Plotting points on top of image (imshow) (uiaxes)

I had the following code (which works) that does an imshow raster data and then plots red dots on top of a list of markers (I.e. the base layer is an image of stars, and the overlay is red dots that mark them).

function plot(this)
   imshow(WORLD.image, [0 1]);
   hold on
   plot([this.centers.x], [this.centers.y], 'r.');
   hold off
end

OK, now I am using GUIDE to create the GUI, and I have the imshow using the parent property to get the image inside of a ui-axes. That part works, but the plot does not seem to take Parent, and besides hold on and hold off does not work (it creates a new window with the plot). How do I fix this? [handles.pictureBox is the handle for the axes control]

imshow(WORLD.mask, [0 1], 'Parent', handles.pictureBox);
hold on
plot([p.centers.x], [p.centers.y], 'r.', 'Parent', handles.pictureBox);
hold off

What I observe is that if I remove the hold on, hold off, then the base image is replaced by the plot. But if I leave it in, the same thing happens, but a pop-up also shown.

[Doctor G]

Oh yes, It is very important that the scale of the axis be maintained between the image and the plot. Right now, I see the plot adjusting the x,y bounds. If the imshow is a image of 1K x 1K, then I want the plot range to be exactly the same so that the labels overlay.

[Doctor G]

I waited two days, and tried stack overflow. I got a great answer in a few hours:

http://stackoverflow.com/questions/29826565/overlay-plot-on-top-of-image-in-uiaxes-gui/29827523#29827523

Answer 1

[Daksh]

I understand that you're experiencing issues with plotting points on top of image while using GUIDE and using "hold on" and "hold off" as "plot()" method seems to be not taking the parent handle for your case.

As per the R2022b documentation for MATLAB, "plot" method indeed accepts a parent handle, kindly refer to this link:

https://in.mathworks.com/help/matlab/ref/plot.html?searchHighlight=plot

plot(handles.pictureBox,[p.centers.x], [p.centers.y], 'r.');

Furthermore, "hold" ("on" and "off" both) also accepts axes handle, kindly use them as follows:

hold(handles.pictureBox,'on');

Hope this helps!