Style Transfer using closed form matting

I’m a newbie to computer vision. I’m trying to perform style transfer of images using Levin’s closed-form solution python implementation from this repository GitHub - MarcoForte/closed-form-matting: Python implementation of A. Levin D. Lischinski and Y. Weiss. A Closed Form Solution to Natural Image Matting. IEEE Conf. on Computer Vision and Pattern Recognition (CVPR), June 2006, New York. I understand the step I have to perform using the prior, and prior with confidence but I don’t know how to do it. Whenever I try I get the foreground image exactly same as the input image. Can anyone help me in understanding what the prior and prior with confidence is and how to perform style transfer using it?