I am currently working on a program involving shop routing, involving an image map obtained from google maps in the background.
When I try to use the data cursor (to show some irrelevant information), I need to click exactly the right pixel to get the data assigned to the plotted points, else I get a data tip error. Is there any way to disable data cursor mode for the background image while enabling it for the scattered points?
My figure looks like this:
edit: In case this helps, the background is defined as an image with following properties:
CData: [1280×1280×3 double]
CDataMapping: 'direct'
You should be able to set the HitTest property of your background image to off - that way the datatip will only show when you click on your data of interest.
Related
This is a fairly entry-level question but I could not find the answer to it here on SO or on Mathworks help.
I want to add a color bar to an image I am loading and then save the image along with the created color bar.
The result I am looking for is like figure 1 on this page except that there is an image instead of the plot and the color bar shows the range of intensities in the image.
The page made me think that running
colorbar(<trarget matrix>);
Would do the trick but that throws an error when I try to apply it to an image.
So my question is, how do I make a color bar for my image and once made what would be a good way to concatenate the two for saving.
I am loading the image using the following snippet
IMGpath = 'barbaraSmall.png';
im = imread(IMGpath, 'png');
%
%colorbar(im); >>Throws an error
imshow(im);
imwrite(im, 'barabara_withMAP.png', 'png');
The syntax that you're using is colorbar(target). According to the documentation,
target is:
"Target for the colorbar, specified as an Axes object, a PolarAxes object, or a graphics object that has a ColorbarVisible property".
You're inputting an image matrix (im) as target which is none of the above mentioned objects. You can simply just enter:
colorbar;
or if you want to give an axes' handle then:
colorbar(gca);
You can save the result using saveas.
saveas(gca, 'barabara_withMAP.png')
I have used matlab's preview window in the following syntax:
figure('Name', 'My Custom Preview Window');uicontrol('String', 'Close', 'Callback', 'close(gcf)');
I am able to successfully get the video stream. Now I want to have a small circle as a region of interest to return the average pixel value within this circle. I want this to be stored and named after a click of a button and recalled later for the further processing.
Could anyone guide me where I can start with?
Please note I dont want user to define ROI instead its always fixed as a small circle at the centre of field view. Whatever the colours comes within the circle I want mean values to be calculated and stored as a reference.
Ps: I am not sure I am correct in calling ROI its simple circle in the field view
You might want to try using a Matlab gui instead of a simple figure. Then you could try something like this.
I am currently using the fill command in MATLAB to create a graph of boxes that were created using the 'fill' command (the actual code is based off this StackOverflow Question.
My issue is that the boxes that I create do not have "corners." I am attaching a PNG that illustrates the issue. Note that you have to look a little carefully since the image was heavily rendered, though in this example my arrows also look weird since they don't have edges either)
I am wondering if anyone has an idea of what might be going wrong? The boxes appear this way immediately after I use the fill command, which has the following structure:
fill(X,Y,MyFaceColor,'FaceAlpha',0.5,'EdgeColor', MyEdgeColor,'LineStyle','','LineWidth',box_line_width,'EdgeAlpha',1)
The function fill appears to leave space for corner markers if they are not explicitly defined. Hence, calling fill with the marker property will solve your problem. However, since markers and linewidths seem to work on different scales, you will have to play around with the marker size to get smooth edges.
Example:
fill(X,Y,'r','FaceAlpha',0.5,'EdgeColor', 'k',...
'LineWidth', 5,'EdgeAlpha',1 , 'marker', '.', 'markersize', 15)
I'm working on creating a GUI in matlab using GUIDE. However, i'm not exactly sure how to do the following, and was looking for some tips/advice.
Problem
I want to open a directory and display all the images in that directory in the GUI interface when if it's selected. However, since I will never know exactly how many images there are I am not entirely sure how to do this in the GUI.
Essentially, I want to open the directory and all the images to be displayed in a grid on the GUI similar to that in iphoto.
Current code
Currently, I can open a directory fine, and get all the required information as follows:
directory = uigetdir(pwd, 'Directory Selector');
files = dir(fullfile(directory, '*.jpg'));
strcat(strcat(directory, '/') , files.name) %outputs each file's location
I'm just not sure how to translate this information into the GUI without writing numerous handles.axes1. I understand that since I know this info I could loop over them, but would I not have to create the axes to begin with?
You probably don't want to do this with individual controls - the reason is that MATLAB will have to render each and every one, which will be slow if the directory has a lot of images. Clearly, you can only display a certain number of images on screen at once. You would also have to write your own scrolling code (or some kind of pagination control).
If you have MATLAB > R2008, you can put images in uitable cells using HTML:
% Example for a control with a 'String' property
set(handles.myControl, 'String', '<html><b>Logo</b>: <img src="http://UndocumentedMatlab.com/images/logo_68x60.png"/></html>');
See also this post and this Undocumented MATLAB page.
A different option would be to use the Windows common controls ListView.
A simpler way of doing this would be to have a single image and a listbox of files; an example is here
You can add components to a GUI pprogrammatically. There's more information here.
Each new axes can be added with something like this:
ah = axes('Parent',hObject,'Position',[left bottom width height]);
where left, bottom, width and height define the size and position of the axes. You'll need to change the position for each axes you create and keep track of the axes handles.
I have a question about the values returned by getPosition. Below is my code. It lets the user set 10 points on a given image:
figure ,imshow(im);
colorArray=['y','m','c','r','g','b','w','k','y','m','c'];
pointArray = cell(1,10);
% Construct boundary constraint function
fcn = makeConstrainToRectFcn('impoint',get(gca,'XLim'),get(gca,'YLim'));
for i = 1:10
p = impoint(gca);
% Enforce boundary constraint function using setPositionConstraintFcn
setPositionConstraintFcn(p,fcn);
setColor(p,colorArray(1,i));
pointArray{i}=p;
getPosition(p)
end
When I start to set points on the image I get results like [675.000 538.000], which means that the x part of the coordinate is 675 and the y part is 538, right? This is what the MATLAB documentation says, but since the image is 576*120 (as displayed in the window) this is not logical.
It seemed to me like, somehow, getPosition returns the y coordinate first. I need some clarification on this.
Thanks for help
I just tried running your code in MATLAB 7.8.0 (R2009a) and had no problems with image sizes of either 576-by-120 or 120-by-576 (I was unsure which orientation you were using). If I left click inside the image, it places a new movable point. It did not allow me to place any points outside the image.
One small bug I found was that if you left-click in the image, then drag the mouse pointer outside the image while still holding the left button down, it will place the movable point outside the image and won't display it, displaying a set of coordinates that are not clipped to the axes rectangle.
I'm not sure of what could be your problem. Perhaps it's a bug with whatever MATLAB version you are using. I would suggest either restarting MATLAB, or clearing all variables from the workspace (except for the image data im).
Might be worth checking to see which renderer you are using (Painter or OpenGL), a colleague showed me some wierd behaviour with point picking when using the OpenGL renderer which went away when using the Painter renderer.
Your code uses the Image Processing Toolbox, which I don't have, so this is speculation. The coordinate system is probably set to the figure window (or maybe even the screen), not the image.
To test this, try clicking points outside the image to see if you can find the origin.