How to set an image object and not a link to it for the background of a widget in kivy?

Question

Python

Good day, the usual setting of the background in kivy is done via Rectangle(source="path/to/image/") , but I need to adjust the image dimensions using opencv before inserting it into the widget, therefore, I need to pass not the path to the Rectangle , but the image object itself
Please tell me how to do this?