Hi Guillaume,
If your image is on a figure, then you could use the 'WindowButtonMotionFcn' callback to invoke a custom function that calls 'plot'. This won't do exactly the same thing as impixelinfo, since the object that contains the text is generated differently than a plot figure, but you may be able to find ways to modify the callback to suit your needs. If this sounds like something that would work, try checking out the documentation page for the callback below:
I hope you find this helpful. Good luck on your project!
