Using repmat instead of subplot - adding grid lines and points

Hi, Im trying to remove the gaps between subplots and have read the following way to do it using repmat that works well.

A=[IM1 IM2 IM3;IM4 IM5 IM6];
A_new = repmat(A, [1 1]);
imshow(A,[low,high]);

1: Is it possible to highlight the separate images by adding say red lines on the composite image to be able to visually see the separation of the images i.e.

2: For each image IM1, IM2 etc. I have the x and y coordinates of points that I want to add to the graphic.

How do I add the x, y positions that correspond to IM1 to the correct location and so on?

thanks Jason

[Adam]

I don't get the point of that repmat - it is basically a null statement. You could plot A and get just the same result as in fact you do anyway!

[Jason]

Thanks Adam

Answer 1

[Adam]

If you know the size of your images then can't you just use a standard plot command

e.g.

A = [rand(100) rand(100) rand(100); rand(100) rand(100) rand(100)];
figure; imshow( A )
hold on
plot( [100 100], [1 200], 'r' )

etc