Create vectors that allow to subdivide the pixels of an image

Hello, I was wondering if someone could tell me how I can subdivide an image, for example img, so that I can store in a vector the positions of the rows and in another vector the columns (which logically would not be integers) to divide each pixel in 5 parts.

img = rand(10,20);
figure, imshow(img,'InitialMagnification','fit');

That is, what I would like is to be able to build a grid that follows the basis of what the poly2mask function does but with all the pixels:

Thank yo so much

Answer 1

[Matt J]

[m,n]=size(img);

y=linspace(0,m,5*m+1).'+0.1; y(end)=[];
x=linspace(0,n,5*n+1).'+0.1; x(end)=[];

[Alejandro Fernández]

Hi, thank you very much for your answer, however I have rendered it and it does not match with what I expected:

img = rand(10,20);
 
[m,n]=size(img);
y=linspace(0,m,5*m+1).'+0.1; y(end)=[];
x=linspace(0,n,5*n+1).'+0.1; x(end)=[];
[X,Y] = meshgrid(x,y);
 
figure, imshow(img,'InitialMagnification','fit');
hold on
plot(X,Y,'.')

[Matt J]

I don't see anything wrong, other than that the XData,YData that you've chosen for the image are oddly shifted,

img = rand(10,20);
 
[m,n]=size(img);
y=linspace(0,m,5*m+1).'+0.1; y(end)=[];
x=linspace(0,n,5*n+1).'+0.1; x(end)=[];
[X,Y] = meshgrid(x,y);
 
figure, imshow(img,'InitialMagnification','fit');
hold on
plot(X,Y,'.')
himg=findobj(gca,'Type','image');
himg.XData=(1:n)-0.5;
himg.YData=(1:m)-0.5;
axis([0,n,0,m])

[Alejandro Fernández]

Ok! Thank you so much for your help!