Insert an image as the background of a figure/gui
By providing the figure handle (matlab gui is essentially a figure) and the file name (with path) of the desired background image, the function will import the image, plot it on an axes that covers the whole figure. The axes is then send to the back which then becomes the background.
The background image will be resized when the figure/gui is resized, however, for best outcome, one should ensure the wdith/height ratio or scale is best match to that of the image.
todo
- make it easy to update the background image. maybe rename the function to updateBackground