However, you have to adjust the subplot command...
function interactivePlot
list_of_images = {rand(5), rand(10), rand(50), rand(100)}
for ii = 1:length(list_of_images)
subplot(2,2,ii)
imagesc(list_of_images{ii}, 'ButtonDownFcn', #newFigure1)
end
end
function newFigure1(h1, h2)
figure()
data = get(h1, 'CData');
imagesc(data)
end
I had same problem, change your function like below then it will be solved:
function newFigure1(h1, h2)
figure()
data = get(h1, 'CData');
colormap(gray);
imagesc(data)
end

Heatmap plots extra axes

I'm using the heatmap function in Matlab to plot some maps, the maps themselves are fine but the program seems to be adding extra borders and axes onto the figures, no idea why this is happening!
My code is:
figure(1)
hFig = figure(1);
set(gcf,'PaperPositionMode','auto')
set(hFig,'Position',[1000 1000 900 800])
colormap('hot');
imagesc(data)
xlabel('X({\mu}m)')
ylabel('Y({\mu}m)')
Here is an image of what I mean by extra axes:
Thanks!
Edit1: Here is the image after the first proposed fix:
Remove the xlabel and ylabel from the last lines of your code. Since you have already used the set function you can integrate them directly by doing
imagesc(data);
colomap('hot');
set(gca,'Xtick',[0:5:50],'XtickLabel',[0:5:50]);
set(gca,'Ytick',[0:5:50],'YtickLabel',[0:5:50]);
colorbar('YtickLabel',{'1000','900','800'});

How do I hide axes and ticks in matlab without hiding everything else

I draw images to axes in my matlab UI, but I don't want the axes and ticks to be visible how do I prevent that, and also where do I make this call?
I do this
imagesc(myImage,'parent',handles.axesInGuide);
axis off;
Is this what you are looking for?
This is definitely somewhere else on this website and in the matlab documentation. Try typing
help plot
Or using the documentation on plotting!
edit: Now that you have shown what you are doing. (You don't need the handles, I just always write them in to clutter my workspace)
myImage = yurbuds0x2Dironman; # don't ask
fH = figure;
iH = imagesc(myImage);
set(gca,'xtick',[],'ytick',[])
Are you able to do it like this?
I support the
set(gca,'xtick',[],'ytick',[]);
approach over the
axis off
one. The reason is set(gca, ...) just removes the labels but keeps the axes, unlike axis off. I am generating a group of images with fixed dimensions to combine later into a video. Deleting the axes creates different size frames that can't be recombined.

Matlab image display in specific old figures

Take an example, I have 2 a sequences of left and right images: left01, right01, left02, right02, etc. How can I display those on only two figures: left and right. Each loop, these 2 figures will be updated with leftxx and rightxx.
"Hold on" will only hold the current figure. Creating figures with figure('Name', 'Left') will not do the trick, as multiple "Left" figures will be created. Yet imshow() does not let me specify the figure to display based on its name.
What I want is something similar to OpenCV, which let you choose which figure (already opened) to display
cvNamedWindow("Left");
cvShowImage("Left", myLeftImg);
"Left" figure will be updated with new img without creating new figure.
Thanks a lot.
Ken.
You need to save a handle on the axes-object within the figure and you need to tell the image-function to precisely which axes you want it to draw.
Try something along the lines of:
figure, h_r = axes;
figure, h_l = axes;
for n=1:whatever
image(right_bitmap, 'Parent', h_r, ...);
image(left_bitmap, 'Parent', h_l, ...);
drawnow;
end;
Update: image expects the handle as property 'Parent' rather than as first parameter.

How to create a new figure in MATLAB?

Usually when I plot in MATLAB, it always draws on the same figure. How do I make it draw in a new figure?
I know it is pretty elementary, but I'm not finding it using Google Search.
figure;
plot(something);
or
figure(2);
plot(something);
...
figure(3);
plot(something else);
...
etc.
While doing "figure(1), figure(2),..." will solve the problem in most cases, it will not solve them in all cases. Suppose you have a bunch of MATLAB figures on your desktop and how many you have open varies from time to time before you run your code. Using the answers provided, you will overwrite these figures, which you may not want. The easy workaround is to just use the command "figure" before you plot.
Example: you have five figures on your desktop from a previous script you ran and you use
figure(1);
plot(...)
figure(2);
plot(...)
You just plotted over the figures on your desktop. However the code
figure;
plot(...)
figure;
plot(...)
just created figures 6 and 7 with your desired plots and left your previous plots 1-5 alone.
The other thing to be careful about, is to use the clf (clear figure) command when you are starting a fresh plot. Otherwise you may be plotting on a pre-existing figure (not possible with the figure command by itself, but if you do figure(2) there may already be a figure #2), with more than one axis, or an axis that is placed kinda funny. Use clf to ensure that you're starting from scratch:
figure(N);
clf;
plot(something);
...
As has already been said: figure will create a new figure for your next plots. While calling figure you can also configure it. Example:
figHandle = figure('Name', 'Name of Figure', 'OuterPosition',[1, 1, scrsz(3), scrsz(4)]);
The example sets the name for the window and the outer size of it in relation to the used screen.
Here figHandle is the handle to the resulting figure and can be used later to change appearance and content. Examples:
Dot notation:
figHandle.PaperOrientation = 'portrait';
figHandle.PaperUnits = 'centimeters';
Old Style:
set(figHandle, 'PaperOrientation', 'portrait', 'PaperUnits', 'centimeters');
Using the handle with dot notation or set, options for printing are configured here.
By keeping the handles for the figures with distinc names you can interact with multiple active figures. To set a existing figure as your active, call figure(figHandle). New plots will go there now.
Another common option is when you do want multiple plots in a single window
f = figure;
hold on
plot(x1,y1)
plot(x2,y2)
...
plots multiple data sets on the same (new) figure.
As simple as this-
figure, plot(yourfigure);