Compare two images of two different folders

Hi!

I´m making a project for college in Matlab that measures the area of blood cells from an image selected by the user of the GUI.

I need to compare a image, that it's in one folder, with the respective mask, that it´s in another folder. The images have the same name. To have results, then I need to multiply them. Can anyone help me in how to make this?

Thank you!