How to show image behind the figure?

Hy all, i want to show my image behind the figure like the below image, let say my image 128x128 pixel, so i have 4x4 squares and i get the arrow (representation of the gradient magnitude and orientation)

But, i just got something like this

I didn't know how to show the gridlines and the arrows.

Any little help is important to me, thanks.

Btw, this is the code (if you need) :

https://1drv.ms/u/s!AmcuE7FJ5zYxhIE04zrTvi_kupT-yA

Answer 1

[Walter Roberson]

If the grid is not to go edge to edge then you will need to draw it yourself.

If it is to go edge to edge, then grid on

[Elder Winter]

I want to show something like this, but if should be, i want to put the image behind that plot, if not, i will just put them both side by side. But the urgent one is how to show my magnitude and orientation like those plot

Answer 2

[Image Analyst]

You can use line() to graw grid lines. You can use quiver() or annotation() to draw arrows.

[Walter Roberson]

annotation() is strange in that it works on the figure rather than on the axes. There are File Exchange contributions to draw arrows on axes.

[Elder Winter]

But could i show something like this histogram of gradient? like this images.

i didn't know how to show it, i thought it's not just grid and quiver right? or there is another function?

[Walter Roberson]

quiver can create the arrows. plot() or line() or surf() or patch() to create the green lines. The same set of functions or viscircles or rectangle to create the circle .

[Elder Winter]

Okay, thank you very much.